For over 37 years, the pages of Health Science magazine have been filled with informative answers to health questions by NHA featured physicians and health experts, including Drs. Alan Goldhamer, Frank Sabatino, and Stephan Esser, as well as nutritionist and dietitician, Jeff Novick. Browse through the many Q&A's reprinted below. Please note that the answers offered are for educational purposes only and should not be interpreted as medical advice.
Ask the Experts
Questions & Answers
How many mg of sodium can I consume each day on a reduced sodium diet?
We recommend that people consume less than 1200 mg of sodium per day. A good rule of thumb is to avoid any foods that contain more than 1 mg of sodium per calorie. If one avoids the use of packaged and processed foods and focuses on the use of fresh fruits and vegetables, minimally processed whole grains and legumes and limited quantities of raw nuts and seeds, you can avoid the problems associated with an excess intake of sodium. A diet that avoids all processed foods will typically contain less than 1200 mg per day.
An article stated lowering your blood pressure below normal with medication is dangerous and increases your risk of stroke. Can you explain this? If this is true, why would naturally low blood pressure not be a serious risk factor for a stroke, too?
There is conflicting information in the medical literature about the risk/reward ratio involving the use of medications for lowering blood pressure. Most authorities agree that for patients with systolic blood pressure (top number) over 160 mm/Hg and/or diastolic blood pressure (bottom number) over 104 mm/Hg, the reduced risk of stroke offsets the multiple risks of most medications. The risks of overtreating blood pressure through the use of medications are not present when blood pressure reduces through diet and lifestyle modification or with the use of fasting. For every point your systolic blood pressure lowers through diet and lifestyle modification, there is a one percent reduction in ALL CAUSE mortality. This risk reduction continues until the systolic blood pressure has been reduced to about 90 mm/Hg. Lowering blood pressure with medication is not the same as lowering blood pressure naturally. Studies of individuals with moderate levels of hypertension treated with medications, in some cases, have shown higher all cause mortality than those in the untreated groups.1
1. Kaplan N. Clinical Hypertension, 7th edition, p. 6.
I am a long-standing vegetarian but have recently been told that I have high blood pressure and will need to take medications. How could this have happened?
High blood pressure is the leading contributing cause of death and disability in industrialized countries. It is the leading justification for prescription medications and the largest reason for visits to doctors.
When blood pressure is reported, the top number, or systolic blood pressure, represents the pressure of the blood in the vessels when the heart contracts. The bottom number, or diastolic blood pressure, represents the pressure of the blood in the vessels when the heart relaxes. Both numbers are important independent indications of health or risk.
For every point the systolic blood pressure is raised over 90 mm/Hg, there is a one percent increased risk of ALL CAUSE mortality, that is death from all causes.
There are many medications that have been found to lower blood pressure and along with it the risk of stroke and heart attack. Although medications can reduce the risk of stroke and heart attacks for those individuals with markedly elevated blood pressure, the effects are surprisingly limited and these limited benefits frequently come with many side-effects including fatigue, chronic cough, and impotence.
Although a vegetarian diet offers some protection against high blood pressure, it is not absolute protection. Reducing salt intake to less than 1 mg of sodium per calorie, exercising aerobically (walking, hiking, biking, swimming, dancing, etc.) almost daily and insuring adequate (at least 7-8 hours) of high quality sleep per day is also important. Also important is maintaining optimum weight (by eliminating all oil, flour and sugar products) and eliminating the use of alcohol, caffeine and nicotine.
If a low-sodium, vegetarian diet that is free of alcohol, oil, and refined carbohydrates, in conjunction with regular aerobic exercise and generous good quality sleep, does not normalize blood pressure, a careful physical and laboratory examination needs to be done to rule out other causes of high blood pressure including tumors, sleep apnea, kidney disease, etc.
The most powerful tool for lowering blood pressure is medically supervised water-only fasting. In studies conducted at the TrueNorth Health Center and published in the scientific literature, we have demonstrated the largest effects ever found and have successfully treated high blood pressure with fasting and a health promoting diet derived exclusively from fresh, raw fruits and vegetables, nuts and seeds and whole grains and beans. These studies can be downloaded from our web site at www.healthpromoting.com.
High blood pressure is something you can usually learn to live without.
Do I have to floss all my teeth?
If you follow a health-supporting, whole foods, plant-based diet, as advocated by NHA nutrition authorities, you will be eating lots of fruits and vegetables — and thus, a lot of plant fiber. As with all plant foods, the nutrients you need — all the protein, vitamins, minerals, essential fats, carbohydrates, etc. — are encased inside the plant’s cells, which are chambers of a tough carbohydrate called cellulose. That cellulose cell wall is what makes plants, plants. (Animal cells are just bounded by a floppy, easy-to-pierce, cell membrane — not a rigid cell wall.) Unlike termites, who have cellulase enzymes in their stomachs to break down plant cell walls, we do not have that enzyme. So, how do we rupture the plant’s cell walls so we can get at the nutrients we need? Fortunately, Mother Nature gave us 32 of the best juicers on the planet: 16 teeth in our upper jaw and 16 in the lower jaw — and the invitation is to use them.
Your mother was right when she told you to, “Chew your food!” — and for good reason. The old saying, “You are what you eat” just is not accurate. Actually, you are what you absorb! Thoroughly breaking down the cell walls of the carrots and kale that we eat is the crucial first step. If we do not do this — and the high-fiber food makes it through your GI system intact and is flushed down the toilet — you might as well have not eaten it in the first place.
That is why we should follow our British friends’ advice to, “Chew your food to a cream!” You want to make “broccoli puree” in your mouth before you swallow it. So, give the act of chewing the time and attention it deserves: put a mouthful of salad or steamed veggies in your mouth and then put the fork down and chew your food to a puree before you swallow it. This makes a huge difference as far as getting the nutrients out of the food, and besides, this time of thorough chewing is when you really taste your food — which is a main reason why you want to eat it in the first place, isn’t it?
Now that we see why using our teeth is so important, — we can see why taking good care of them is crucial. When we eat starchy foods and fruits, some of the starches and sugars will build up along the gum line — and that invites infection.
When gums get infected with bacteria, the gum tissue starts to recede. As it does, more and more of the tooth begins to show. You have probably heard the old saying, “He is long in the tooth.” That does not refer to someone getting old, as much as it is a comment on their poor oral hygiene. Gum recession is the prelude of the tooth getting loose and falling out.
When you lose your teeth, you lose your ability to chew, and then, nutrition declines severely. One of the major reasons people get frail when they get old is because they haven’t been taking care of their mouth and they lose their teeth. If you can’t chew well, you can’t absorb your nutrients and soon nutrition goes downhill. Ask any person who just got a full set of false teeth and ask them if they would rather have their natural teeth back? Almost everyone would answer with a resounding, “YES!”
The material that builds up on the gum line is called tartar, and you want to remove it daily by thorough flossing and brushing to avoid tooth decay and tooth loss. Flossing lets you cleave off the tartar between your teeth, where the toothbrush cannot reach.
When paleontologists look at the cavemen skulls, they see how many of these people died from dental abscesses. It’s a gruesome way to go, and it is no surprise to find that our caveman ancestors were very poor flossers; there is very little evidence of dental floss in the fossil records, and they certainly paid the price for that!
Not only is it important to brush and floss to prevent losing your teeth, but also, as the gums get inflamed, inflammatory proteins enter the bloodstream. These molecules can then inflame the linings of the arteries and other blood vessels. This inflammation, in turn, can set the stage for cholesterol plaque deposition — the main culprits in heart attacks and strokes.
It’s so important to use dental floss — frequently and properly; if you don’t know how to floss, ask your dentist or dental hygienist to show you how. Becoming a regular flosser not only feels good, but it is one the cheapest forms of health insurance you can buy.
So, the answer to the question, “Do I have to floss all of my teeth?” is, “Only the ones you want to keep.”
A friend gave me a pedometer and I discovered that I am usually walking under 4,000 steps a day. I work in an office and sit at a desk all day. I would like to use this little gadget to help motivate me to exercise more. What would be an ideal number of “steps” to strive for? About how long would it take to accomplish this each day? Any suggestions would be appreciated.
A pedometer is an excellent way to track your daily activities. The recommendation is to achieve a minimum of 10,000 steps a day. On average, 2,000 steps is about the equivalent of walking 1 mile and burning 100 calories. So, achieving 10,000 steps is the equivalent of walking 5 miles and burning approximately 500 calories. This will vary based on someone’s body weight, stride length and intensity, but it is a simple way of providing a consistent estimate. In regard to time, this is the equivalent of 60-90 minutes of total activity throughout the day. While there is no set standard for steps and activity levels yet, see the chart below for the general ranges I use.
Extremely Inactive, 0-3,000
Somewhat Active, 6,000-10,000
Regularly Active, 10,000-12,000
Highly Active, 12,000-15,000
How often and long should someone fast who is living healthfully?
In an ideal world, fasting would rarely, if ever, be needed. Individuals who ensure a good diet, a generous quantity of high-quality sleep, vigorous exercise, etc., may still suffer the consequences of emotional stress, air pollution, and other negative influences. Many people find that periodic fasting allows them the opportunity to do physical and mental “housecleaning” that can make a tremendous difference in the quality of their lives.
You should fast for as short a period of time as possible, but as long as necessary to allow the body to generate and resolve any healing crises that may develop. It is not uncommon to have healthy individuals fast for one or two weeks and use the body’s response to the fast to determine if additional time is needed. Remember that fasting is the complete abstinence from all substances except pure water, in an environment of complete rest. If you are going to undertake a fast, do it properly — under the supervision of a physician trained in the use of fasting.
We asked Alan Goldhamer, D.C., for some answers to the following fasting questions. If you are going to undertake a fast, do it properly — always under the supervision of a physician trained in the use of fasting.
