In a New York Times editorial several years ago, William Safire wrote an essay entitled "Why Die?"1 According to the writer, nothing makes the weak strong or the fearful brave as much as the body's innate drive to stay alive. His point was that the genetic clock is set to run no more than 120 years, although many people would like to live much longer. A recent government report summarized the will to survive, noting that the inevitability of agingand with it the specter of dyinghas always haunted human life; and the desire to overcome age has long been a human dream.2
This powerful inherent drive to stay alive has encouraged some pharmaceutical companies to consider developing the ultimate blockbuster druga so-called "antiaging" pill. A number of biotechnology firms already have begun the search for a chemical that would slow down the aging process or prevent cancer, osteoporosis, and heart disease. Studies designed to show that a drug will retard aging, however, would be lengthy and likely would last longer than the investigators themselves. Because the FDA does not consider aging a disease, it may not even permit such studies to occur.
There are manufacturers of nutritional products that already advertise their antioxidant formulations as a means to retard aging. (Age retardation is the slowing down of the biological processes involved in aging, resulting in delayed decline and degeneration.2) These compounds are alleged to work by combating the effects of free radicals and delaying the decay of mitochondria, the organelles within the cell that convert amino acids, fatty acids, and sugars into energy. Free radicals can disrupt protein synthesis and repair and can cause minor errors in DNA replication. Whereas antioxidants may have some health benefits for some people, no scientific evidence exists to justify the claim that they have any effect on human aging.3
It has long been known that endocrine factors are closely tied to a number of the most prominent elements of aging. Thus a number of hormones have been touted as age retardants, including growth hormone, dehydroepiandrosterone, pregnenolone, testosterone, estrogen, melatonin, and progesterone. None has been proven to slow, stop, or reverse aging, however.4
Since at least the mid-1930s, medical science has discovered that substantial reductions in the food intake of many animals can have a dramatic effect on life span. In mice and rats, researchers have found that life span can be extended by more than 30%. Studies also have found similar extensions of life in a number of other mammalian species, including monkeys.5 Caloric restriction in animals reduces levels of insulin-like growth factor 1, a protein, and prevents oxidative damage to body tissues.
Although caloric restriction might extend the longevity of humans, as it does in a number of animal species, no study in humans has proved that it will work.3 Short-term trials now are being conducted at the National Institute on Aging in Bethesda, Md. Volunteers in these trials have been on a stringent diet for up to 1 year, while researchers monitor their metabolism and other factors that could hint at how they are aging.
Telomeres are the repeated sequences found at the end of chromosomes that shorten with increased cell divisions. There is evidence that telomere length plays a role in determining cellular life span in normal human fibroblasts and some other normal cell types.6 Although telomere shortening may play a role in limiting the life span of certain cells, there is no evidence that it plays a role in determining human longevity.7
In a 2003 article in a major medical journal, 2 researchers reported on what is apparently a more measured means to achieve an increased life span.8 Their thought is to address or reduce risk factors that lead to heart attacks and strokes in everyone aged 55 years and older and everyone with existing cardiovascular disease. This approach aims at extending life but not retarding aging.
There is a major difference, although the results may appear similar. Life extension is an increase in the number of years that a person remains alive and is accomplished by combating diseases of the aged or slowing down aging. The treatment consists of a once-daily "polypill," which contains a statin, 3 blood pressure-lowering drugs (a thiazide, a beta-blocker, and an angiotensin-converting enzyme [ACE] inhibitor); folic acid (0.8 mg); and aspirin (75 mg). The researchers estimate that the combination reduces ischemic heart disease by 88% and stroke by 80%.
In addition, the authors claim that one third of the people over age 55 taking this pill would benefit, gaining on average 11 years of life free from heart attack and stroke. The combination drug would lower 4 risk factors: low-density lipoprotein cholesterol, blood pressure, platelet function, and serum homocysteine.
The authors admit that the polypill may not be suitable for some people. They note that beta-blockers are contraindicated for asthmatics and that some individuals are intolerant of aspirin. Monitoring for the effects of statins and ACE inhibitors also should be considered.
Even newer than the "polypill" concept is the "polymeal." It includes 7 ingredients: dark chocolate, wine, fish, almonds, fruit, garlic, and vegetables. The components can be taken combined in a meal or individually at different times of the day. According to the authors of a recent article, the daily consumption of these foods would reduce cardiovascular disease by 76% and would result in an increase of 6.6 years in total life expectancy for men.9 The results should be similar for women. For those people earnestly seeking to prevent heart disease, the polypill can be combined with the polymeal.
The polypill and/or the polymeal may turn out to be part of the answer to increasing life expectancy, but there are a host of hurdles to overcome. The drug combination and the diet could be used in conjunction with lifestyle changes, proper medical care, and exercise to help delay or prevent the occurrence of age-related disease. It is unlikely, however, to expect that any of these practices will ever increase longevity by modifying the aging process.
Experts in the field of aging note that men and women in the developed world typically live longer now (75 and 80 years, respectively) than they did throughout much of history, for a number of reasonsincluding sanitation, vaccines, and antibiotics. This increase in longevity is due not to altering the way people age, but to altering the way people live.10
There is recent evidence from a prospective study of mortality that giving support and comfort to friends, relatives, and neighbors can influence longevity.11 Such contributions appear to trigger a desire for self-preservation, and thus volunteering may improve both mental and physical health.
Despite advertisements from a number of nutritional product manufacturers and longevity clinics, currently no diets, vitamin, mineral, or hormone supplements, or behavior or lifestyle choices have been demonstrated to slow down the aging process in humans.3 That possibility may lie in long-term genetic research and the discovery of age-retardant genes (3 genes have been identified that appear to promote long life by protecting against the diseases of old age) or in the development of stem cells that replace dead or dying cells. Researchers have targeted protective genes and proteins that slow aging in laboratory animals and promote longevity in humans. Experimental drugs that mimic these effects one day may treat the effects of aging.
In the meantime, the best course of action is to follow the advice of Sardinians, Okinawans, and California Seventh-day Adventists, who live the longest.12 Their consensus is (1) do not smoke; (2) put family first; (3) be active every day; (4) keep socially engaged; and (5) eat fruits, vegetables, and whole grains. It also may be wise to stop thinking about or dwelling on your age; recognize your mortality; and live each day to the fullest.
Mr. Sherman is president of Sherman Consulting Services Inc.
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One study linked multiple pregnancies to an increased risk of developing atrial fibrillation later in life, and another investigated the association between premature delivery and cardiovascular disease.
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