The Spanish explorer Ponce de León wasn’t really looking for the Fountain of Youth when he trekked through Florida. That’s only a legend that wasn’t attached to his name until after his death. The idea of anti-aging remedies dates back to at least 3500 BCE, and the hope is alive and well today. Who wouldn’t like to turn back the clock and regain their lost youth? Who wouldn’t want to ward off death?
Longevity clinics have proliferated in recent years. They offer everything from “age optimization services” to “aesthetic facial rejuvenation,” from “youth maintenance” to “hormone optimization,” from supplements to stem cells. The claims they make are not grounded in science; they are misleading and sometimes even illegal. Jerry Mixon, M.D., of the Longevity Medical Clinic in Washington State, was disciplined for improperly diagnosing and treating four patients for growth hormone deficiency after advertising “comprehensive hormone supplementation as an anti-aging remedy.” Many diverse treatments are being promoted as “anti-aging” remedies. What does the scientific evidence say about them?
Antioxidants. Eating foods high in antioxidants may help reduce the risk of cancer and other disorders; but there is no good evidence that taking anti-oxidant supplements is helpful, and in some cases it causes harm. There is no evidence that people taking those supplements will live longer or age more slowly.
No currently marketed intervention—none—has yet been proved to slow, stop or reverse human aging, and some can be downright dangerous.
Hormone treatments include estrogen, testosterone, DHEA, human growth hormone, and diet supplements that claim to increase the body’s production of these hormones. These hormones have legitimate uses for treating diagnosed medical conditions, but they all carry risks and side effects and they do not slow the rate of aging. Estrogens were widely promoted to “keep women young” until studies showed they did more harm than good. Testosterone is being hyped as a cure-all for aging men, but it is useful only for men with diagnosed hormone deficiency.
Supplement mixtures. There are antiaging supplement mixtures galore. A typical example is Seanol Longevity Plus, which contains “nature’s most powerful antiaging supplement,” brown seaweed extract, along with resveratrol, iodine, and vitamin D. There have been no clinical studies of the product, and there is no evidence that the ingredients affect aging either singly or in combination.
Resveratrol is found in red wine. It activates sirtuins, proteins that assist in DNA repair. The French drink wine and have less heart disease, and studies in mice led to the belief that resveratrol supplements would retard aging and prolong life in humans. There is insufficient evidence to establish resveratrol’s safety or effectiveness in humans, and mimicking the doses of the mouse studies would require taking around 80 of the typical supplement pills a day.
Calorie restriction. Severe calorie restriction has been successful in retarding aging and increasing maximum life span in a variety of organisms including rodents, fish, flies, worms, and yeast. One study of Rhesus monkeys appeared promising but the results have been questioned as possibly due to confounders such as weight and quality of diet. The implications for humans are unclear. It requires a degree of deprivation that few people would be willing to accept, and it would make adequate nutrition problematic; but understanding the mechanism involved might possibly lead to a useful intervention for humans.
Telomeres are repeated nucleotide segments at the end of DNA molecules. Some of these are lost every time a DNA molecule replicates, and if they were all lost, accurate copying of essential DNA information would be impossible and the cell would die. Shortened telomeres are associated with aging, and an enzyme called telomerase retards the shortening process, so it was only natural to guess that telomerase would retard aging. But it has not been established that shortened telomeres cause aging. In at least one species of seabird, telomeres become longer with age. And telomerase may promote cancer; reducing telomerase levels is being investigated as a cancer treatment. Nevertheless, there are products on the market that claim to boost telomerase. One example is Product B, containing four vitamins and 30 herbal ingredients including horny goat weed, thistle, ginseng, and green tea. There is no rationale for the mixture; the product appears to have been formulated by dartboard. Neither the individual ingredients nor the proprietary mixture have been tested to see whether they actually have any effect on telomerase. Or whether they actually retard aging or prolong life. Telomerase research is an intriguing area of study, and we can expect to know more in the coming years.
Happiness. People who are happy live longer, but that’s probably because people with poor health don’t live as long, and poor health makes people less happy.