1. What can I expect while fasting?
Fasting can be an intense and life-changing experience. It is analogous to rebooting a hard drive on a computer. Many problems can be cleared up just by giving the system a fresh start. Many people feel various symptoms associated with the detoxification processes associated with fasting and these can include headache and joint and muscle ache (especially low back ache), weakness, nausea and occasionally vomiting, skin rashes and assorted discharges, etc. Fortunately, these unpleasant symptoms are more than offset by the many positive results that occur as a result of fasting — including weight loss, normalization of blood pressure, blood sugar, lipids, and other metabolic factors, the resolution of inflammation, benign growths, and most importantly neuroadaptation that allows one to overcome their addictions to drugs, salt, sugar, fat, and processed foods. Fasting can make good foods taste good again.
2. How do I know if I need to fast?
When people need a fresh start, a real rest or have health problems that are not resolving despite their best efforts to eat and live well, a period of medically supervised fasting may be a consideration.
3. What is the difference between water and juice fasting?
Fasting is water-only. Juice fasting is eating a restricted diet. The profound biological adaptations associated with water-only fasting do not occur with the same intensity as with modified feeding programs like drinking only juices.
4. How do I get ready for a fast?
For most patients, eating a diet of only fruits and vegetables for several days prior to fasting is the best preparation.
5. Will I feel hungry during the fast?
Most patients do not complain about hunger after the first few days.
6. Will I lose a lot of weight?
Average weight loss is one pound per day.
7. Will fasting help me get over addictions such as sugar, caffeine and tobacco?
Fasting is the most powerful tool available to assist in overcoming the physical component of addictions.
8. How long will I have to fast?
We can give you an estimate based on completion of your admission forms located on our website at www.healthpromoting.com and review of your medical history and available laboratory test results. Optimum fasting duration varies from a few days to several weeks and is specific for each individual.
9. Can fasting help me conquer allergies and asthma?
Fasting, diet and lifestyle modification can be effective tools in managing allergies and asthma.
10. What other conditions respond to fasting?
Conditions that are caused or made worse by dietary excess often respond dramatically to fasting. Cardiovascular disease including high blood pressure, type II diabetes, obesity, autoimmune disease including arthritis (OA, RA, PA) Lupus (SLE) hashimotos thyroiditis, asthma, psoriasis, excema, colitis and IBS are the most common conditions we work with.
I want to make a major diet and lifestyle change to improve my health. How can fasting help me accomplish my goal?
It is very challenging to make and sustain dietary changes. Our brains evolved in an environment of scarcity and have exquisite caloric density detection mechanisms. In general, the higher the caloric density (calories per pound of edible food) the more “valuable” the food is considered by our brain. The brain rewards the body by releasing dopamine which causes us to experience pleasure. This system worked very well in the world of our ancient ancestors and helped insure that people got enough to eat. Those who avoided being eaten lived to reproduce and passed on their genes and behavioral tendencies.
Recently, humans discovered that certain chemicals could artificially stimulate dopamine production in the brain resulting in intense pleasure. These chemicals, including alcohol, nicotine, caffeine, etc., are very popular. Continued use leads to addiction and all of the problems associated with addiction.
Certain chemicals can be added to our food that results in the artificial stimulation of dopamine in the brain. These “pleasure trap” chemicals including oil and sugar fool the satiety mechanisms in the brain and result in consistent overeating and the resulting diseases of dietary excess including obesity, high blood pressure, diabetes and autoimmune disorders.
Attempts to resolve obesity and the diseases of dietary excess with diets, drugs, and surgery have been remarkably ineffective. Moderation in diet works no better than moderation in drinking for alcoholics. If you are an alcoholic, the answer is to avoid drinking. If you are overweight, the answer is to avoid eating the chemicals that result in obesity, including foods containing added oil and refined carbohydrates including sugar.
Just as alcoholics can benefit from an inpatient stay and professional support, people attempting to make major diet and lifestyle changes can benefit from time in a facility designed to effectively educate, evaluate and monitor an individual through a period of fasting.
Water-only fasting is equivalent to rebooting a hard drive on a computer. Many problems will clear up after fasting, including addiction to the chemicals associated with the dietary pleasure trap. After fasting properly, good food tastes good again. Fasting can be a powerful tool to help you recalibrate internal mechanisms and overcome obesity, high blood pressure, diabetes, and many autoimmune disorders.
If you are having trouble making diet and lifestyle changes, consider the possibility of undergoing a period of medically supervised fasting.
Coconut water, coconut oil, and almost everything “coconut” has become all the rage in recent years. Are there any problems with consuming it?
Mainstream America has recently embraced the coconut as a “health food,” and now coconut products can be found on the shelves of every gas station, supermarket, and specialty store. I consider coconut a fun tropical delicacy. It should not be a staple of your diet due to its high saturated fat content. But for special occasions, unique treats, and gastronomic “fun,” it is a delight. As with the other two topics here, coconut is not a miracle food, and compelling health claims for its consumption are lacking.
My recommendation is to evaluate your health goals prior to reaching for coconut foods and ingredients. If you are on a strict “disease reversal” program for obesity, heart disease, or diabetes, then coconut should be avoided. If, however, you are a healthy hygienist/plant-based individual who has no major health concerns and enjoys unique flavors, then a bit of fresh coconut water on a hot day as a treat, some fresh coconut jelly out of the husk, or some shredded coconut rolled with ground dates as a dessert can add variety and flavor to your health-promoting program. If you do crave a little coconut, though, please avoid the oil since just like olive oil it is a dense source of calories and saturated fat, both of which can undermine your best health.
I know that dramatic benefits can be received by adopting a Hygienic lifestyle. To what degree will I still receive those benefits if I fall off the wagon periodically?
The key word here is “periodically.” Clearly, you do not need to be 100 percent compliant in order to be healthy. Under normal circumstances, your body is able to compensate to a certain degree for your occasional dietary and lifestyle indiscretions.
But occasional indiscretions can quickly be-come habitual ones. Many people find that it is easier for them to develop consistent, long-term, health-promoting behaviors if they eliminate certain old habits entirely, rather than constantly tempting themselves with concentrated sources of sugar, fat, and salt.
Keep in mind that cravings for sugar, fat, and salt helped insure the survival of our species. In a natural setting, concentrated sources of sugar, fat, and salt are scarce. There are no hamburger bushes or chocolate chip cookie trees. Heated, processed, refined foods do not exist in a natural setting. As a consequence, during our evolutionary history there was no reason to rule out our natural desire for those substances. In fact, in a natural setting these very drives lead us to fruits, vegetables, and other whole, natural foods.
Today, we have countless varieties of processed foods (each designed to fool your natural instincts), and the desire to eat them is strong. So you may find that it is easier just to draw the line and not to “occasionally” tease yourself with things that may lead to further consumption.
The longer you practice these health promoting recommendations, the less powerfully unhealthful foods will call out to you. That is why we stress the importance of consistency with your diet and lifestyle patterns as part of an overall strategy that will lead to long-term health and happiness.
Is the raw food diet the “ideal diet?”
The argument that raw food is “natural” because most other animals obtain their food in the uncooked and unprocessed state is not a strong one, since those who champion this proposition do not recommend, at the same time, the other lifestyle necessities that accompany it — specifically, that animals do little else than eat, sleep, and mate during their relatively short lives.
Many people find it difficult to eat the quantity of raw food necessary to get sufficient calories. They may be much better off eating some steamed vegetables because lightly steaming vegetables does not substantially decrease the nutrients and makes it physically easier to eat and digest more food.
Can you recommend a starting point for people who want to design a healthful diet that meets their individual needs?
I recommend to most of my patients that they eat large volumes of fresh, raw fruits and vegetables (three to five pounds per day, yielding 600 to 1,100 calories) and get enough cooked, starchy vegetables (such as potatoes, yams, and hard squashes) and whole grains and legumes (such as brown rice, millet, quinoa, corn, lentils, and other beans) so they can maintain good strength and energy levels and not get too skinny. If vegetable foods naturally high in fat and protein are used, I recommend limiting them to half of an avocado, or one to two ounces of raw nuts, or three to four ounces of soy products per day.
By volume, the diet is mostly raw; however, as a percentage of calories, cooked foods make up a significant part of the diet. The use of heat helps to break down some of the otherwise indigestible fiber, in-creasing the potential available energy from these cooked foods. Humans have been using heat to process their foods for more than 500,000 years but blending and juicing food for a much shorter time. When it comes to natural, eating heat-processed starchy foods is natural for humans. Starchy root vegetables are an excellent source of calories, vitamins, minerals, fiber, and water, as well as an abundant source of phytochemicals.
When general advice is not enough to resolve your concerns, consult an IAHP doctor and allow him or her to review your history, perform a physical examination, order necessary laboratory testing, and design an individualized diet and lifestyle recommendations.
I’ve been reading about the health benefits of taking Celtic salt every day. Are there really any benefits to this?
We humans love to look for “magic.” Whether in pill or potion form, we love to find, buy, sell and trade “healing” substances. And the more exotic or costly, the more powerful they must be, according to our simplistic thinking.
Celtic sea salt (and other various “exotic salts” with minerals) is yet one more apparition of the same. Salt—in all forms—has significant health repercussions. As an occasional “seasoning” of food, many people can likely tolerate small quantities of salt with little harm. However, the Western world is not one of moderation. The average American consumes two to three times the federally recommended intake of 1500–2300 mg of salt per day. In fact, many individuals consume that amount of salt in one meal of processed food. Clearly, inadequate salt consumption is not a problem for most Americans.
Salt negatively impacts health in many ways. First, it is an appetite stimulant. In our culture, waistlines are bulging, and eating more calories of salty, processed food is not the answer. Second, salt attracts water. Salt causes the body to retain fluid, increasing blood pressure, exhausting the kidneys, and increasing the work load of the heart. Eating just an extra 1000 mg of salt per day can increase blood pressure by 5 to 10 points. When 1 in 3 Americans has high blood pressure, excess salt consumption is a real problem.
On the culinary front, salt is often used to mask less-than-healthy and less-than-ideal foods. If food is old, overcooked, or of low quality, adding salt makes it more palatable. From both a health and a culinary perspective, excessive use of salt is not ideal. In addition, using “healing” salts has shown to have little, if any, true health benefit for the majority of people.
