If you have been taking human growth hormone (HGH) because you believe it is an antiaging agent, you may want to reconsider. A new study from Johns Hopkins University School of Medicine shows that levels of human growth hormone in the body do not seem to affect life span positively or negatively.
In fact, the research team, led by Roberto Salvatori, MD, associate professor in the Department of Endocrinology at Johns Hopkins, found that people who are severely deficient in human growth hormone appear to live just as long as people who have normal levels of the hormone. Therefore, claims that HGH can slow down the aging process seem to be unfounded.
These results may give pause to the tens of thousands of people who take human growth hormone to ward off the advances of aging. Ever since Rudman and his colleagues reported in 1991 that elderly men given HGH experienced fat loss, an improvement in their skin health, and an increase in muscle mass, there has been a growing and profitable market in promoting HGH to individuals as an antiaging agent. It should be noted, however that the Food and Drug Administration (FDA) has not approved HGH as an antiaging therapy, and that its distribution for this purpose is illegal in the United States.
This is not the first study to suggest that HGH has no value as an antiaging agent. A 2007 study from Stanford University, for example, published in the Annals of Internal Medicine, noted that a review of controlled, randomized trials encompassing 220 healthy elderly individuals found no evidence to support the use of HGH as an antiaging therapy but did find increased rates of adverse events among users.
In the current study, researchers evaluated a population of 65 dwarves that live in a rural area of Brazil. The scientists found that each member of the group have two mutant copies of a gene that is responsible for releasing HGH, which results in a severe congenital deficiency of the hormone and the dwarf state. After genetic tests validated the mutation, the researchers collected data from the dwarves and their 128 unaffected siblings and compared life span information within the group and with the general population.
The investigators found that the individuals who are severely deficient in HGH seem to have the same life span as those who have normal levels of the hormone. Salvatori noted that “our results don’t seem to support the notion that lack of HGH slows or accelerates the aging process.”
The scientists then took their investigation one step further and explored whether having just one copy of the mutant gene might have an impact on lifespan. Because having a single mutant gene does not affect stature, the scientists had to conduct genetic testing on individuals to identify who had the single gene. They compared individuals in two age groups, ages 20 to 40 and those 60 to 80, and found that the presence of a single abnormal gene does not affect life span either.
Overall, human growth hormone levels do not appear to impact life span in a positive or negative direction. Upon extrapolation, taking supplements of human growth hormone would seem to have no value as an antiaging agent. The study’s findings are available in the Journal of Clinical Endocrinology and Metabolism.
Johns Hopkins University School of Medicine
Liu H et al. Annals of Internal Medicine 2007 Jan 16; 146(2): 104-15
Rudman D et al. Hormone Research 1991; 36 Suppl 1:73-81