An article published online on February 7, 2008 in the American Journal of Epidemiology revealed the finding of Alan Kristal, DrPH of the Fred Hutchinson Cancer Research Center in Seattle and colleagues that the type of diet normally prescribed for cardiovascular health may also keep the prostate healthy.
The current study included 4,770 participants in the placebo arm of the Prostate Cancer Prevention Trial, which evaluated the effects of the drug finasteride. The current subjects were free of symptoms of benign prostatic hyperplasia (BPH, or enlargement of the prostate) at the beginning of the study, and received annual screenings for the condition over a seven year average period. Food frequency questionnaires were administered to assess dietary intake one year following enrollment.
At the end of the trial, 876 cases of BPH had been identified. Consuming a high fat diet was associated with a 31 percent increase in BPH risk when those whose fat intake was in the top one-fifth of participants were compared with subjects in the lowest fifth. Eating red meat at least once per day increased the risk of BPH by 38 percent compared with those who consumed it less than once per week, yet consuming lean protein was associated with a protective effect. Consuming vegetables was also associated with a protective effect, with a 32 percent risk reduction evidenced among those who consumed four or more servings of vegetables daily compared with those who reported eating less than one serving per day. Drinking alcohol in moderation, defined as two drinks per day, conferred a 38 percent reduction in risk. Weaker protective associations were found with lycopene, zinc, and supplemental vitamin D; however, the authors note that their assessment of supplement use was incomplete.
“It is known that obesity increases the risk of BPH,” observed Dr Kristal, who is associated head of the Cancer Prevention Program in the Public Health Sciences Division at the Hutchinson Center. “The dietary pattern that is associated with obesity among men in the United States is high fat consumption. The results of this study clearly show a link between a high-fat diet and increased risk of BPH.”
“We don’t really know how it’s working but it’s pretty clear that eating a high amount of fat – and it doesn’t appear to matter what kind of fat – increases the risk of BPH,” he added.
Consuming a high fat diet increases the body’s inflammatory response, as well as circulating hormones such as estrogens and androgens, which may affect prostate tissue, while greater vegetable and alcohol intake has been associated with a reduction in obesity, estrogens, androgens and sympathetic nervous system stimulation. “It is possible that these physiological effects moderate both the hormonally regulated prostate growth and heightened smooth-muscle tone that cause BPH,” the authors explain.
“Although confirmatory studies are needed, it is possible that dietary modification could be useful for preventing BPH and the management of BPH symptoms,” they conclude.