Real health comes from healthy living, and that is made up of a well-balanced hygienic program. For best results, eat 80 to 90% of your diet from minimally processed, whole foods with no (or minimal) dietary salt added. Then you can enjoy sumptuous flavors of high-quality foods without worrying about the health-suppressing effects of salt.
Advocates of the Mediterranean Diet insist that olive oil has health benefits that other oils do not. Are there any special benefits, or harm, associated with consuming olive oil?
Olive oil sounds so wonderful—who doesn't love the idea of a bottle of “cold pressed, extra Virgin” olive oil on the counter? It just sounds so…so…natural. However, just because something is “natural” doesn't mean it is healthy. After all, lard is natural.
Unfortunately, as poetic as it sounds, olive oil is nothing but fat in a bottle—120 calories worth of fat per tablespoon to be exact. Yes, you can always find a few silver linings on the cloud if you look hard enough; or as our friend Dr. John McDougall likes to say, “People like to hear good things about their bad habits.”
Most of the science on olive oil is conflicted by mistakenly correlating a “Mediterranean Diet” with increasing olive oil consumption. Most of the health effects of the traditional Mediterranean diet come from the increased consumption of fruits, vegetables, and whole grains in conjunction with an active lifestyle. It is not the presence of the olive oil that provides the greatest health benefits but, more aptly, the absence of many other toxic substances, including heavily processed foods and foods of animal origin.
So, if you are trying to lose weight, reduce heart disease risk, and reduce generalized inflammation, then skip the olive oil for cooking and in your overall diet. Some of you may be saying, “But, isn't olive oil better than using butter, lard, or margarine?” And in response let me pose a better question: Do you want your best health, or just better health?
Do you recommend that healthy people take an aspirin every day to help prevent a heart attack?
Taking a daily low-dose aspirin to reduce the chances of a first cardiovascular event is known as primary prevention. When used in this manner, aspirin has been shown to lower the risk of heart attacks in men, and strokes in women (but not vice-versa).1
However, like any other drug, aspirin carries risks; the most significant one in clinical practice is gastrointestinal bleeding, which can be life-threatening. Therefore, anyone considering aspirin will need to determine not only if the benefits outweigh the harms, but if the magnitude of aspirin’s benefit warrants the commitment to what is generally a long-term therapy.
National guidelines recommend the use of aspirin when there is a net benefit in both men between the ages of 45-79, and women between the ages of 55-79.2 Online calculators are available to estimate one’s risk of having a heart attack (in men) or stroke (in women) over the next ten years.3,4 These numerical scores are determined by the presence of factors that increase one’s risk of cardiovascular disease, such as older age, smoking, diabetes, and high blood pressure. The ten-year likelihood of gastrointestinal bleeding due to aspirin can also be estimated based on one’s age.5,6 If the risk of a cardiovascular event is greater than the risk of gastrointestinal complications in the next ten years, aspirin is said to be beneficial.
When taken for about six and a half years, aspirin has been shown to lower the risk of a first heart attack in men by 0.37 percent, and the risk of a first stroke in women by 0.30 percent. Over that same time period, aspirin increases the risk of major bleeding (mostly gastrointestinal) in men by 0.33 percent, and in women by 0.25 percent.1 This translates into a net benefit of 0.04 percent for men and 0.05 percent for women. Each individual who meets the criteria for prophylactic aspirin will need to decide if these numbers are personally meaningful prior to starting treatment.
Finally, people should be aware that in other parts of the world such as Canada, expert panels do not recommend the use of aspirin for primary prevention of heart attacks and strokes.7 Rather than relying on a medication which provides very small benefits and has significant risks, a more rational approach for prevention would be to address one’s modifiable risk factors. While age and family history cannot be changed, all of the chronic conditions that raise one’s chances of developing cardiovascular disease are strongly influenced by diet and lifestyle. Specifically, high blood pressure, diabetes, obesity, and high cholesterol have been shown in scientific studies to be improved by diets rich in plant-based foods.8-11 By following an eating style like the one promoted by the NHA, and also engaging in regular exercise and avoiding tobacco use, the probability that one will suffer a first heart attack or stroke can be dramatically reduced without the need for a daily pill.
1. Berger JS. et al. Aspirin for the primary prevention of cardiovascular events in women and men: a sex-specific meta-analysis of randomized controlled trials. JAMA;295:306-13.
2. Aspirin for the Prevention of Cardiovascular Disease, Topic Page. December 2009. U.S. Preventive Services Task Force.
5. Hernandez-Diaz S, Rodriguez LA. Incidence of serious upper gastrointestinal bleeding/perforation in the general population: review of epidemiologic studies. J Clin Epidemiol. 2002;55:157.-63.
6. Hernandez-Diaz S, Rodriguez LA. Cardioprotective aspirin users and their excess risk of upper gastrointestinal complications. BMC Med. 2006;4:22.
7. Bell AD. et al. The use of antiplatelet therapy in the outpatient setting: Canadian Cardiovascular Society guidelines. Can J Cardiol 2011;27:S1–59.
8. Tonstad S. et al. Type of vegetarian diet, body weight, and prevalence of type 2 diabetes. Diabetes Care. 2009 May;32(5):791-6.
9. Gardner CD. et al. The Effect of a Plant-Based Diet on Plasma Lipids in Hypercholesterolemic Adults. A Randomized Trial. Ann Intern Med. 2005;142:725-733.
10. Ye EQ, et al. Greater whole-grain intake is associated with lower risk of type 2 diabetes, cardiovascular disease, and weight gain. J Nutr. 2012 Jul;142(7):1304-13.
11. Barnard N.D. et al. A low-fat vegan diet improves glycemic control and cardiovascular risk factors in a randomized clinical trial in individuals with type 2 diabetes, Diabetes Care, 2006, 29(8), pp. 1777–1783.
Should otherwise healthy men who have no symptoms take saw palmetto or a multivitamin with saw palmetto in it?
It is important to understand that saw palmetto is not a nutrient that is necessary to the prostate; it is a foreign substance just like a prescribed drug. Do not be fooled by false claims about saw palmetto such as "supports prostate health," as it does nothing of the sort. If a man is having symptoms referable to the prostate, such as urinating at night or straining to urinate, and the symptoms are bothersome to him and interfere with his quality of life, then medication that is effective at relieving symptoms can be considered. Unfortunately, saw palmetto does not fall into that category because it has been shown in numerous studies (including a recent one that used three times the usual dose) to be of no value.1,2
On the other hand, if a man is not having any symptoms related to his prostate, it makes no sense for him to waste his money on something that he doesn't need, is ineffective for its stated purpose, and is considered an "endocrine disrupter," as it may interfere with the action of the male hormone testosterone.3
1. Barry MJ, Meleth S, Lee JY, et al. Effecf of Increasing Doses of Saw Palmetto Extract on Lower Urinary Tract Symptoms. A Randomized Trial. JAMA. 2011;306(12):1344-1351.
2. Bent el al. Saw palmetto for benign prostatic hyperplasia. N Engl J Med. 2006 Feb 9;354(6):557-66.
3. Tacklind J, MacDonald R, Rutks I and Wilt TJ, 2009. Serenoa repens for benign prostatic hyperplasia. Cochrane Database Systematic Reviews 15 (2):CD001423. The Cochrane Library 2010, Issue 4.
Should otherwise healthy people take a multivitamin every day?
There is zero evidence that in otherwise healthy people multivitamins or multiminerals provide any benefit whatsoever. They may be associated with harm, despite what the person or company selling them tells you. There has never been a study of a multivitamin or other supplement that matched the positive effects of eating a healthy diet.1 Whole, natural foods such as fruits and vegetables contain far more health-promoting and disease-fighting chemicals than the relatively few that have been discovered and can be packaged into a multivitamin. Certain plant foods have literally hundreds of antioxidants, many of which may act synergistically,1 making the idea of taking a pill with three or four, or even ten, antioxidants nonsensical.
An expert panel meeting on multivitamins/multiminerals at the National Institutes of Health concluded that there is no good evidence that these supplements are of any value in preventing a wide range of diseases, such as cancer, cardiovascular disease, high blood pressure, and cataracts.2 The World Cancer Research Fund and the American Institute for Cancer Research recommend that people avoid the use of supplements for cancer prevention as they may upset the balance of nutrients in the body and increase cancer risk.3
A common misconception about multivitamins/multiminerals and other supplements is that "they can't hurt." A number of scientific studies on supplements have proven this notion to be false. For example, supplemental vitamin E was shown to be associated with an increased risk of prostate cancer and death from all causes in healthy men,4,5 and supplemental calcium was linked to an increased risk of heart attacks in healthy postmenopausal women.6 The Iowa Women's Health Study, a trial of over 38,000 older women, found that multivitamins significantly increase the chance of dying from any cause; this same study also noted higher death rates in women taking supplements such as vitamin B6, magnesium, and zinc.7
Despite this evidence, many people will continue to religiously take their multivitamin every day. One reason for this may be that people do not usually notice any immediate adverse effects while they are taking multivitamins, so they will not associate these supplements with the harm that they are causing in the long run.8
The safest way to obtain nutrients is by following the recommendations of the NHA and eating fruits, raw and cooked vegetables, whole grains, and legumes (dried beans). These foods not only satisfy our requirement for vitamins and minerals, but they have been shown to help maintain a healthy weight and lower the risk of chronic diseases such as diabetes, cardiovascular disease, and cancer.
1. Caballero B. Should healthy people take a multivitamin? Cleveland Clinic Journal of Medicine October 2010 vol. 77 10 656-657.
2. Huang HY, Caballero B, Chang S, et al. The efficacy and safety of multivitamin and mineral supplement use to prevent cancer and chronic disease in adults: a systematic review for a National Institutes of Health state-of-the-science conference. Ann Intern Med 2006; 145:372–385.
3. Food, nutrition, physical activity, and the prevention of cancer: A global perspective. Washington DC: AICR; 2007. World Cancer Research Fund/American Institute for Cancer Research.
4. Lippman SM, Klein EA, Goodman PJ, et al. Effect of selenium and vitamin E on risk of prostate cancer and other cancers: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). JAMA 2009; 301:39–51.
