Flaxseed Dietary Supplement versus Hormone Replacement Therapy in Hypercholesterolemic Menopausal Women
Lemay, A., Dodin, S., Kadri, N., Jacques, H., Forest, J-C. 2002. Obstet Gynecol. 100:495-504.
Evidence supporting the role of phytoestrogenic isoflavones derived from soy, in reducing the incidence of hot flashes, and in improving lipid levels, has been previously reported. An alternative to increasing dietary intake of soy is supplementation of the diet with flax seed, a rich source of phytoestrogenic lignans, alpha-linolenic acid and soluble fiber mucilage. Because of the effects of phytoestrogens to minimize the symptoms of menopause and to reduce the risk of cardiovascular disease, the present study assessed the effects of dietary flax seed supplementation versus hormone replacement therapy (HRT) in a group of hypercholesterolemic menopausal women. Twenty-five hypercholesterolemic women followed a regular diet for 4 months, then were randomized to add 40 g/day of flax seed (containing 21 mg of total lignans, 16 g of fat comprised of 53% linolenic acid, and 11 g of fiber) or daily 0.625 mg estrogens, either alone (in women with hysterectomy) or with 100 mg progesterone (in women with an in-tact uterus) for two months. After a two-month washout period, women crossed over to the alternate treatment for two months. Flax seed supplementation was found to be as effective as estrogen or estrogen plus progesterone in alleviating mild menopausal symptoms. However, only the HRT regimen was effective in improving the lipid profile in hypercholesterolemic patients. The lack of effects of the flax seed supplementation in modifying lipid levels is in contrast to beneficial effects observed in previous studies. Both the HRT and flax seed decreased serum glucose and insulin, and decreased fibrinogen and plasminogen activator inhibitor type 1, which would be favorable in the presence of hypercholesterolemia. Further studies are needed to evaluate the effects of flax seed compared with placebo and HRT on other cardiovascular risk factors and on other tissues, such as the endometrium, bone and breast. Further studies are needed to examine the potential of phytoestrogens not only in healthy menopausal women, but also in women with metabolic problems related to cardiovascular disease or for those who are unable to use conventional HRT.