The Science and Pseudoscience of Aging


Some animals (such as hydras and some jellyfish) can apparently live forever, but we humans are all going to die. Longevity is desirable, but aging—a slow process of deterioration—is not. Hearing declines (half of those older than seventy-five have disabling hearing loss), as does visual acuity (by age eighty, 70 percent of white Americans have cataracts [National Eye Institute 2019]). Reflexes are slower; reaction time increases. Strength declines, and bone density decreases. The skin thins and bruises more easily. Wrinkles develop; the hair turns gray and then white. Height decreases by one to three inches. Dementia increases with age, affecting 19 percent of those between ages seventy-five and eighty-four and nearly half of those over eighty-five. Numerous diseases become more common, such as diabetes, cancer, and cardiovascular disease. If they live long enough, almost all men will develop prostate cancer although most of them will die with it rather than because of it.

As my brother says, “Old age is highly overrated.” Most of us want to live as long as possible but would like to avoid the deterioration of aging. So it’s only natural that antiaging remedies abound. Sadly, most of them are just false hope, hype, and snake oil. The consequences of aging are not all bad: the elderly have extensive life experience, more general knowledge, and more wisdom. And they report greater happiness.

Maximum Human Life Span

The so-called Blue Zones are geographical locations where people are said to live longer than elsewhere. These include Sardinia, Okinawa, Loma Linda (California), the Nicoya Peninsula in Costa Rica, and Icaria (Greece). The first Blue Zone was reported by Poulain et al. (2004), and the concept has been popularized by Dan Buettner, who writes books promoting a Blue Zone diet (Buettner n.d.). Reports of longevity are often questionable, however, because of poor record-keeping and confusion with parents or grandparents who had the same name. The record for the longest definitely verified life span belongs to Jeanne Calment of France, who died in 1997 at age 122. She was deaf and blind (having refused cataract surgery) but remained mentally sharp.

Calment benefitted from a real estate transaction that seemed like a good deal at the time but proved to be a bad bargain for the buyer. As related on Wikipedia:

In 1965, aged 90 and with no heirs left, Calment signed a life estate contract on her apartment with notary public André-François Raffray, selling the property in exchange for a right of occupancy and a monthly revenue of 2,500 francs (€380) until her death. Raffray died in 1995, by which time Calment had received more than double the apartment’s value from him, and his family had to continue making payments. (“Jeanne Calment” 2021)

To what do long-lived people attribute their longevity? Each of them offers an explanation, but they seldom agree. Some of their theories seem plausible, but some are imaginative nonsense and might even be harmful, for instance, eating raw eggs every day. What was Calment’s secret? She attributed her longevity to a diet rich in olive oil, but it was more likely due to good genes and good luck. She came from a long-lived family. She smoked and drank alcohol but very sparingly. In her later years, she was 4’ 6” tall and weighed eighty-eight pounds.

Causes of Aging

Researchers have failed to find a uniform marker for aging. The aging process seems to be different for different individuals; it is varied, chaotic, and idiosyncratic. There is probably no single cause, but many causes have been proposed: collagen breakdown, UV light, oxidation, inflammation, insulin resistance, glycation, free radicals, accumulation of DNA copying errors, telomere shortening, accumulation of waste products, heterochromatin loss, and many others. I suspect that many of these factors are contributory and that they interact with each other.

Ray Kurzweil believes that science will soon discover the key to immortality, and if he can just stay alive until then, he believes he will be able to live forever. He optimistically takes 250 supplement pills a day, gets weekly IV infusions, uses acupuncture and Chinese herbs, and does other things that he thinks might help keep him alive. His approach is nothing but hope and speculation.


Telomeres are repeated sequences of nucleotides at the end of a chromosome. One of the ideas for prolonging life that has seemed most promising is based on the observation that telomeres shorten with age. The hope is that if we could prevent that shortening, it might prolong life. For vertebrates, the sequence is TTAGGG. The repeats number in the hundreds or even thousands. They protect the end of the DNA strand, analogous to the way an aglet (the hard piece at the end of a shoelace) prevents a shoelace from unraveling. When cells divide, DNA is copied, but copying does not accurately extend to the end of the telomere. Therefore, with every copy the telomere becomes shorter. The number of times a cell can divide is limited. That’s called the Hayflick limit and is around forty to sixty replications for human cells in cultures in the lab. Supposedly when the telomeres get too short, the cell can no longer divide, and death results. Telomere shortening has been shown to correlate with aging and with age-related diseases. The theory is that if only we could prevent telomere shortening, we could conquer aging. The enzyme telomerase effectively lengthens telomeres, and many antiaging products promise to increase telomerase levels.

That may seem persuasive, but the reality is more complicated. Accurate measuring of telomere length is problematic. Telomere shortening might accompany aging but not be the cause of aging. And it’s not universal. In some animals, telomeres lengthen with age. Increasing telomerase may not be such a good idea because it may facilitate the development of cancers. Treatments aimed at lengthening telomeres have not been proven to prevent aging. There is one species of bats whose telomeres don’t shorten with age (Martella 2018). They live far longer than other bat species and are more resistant to disease. They do not express telomerase. Scientists are studying them, hoping their research may suggest a way to address human aging.