5. Miller ER 3rd, Pastor-Barriuso R, Dalal D, Riemersma RA, Appel LJ, Guallar E. Meta-analysis: high-dosage vitamin E supplementation may increase all-cause mortality. Ann Intern Med 2005; 142:37-46.
6. Bolland MJ, Grey A, Avenell A, Gamble GD, Reid IR. Calcium supplements with or without vitamin D and risk
Should athletes following a plant-based diet take taurine supplements?
With rare exceptions, taurine deficiency does not occur in humans because it is an amino acid produced naturally in the body after the first few weeks of life.1 However, because taurine can also be obtained from the diet and is found principally in animal products, blood levels of taurine tend to be lower in vegans than in people who consume meat.2 Furthermore, since high concentrations of taurine are found in muscle, it has been hypothesized that athletic performance could be improved by ingesting supplements that contain it. Taurine is found in many “energy” drinks for this reason.
Marketing hype notwithstanding, taurine supplementation has not been shown to be either necessary or helpful for athletes, including vegan ones. Although taking taurine supplements will lead to higher levels of taurine in the blood, it does not increase the amount of taurine in muscle, and more importantly, has no effect on muscle metabolism during exercise.3 Claims by some supplement makers that taurine “may enhance athletic performance” are simply not supported by any credible evidence.4,5,6,7
Ingestion of energy drinks containing taurine is linked to a number of short-term harms. These include increased blood pressure,8 increased platelet aggregation,9 and de-creased endothelial function,9 all of which are associated with an increased risk of cardiovascular events. Because energy drinks have a number of ingredients in addition to taurine, conclusions cannot be drawn as to whether or not taurine is responsible for these effects. However, there are no data on the safety of long-term supplementation with taurine.
As is the case with any drug or supplement, I would never recommend a substance that was not shown to have a significant benefit and was not proven to be safe when taken for an extended period of time. In vegan athletes in particular, there is not a single study in the entire scientific literature showing any benefit of taurine supplementation on any parameter of fitness or sports performance.
1. Brosnan JT, Brosnan ME. The sulfur-containing amino acids: an overview. J Nutr 2006;136(suppl):1636S–40S.
2. Lourenco R, Camilo ME. Taurine: a conditionally essential amino acid in humans? An overview in health and disease. Nutr Hosp. 2002;17:262-270.
3. Galloway SD, Talanian JL, Shoveller AK, Heigenhauser GJ, Spriet LL. Seven days of oral taurine supplementation does not increase muscle taurine content or alter substrate metabolism during prolonged exercise in humans. J Appl Physiol. 2008;105:643-651.
4. Rutherford JA, Spriet LL, Stellingwerff T. The effect of acute taurine ingestion on endurance performance and metabolism in well-trained cyclists. Int J Sport Nutr Exerc Metab. 2010;20:322-329.
5. Gwacham N, Wagner DR. Acute effects of a caffeine-taurine energy drink on repeated sprint performance of American college football players. Int J Sport Nutr Exerc Metab. 2012;22:109-116.
6. Pettitt RW, Niemeyer JD, Sexton PJ, Lipetzky A, Murray SR. Do the non-caffeine ingredients of energy drinks affect metabolic responses to heavy exercise? J Strength Cond Res. 2012 Oct 3.
7. McLellan TM, Lieberman HR. Do energy drinks contain active components other than caffeine? Nutr Rev. 2012;70:730-744.
8. Franks AM, Schmidt JM, McCain KR, Fraer M. Comparison of the effects of energy drink versus caffeine supplementation on indices of 24-hour ambulatory blood pressure. Ann Pharmacother. 2012;46:192-199.
9. Worthley MI, Prabhu A, De Sciscio P, Schultz C, Sanders P, Willoughby SR. Detrimental effects of energy drink consumption on platelet and endothelial function. Am J Med. 2010;123:184-187.
Do you recommend that people with no history of bone fractures get a bone density test to screen for osteoporosis?
Osteoporosis is a deterioration of bone and an abnormal reduction in bone mass that can lead to a fracture. Fractures of the hip and spine are associated with chronic pain, disability, and death; half of patients with a hip fracture are left permanently unable to walk without assistance, and many will require long-term care.1
Bone density testing, also known as DXA scanning, is an x-ray exam that assesses the amount of calcium and other minerals deposited in bones (usually the hip and spine). This measurement, when combined with several other variables such as height and weight, can estimate an individual's risk of having a bone fracture in the future.2 It is also sufficient on its own to make a diagnosis of osteoporosis. National guidelines recommend that all women over the age of 65, and postmenopausal women over the age of 50 at increased risk of bone fractures have a DXA scan performed.3,4 Some organizations also recommend that all men over the age of 70 (and men over the age of 50 who are at increased risk for bone fractures) get tested.3 Smoking, heavy alcohol use, and rheumatoid arthritis are examples of risk factors for fracture.3
If osteoporosis is diagnosed on a DXA scan, a patient may become motivated to take actions that have a positive effect on bone health, such as engaging in weight-bearing exercise and giving up poor eating habits. However, the fundamental purpose of a DXA scan is to ascertain if the person undergoing the test qualifies for osteoporosis medication, which in almost all cases will be a medication from the drug class known as bisphosphonates (e.g., Fosamax). Using bisphosphonates in women with no history of hip or spine fractures is known as primary prevention. National guidelines recommend medication for all postmenopausal women who are diagnosed with osteoporosis on a DXA scan, even if they have never suffered a fracture.3 Physicians are also advised to prescribe medication for women who have less severe bone loss on DXA testing, but a high probability of future fractures due to the presence of multiple other risk factors.3 These recommendations are based on studies with conflicting conclusions, depending on how a fracture was defined and whether the effectiveness of the medication (a bisphosphonate) was based on an improvement in bone mineral density or an actual decrease in fractures.5-8
When postmenopausal women with no history of hip or spine fractures were specifically analyzed, and a fracture was defined as one that caused symptoms (as opposed to a fracture diagnosed by x-ray criteria alone), there was no evidence of clinically meaningful benefits with the use of bisphosphonates.9 Women taking bisphosphonates did not have a lower incidence of fractures that had a significant impact on their life. In addition, this family of drugs is associated with rare but serious side effects including osteonecrosis of the jaw and "atypical" fractures of the hip bone that possibly would never have occurred if bisphosphonates had not been taken.10
Like any other medical test, a DXA scan should probably not be ordered unless it is going to alter the management of the patient. In the case of someone who has sustained a fragility fracture (i.e., one that occurs with minimal trauma), there is a very high risk for another fracture and the risk-benefit profile favors the use of bisphosphonates. Doing a DXA scan in this case, while helpful, is not absolutely necessary as it will not give the treating doctor any additional information as to how to treat the patient. In the case of someone who does not have a history of breaking a bone and would not take bisphosphonates even if he or she was diagnosed with osteoporosis, then it makes little sense to have a bone density test. The exception to this is the person who would adopt healthy lifestyle choices as a result of a DXA scan showing low bone mass or osteoporosis.
1. Riggs BL, Melton LJ 3rd. The worldwide problem of osteoporosis: insights afforded by epidemiology. Bone 1995; 17(suppl 5):505S–511S.
2. WHO Fracture Risk Assessment Tool. http://www.shef.ac.uk/FRAX/
3. National Osteoporosis Foundation. Clinician's Guide to Prevention and Treatment of Osteoporosis. Washington, DC, National Osteoporosis Foundation, 2010.
4. Screening for Osteoporosis, Topic Page. January 2011. U.S. Preventive Services Task Force.
5. Wells GA, et al. Alendronate for the primary and secondary prevention of osteoporotic fractures in postmenopausal women. Cochrane Database Syst Rev 2008;(1): CD001155.
6. Wells GA, et al.. Etidronate for the primary and secondary prevention of osteoporotic fractures in postmenopausal women. Cochrane Database Syst Rev 2008;(1):CD003376.
7. Wells GA, et al.. Risedronate for the primary and secondary prevention of osteoporotic fractures in postmenopausal women. Cochrane Database Syst Rev 2008;(1): CD004523.
8. Cummings SR, et al. Effect of alendronate on risk of fracture in women with low bone density but without vertebral fractures: results from the Fracture Intervention Trial. JAMA 1998;28:2077–82.
9. Therapeutics Initiative. A Systematic Review of the Efficacy of Bisphosphonates. Therapeutics Letter. 2011 Sep-Oct 83: 1-2.
10. Bisphosphonates: Do they prevent or cause bone fractures? Drug and Therapeutics Bulletin of Navarre. Vol. 17, No 5, Nov-Dec 2009.
Should otherwise healthy people take calcium supplements to prevent osteoporosis and bone fractures?
For men and women eating a healthy diet, there is no need to take calcium supplements or multivitamins with calcium in them. Calcium supplements increase the risk of cardiovascular events, especially heart attacks.1,2
Calcium supplements cause more cardiovascular events than the small number of fractures they prevent, so they have a net negative effect. To help keep your bones strong, you need to optimize calcium intake from the diet.
- people who take calcium supplements in addition to other supplements are 86 percent more likely to experience a heart attack than people who do not take any supplements3
- people who take calcium supplements by themselves are 139 percent more likely to experience a heart attack than people who do not take any supplements3
- 1000 women need to be treated with calcium supplements for 5 years to prevent 3 fractures1,2
Calcium should be obtained from food, not pills, because the calcium in food is absorbed slowly throughout the day and the calcium from pills floods the bloodstream with calcium in a short period of time. This can cause an increase in the level of calcium in the blood4, leading to calcification of arteries, including those in the heart. Calcification of the arteries raises the chances of a heart attack. Calcium supplements also increase the risk of kidney stones by about 20 percent4 and double the risk of abdominal conditions resulting in admission to a hospital.5 There is no evidence that calcium from food has any negative effects, so if you are following the diet recommended by the NHA, you are getting sufficient calcium without the risk of any harm. Calcium supplements and multivitamins with calcium in them cannot be considered safe, despite what the message on the pill bottle may say.
1. Bolland MJ, Grey A, Gamble GD, et al. Calcium and vitamin D supplements and health outcomes: a reanalysis of the Women's Health Initiative (WHI) limited-access data set. Am J Clin Nutr 2011;94:1144–9.
