Q. I haven't heard much about human growth hormone lately. Is there any new evidence to support its use in helping older men?
A. The pituitary gland in the brain makes and secretes natural growth hormone. In combination with other hormones, such as IGF-1 (insulin growth factor 1), it is responsible for body development early in life.
Throughout your life, growth hormone continues to play a role in protein production and helps the body use fat for energy. Children deficient in growth hormone do not grow to their full potential height and have short stature. The FDA approved a synthetic human growth hormone (HGH) as a replacement in these children, which helps them grow taller.
In the early 1980s, synthetic HGH became a popular but illegal performance-enhancing drug. The hype around HGH and superior athletic performance has always been greater than the reality. In fact, multiple clinical trials comparing HGH to a placebo have never shown an athletic advantage for people who use it.
As we age, the amount of growth hormone secreted by our pituitary gland naturally declines. By age 55, blood levels of growth hormone are about one-third lower than they are in people ages 18 to 35. This drop also coincides with the reduced muscle mass and increased body fat that happens with aging.
It's easy to see why HGH was touted as an "anti-aging" supplement. But does it make you feel and look 10 years younger, as some would suggest? We do know that healthy adults who take HGH can increase muscle by about 6% and reduce body fat by about the same amount. Strength also improves in some muscle groups, but not in all.
But there are downsides to using HGH. It can cause insulin to be less effective, which can raise blood sugar levels and increase the risk of diabetes. HGH also can lead to joint and muscle pain, breast enlargement, fluid retention, high blood pressure, and carpal tunnel syndrome. And then there is this: animal studies suggest that lower levels of growth hormone activity may lead to longer life. So, theoretically, HGH injections might actually shorten life span, challenging the notion that HGH is anti-aging.
The FDA has approved HGH in adults only for a few uncommon conditions, such as documented growth hormone deficiency. Synthetic human growth hormone is a prescription drug and cannot be obtained legally without a doctor's approval. To have any effect, it must be injected. Don't waste your money on pills containing HGH. The active ingredient is not absorbed when taken by mouth.
You can slow the tick of the clock with the time-tested formula of eating a healthy diet with enough protein and pursuing a regular program of aerobic and resistance exercise. This approach is better than any drug for enhancing your vigor and enjoyment of life.
by Howard LeWine, M.D.
Editor in Chief, Harvard Men's Health Watch
