The doctor of the future will give no medicine, but will interest his patients in the care of the human frame, in diet, and in the cause and prevention of disease.
Congratulations! It's the year 2057, and today is your birthday! You blow out all 111 candles in one big puff. You're in great shape, just as fit now as when you turned 80, way back in 2026.
Impossible? Too good to be true? I don't think so. After spending the past five years researching and writing a 600-page book on anti-aging medicine, I believe we physicians can help our patients slow down the aging process.
Anti-aging medicine is a newly emerging specialty, and thousands of physicians in the United States now call themselves anti-aging doctors. Researchers around the world are focusing on various aspects of the aging question, with the expectation that significant breakthroughs are imminent. Two main professional membership organizations have emerged: the American Academy of Anti-Aging Medicine and the International College of Advanced Longevity Medicine. Both organizations offer certification exams for anti-aging medicine, which may soon lead to official medical specialty status.
Anti-aging physicians believe that most illnesses associated with aging can be prevented, or at least slowed, through optimum cellular health. These doctors emphasize nutrition, physical fitness and a range of complementary therapies. They frequently prescribe nutritional supplements, including vitamins, minerals, botanical medicines and natural hormones.
For proponents of anti-aging medicine, maximum life span, optimum health and quality of life are inseparable concepts. The purpose of anti-aging medicine is not to extend the final years of decline and decay, but rather to increase the healthy middle years.
Theories of aging abound, but they all fall into two general categories: damage theories and program theories. Damage theories contend that aging results from the cumulative wear and tear on our cells, which is caused almost exclusively by free radicals. Program theories suggest that human genes are precoded for a specific age of death.
Gerontologists and anti-aging researchers agree that a human's genetically programmed maximum life expectancy is about 120 years. Human life span cannot (yet) be extended beyond that limit, but it can be shortened by the cumulative effects of a lifetime of cellular damage. In other words, cumulative damage is what deprives us of our genetically endowed maximum life span.
One of the newest program theories focuses on telomeres, which are sequences of protein extending from the ends of chromosomes. Telomeres act to maintain the integrity of their chromosome. With each cell division, the telomeres shorten, eventually leading to loss of chromosomal protection and consequent age-related cellular degeneration and death. In contrast, "immortal" germ and cancer cells are capable of producing the enzyme telomerase, which repairs and replaces telomeres, keeping those cells alive forever. Researchers postulate that human cells could likewise be kept alive forever via telomerase therapy.
For now, free-radical theory, first articulated by Denham Harman in 1954, remains the most widely accepted theory of aging. Free radicals, the rogues of cell biology, are highly energetic molecular fragments that possess a free electron. According to the theory, free radicals damage cells by regularly crashing into crucial cell structures, including DNA, mitochondria, membranes and enzymes. Decades of cumulative free-radical damage lead to cellular failure and degenerative disease.
Free-radical theory holds that 90 percent of all deaths—including all heart attacks, strokes, and cancers—are the end result of free-radical damage, coupled with declining protective and repair mechanisms. The theory postulates that the most potent strategy for extending human life span is to prevent free-radical damage while enhancing cellular repair and regeneration.
In the not-too-distant future, genetic engineering may allow us to extend human life span well beyond the current 120-year limit. For now, however, anti-aging therapies are limited to slowing down free-radical damage (with diet and antioxidants), reversing metabolic decline (with hormones) and enhancing healing systems (with nutrients, hormones and phytochemicals).
In my book, I propose a comprehensive theory of aging, which I call renewal theory. This theory suggests that the body's healing systems depend on three functions to attain optimum health: protection, repair and regeneration. Our bodies prevent disease by protecting healthy cells and repairing damaged ones. When these options fail, regeneration replaces damaged or dead cells with new ones.
Protection, repair and regeneration are hindered by suboptimal nutrition. Conversely, when antioxidants, essential nutrients, phytochemicals, anti-aging hormones and other nutritional resources are in optimum supply, the rate of damage diminishes. Healing is accelerated and aging is slowed.
To optimize bioavailability of these protective nutrients and to reduce exposure to free radicals, I recommend a low-fat vegan diet based on organically grown, additive-free, minimally processed foods from the "new four food groups": grains, beans, fruit and vegetables. By reducing fat and eliminating refined sugars, white flour, pesticides, additives, preservatives, alcohol and other toxins, the diet minimizes free-radical exposure (i.e., damage) while maximizing intake of nutrients that support tissue repair, healing, antioxidant protection and cellular regeneration.
Fat reduction is especially important. Because fats are so vulnerable to oxidation, they are the greatest contributor to the free-radical overload that is responsible for our epidemics of heart disease, stroke and cancer. Animal foods (beef, fowl, fish, dairy) are high in fat, low in essential nutrients, and devoid of protective phytochemicals and fiber. In contrast, a plant-based diet is rich in phytochemicals, essential nutrients, fiber and antioxidants.
For optimum health and maximum life span, we need more of the essential nutrients, phytochemicals, anti-oxidants and other nutritionally based healing factors than diet alone can supply. Anti-aging doctors therefore routinely prescribe nutritional supplements.
One might reasonably ask, "If I am eating an optimum diet, why are supplements necessary?" The answer is that our genes are programmed to survive on nutritional bare bones. Although we are well equipped to survive a famine, we lack a proper program for optimum tissue repair and protection from oxidative damage. Moreover, the older we get, the less well protected we are. No diet, however excellent, can provide the nutrient levels needed to provide maximum damage protection and repair.