2. Bolland MJ, Avenell A, Baron JA, et al. Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis. BMJ 2010;341:c3691.
3. Li K et al. Associations of dietary calcium intake and calcium supplementation with myocardial infarction and stroke risk and overall cardiovascular mortality in the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition Study (EPIC-Heidelberg). Heart 2012. DOI:10.1136/ heartjnl-2011-301345.
4. Karp HJ, Ketola ME, Lamberg-Allardt CJ. Acute effects of calcium carbonate, calcium citrate and potassium citrate on markers of calcium and bone metabolism in young women. Br J Nutr 2009;102:1341e7.
5. Lewis JR, Zhu K, Prince RL. Adverse events from calcium supplementation: relationship to errors in myocardial infarction self-reporting in randomized controlled trials of calcium supplementation. J Bone Miner Res. 2012;27:719e722.
Newcomers to NHA often ask about getting all the nutrients they need from a whole-food, plant-based diet. Many people have a specific concern about getting enough protein. Should they be concerned?
A diet derived exclusively of whole, natural foods, including fresh fruits and vegetables, and the variable addition of whole grains, nuts, and legumes, provides us with the quantity and quality of nutrients needed for optimum health. These nutrients include protein (for its essential amino acid components), fat (for its essential fatty acid components), complex carbohydrates (as a clean-burning source of fuel), vitamins (for their role as catalysts and cofactors), minerals (that serve as structural components), fiber (as a necessary source of roughage), water (the universal solvent), and phytochemicals (for the possible role they play in supporting and protecting the body). On the specific issue of protein — a healthful, calorie-sufficient, whole-food, plant-based diet will supply between 50 to 80 grams of high quality protein per day.
Many people say that they do not feel “full” or “satisfied” when they go for more than a few days or weeks on raw foods, and then they tend to go off their diet and binge.
There are numerous psychological and physiological factors that may contribute to why a person may binge on food. One reason may be that the person is not getting enough to eat and simply may crave more food! They might not be getting enough available energy from the foods they are eating.
Uncooked vegetables, ripe fruits, and nuts are healthful, extremely nutritious, and easy to prepare. Some people argue that a raw-food diet is the natural and ideal diet of humans. This may be more of a romantic notion than a practical reality for most people.
If you decide to eat a diet made up of raw foods only (i.e., fruits, vegetables, and nuts), you will need to eat a very large volume of food in order to get sufficient calories to maintain your weight and energy levels. On average, raw vegetables contain 100 calories per pound; fruit contains approximately 300 calories per pound. Because most people need about 2,000 calories per day, you would need to eat at least 12 to 15 pounds of fruits and vegetables each day.
A diet of only fruit over a prolonged period of time can present serious problems for many individuals. Modern, hybridized fruit is high in sugar and relatively low in mineral concentration. Contrary to the unsubstantiated claims by some that we are natural “fruitarians,” a diet of only fruit often leads to a compromise in health.
The inclusion of raw nuts increases the caloric and mineral density of the diet, but also increases the percentage of calories from fat, yielding a high-sugar, high-fat diet that is far from ideal for most individuals. The inclusion of large volumes of raw vegetables helps increase the mineral and fiber content, but salad only provides approximately 100 calories per pound, most of which is used in its digestion and elimination.
Starches such as potatoes, yams, hard squashes, etc., are a good source of calories, without the excess fat and protein. Grains and legumes are, too, but some people are intolerant of the gluten found in wheat, rye, barley, etc. Rice, quinoa, millet, lentils, and soybeans are preferable, but even these foods can present a problem for some people.
Is it safe to use sunscreen?
Sunscreens are used to prevent photoaging (premature aging of the skin) and to reduce
the risk of skin cancer, the most common form of cancer. There are two types of sunscreens: chemical and physical. Chemical sunscreens absorb ultraviolet light and include a variety of agents. Because chemical sunscreens penetrate the skin and can be detected in minute amounts in the blood,1 concern has been raised by some environmental groups that they may have negative effects on health. Studies showing possible harmful effects of a common ingredient in chemical sunscreens were performed by feeding laboratory animals high oral doses of the medication rather than by topical application.2,3 Therefore, while there is no direct evidence in humans that they cause hormonal or any other significant health problems with typical use, there are certainly theoretical risks.
On the other hand, physical sunscreens form a shield on the skin and block ultraviolet rays; they are not absorbed into the body. Titanium dioxide and zinc oxide are the two ingredients that are FDA-approved for this purpose. The problem with physical sunscreens is that they leave a white, pasty layer on the skin after they are applied. To remedy this, sunscreen ingredients can be ground into fine particles through a process called “nanotechnology.” The result is an improvement in their appearance on the skin and enhancement of their ability to block ultraviolet rays. Physical sunscreens containing these nanoparticles do not appear to get through the outermost layer of intact skin and are likely to be safe.4
For those who would rather not rely on sunscreens, it is possible to significantly reduce the risk of skin cancer without using them at all. By staying out of the sun during the hours of peak intensity (10 a.m. to 4 p.m.), and wearing protective hats and clothing, exposure to ultraviolet rays can be minimized. Because ultraviolet radiation is the most significant environmental risk factor for all types of skin cancer,5 sun-protective behaviors should be considered a component of a healthy lifestyle. If one does choose to use a sunscreen, the label should contain the phrases “broad spectrum” and “water-resistant,” and list an “SPF” rating of 30 or higher.6 Physical sunscreens are likely to be preferred over chemical sunscreens by health-conscious people, and many products are available that have just a few simple ingredients in addition to the blocking agents themselves.
1. Benson HAE. 1999. Absorption of sunscreens across human skin: an evaluation of commercial products for children and adults. British Journal of Clinical Pharmacology 48(4): 635-37.
2. Schlumpf M, Cotton B, Conscience M, et al. In vitro and in vivo estrogenicity of UV sunscreens. Environ Health Perspect. 2001; 109:239-244.
3. Ziolkowska A, Belloni AS, Nussdorfer GG, Nowak M, Malendowicz LK. Endocrine disruptors and rat adrenocortical function: studies on freshly dispersed and cultured cells. Int J Mol Med. 2006;18:1165-1168.
4. Campbell, C. S. J, et al. Objective assessment of nanoparticle disposition in mammalian skin after topical exposure. Journal of Controlled Release, 162 (2012), 201-207.
5. http://www.cancer.gov/cancertopics/pdq/genetics/skin/Health Professional/page1/AllPages/Print
6. Jou, P, et al. UV protection and sunscreens: What to tell patients. Cleveland Clinic Journal of Medicine 2012; 79(6):427-436; doi:10.3949/ ccjm.79a.111102.1
Various Medical Conditions
Do you recommend that diabetics avoid white potatoes?
I certainly do not. I encourage my diabetic patients to eat freely of baked, steamed, microwaved, or boiled potatoes of any variety (prepared without added salt, oil, or sugar) as part of a healthy diet that also includes fruits, raw and cooked vegetables, whole grains, and legumes. The idea that white potatoes are problematic for diabetics stems partly from the concept of the glycemic index, and partly from the inaccurate way that potatoes have been categorized in some scientific studies.
The glycemic index measures the extent to which a food raises blood sugar levels after it is eaten.1 Because white potatoes have been characterized as having a high glycemic index, it is often assumed that they can worsen diabetes. However, the glycemic index has not been found to be a useful concept when devising optimal diets for diabetics.2,3 One of the major problems with the glycemic index is its variability; not only do blood sugar responses to similar foods differ between individuals, they can vary significantly in the same person on different occasions.4 A recent review of the scientific literature conducted by the American Diabetes Association concluded that there is little difference in blood sugar control between "low-glycemic index" and "high-glycemic index" diets.5 For this reason, in their most updated guidelines, the American Diabetes Association has deleted a statement suggesting benefit from the glycemic index.6
Studies that have associated white potatoes with worsening of blood sugar control included the consumption of fried potato products (i.e., french fries and potato chips) under the category of "potatoes."7,8 It is therefore not surprising that potato intake led to worse health outcomes when studied in this way. However, when processed potatoes are excluded, there is no evidence that white potato consumption is linked to diabetes or other negative effects on health. On the contrary, when looking at the nutritional makeup of a potato, it becomes clear that it can be included in a health-promoting eating plan. While I don't want people to become obsessed with the nutrient composition of the foods that they are eating, it is important to know that potatoes rank high in a number of areas. For example, a medium-sized Russet potato:
- has only 168 calories9
- is an excellent source of vitamin C9
- has no sodium, fat, or cholesterol9
- is a good source of potassium and vitamin B69
- has 8 percent of the daily requirement for fiber9
- has one of the highest overall antioxidant activity among vegetables (more than broccoli) 10
- is a source of "resistant starch," which improves insulin sensitivity11
I can assure you that our epidemic of diabetes is not a result of Americans' eating too many baked or boiled potatoes. Furthermore, there is no evidence that in people already diagnosed with diabetes, white potato consumption (when consumed without added oil, salt, or sugar) worsens control of blood sugar levels. Diabetes (as well as obesity and metabolic syndrome) are due to eating a diet composed of foods that are calorically dense, low in fiber and other beneficial nutrients, and high in fat. Potatoes have none of these attributes and should be regarded as an excellent food for both diabetics and nondiabetics. Labeling white potatoes as unhealthy because of the problems associated with french fries and potato chips is akin to claiming that apples are not wholesome because eating apple pie causes weight gain.
1) Monro JA, Shaw M. Glycemic impact, glycemic glucose equivalents, glycemic index, and glycemic load: definitions, distinctions, and implications. Am J Clin Nutr. 2008 Jan;87(1):237S-243S.
2) Wolever TM, Gibbs AL, Mehling C et al. The Canadian Trial of Carbohydrates in Diabetes (CCD), a 1-y controlled trial of low-glycemic-index dietary carbohydrate in Type 2 diabetes: no effect on glycated hemoglobin but reduction in C-reactive protein. Am. J. Clin. Nutr. 87(1), 114–125 (2008).
