Men with advanced prostate cancer are typically treated with drugs that prevent the body from making or using testosterone. A hormone (or an androgen, as it’s known), testosterone drives prostate cancer cells to grow faster, so shutting it down is essential to keeping the illness in check. About 600,000 men with advanced prostate cancer in the United States today are undergoing this type of anti-hormonal treatment, which is called androgen deprivation therapy (ADT). But even as ADT helps men live longer, it exerts a toll on the body. Men can lose muscle and bone mass, gain weight, and they face higher risks for heart disease and type 2 diabetes.
The good news is that a few helpful strategies can lessen these metabolic side effects. Engaging in aerobic exercise and resistance training, for instance, has been shown to drop levels of inflammation in the body that might otherwise lead to heart disease. Quitting smoking is similarly beneficial, since tobacco smoke’s toxic effects on the heart are more pronounced in the absence of testosterone.
In a new study, researchers have shown that taking daily walks and eating a low-carbohydrate diet can also lessen ADT’s harms. During the investigation, 42 men who were just starting on ADT were split into two groups: Half the men took daily walks lasting at least half an hour five days a week, and were instructed to limit their carbohydrate intake to no more than 20 grams per day. The other half of the men (the control group) maintained their usual diet and exercise patterns.
After six months, typical weight loss among men in the walking/low-carbohydrate group was about 20 pounds, compared to a nearly 3-pound weight gain among men who stuck to their usual dietary and exercise routines. Men in the walking/low-carbohydrate group also had significantly higher blood levels of high-density lipoprotein (HDL), which removes cholesterol and lessens risks of atherosclerosis and heart disease. And they also had significant improvements in insulin resistance (a pre-diabetic condition), but only at three months and not when the levels were checked again three months later.
The study’s lead author, Dr. Stephen Freedland from Cedars-Sinai Medical Center in Los Angeles, California, says exercise combined with low-carbohydrate diets appears to be a promising strategy in men undergoing ADT that should be studied further. Dr. Marc Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, and editor in chief of HarvardProstateKnowledge.org, agreed, pointing out that weight gain can be a real problem for men that endures even after ADT is discontinued. “The weight loss in the experimental group is encouraging and should be validated in larger studies,” he said. “In the meantime, combining exercise with low-carbohydrate diets is a common-sense strategy that clinicians should recommend to their patients.”