In 2009, the American Medical Association (AMA) assessed the risks and benefits of growth hormone, testosterone, estrogen and DHEA for anti-aging. The AMA concluded that the risks outweigh the potential benefits. As part of the anti-aging industry that has mushroomed in the last decade, growth hormone offers the most illustrious of histories.
Although much maligned, the 19th Century scientist Adolphe Brown Sequard provided his elixir for free—an extract in water from the testicles of two-year old dogs and guinea pigs mixed with semen and blood from the testicular veins—to anyone that requested it, at an estimated cost of $42,000 in today’s money. His search for the anti-aging hormone testosterone did, however, lead to the birth of the science of endocrinology. His philanthropic donation was a far cry from today’s industry. Global Industry Analysts report that the world market for anti-aging products reached $115.5 billion last year, roughly the size of Iraq’s gross domestic product.
The findings by the AMA expose a paradox of using powerful chemicals for anti-aging purposes. Although most of these hormones help the body look “young,” there are dangerous side effects. For example, adults whose pituitary glands overproduce growth hormone have premature heart and lung failure, as well as abnormal growth of other organs and tissues. We know that the steroid testosterone produces muscle mass, but it also results in short-term sexual and reproductive disorders, fluid retention, and severe acne. Possible long-term effects may include heart damage, stroke, and brain tumors.
In fact, lower growth hormone levels may indicate good health. So, although research with hormone replacement has resulted in some positive short-term results, it is clear that negative side effects also may occur as increased risk for cancer, cardiovascular disease, and behavior changes. This evidence still leaves us with a safer path—one of the best known methods for increasing the lifespan is simply consuming fewer calories. A low caloric diet reduces hormone levels and seems to activate specific genes that are responsible for longevity.
As far back as 1935, Mary Crowell and Clive McCay of Cornell University conducted experiments on laboratory animals to determine if caloric intake affects longevity. The results have shown that laboratory animals—across all species studied— extended their lives by 30% to 40% and age more slowly when they are fed healthy, very low calorie diets that contain essential nutrients.
In his book, Beyond the 120 Year Diet: How to Double Your Vital Years, Roy Walford proposed that longevity can be significantly increased by a diet that is high in nutrients but contains about a third less calories. Although Walford died of Lou Gehrig's disease at age 84, he expressed one of three distinct pathways that we know that affect longevity — the other two being insulin/IGF signaling and the mitochondrial electron transport chain pathway (see future articles). While the National Institutes of Health undertake their first preliminary study on caloric restrictions with humans, we can promote our chances of longevity by not over-indulging and consuming quality rather than quantity.
Mario Garrett PhD is a professor of gerontology at San Diego State University. He can be reached at mariusgarrett@yahoo.com © Mario Garrett 2011 blogs at http://iage-marius.blogspot.com/
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