3) Ma Y, Olendzki BC, Merriam PA et al. A randomized clinical trial comparing low-glycemic index versus ADA dietary education among individuals with Type 2 diabetes. Nutrition 24(1), 45–56 (2008).
4) Vega-López S, Ausman LM, Griffith JL, Lichtenstein AH. Interindividual variability and intra-individual reproducibility of glycemic index values for commercial white bread. Diabetes Care 30(6), 1412–1417 (2007).
5) Wheeler ML, Dunbar SA, Jaacks LM et al. Macronutrients, food groups, and eating patterns in the management of diabetes: a systematic review of the literature, 2010. Diabetes Care 35(2), 434–445 (2012).
6) American Diabetes Association. Evidence for changes in recommendations.Standards of Medical Care in Diabetes – 2012. http://www.care.diabetes%20journals.org/content/suppl/2012/01/06/35%20Su...
7) Halton TL, et al. Potato and French fry consumption and risk of type 2 diabetes in women. Am J Clin Nutr. 2006;83(2):284-290.
8) Mozaffarian D, et al. Changes in Diet and Lifestyle and Long-Term Weight Gain in Wome and Men. N Engl J Med 2011; 364:2392-2404
9) USDA National Nutrient Database for Standard Reference, Release 25. http://ndb.nal.usda.gov/ndb/foods/show/3069?fg=&man=&lfacet=&format=&cou...
10) Wu X, Beecher GR, Holden JM, et al. Lipophilic and hydrophilic antioxidant capacities of common foods in the United States. Journal of Agricultural and Food Chemistry. 2004; 52:4026-4037
11) Murphy MM, Douglass JS, Birkett A. Resistant starch intakes in the United States. J Am Diet Assoc. 2008;108:67-78.
I have gout and was told that I have to avoid certain vegetables as well as beans, because they have a high-purine content. Is this necessary?
Gout is a form of arthritis that affects about 1 out of every 25 adults in the U.S.1 It is due to an excess total body burden of uric acid, and is an extremely painful condition. If not managed properly, it has the potential to destroy joints over time. Because chemicals called purines are broken down into uric acid in the body, patients with gout have traditionally been advised to avoid foods with a high purine content.2,3 Among these are most animal products, legumes, asparagus, mushrooms, oatmeal, cauliflower, and spinach.4
Studies have shown that consumption of meat and seafood are clearly associated with higher levels of uric acid in the blood and the development of gout (each additional daily serving of meat increases the risk of gout by 21 percent; each additional weekly serving of seafood increases the risk of gout by 7 percent).5 However, intake of “high-purine” vegetables and other plant foods has no casual relationship with gout, 6,7 and vegetarian diets high in purines have been associated with lower levels of uric acid in the blood.8 The protein from plant sources may actually have a protective effect.5 These facts are reflected in the 2012 American College of Rheumatology Guidelines for Management of Gout, in which vegetable intake is encouraged, and the topic of purines in relation to vegetables, legumes, etc., has been purposely omitted.9
Gout frequently coexists with other medical conditions due to an unhealthy lifestyle, such as high blood pressure, diabetes, high cholesterol, and obesity. The diet that can improve or eliminate these chronic medical conditions will do the same for gout, and it is a simple prescription: eat a wide variety of fruits, raw and cooked vegetables, legumes, and whole grains, and eat until you are full. There is no need to keep track of purine or calorie content if one is strictly following these principles. Finally, one should avoid alcohol and foods or drinks that contain high-fructose corn syrup. These have been shown to raise both uric acid levels in the blood and the risk for gout, and have a number of other undesirable effects on health.9
1. Zhu Y, Pandya BJ, Choi HK. Prevalence of gout and hyperuricemia in the US general population: the National Health and Nutrition Examination Survey 2007–2008.
Arthritis Rheum 2011;63:3136–41.
2. Emmerson BT. The management of gout. N Engl J Med 1996;334:445-451.
3. Fam AG. Gout, diet, and the insulin resistance syndrome. J Rheumatol 2002;29:1350-1355.
4. http://www.ukgoutsociety.org/docs/goutsociety-allaboutgoutanddiet-0113.p... Accessed on July 12. 2013.
5. Choi HK, Atkinson K, Karlson EW, Willett W, Curhan G. Purine-rich foods, dairy and protein intake, and the risk of gout in men. N Engl J Med. 2004 Mar 11; 350(11):1093-103.
6. Zgaga L, Theodoratou E, Kyle J, Farrington SM, Agakov F, Tenesa A, Walker M, McNeill G, Wright AF, Rudan I, Dunlop MG, Campbell H. The association of dietary intake of purine-rich vegetables, sugar-sweetened beverages and dairy with plasma urate, in a cross-sectional study. PLoS One. 2012;7(6):e38123.
7. Choi H (2006) Epidemiology of crystal arthropathy. Rheum Dis Clin North Am 32, 255–73.
8. Yamakita J, Yamamoto T, Moriwaki Y, Takahashi S, Tfutsumi Z, Higashino K. Effect of Tofu (bean curd) ingestion on uric acid metabolism in healthy and gouty subjects. Adv Exp Med Biol 1998;431:839–4.
9. Khanna D. et al. 2012 American College of Rheumatology guidelines for management of gout. Part 1: systematic non-pharmacologic and pharmacologic therapeutic approaches to hyperuricemia.
I suffer from kidney stones and was told by my doctor that I cannot eat a lot of my favorite healthy foods because they contain large amounts of oxalate. Is it necessary for me to restrict my diet in this way?
While there are several types of kidney stones, the majority are composed of calcium oxalate.1 High levels of oxalate in the urine promote the formation of this type of stone.1,2 Therefore, patients who have had one or more episodes of calcium oxalate stones are traditionally advised to avoid foods that are high in oxalate. There are dozens of health-promoting foods that are commonly found in reference lists of “high-oxalate foods,” but the only ones that have conclusively been shown to raise urinary levels of oxalate are:3
1. beets, spinach, and rhubarb
4. whole wheat
5. all dried beans
Despite their high oxalate content, there is actually little evidence that restricting the above foods reduces the likelihood of developing calcium oxalate stones. When people with a history of kidney stones were compared with people without such a history, there was no difference in oxalate intake.2 Similarly, when people with the highest levels of oxalate consumption were compared with people consuming the lowest levels, the risk of developing stones over time was not substantially different.4 Stone formation is a complex process that involves multiple dietary and lifestyle factors besides oxalate ingestion.5 In addition, endogenous (made within the body) metabolism of amino acids and other substances accounts for a large proportion of the oxalate that ends up in the urine.6,7
When counseling patients who have had calcium oxalate stones in the past, I educate them about the beneficial effect that a whole-foods, plant-based diet (like the one recommended by the NHA) may have on lowering the risk of a kidney stone recurrence. This eating style has a number of protective factors that interfere with the formation
of calcium oxalate stones, including high water content; high levels of potassium, magnesium and citrate; adequate levels of calcium; and the absence of animal protein.8 I also stress the importance of avoiding added sodium, which increases the amount of calcium in the urine.9 Restricting he consumption of foods that are high in oxalate is an unproven intervention in preventing future episodes of calcium oxalate stones, and is not part of my standard advice for these patients. The exception to this would be bariatric surgery patients, whose risk for calcium oxalate stones is exceptionally high due to excess absorption of oxalate from the intestines.10,11
1. Coe FL, Parks JH, Asplin JR. The pathogenesis and treatment of kidney stones. N Engl J Med 327:1141-1152, 1992.
2. Curhan GC, Willett WC, Speizer FE, Stampfer MJ. Twenty-four-hour urine chemistries and the risk of kidney stones among women and men. Kidney Int 59:2290-2298, 2001.
3. Massey LK, Roman-Smith H, Sutton RA. Effect of dietary oxalate and calcium on urinary oxalate and risk of formation of calcium oxalate kidney stones. J Am Diet Assoc. 1993 Aug;93(8):901-6.
4. E.N. Taylor, G.C. Curhan. Oxalate intake and the risk for nephrolithiasis. J Am Soc Nephrol, 18 (2007), pp. 2198–2204.
5. Heilberg, Ita P; Goldfarb, David S. Optimum nutrition for kidney stone disease. Advances in Chronic Kidney Disease 2013 Mar;20(2):165-174.
6. Hagler L, Herman RH. Oxalate metabolism. I. Am J Clin Nutr 26: 758–765,1973.
7. Menon M, Mahle CJ. Oxalate metabolism and renal calculi. J Urol 127:148-151, 1982.
8. T. Meschi, U. Maggiore, E. Fiaccadori et al. The effect of fruits and vegetables on urinary stone risk factors. Kidney Int, 66 (6) (2004), pp. 2402–2410.
9. H.L. Bleich, M.J. Moore, J. Lemann Jr., N.D. Adams, R.W. Gray. Urinary calcium excretion in human beings. N Engl J Med, 301 (10) (1979), pp. 535–541.
10. Kumar R., Lieske J.C., Collazo-Clavell M.L. et al. Fat malabsorption and increased intestinal oxalate absorption are common after Roux-en-Y gastric bypass surgery. Surgery 2011; 149: 654-661.
11. Froeder L., Arasaki C.H., Malheiros C.A. et al. Response to dietary oxalate after bariatric surgery. Clin J Am Soc Nephrol 2012; 7:2033-2040.
I was diagnosed with an underactive thyroid three years ago and have been on medication since that time. If I follow a plant-based diet, can I ever get off my thyroid medication?
There are multiple causes of hypothyroidism (underactive thyroid), but the majority of cases in this country and other parts of the world where iodine deficiency is uncommon are attributed to Hashimoto’s thyroiditis.1 This condition is due to an “autoimmune” destruction of the thyroid gland; for unknown reasons, the body develops antibodies that target the thyroid gland as if it were an invading pathogen.2 The presence of other autoimmune conditions, such as celiac disease, increases one’s chances of developing Hashimoto’s thyroiditis.2 The disease generally results in the thyroid gland losing its ability to produce thyroid hormone. When this occurs, thyroid hormone must be replaced via medication or the symptoms of hypothyroid-ism will develop.
