Taking growth hormone can produce serious side effects
DEAR DOCTOR K:
I'm a 77-year-old man. I've read about the effects of growth hormone, and they sound great. Is there a downside?
I've also seen the many "anti-aging" claims associated with growth hormone, and I understand their appeal. Like most people, I want to live a long time, but I don't want to grow old.
But does growth hormone (GH) work? And is it safe? Those are both complicated questions to answer, but here goes.
GH is a protein produced by the pituitary gland in the brain. It gets its name from the fact that it is important in stimulating growth during childhood. Children born with a growth hormone deficiency are destined to be very short, unless they are treated with growth hormone early in life.
What about using GH in aging adults? First of all, there is absolutely no evidence that taking GH supplements will lengthen a person's life.
However, it does appear to have some beneficial effects. GH promotes an increase in muscle mass and a decrease in body fat. As men age, GH levels fall. During the same time span, muscle mass declines and body fat increases. And so (the theory goes), the way to arrest these effects of aging is to inject GH.
To evaluate the safety and effectiveness of GH in healthy older people, a team of researchers reviewed 31 high-quality studies. Together, these studies evaluated 220 people who received GH and 227 people who did not. Two-thirds of the subjects were men and their average age was 69. The dosage of GH varied, as did the duration of therapy.
As compared to the subjects who did not get GH, the treated individuals gained an average of 4.6 pounds of lean body mass and shed a similar amount of body fat. There was a slight drop in total cholesterol levels, but no significant changes in LDL ("bad") cholesterol, HDL ("good") cholesterol, triglycerides, aerobic capacity, bone density, or fasting blood sugar and insulin levels. So far, so good.
Now comes the bad news. People who used GH experienced a high rate of side effects. These included fluid retention, joint pain, breast enlargement and carpal tunnel syndrome.
A bigger concern is cancer. In laboratory studies, GH promotes the multiplication of cancer cells. Some epidemiological studies have found that people with naturally high levels of GH had higher rates of cancer. These studies by no means prove that taking GH supplements would raise a person's risk of cancer, but it's plausible that they might.
So I don't recommend taking GH supplements to help fight the ravages of time, although new evidence could cause me to change my mind. But that doesn't mean you have to sit back and let Father Time peck away at you. Instead, use the time-tested combination of diet and exercise. You'll reduce your risk of many chronic illnesses and -- it's true -- slow the ticking of the clock.
(Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.)
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