To obtain just 200 international units of vitamin E, for example, you would have to consume about a pound a day of sunflower seed or wheat germ. To get just one gram of vitamin C, you'd have to eat 12 bell peppers, 12 cups of raw broccoli, 13 grapefruits or 15 oranges. These vitamins are just two of the 50 or so essential nutrients that we need (see Figure 3). Without supplementation, obtaining optimal protective levels of each is impossible.
One of the most powerful anti-aging tools is also absolutely free: exercise. Physicians are familiar with the cardiovascular benefits, improved insulin response and bone strengthening that come with regular exercise. Less widely appreciated benefits include heightened immunity, cancer protection and slower neuromuscular aging.
A regular program of aerobics, strength and stretching induces a complex array of biochemical and metabolic changes that improve longevity. Among these changes are increased levels of anti-aging hormones, increased production of endogenous antioxidants, and higher levels of endorphins, cytokines and enzymes. Exercise also enhances glutamine production, which protects the aging immune system.
In addition to prescribing dietary and exercise regimens, anti-aging doctors routinely employ laboratory tests. They use these tests to assess nutrient or toxin levels or the health status of an organ or system. The tests include the:
- Oxidative Stress Panel—which measures hydroxyl radical activity, glutathione status and lipid peroxides. This test provides information about free-radical activity and how well the patient's protective mechanisms are working.
- Antioxidant Profile—which assesses levels of key protective antioxidants, including vitamin A, alpha and beta carotene, lycopene, alpha and gamma tocopherol, ascorbic acid, and co-enzyme Q-10.
- Comprehensive Digestive Stool Analysis—which measures an array of intestinal parameters, including markers for digestion, absorption, healthy flora and pathogens.
Levels of key anti-aging hormones—such as DHEA, pregnenolone, IGF-1 and the sex steroids—are often tested as well. The results of all these tests are typically used to design individual nutritional supplement programs.
In this brief article, I have sketched a broad overview of anti-aging medicine. For more details, readers are encouraged to consult the following bibliography, which lists selected general reference texts.
I believe that anti-aging medicine can be integrated into many types of medical practice. Regardless of specialty, we can help our patients live healthier, happier, longer lives by encouraging them to eat well, take supplements and exercise regularly.
Theories of Aging
The following are just a few of the many current theories of aging:
- Hayflick limit theory—based on the classic observation that human fibroblasts in tissue culture always divide about 50 times and then suddenly stop—proposes that cellular aging depends on an internal clock.
- Waste accumulation theory postulates that cellular garbage—including lipofuscin age pigments and other toxic debris—builds up in the cell, gradually interfering with normal functioning and eventually killing it.
- Cross-linkage theory posits that cross-links between protein molecules (caused by free radicals) hamper flexibility of tissues and choke off nutrient supply and waste removal.
- Mitochondrial theory holds that cumulative free-radical damage to mitochondrial DNA impairs cellular energy production, leading to organ failure and accelerated aging.
- Autoimmune theory postulates that an aging immune system gradually loses its ability to distinguish between self and other and then generates auto-antibodies that attack host tissues.
- Calorie restriction theory holds that life span can be extended by restricting caloric intake.
- Errors and repairs theory states that accumulated damage to DNA results in coding errors that cause biosynthesis of flawed proteins.
- Neuroendocrine theory holds that declining levels of key anti-aging hormones lead to decline and death.
Anti-aging supplement programs typically begin with essential nutrients: vitamins, minerals and essential fatty acids. These can be delivered via multivitamin/mineral capsules, flax-seed-oil capsules, and borage-oil capsules. Additional doses of vitamins C and E may provide added antioxidant protection, as may coenzyme Q-10, a mitochondria-based antioxidant and energy transfer molecule.
In addition to these essential nutrients and antioxidants, anti-aging doctors also prescribe several other nutritional medicines, including:
Found only in plant-derived foods, phytochemicals are literally the medicine in food: they are the active principles in herbal medicines and everyday plant foods. Many phytochemicals may act as antioxidants. This rather newly discovered group of "supernutrients" includes the:
- Carotenoids in tomatoes and carrots.
- Allyl sulfides in garlic and onions.
- Sulforaphane in broccoli.
- Proanthocyanidins in grapes.
- Protease inhibitors and phyto-sterols in soy.
Of the dozens of herbs that might qualify as "anti-aging," the three best researched are:
- Ginseng, which strengthens the immune system, stimulates the endocrine system, enhances mental function and protects against stress.1
- Garlic, which exerts age-slowing effects on the cardiovascular and immune systems.2
- Gingko, which slows aging by boosting blood flow to all organs and systems.3
By helping to "age-proof" the brain, neuronutrients such as phosphatidylserine, acetyl-L-carnitine ginkgo, pregnen-olone and docosahexanoic acid (DHA) help protect against age-related cognitive decline.4
While physicians are familiar with estrogen, progesterone and testosterone replacement therapy (and in prescribing these are practicing a kind of anti-aging medicine), they tend to be less comfortable with:
- Melatonin, the most powerful naturally occurring antioxidant, which "resets" the aging clock in the pineal gland.
- DHEA, the most abundant hormone in the human body, which declines with age. Higher DHEA levels may decrease the risk of death from age-related disease.
- Pregnenolone, DHEA's precursor, which may heighten immunity, reduce stress and improve memory.
Other hormones commonly prescribed by anti-aging doctors include the sex steroids, thyroid hormone and growth hormone.
San Francisco Medical Society