One study reports on flax and flaxseed oil in menopausal women, the second conducts a general review of the literature.

One study is positive; the other is not.

Researchers from the Mayo Clinic recruited 29 postmenopausal women with at least 14 hot flushes (flashes) per week for a month and refused to take estrogen because of a perceived increased risk of breast cancer. They were assigned to 40 grams of crushed flaxseed daily for 6 weeks.

And, the results.

  • 21 women completed the study.
  • The frequency of hot flashes decreased 50% over 6 weeks.
  • The overall hot flash score decreased an average 57% for the women who completed the trial.

The bottom line?
The authors suggest, “Dietary therapy using flaxseed may also decrease hot flushes in postmenopausal women who do not take estrogen.

Maybe, but one small study where almost 40% of the participants quit is not definitive. Furthermore, in the same issue of the same journal, a broad-based evaluation of flaxseed studies in humans concludes the studies are of poor quality.

For the treatment of constipation/laxative, attention-deficit hyperactivity disorder, hyperlipidemia, atherosclerosis/coronary artery disease, breast cancer, breast pain, menopausal symptoms, hyperglycemia/diabetes, high blood pressure, lupus nephritis, HIV/AIDS, and prostate cancer, clinical study results do not support flaxseed and flaxseed oil to treat any condition at this time.

8/30/07 19:09 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.