Because the rate of remission of Hashimoto’s thyroiditis is low, treatment is generally lifelong, and advising a patient with this disease to stop taking thyroid medication is not common practice. However, hypothyroidism caused by Hashimoto’s thyroiditis is not always permanent, and cases of recovery of thyroid function (even after months
or years following the diagnosis) have been reported.3-8 Unfortunately, there is no simple way to predict which patients will be among the few who are successfully able to discontinue thyroid replacement. While there has been no research looking at the effect of a plant-based diet on the likelihood of remission, a gluten-free diet in patients who also have celiac disease may lower autoantibody levels.9 Because the prevalence of celiac disease is several-fold higher in patients with autoimmune thyroid diseases than in the general population, patients with Hashimoto’s thyroiditis should be assessed for celiac disease and advised to strictly avoid gluten if they test positive.10-12
For patients with Hashimoto’s thyroiditis who are extremely averse to taking medication, a four-week trial of withdrawing thyroid replacement can be attempted under a physician’s supervision; severe symptoms are highly unlikely to develop in this short period of time.5 At the end of four weeks, blood tests should be performed to assess if the thyroid is producing sufficient amounts of hormone to sustain normal body functions. If it is, medication can continue to be safely withheld as long as thyroid hormone levels are monitored on a regular basis thereafter to detect a recurrence of deficiency.
No more than 24 percent (or possibly much less) of patients with Hashimoto’s thyroiditis will have enough thyroid reserve to eliminate the need for thyroid medication.7,8,13 This means that the necessity of a daily pill will be an unavoidable reality for the majority of patients with this condition. However, NHA members and others who dedicate themselves to healthy living should rest assured that therapy for Hashimoto’s thyroiditis (synthetic thyroid hormone) is safe and effective and will not in any way prevent them from living a long life.
1. Garber JR et al. Clinical practice guidelines for hypothyroidism in adults: cosponsored by the American Association of Clinical Endocrinologists and the American Thyroid Association. Endocr Pract. 2012 Nov-Dec;18(6):988-1028.
2. Weetman AP. Chronic Autoimmune Thyroiditis. In: Braverman LE, ed. Werner & Ingbar’s The Thyroid: A Fundamental And Clinical Text. Philadelphia, Pennsylvania, USA: Lippincott Williams and Wilkins; 2013:524-535.
3. Comtois R, Faucher L, Lafflech L. Outcome of hypothy-roidism caused by Hashimoto’s thyroiditis. Arch Intern Med 1995;155:1404.
4. Takasu N, Yamada T, Takasu M, Komiya I, Nagasawa Y, Asawa T, Shinoda T, Aizawa T, Koizumi Y. Disappearance of thyrotropin-blocking antibodies and spontaneous recovery from hypothyroidism in autoimmune thyroiditis. N Engl J Med. 1992 Feb 20;326(8):513-8.
5. Utiger RD. Vanishing hypothyroidism. N Engl J Med 1992;326:562.
6. Comtois R, Faucher L, Laflèche L. Outcome of hypothyroidism caused by Hashimoto’s thyroiditis. Arch Intern Med. 1995 Jul 10;155(13):1404-8.
7. Nikolai TF. Recovery of thyroid function in primary hypothyroidism. Am J Med Sci 1989;297:18–21.
8. Takasu N, Komiya I, Asawa T, Nagasawa Y, Yamada T. Test for recovery from hypothyroidism during thyroxine therapy in Hashimoto’s thyroiditis. Lancet 1990;336:1084–6.
9. Valentino R, Savastano S, Tommaselli AP, Dorato M, Scarpitta MT, Gigante M, Lombardi G, Troncone R. Unusual association of thyroiditis, Addison’s disease, ovarian failure and celiac disease in a young woman. J Endocrinol Invest. 1999 May;22(5):390-4.
10. Hadithi M, de Boer H, Meijer JW, Willekens F, Kerckhaert JA, Heijmans R, Peña AS, Stehouwer CD, Mulder CJ. Coeliac disease in Dutch patients with Hashimoto’s thyroiditis and vice versa. World J Gastroenterol. 2007 Mar 21;13(11):1715-22.
11. Valentino R, Savastano S, Tommaselli AP, Dorato M, Scarpitta MT, Gigante M, Micillo M, Paparo F, Petrone E, Lombardi G, Troncone R. Prevalence of coeliac disease in patients with thyroid autoimmunity. Horm Res. 1999;51(3):124-7.
12. Boelaert K, Newby PR, Simmonds MJ, Holder RL, Carr-Smith JD, Heward JM, Manji N, Allahabadia A, Armitage M, Chatterjee KV, Lazarus JH, Pearce SH, Vaidya B, Gough SC, Franklyn JA. Prevalence and relative risk of other auto-immune diseases in subjects with autoimmune thyroid disease. Am J Med. 2010 Feb;123(2):183.e1-9. doi: 10.1016/j.amjmed.2009.06.030.
13. Gaglia, JL, Garber, JR. Thyroid Disorders. In: Camacho, PM, ed. Endocrinology and Metabolism : A Colour Handbook. London, GBR. Manson Publishing Ltd; 2011: 9-31.
I heard that there are new recommendations for treating people with cholesterol medications. Are these relevant to someone following a whole-food, plant-based diet?
In November, 2013, updated national guidelines were released on treating blood cholesterol with medications known as “statins” (e.g., Lipitor) in people who are at high risk of future heart attacks and strokes.1 This includes those with a history of a cardiovascular event; diabetes; or a genetic condition that leads to extremely high levels of LDL cholesterol. People who do not fall into any of the above three groups but have a 10-year calculated risk of heart attack or stroke of 7.5 percent or greater are also classified as “high-risk.” This calculation takes a number of factors into account, such as blood pressure, tobacco use, gender, and age.2 Unfortunately, every single man and woman will have a 10-year risk of 7.5 percent or more once they are in their sixties, even if they have optimal blood pressure and cholesterol, do not smoke, and have no other risk factors.2 However, because all medications have side effects, people who are otherwise at low risk for cardiovascular events should understand the magnitude of the potential benefits of statins. When taken by otherwise healthy people for an extended period of time, these medications have been shown to:3
1. lower one’s risk of dying from any cause by 0.42 percent
2. lower one’s risk of a heart attack by 0.46 percent
3. lower one’s risk of a stroke by 0.34 percent
These reductions in risk need to be weighed against the possible harms of statins. The most significant concerns with these drugs are a small but significant increase in the risk of new-onset diabetes,4,5 and varying degrees of muscle damage.6
Lifestyle modification forms the cornerstone of health promotion and prevention of cardiovascular disease. While this fact has not received much media attention, it is clearly stated in the new guidelines.1 In addition, on the same day that the cholesterol guidelines were released, another authoritative set of guidelines was published that deals exclusively with lifestyle management for reducing cardiovascular risk.7 Besides engaging in regular physical activity and avoiding tobacco smoke, adopting a diet that is consistent with the one recommended by the NHA (whole-food, plant-based, low in saturated fat and added sodium) is specifically emphasized. These lifestyle measures, along with maintaining a healthy weight, should be the primary focus of any efforts to lower one’s risk of heart attack and stroke. Discussions between doctors and patients about the importance of healthful living as a means of cardiovascular risk reduction should certainly precede the topic of cholesterol medication.
1. Stone NJ et al. 2013 ACC/AHA Guideline on the Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular Risk in Adults. Journal of the American College of Cardiology (2013), doi:10.1016/j.jacc.2013.11.002.
3. Tonelli M, Lloyd A, Clement F et al. Alberta Kidney Disease Network. Efficacy of statins for primary prevention in people at low cardiovascular risk: a meta-analysis. CMAJ. 2011;183:E1189-1202.
4. Carter AA, Gomes T, Camacho X et al. Risk of incident diabetes among patients treated with statins: a population-based study. BMJ 2013; DOI: 10.1136/bmj.f2610.
5. Zaharan NL, Williams D, Bennett K. Statins and risk of treated incident diabetes in a primary care population. Br J Clin Pharmacol2013;75:11218-24.3.
6. Sathasivam S, Lecky B. Statin induced myopathy. BMJ. 2008;337:a2286.
7. Eckel RH, Jakicic JM, Ard JD et al. 2013 AHA/ACC Guideline on Lifestyle Management to Reduce Cardiovascular Risk: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol 2013;Nov 12 [Epub ahead of print].
I am 60 years old, have no health problems and take no medications. Should I get the shingles vaccine?
Shingles is a painful rash that can develop in anyone who has ever had chickenpox, which is virtually everyone who was born before the vaccine for chickenpox became part of the routine childhood vaccination schedule in the 1990s. The risk of developing shingles over the course of one’s lifetime is approximately one in three.1 The rash itself resolves on its own within a few weeks, and once you have had an episode of shingles, it is relatively rare to get it again. However, a significant minority of people with shingles will have persistent pain (“postherpetic neuralgia”), which can be debilitating and impair one’s quality of life.
According to national guidelines, the shingles vaccine is recommended for all men and women 60 years old and above who do not have conditions that weaken the immune system.2 In this age group, the vaccine has been shown to decrease an individual’s risk of both shingles (by 1.7 percent) and postherpetic neuralgia (by 0.27 percent) over a follow-up period of slightly more than three years.3 The vaccine was approved in May, 2006, and serious adverse events in people who received the vaccine were not more frequent than in those who took a placebo.4 However, the duration of protection beyond four years after vaccination is unknown, and similar to other new medical therapies, there are no long-term safety data available.
The idea of injecting an infectious agent and foreign substances (in this case, neomycin as well as cow and pig derivatives)4 into one’s body will obviously violate the principles of many people who are doing everything they can to stay well through diligent adherence to a healthy lifestyle.
The shingles vaccine is not a prerequisite for health, and the human race did manage to survive without it prior to 2006. In addition, there is evidence that a plant-based diet, which has no potential side effects, may have some benefit in preventing shingles. For example, consuming eight or more portions of fruits and vegetables daily has been associated with one-third the risk of shingles compared to much lower intakes of these foods.5
While a healthy diet certainly does not guarantee 100 percent protection from developing shingles, neither does the vaccine. As with all medical interventions,
the final decision on having the shingles vaccine should always be based on an individual’s preferences and values.