Kurzweil’s fantastic anti-aging program. And then there’s Ray Kurzweil. A futurist, he is convinced that the Singularity is near, and in the near future science will conquer diseases, aging, and death itself. He’s convinced that if he can just stay alive to the age of 120, he will be able to profit from those scientific advances and will live forever, as he explains in his book Fantastic Voyage: Live Long Enough to Live Forever. He collaborated with an anti-aging doctor named Terry Grossman to develop his personal plan: choking down a whopping 250 supplement pills every day at specified times along with 10 glasses of alkaline water, 10 cups of green tea, red wine, herbs, and a special diet; plus spending a day each week in the clinic getting IV vitamin infusions. He is confident that this regimen will keep him alive longer; I am not. And I’m not sure I would want to live like that even if the regimen were backed by good science.
Death is an intrinsic part of life. According to an article in Scientific American by S. Jay Olshansky, Leonard Hayflick, and Bruce A. Carnes, three of the world’s leading aging scientists, “It is an inescapable biological reality that once the engine of life switches on, the body inevitably sows the seeds of its own destruction.” In the process of cell division, errors are made in copying DNA. As the mitochondria in our cells generate the energy that sustains us, they produce free radicals that cause damage. And radiation and other environmental factors cause mutations. There are repair mechanisms that limit the damage, but they are imperfect. Even if diseases of the elderly like cancer and heart disease could be eliminated, aging would carry on unimpeded, and people would still die eventually.
Humans are not programmed for destruction at a sell-by date. Aging is not a disease, but a side effect of the many different genetically determined processes that keep us functioning. Like everything else in medicine, it’s complicated.
Average life expectancy is longer today than at any time in human history, thanks to science, technology, and medicine. Sanitation, vaccines, and medical care have allowed people in the developed world to reach an average age of 75 for men and 80 for women.
Aging is not a disease, but a side effect of the many different genetically determined processes that keep us functioning. Like everything else in medicine, it’s complicated.
The maximum recorded human lifespan is 122 years. Can we prolong that? Probably not by much. And we don’t really want just longer life, we want more years of functional, quality, meaningful life. There would be little point in keeping a brain-dead, immobile body alive to the age of 130, even if we could do that.
People are always looking for simple solutions. Chiropractors have claimed that their adjustments add years to life. In an online forum a few years ago, chiropractors debated whether it was possible to die if the spine was in perfect alignment. Some of them apparently believed that keeping your spine straight would keep you alive forever. An interesting view, since chiropractors don’t live as long as medical doctors or even as long as the national average. Some people believe you can’t possibly get sick if you just eat the proper diet–but of course they disagree with each other about what that diet is. It would be wonderful if we could reverse aging, prolong life, and prevent cancer by simple measures like changing our diet, taking supplements, or visiting the chiropractor; but we can’t. Preventive health measures like nutritious diet, exercise, vaccines, and avoidance of carcinogens such as tobacco will not extend the natural lifespan; but they can help reduce premature death, suffering, and disability from diseases.
Don’t believe the headlines. The media love to hype “Fountain of Youth” claims. As I was writing this, a message popped up in my e-mail: “Breaking news: Is coffee the key to health and longevity?” It was a first report of an association between coffee consumption and longer telomeres. Not yet confirmed; correlation is not causation; headline not justified.
Scientists have made great strides in understanding the processes involved in aging. We should listen to them rather than to entrepreneurs who are selling questionable products. In the aforementioned article in Scientific American, 51 scientists who study aging collaborated on a position statement about the current status of the science of aging. It contained this warning: “No currently marketed intervention—none—has yet been proved to slow, stop or reverse human aging, and some can be downright dangerous.” And “Anyone purporting to offer an anti-aging product today is either mistaken or lying.” Buyer beware!
As the panel of scientists said, no currently marketed intervention has been proved to affect aging. We are all going to die, and we are all going to experience reduced capabilities as we age. Rather than grasping at straws and believing false promises, we might as well try to cope with reality. We can lead a healthy lifestyle. We can change our attitudes, celebrating aging rather than deploring it. Studies show that the elderly are happier than younger people. As Betty Friedan said, “Aging is not lost youth but a new stage of opportunity and strength.”
This article was originally published as a SkepDoc column in Skeptic magazine.