Surveyors of anti-aging elixirs tout human growth hormone as a remedy for all things sagging-from skin to libidos — and claim it can even prevent or reverse aging. But researchers at the Stanford University School of Medicine say there’s no evidence to suggest that this purported fountain of youth has any more effect than a trickle of tap water when it comes to fending off Father Time.
“There is certainly no data out there to suggest that giving growth hormone to an otherwise healthy person will make him or her live longer,” said Hau Liu, MD, a research fellow in the division of endocrinology and in the Center for Primary Care and Outcomes Research, and first author of a review study to be published in the Jan. 16 issue of Annals of Internal Medicine. “We did find, however, that there was substantial potential for adverse side effects.”
Those negative side effects included joint swelling and pain, carpal tunnel syndrome and a trend toward increased new diagnoses of diabetes or pre-diabetes. “You’re paying a lot of money for a therapy that may have minimal or no benefit and yet has a potential for some serious side effects,” Liu said. “You’ve got to really think about what this drug is doing for you.”
Growth hormone is widely promoted on the Internet and its use as a purported anti-aging drug has caught the attention of the popular media, ranging from the “Today Show” to Business Week.
Between 20,000 and 30,000 people in the United States used growth hormone as an anti-aging therapy in 2004, a tenfold increase since the mid-1990s, according to the authors of an unrelated study published in the Journal of the American Medical Association in 2005. This increase comes despite both the high cost of such therapy – often more than $1,000 a month – and the illegality of distributing growth hormone for anti-aging therapy in this country. Those numbers prompted Liu and some colleagues to see if the medical literature provided any support for such therapy.
Growth hormone is naturally produced by the pituitary gland, a pea-sized organ at the base of the brain. Production is highest during childhood and the hormone-drenched adolescent years, then typically starts tapering off around age 30, continuing to decline into old age. Growth hormone is critical to proper development in children, particularly their height, and injections of growth hormone are considered a legitimate treatment for short children and for adults whose pituitary glands don’t produce enough growth hormone to maintain normal metabolism. But most promoters of growth hormone as an anti-aging therapy target the healthy elderly.
Liu’s team undertook a systematic review and analysis of published studies, excluding any that looked at diseases for which growth hormone is an accepted therapy. They focused solely on studies using growth hormone to treat the elderly, specifically those whose main maladies were nothing worse than age and being mildly to moderately overweight. They also included only studies that evaluated the use of the hormone in randomized, controlled clinical trials.