A study by Mayo Clinic physician and North Central Cancer Treatment Group (NCCTG) researcher Sandhya Pruthi, M.D., and colleagues found that flaxseed provided no benefit in easing hot flashes among breast cancer patients and postmenopausal women. The study is in the current online version of the journal Menopause.

The randomized, placebo-controlled study followed 188 women between October and December 2009 and found no statistically significant difference in mean hot flash scores between women taking flaxseed and those taking a placebo. Preliminary data published in 2007 by Mayo Clinic investigators had suggested that consuming 40 grams of crushed flaxseed daily might help manage hot flashes.

"Hot flashes are common among women during the menopause transition or following breast cancer treatment," says Dr. Pruthi, of Mayo Clinic's Breast Diagnostic Clinic. "While preliminary data from our 2007 pilot study showed a reduction in hot flashes associated with the consumption of ground flaxseed, our new study did not result in a significant decrease in hot flashes with eating flaxseed compared to placebo."

Dr. Pruthi says patients shouldn't give up flaxseed if they enjoy it. "Flaxseed may be beneficial for people who want to add fiber and bulk to their diet to manage constipation," says Dr. Pruthi, "but more research is needed to identify whether flaxseed has any other health benefits."