Men's Health: Cholesterol drugs' cancer benefit remains a mystery

Studies have suggested that men who take cholesterol-lowering drugs known as statins have a lower risk for developing prostate cancer, but researchers have yet to find an explanation for the apparent benefit.

One theory is that because cholesterol is needed for the production of male hormones -- and these hormones can fuel the growth of prostate tumours -- then lowering cholesterol may protect the prostate by reducing male hormone levels. But research led by Susan Hall, a scientist at the New England Research Institutes in Watertown, Mass., suggests that's not the case.

Hall and her colleagues investigated whether blood levels of the male hormone testosterone varied by statin use in more than 1,800 men living in Boston. About 12 per cent of these men were statin users and, on average, they were older, heavier, had more chronic illnesses and used more medications than their non-statin using counterparts.

After the researchers adjusted for these other risk factors for low testosterone, there was no association between statin use and testosterone level. "In other words, being on statins was a marker for having other risk factors for lower testosterone," Hall says. "People with diabetes are more aggressively treated with statins, for example."

Hall says the study was not intended to address other proposed explanations for statins' apparent ability to protect against prostate cancer, such as blockage of the growth or spread of cancer cells and the blood vessels that feed them.

She points out statins are the most commonly prescribed drugs in the world and are taken over the long term, so the fact they appear to have little influence on male hormone levels is probably reassuring.