Is Human Growth Hormone a Key to Longevity?

Oct. 11 -- FRIDAY, Oct. 10 (HealthDay News) -- Adults who long for the vitality of their younger days may be curious about trying injections of human growth hormone, the same substance allegedly used by some Major League Baseball players to boost their athletic performance.

But can it really turn back the hands of time?

Studies of human growth hormone in healthy adults are limited. And what rigorous scientific evidence there is suggests that the risks -- and they can be substantial -- outweigh the benefits.

"I think people are looking for a pill or an injection or something that will cause them magically to become younger," said Dr. Hau Liu, associate chief of endocrinology and co-director of chronic care management at Valley Medical Center in San Jose, Calif. "At least from our view of the data, our conclusion is that it's not the fountain of youth."

Liu was lead author of an analysis of data culled from randomized, controlled trials of growth hormone use in healthy older adults. His team's study, published last year in the Annals of Internal Medicine, found an association between growth hormone use and slight changes in body composition, but no changes in other important health outcomes.

What's more, users of growth hormone had high rates of soft tissue swelling and joint pain, compared to people who didn't get these injections. There was also an increased risk of impaired blood sugar control or diabetes. Although this finding was not statistically significant, Liu suggests that it is "worrisome" given the epidemic rise of type 2 diabetes in the United States.

Human growth hormone is a protein made by the pituitary gland. It's important for normal development and maintenance of tissues and organs, and is especially important for normal growth during childhood, according to the U.S. National Institute on Aging.

As people enter their 40s, the amount of growth hormone produced starts to decline. And, despite a lack of solid evidence, some people believe that bolstering levels of the hormone through injections will help stave off the effects of aging.