Feb. 26, 2003 -- Sorry, folks, but the concept of effortlessly reversing the natural aging process with human growth hormone (HGH) injections has some serious holes -- beyond those in the skin. And the idea that you can achieve this future youth with pills is even harder to swallow.
So say leading researchers in the latest round of what is becoming a controversial healthcare topic -- using growth hormones as therapy in otherwise healthy seniors to try to stop the ravages of time. These injectable hormones, naturally produced in the pituitary gland, are designed for those with a growth hormone deficiency and whose growth has been thwarted. But in recent years, they have been administered to growing numbers of the elderly, whose hormone levels naturally decline as they reach their 60s to levels half of those in their 20s or 30s. While various studies show that injecting these substances can build muscle and bone mass and help reduce body fat, these effects come at a price.
And that worries some experts, who have mounted a recent campaign against those who use HGH products for "off-label" purposes. Earlier this month, scientists who study aging challenged claims by those in the so-called "anti-aging movement" that growth hormones can stop the ravages of time in healthy seniors. And last month, the American Society of Plastic Surgeons joined the debate, issuing a statement to its members against using these products.
This week, a leading researcher challenges their use in TheNew England Journal of Medicine. "The point needs to be made that the only people who should be taking growth hormones are those with a history of pituitary diseases -- not those who take them for anti-aging or athletics," says endocrinologist Mary Lee Vance, MD, who wrote the journal article. "They have potential to be dangerous."
Vance, a longtime growth hormone researcher, tells WebMD she wrote the article to warn doctors and their patients of these products' "misuse for commercial reasons." As many as one in three people uses growth hormones for reported anti-aging benefits -- and not the FDA-approved deficiencies resulting from disease. She is especially concerned about the use of commercially available over-the-counter pills, a combination of several amino acids that are advertised as able to produce these youthful benefits.
"These amino acids taken orally are not known to do anything except waste money," she tells WebMD. "They are not anywhere similar to the injected growth hormones. But people are misunderstanding this in their effort to find a magic bullet that will make then feel and look better."
Since 1990, when the first study on the anti-aging effects of injected HGH was published in The New England Journal of Medicine, its use for anti-aging purposes has been a hot topic of study. In that trial, often cited by anti-aging HGH proponents, improvements were noted in the 12 men studied. The study showed gains in muscle mass and bone density, but it didn't assess muscle strength. The study also showed a few negative effects such as increases in blood pressure and blood sugars.
Last November, one of the largest studies published suggested that injected HGH did build muscle and bone mass and help healthy seniors lose weight. However, 40% of the 131 men and women studied developed serious side effects -- including arthritis-like joint pain and swelling, carpal tunnel syndrome, and diabetes-like changes in blood glucose levels. These side effects stopped after the study participants stopped taking the hormones, says that trial's lead researcher.
"While they did have an increase in muscle mass, there was no increase in muscle strength or exercise endurance," says Marc R. Blackman, MD, scientific director for clinical research at the National Center for Complementary Medicine, a branch of the National Institutes of Health. "The improvements they experienced were not functionally relevant."
Blackman, a leading researcher in this area for 25 years who has personally conducted several studies, says, "While the use of injected growth hormone is exciting, they are not ready for prime time." He, too, is especially concerned about the use of amino acid pills, which are sold on various anti-aging web sites and through magazines. These amino acid pills are marketed as having the potential to increase the body's own growth hormone levels.
"I have been imbedded in this research for a long time, and there are no controlled studies that I know of to support any of the claims made on the use of these pills," he tells WebMD. "The claims are ridiculous, because growth hormones taken by mouth are degraded by enzymes in stomach. But they can be dangerous for many other reasons."
Besides increasing risk of liver damage, these products could interfere with other medications, such as the blood-thinner Coumadin. "They can either exacerbate its effect and cause a bleeding tendency, or lessen its effects and the benefits of preventing clotting could be reduced," says Blackman. "Since these pills haven't been well tested, we really don't know their long-term effects."
While proponents of these products cite numerous studies of their safety, Blackman says these trials typically last only for a few days or weeks and involve few participants. And they have not "tested" these pills against placebos, says Blackman -- the gold-standard method of clinical study.
Even plastic surgeons are now advising their colleagues against administering HGH products, which allegedly reduce wrinkles and improve skin health. In the January issue of the medical journal Plastic and Reconstructive Surgery, surgeon W. Glenn Lyle, MD, chair of the Plastic Surgery Educational Foundation, published an article critical of these products.
"Plastic surgeons are often called upon to do things to make patients look better, but these products' use is unproven and there are potential dangerous side effects that have been proven," Lyle tells WebMD. "Plastic surgeons that are administering these products are doing it outside the bounds of what they were trained to do."
But HGH proponent Ronald Klatz, MD, president of the Academy of Anti-Aging Medicine, tells WebMD that his organization properly trains anti-aging doctors to use HGH safely. "We have yet to see serious sustained side effects in anti-aging patients treated under the recommended protocols taught at our conferences," says Klatz, author of Growing Young with HGH. "No patient who is not found to be deficient by lab parameters is recommended to be on HGH."