By Dr. Frank Sabatino

For almost a century, it has been known that restricting calories, while still maintaining adequate nutrition, promotes longevity in a wide variety of species. (1) In the 1980s, I was personally involved in calorie restriction research on rodents in which restricting food intake to 50-70% of that eaten by normally fed rats  resulted  in significant increases in  longevity,  and marked reductions in age-related physiological deterioration and chronic disease. (2) I especially enjoyed this non-invasive research because it focused on keeping animals comfortable and alive as long as possible, rather than promoting the suffering and killing that often occur in animal research.

In an effort to understand how the simple modification of calorie intake could promote such profound changes in health and lifespan,  one of the most important biological mechanisms that was proposed focused on the circulating levels and of blood sugar (glucose) and the hormone insulin that were shown to be significantly reduced by calorie restriction .  This decrease in blood sugar reduced the accumulation of toxic compounds, Advanced Glycation End-products  (AGEs),  formed by the binding of glucose to proteins, that cause detrimental alterations in the structure and function of proteins and promote biological aging.

In this chemical reaction, sugar molecules cross-link the amino acid chains of protein interfering with their normal movement and function, producing AGEs that are considered a main driver of accelerated aging . In fact many aging changes are directly associated with the buildup of AGEs, including chronic inflammation, compromised action of hormones and enzymes, damage to collagen in skin and blood vessels associated with the loss of skin elasticity and cardiovascular disease,  damage to lens protein in the eye that causes cataracts, decreased cognitive function, and an increase in neurotoxicity and amyloid-beta deposits found in the brains of people with Alzheimer’s disease. Therefore, as important as it is to maintain a healthy level of  blood sugar to satisfy your energy needs, consistent and long term elevations of blood sugar, as seen in the development and outcome of diabetes. is a major toxic threat that can ravage the body.   

It is important to realize that  AGEs are not only produced by internal elevations, alterations and interactions of sugar and protein in the body, but are also found in significant amounts in foods when protein and fat combine with sugar especially at higher cooking temperatures. This is where we see a major and remarkable protective benefit of a whole food plant focused diet that is not discussed enough. The highest content of AGEs, an their toxic by-products, are found in animal foods high in fat and protein, including all meat, cheese, eggs and butter), all processed oils and ultra-processed fast foods (French fries, fried bakery products etc. ) that have been exposed to high, dry-heat cooking methods, including barbecuing, browning, roasting, grilling, frying and toasting. Whole plant foods lower in fat, and devoid of processed oils,  including raw and lightly cooked vegetables, legumes and whole grains have significantly lower, safe levels of AGEs.

Diets exceeding more than 15,000-20,000 kilo units of AGEs per day are associated with dangerous inflammation, free radical oxidative stress and premature aging.  The typical standard diet of most Americans far exceeds this amount. The high intake of dietary AGEs has also been associated with a significant increase in the risk of breast cancer. (3) The following examples emphasize the benefit of whole plant food. If you measure the AGEs in 3.5 ounces of  whole plant foods , including fruits, apples, carrots, celery, greens, other vegetables, potatoes, oatmeal, whole grains/breads, and beans,  it ranges from 10-200 kilo units. In dangerous contrast, the content of AGEs in the same amounts of beef, chicken, various cheeses, and butter range from 6,000-23,000 kilo units, with fried bacon checking in at an unfathomable, unconscionable 92,000 kilo units!!

It is also necessary to consider that as the fat content of plant foods increases, so does the content of AGes. Nuts and olives, with their high fat content provide  1500-6000 kilo units per a 3.5 ounce portion,  but if you consume these more calorie-dense foods in the recommended smaller amounts of 1-2 ounces a day, AGE’s excess is not a problem. Also note that when olives are processed into an equal amount of olive oil, the AGE’s content is 7 times greater, providing another reason why it is so important and healthier to consume your fats and oils from whole foods rather than bottled oils .

Strategies for reducing AGEs

• Eliminate all refined sugar and ultra-processed foods.
• Eliminate high-fat animal products (meat, cheese, butter, mayonnaise).
• Eliminate bottled and cooked oils and all fried food.
• Consume a diversity fresh fruits, vegetable, whole grains/breads/pastas, legumes.
• Consume raw, not roasted,  nuts and seeds 1-2 ounces daily.
•    Cook with lower moist heat not dry high heat frying, grilling and broiling that can increase AGE’s 10-100 times
•    Cook in water or broth: boiling, steaming, light sautéing /poaching
• Marinate foods in acidic or citrus-based sauces, lemon, balsamic vinegar  or tomato juice (reduces AGEs by 50%)

Reducing the AGEs content in your diet and body can significantly reduce the risk of chronic inflammation, chronic disease and compromised aging. This is best accomplished by eating an unprocessed  diet of whole plant food without added sugar and oil that contains both  raw and cooked items prepared by simple and gentle cooking methods.

References

1. McCay CM and Crowell MF. Prolonging the lifespan. The Scientific Monthly 39:405-414.

2. Masoro EJ. Calorie restriction and aging: an update. Exp Gerontol. May 2000;35(3):299-305.

3. Omofuma OO, et al. Dietary advance glycation end-products (AGEs) and risk of breast cancer in the Prostate, Lung,  Colorectal and Ovarian Cancer Screening Trial (PLCO). Cancer Prev Res (Phila) Mar 13, 2020;13(7):601-610.