3. Oxman MN. et al. A Vaccine to Prevent Herpes Zoster and Postherpetic Neuralgia in Older Adults. N Engl J Med 2005;352:2271-2284
4. http://www.merck.com/product/usa/picirculars/z/zostavax/zostavax pi2.pdf
5. Thomas SL. Et al. Micronutrient intake and the risk of herpes zoster: a case-control study. Int J Epidemiol. 2006 Apr; 35(2):307-14.
Vitamin D and Vitamin B12
I am a vegan and use nutritional yeast for the B12 content. I add the yeast to a potato recipe and was wondering if the heat destroys the B12.
While cooking does affect some nutrients, I would not worry about it in regard to B12 because B12 is heat stable.
However, I would not recommend nutritional yeast as a reliable source of vitamin B12. Nutritional yeasts do not contain B12 unless they are fortified with it and not all of them are fortified with B12. In addition, B12 is light sensitive and nutritional yeasts are often stored in bulk bins or plastic bags that are exposed to light.
If you are a vegan and want a reliable source of B12, I would recommend that you take a vitamin B12 supplement.
I am concerned that I may be deficient in vitamin D. An online doctor is offering a vitamin D blood test that can be performed at home and then mailed in for the result. Is the test accurate?
Whether or not the test you are referring to is accurate is less important than how the result will be interpreted. I don’t recommend that people have any aspect of their health, such as blood levels of vitamin D, assessed in the way that you are describing. While I certainly can sympathize with those who wish to avoid doctors as much as possible, people should realize that good medical decisions cannot be made with such limited data. An isolated blood test showing low vitamin D levels can lead a patient to take high-dose vitamin D supplementation to “correct” the ap-parent deficiency. While this may be appropriate in certain situations, there are health conditions in which this could result in great harm. As just one example, in the majority of cases of hyperparathyroidism (a condition that results in elevated blood levels of calcium and is not rare), vitamin D levels are low.1,2 This is a protective mechanism carried out by the body to decrease the amount of calcium absorbed from the intestines.1 Ingestion of high doses of vitamin D in a patient with hyperparathyroidism can result in dangerously high levels of calcium in the blood as well as strokes.3,4 A patient would have no way of knowing he or she was at risk for these complications unless a complete evaluation had been done. I therefore advise people to avoid online vitamin D tests as well as any other home-based testing in which a full evaluation is necessary for a proper diagnosis.
1. Norman J, Goodman A, Politz D. Calcium, parathyroid hormone, and vitamin D in patients with primary hyperparathyroidism: normograms developed from 10,000 cases. Endocr Pract. 2011 May-Jun;17(3):384-94.
2. Holick M. Vitamin D deficiency. N Engl J Med 2007;357:266-81.
3. Shahzad Riyaz S, Tymms J. Hypercalcemia: A rare cause of cerebral infarction. Central European Journal of Medicine. December 2008, Volume 3, Issue 4, pp 514-516.
4. Henderson GV, Caplan LR. Hypercalcemia and Stroke. Uncommon Causes of Stroke, Edited by Julien Bogousslavky and Louis R. Caplan. 2001; 110-114.
I just turned 40 and am worried about developing breast cancer. Do you suggest I get a mammogram?
There are two types of mammograms: a screening mammogram detects breast cancer in a woman who has no symptoms; a diagnostic mammogram evaluates a breast lump that has been detected by other means. My answer to your question specifically applies to screening mammograms in women at average risk for breast cancer. The term “average risk” means that you don’t have a known genetic mutation that predisposes to the development of breast cancer, and you don’t have a history of radiation to the chest for prior cancer. While having a family history of breast cancer in a first-degree relative (i.e., mother or sister) does make a woman more likely to develop breast cancer, the absolute increase in risk is not considered significant enough to influence the decision to do a mammogram.1
The purpose of a mammogram is to decrease the risk of dying from breast cancer. Based on evidence that there is a net benefit, national guidelines1 recommend that women between the ages of 50 and 74 who are at average risk for breast cancer obtain a mammogram every two years. However, the benefits of mammograms are small, and women should be made aware of this fact prior to obtaining the test. For example, in the case of a woman between the ages of 50-59 who gets a mammogram every one to two years for 10 years, she reduces her risk of dying from breast cancer by approximately 0.07 percent.2 However, over those 10 years, she also has between a 5-20 percent chance of having a “false-positive” result on one of the mammograms.2,3 This means that the mammogram is suspicious for breast cancer, but there is really no cancer there. Besides the anxiety associated with the possibility of harboring breast cancer, this woman will be subjected to a biopsy that she doesn’t need.
A more concerning risk of mammograms is that of overdiagnosis, which refers to breast cancers detected that were never destined to cause symptoms or result in death. Because it is not possible to know which breast cancer diagnosis is “overdiagnosis,” all of these cancers are treated with surgery, chemotherapy, radiation, or some combination. The risk of overdiagnosis increases with age, and has been estimated to be between 0.1 and 0.7 percent.1,2,4
As is the case with all medical treatments and tests, each woman needs to decide for herself if the benefits of mammograms outweigh the risks. Women certainly do not need to feel guilty if they choose to forgo mammograms. On the other hand, if a woman has made up her mind that a mammogram is the right thing for her, I will fully support her decision as long as she has been educated about the limitations of this test.
1. Screening for Breast Cancer, Topic Page. July 2010. U.S. Preventive Services Task Force. http://www.uspreventiveservicestaskforce.org/uspstf/uspsbrca.htm
2. The Benefits and Harms of Mammography Screening: Understanding the Trade-offs. Steven Woloshin, MD, MS; Lisa M. Schwartz, MD, MS JAMA. 2010;303(2):164-165. doi:10.1001/jama.2009.2007
3. Gøtsche PC, Nielsen M. Screening for breast cancer with mammography. Cochrane Database Syst Rev. 2009;(4):CD001877
4. Mandelblatt JS, Cronin K, Bailey S, et al; Breast Cancer Working Group of the Cancer Intervention and Surveillance Modeling Network. Effects of mammography screening under different screening schedules: model estimates of potential benefits and harms. Ann Intern Med. 2009;151(10):738-747
I read on the Internet that taking folic acid during pregnancy is dangerous. Is there any truth to this?
While I do not recommend that people take supplements without a clear medical indication, there are situations where they are appropriate. Taking 0.4 mg of synthetic folic acid daily (in addition to eating folate-rich foods such as green vegetables) starting at least one month before conception and continuing for the first 12 weeks of pregnancy, is recommended by multiple organizations to reduce the risk of congenital defects known as spina bifida and anencephaly. With a doctor’s prescription, prenatal vitamins containing 0.4 mg of folic acid can now be obtained free of charge in many pharmacies. Because there is some misinformation on the Internet regarding the use of prenatal folic acid, let’s look at some of the claims regarding the alleged dangers of folic acid supplementation in pregnant women.
Claim #1: Folic acid supplementation by pregnant women increases the risk of childhood asthma.
Here is a direct quote from the study1 cited as evidence for this misleading statement:
“Folic acid supplements taken in pre- or early pregnancy were not associated with asthma at any age.”
While folic acid supplementation taken after week 30 of pregnancy was associated with an increased risk of asthma in the child, guidelines recommend that women take folic acid through week 12 of pregnancy, which this study confirmed as being safe.
Claim #2: There is an increased incidence of cardiac birth defects in women who reported using folic acid supplements early in pregnancy.
What the referenced study2 actually said:
“As it is very unlikely that folic acid itself can increase the risk for a congenital malformation, a reasonable explanation is the effect of a confounder which both increases the risk for a cardiac defect and the use of folic acid.”
In other words, the authors of the study hypothesized that there is some unmeasured variable that is responsible for the small increase in cardiac malformations that was seen, rather than the folic acid itself.
Claim #3: Prenatal folic acid supplementation has been linked to breast cancer later in life.
This statement is based on data from one study3 conducted in the 1960s that showed an increased risk of future breast cancer among women who took 5 mg of folic acid daily (an amount which is more than twelve times the current recommended dose) throughout their pregnancy and until the time of delivery. This has little relevance to national guidelines, which advise women to take 0.4 mg daily through week 12 of pregnancy.
The following organizations recommend prenatal folic acid supplementation:
1. American Academy of Family Physicians4
2. American Academy of Pediatrics5
3. American College of Obstetrics and Gynecology6
4. Centers for Disease Control and Prevention7
5. National Academy of Sciences Institute of Medicine8
6. United States Preventive Services Task Force9
7. United States Public Health Service10
Prenatal supplementation with folic acid, ideally starting at least one month before conception and continuing through the first 12 weeks of pregnancy, is not a controversial issue. It is a recommendation based on overwhelming evidence of benefit as well as safety. I encourage women planning a pregnancy to take folic acid as put forth in the guidelines.
1. Whitrow MJ. Effect of Supplemental Folic Acid in Pregnancy on Childhood Asthma: A Prospective Birth Cohort Study. Am J Epidemiol. 2009 Oct 30.
2. Källén B. Congenital malformations in infants whose mothers reported the use of folic acid in early pregnancy in Sweden. A prospective population study. Congenit Anom (Kyoto). 2007 Dec;47(4):119-24.
3. Charles D et al. Taking folate in pregnancy and risk of maternal breast cancer. BMJ 2004;329:1375-6.
5. Folic acid for the prevention of neural tube defects. American Academy of Pediatrics. Committee on Genetics. Pediatrics 1999;104:325-7
6. ACOG Committee on Practice Bulletins. ACOG practice bulletin. Clinical management guidelines for obstetrician-gynecologists. Number 44, July 2003. (Replaces Committee Opinion Number 252, March 2001). Obstet Gynecol 2003;102:203-13.
8. Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes: Folate, Other B Vitamins, and Choline. Washington, DC, National Academy Press, April 17, 1998.
9. U.S. Preventive Services Task Force. Folic acid for the prevention of neural tube defects: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med 2009;150:626-31.
10. Centers for Disease Control. Recommendations for the use of folic acid to reduce the number of cases of spina bifida and other neural tube defects. MMWR 1992;41(No. RR-14).