A Mayo Clinic and North Central Cancer Treatment Group (NCCTG) study has shown that flaxseed provides no benefit in easing hot flashes among breast cancer patients and postmenopausal women. They conducted a randomized, placebo-controlled study on 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 seemed to suggest that consuming 40 grams of crushed flaxseed daily might help manage hot flashes but now it seems that this is not the case.
Flaxseed may not help hot flashes, but is a good addition to a healthy diet as it has protective effects, particularly for women. Flaxseed is particularly rich in lignans, special compounds also found in other seeds, grains and legumes that are converted by beneficial gut flora into two hormone-like substances called enterolactone and enterodiol. These hormone-like agents demonstrate a number of protective effects against breast cancer and are believed to be one reason a vegetarian diet is associated with a lower risk for breast cancer. Studies show that women with breast cancer and women who are omnivores typically excrete much lower levels of lignans in their urine than vegetarian women without breast cancer.
Flaxseeds are also a very good source of fiber that can lower cholesterol levels in people with atherosclerosis and diabetic heart disease, reduce the exposure of colon cells to cancer-causing chemicals, relieve the constipation or diarrhoea of irritable bowel syndrome sufferers, and help stabilize blood sugar levels in diabetic patients. Flax seeds are also a good source of magnesium, which helps to reduce the severity of asthma by keeping airways relaxed and open, lowers high blood pressure and reduces the risk of heart attack and stroke in people with atherosclerosis and diabetic heart disease, prevents the blood vessel spasm that leads to migraine attacks and generally promotes relaxation and restores normal sleep patterns. This latter is particularly relevant for menopausal women as sleep patterns are often disturbed by the fluctuating hormone levels.