Men's Health: Flaxseed may put the breaks on prostate cancer

Men diagnosed with prostate cancer may be able to slow the growth of the tumour by adding some flaxseed to their diet.

Flaxseed is rich in beneficial omega-3 fatty acids and is an abundant source of lignan, a plant chemical that may block the cancer-promoting effects of hormones like testosterone and estrogen.

For these reasons, Wendy Demark-Wahnefried and her colleagues at Duke University Medical Center in Durham, N.C., studied flaxseed supplements in 161 men who had been diagnosed with prostate cancer and were scheduled to have the gland surgically removed.

In the month prior to surgery, these men were randomly assigned to maintain their regular diet or make one of three dietary changes: take 30 grams of flaxseed a day, restrict their fat intake to less than 20 per cent of daily calories, or do both.

Laboratory analysis of prostate tissue samples revealed that prostate cancer cells in the two flaxseed groups grew at rates that were 30 to 40 per cent slower than in the no-change and low-fat groups.

However, Demark-Wahnefried cautions that researchers don't know if these men would have received any tangible benefit from the slower cell growth, such as a reduced risk of cancer recurrence, and therefore flaxseed treatment needs to be studied further before it can be recommended. "It's not ready for prime time yet."

She and her colleagues included a low-fat diet in the study because previous research had suggested it might slow prostate cancer growth.