The ‘active’ mammalian lignans produced in the body with flax consumption have hormonal effects in women and may help to relieve menopausal symptoms such as hot flashes. They act by binding to estrogen receptors on cell membranes. These mammalian lignans are not as powerful as natural estrogens, but they can act as either estrogen mimics or estrogen antagonists, depending on the presence of stronger estrogens. Estrogen antagonists oppose the actions of endogenous estrogens.

When blood levels of the endogenous estrogens are normal⎯as occurs in premenopausal women⎯the lignans can bind to the estrogen receptor and block the actions of endogenous estrogens – thus helping to reduce the risk of hormone related breast and ovarian cancers. After menopause, the levels of endogenous estrogens in the blood decrease naturally because the ovaries release less natural estrogens. In this case, the lignans act like weak estrogens and can in this way act to alleviate menopausal symptoms.

The consumption of 25 g of flax daily has been shown to stimulate vaginal cell maturation in 25 postmenopausal women, suggesting an estrogenic effect of flax on the reproductive tract. A comparison of the effects of 40 g of ground flax daily or oral estrogen-progesterone hormone replacement (0.625 mg conjugated estrogens per day) for two months has been conducted in twenty-five menopausal women with mild symptoms. Flax was as effective as hormone replacement therapy in improving mild menopause symptoms.

Kelley Fitzpatrick
Director of Health & Nutrition
Flax Canada