Antiaging Approaches

Severe calorie restriction has been shown to prolong life and improve health in many animals. However, studies of primates have had mixed results, and no data is available for humans. We’re talking about severe calorie restriction—a diet that few people would be able or willing to follow long term. Intermittent fasting may improve the symptoms of asthma and reduce the risk of Alzheimer’s and Parkinson’s. Fasting before chemotherapy seems to result in fewer side effects and a better response.

Rapamycin has been shown to increase lifespan in animals and reduce many of the signs of aging. But it carries serious risks. Also known as sirolimus, rapamycin is a compound originally discovered in the bacterium Streptomyces hygroscopicus from Easter Island. It is an immunosuppressant drug that inhibits activation of T cells and B cells. It has many medical uses, notably to prevent rejection of kidney transplants. Up to 20 percent of patients develop adverse effects, ranging from edema and high blood pressure to infections, lymphoma, and other malignancies (Pfizer n.d.).

Resveratrol (found in red wine) increased the survival of obese mice fed a high calorie diet. Some hoped that resveratrol would allow people to overeat with impunity, but clinical trials in humans were disappointing. The daily dose that was effective in mice would have corresponded to thirty-five bottles of wine for a human. Metformin, aspirin, coffee, alcohol in moderation, curcumin, ibuprofen, and other substances have shown positive results in some studies, but the effects were not strong enough to warrant recommending them for everyone.

Examples of Bogus Remedies

Products claiming antiaging benefits abound. Here are a few of them.

Serovital contains five amino acids (lysine, arginine oxo-proline, N-acetyl cysteine, and L-glutamine) and a powdered herb, Japanese catnip. It claims to raise HGH levels by a whopping 682 percent, but that is based on a single study of only sixteen subjects. Even if it did actually raise HGH levels, there is no evidence of clinical benefit and no evidence that HGH slows aging. Proponents claim that “boosting HGH blood levels can reduce body fat; build muscle; improve sex life, sleep quality, vision and memory; restore hair growth and color; strengthen the immune system; normalize blood sugar; increase energy; and ‘turn back your body’s biological clock.’” That’s not true, and increased HGH levels can be dangerous. Harmful side effects include an increased risk of cancer and cardiovascular disease. High levels of HGH may even accelerate the aging process. According to Quackwatch, “So-called growth hormone releasers” should be regarded as fakes (Barrett 2016).

The company that sells Product B claims that “Almost every known disease can be attributed to the shortening of telomeres,” and Product B supposedly reverses telomere shortening. It’s a mixture of four vitamins and a proprietary blend of some thirty herbal products, such as thistle, horny goat weed, ginseng, and green tea. Most of these have never been shown to activate telomerase. In fact, several of the ingredients are known to inhibit telomerase.

PatchMD sells a product that makes antiaging claims for vitamins A, C, D, B3, B6, B9, curcumin, clove extract, ginger root extract, Indian gooseberry extract, L-carnitine, CoQ10, resveratrol, choline, glutathione, NAC, and alpha-lipoic acid. It combines all these in a convenient Anti-Aging Topical Skin Patch, supplying the nutrients via the skin. They claim all these ingredients are backed by science for their antiaging effects, but that’s a real stretch. It’s based mainly on their antioxidant and anti-inflammatory properties. At least they provided a proposed (pseudo-)scientific rationale.

Vital Stem is advertised as a miracle antiaging remedy. It is a mixture of vitamin D, leucine, blueberries, green tea leaf extract, and L-carnosine. It supposedly increases the body’s production of stem cells. Does it? How could we know? Like those other questionable remedies, it has never been properly tested.

To prove that a product increases longevity, it would be necessary to follow a large group of people with and without the product over many years to see if there was really a clinically significant difference. This would be impractical if not impossible. It has not been done and is not likely to be done. To prove that a product has antiaging effects, we would have to have a way to reliably measure those effects. We would need to have a better understanding of what causes aging and show with a good, controlled study that the product produces better clinical outcomes than a placebo.

The Bottom Line

Science is working on it but hasn’t yet found a reliable way to increase longevity or avoid aging. But science has shown us how to reduce the risk of preventable diseases and premature death. We can exercise, stop smoking, avoid obesity, control blood pressure and cholesterol levels, get vaccinated, and eat a healthy diet based largely on plants. A 2011 study showed that if seven risk factors are addressed (diabetes, midlife obesity, midlife hypertension, smoking, depression, low educational level, and physical inactivity), fully half of all Alzheimer’s cases could be prevented (Barnes and Yaffe 2011).

Prominent gerontologist and researcher Jay Olshansky says there is no such thing as antiaging medicine. He says the secret to aging is that there is no secret. Dr. Joe Schwarcz of McGill’s Office for Science and Society said it best: “The science [of antiaging] is all wet and drips with crackpot notions.”

This article was originally published as a Reality Is the Best Medicine column in Skeptical Inquirer.

Dr. Hall is a contributing editor to both Skeptic magazine and the Skeptical Inquirer. She is a weekly contributor to the Science-Based Medicine Blog and is one of its editors. She has also contributed to Quackwatch and to a number of other respected journals and publications. She is the author of Women Aren’t Supposed to Fly: The Memoirs of a Female Flight Surgeon and co-author of the textbook, Consumer Health: A Guide to Intelligent Decisions.

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