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Longevity researcher Thomas Perls: study proves growth hormone injections are harmful

By Brian Fitzgerald

Ponce de Leon searched in vain for the fountain of youth, and those today looking to extend their lives by taking human growth hormone (HGH) will discover little more than a fountain of misinformation, according to BU longevity researcher Thomas Perls. They may also have a nearly 50-50 chance of falling victim to the hormone’s side effects.

Thomas Perls Photo by Gina DiGravio

Ads tout such claims for the hormone as “energizing your body’s master energy center,” but results of a clinical study published in the November 13 issue of the Journal of the American Medical Association (JAMA) show that while the HGH injections did increase lean muscle mass and fat loss in test subjects, the gains were accompanied by adverse reactions in almost half the cases. Perls, a MED associate professor, whose own longevity research examines nutrition, lifestyles, and genes -- not magic hormone energy potions -- hopes that the JAMA study will ring the “death knell” for the use of HGH as an anti-aging agent.

Perls says that these questionable anti-aging medicines, which have grown into a multibillion-dollar-a-year business recently, is nothing new. “There has been a long history of advertising hormones, dating back to the 1700s, as a fountain of youth,” he says. “I think that what we’re experiencing today is really no different from the snake oil salesmanship that took place back then.”

Despite the hype of a previous study a decade ago suggesting the possibility that HGH can stave off some of the negative effects of aging -- including decreased muscle mass and strength, increased body fat, thinning of the bones, and a decline in cardiovascular endurance -- Perls says that there is no convincing evidence that current anti-aging remedies can slow aging or increase longevity in humans. “At the same time,” he says, “there have been studies that prove not only that they do not work, but that they cause harm. And the research published in JAMA is a high-profile study showing just that.”

The recent study, conducted jointly by investigators from the National Institute on Aging (NIA) Intramural Research Program and investigators from the Johns Hopkins University School of Medicine in Baltimore, suggests that growth hormone and related substances, particularly given in combination with testosterone in older men, “may one day be a promising therapeutic of certain age-related conditions,” says Marc R. Blackman, the study’s lead investigator. Still, “it is not ready for prime time. There is much we still don’t know about its efficacy,” he continues, “and more importantly, there are too many known and potential adverse consequences associated with it. It is a fascinating and promising area of research, but at this time we can’t recommend it for use outside of a carefully controlled and monitored clinical trial.”

Numerous side effects, including prediabetes, diabetes, aching joints, and swollen tissues, are cited in the study, which was supported by grants from the NIA and the National Center for Research Sources. Although a 6.8 percent increase in strength was reported in men who took HGH and testosterone, between 24 and 46 percent of those treated with HGH experienced peripheral edema, carpal tunnel syndrome, and joint pain. The study involved 57 healthy men and 74 healthy women aged 65 to 88.
HGH is manufactured by the pituitary gland, a pea-sized structure at the base of the brain. After age 35, although the body continues to produce the hormone, it releases less of it. HGH injections increase pituitary output, but in many cases exacerbate resistance to insulin, the hormone that allows blood sugar, or glucose, to be taken into the body’s cells and used for energy.

Anti-aging hucksters
“There are reputable companies, such as Genzyme, that make HGH for FDA-approved uses, such as treating children whose pituitary glands do not make amounts of the hormone sufficient for normal growth,” says Perls. “But there are more than a thousand of these anti-aging hucksters -- or practitioners, as they would undoubtedly prefer to be called -- who make the stuff for people who don’t have childhood growth hormone deficiency.”

Proponents of HGH, including Dr. Ronald Klatz, president of the American Academy of Anti-Aging Medicine in Chicago, say that the side effects reported in the JAMA study were caused by doses of the hormone that were inappropriately high -- two to three times higher, they say, than needed for rejuvenation purposes. Perls says that a follow-up study administering reduced doses may help clear the air. “It would be worthwhile to deal with any criticisms of the study, however unfounded they are, with an additional study,” says Perls. “But I’m not sure how easy it would be to do another study because of the incidence of side effects.”

Some federal officials have estimated the number of older adults injecting HGH at 25,000 to 30,000, with a price tag of $15,000 a year for each person. Writing prescriptions for the hormone as an anti-aging treatment is not illegal, but it has generated a bitter debate between the gerontological medical establishment and doctors who run “anti-aging clinics.” Thousands of other people use less expensive growth hormone pills and sprays, which don’t work, according to S. Mitchell Harman, one of the JAMA study researchers, because the HGH molecule is too large to pass into the bloodstream unless injected.

“They’ll come up with anything to entice the public,” says Perls. “First it was melatonin. Then it was DHEA.” Melatonin, a hormone produced by the pineal gland, and dehydroepiandrosterone (DHEA), a hormone produced by the adrenal glands, are available without a prescription because they are classified as food supplements. Blasted by the NIA, these heavily promoted “miracle” compounds became popular with aging baby boomers in the early 1990s, but sales tapered off about five years ago. “They had bad side effects and weren’t selling on the market. After human growth hormone is no longer popular, they’ll come up with something else,” says Perls. “The ones that promote these so-called aging cures don’t care about the science, they just care about their pocketbooks.”

Fountain of aging well
There is no fountain of youth, he says, but there is what he likes to call “the fountain of aging well.”

In 1994, Perls and MED research associate Margery Hutter Silver, then researchers at Harvard, launched the New England Centenarian Study (NECS) -- the largest genetic study of people over 100 years old in the world. Perls and Silver, who came to BU last February, write in their book Living to 100: Lessons in Living to Your Maximum Potential at Any Age (Basic Books, 1999) that one key to surviving to an old age is no real secret. “The only thing we know that can really slow down aging, and perhaps also delay the diseases associated with aging, is caloric restriction,” Perls says. Indeed, obesity is rare among centenarians.

The researchers with the NECS, now based at Boston Medical Center, also discovered a “genetic booster rocket” for longevity after analyzing the genomes of 308 centenarians and their siblings. They pinpointed a region on human chromosome 4 that is likely to contain a gene or genes associated with extraordinary life expectancy. “With scientists at a company called Centagenetix in Cambridge, we’ve been working to find the gene that plays a role in lifespan,” says Perls. Exploring the gene’s biochemical pathways could lead to the development of a drug that mimics the effect of the gene -- with benefits outweighing the risks, unlike the current so-called anti-aging supplements.

George Bernard Shaw was in his 90s when he gave this bit of advice to young people: “Do not try to live forever. You will not succeed.” However, says Perls, “most of us have what it takes to get to our mid to late 80s in very good health if we regularly exercise, maintain a lean body mass, and don’t smoke -- doing those things will enable most of us to preserve our health and vitality.”

10 January 2003
Boston University
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