Key Findings
The effects of flaxseed as compared with a classic hormone replacement therapy (HRT) regimen on serum lipids in women presenting with elevated levels of cholesterol was assessed. The results of this 10-month cross-over study indicated that although 40 g of crushed flaxseed is as effective as 0.625 mg of conjugated equine estrogens with or without 100 mg of micronized progesterone in relieving mild menopausal symptoms and in lowering serum levels of glucose and insulin, only oral HRT is effective in improving the lipid profile and in achieving favorable changes in biochemical markers related to cardiovascular health in hypercholesterolemic postmenopausal women. Other studies will be required to evaluate the effects of flaxseed and flaxseed constituents compared with placebo and various HRT formulations not only on other cardiovascular risk factors but also on other tissues (mainly the endometrium, bone, and breast), the integrity and function of which are affected by hormonal deprivation and replacement at menopause.
ABSTRACT
OBJECTIVE: To assess serum lipid changes by a phytoestrogen dietary supplement compared with oral estrogen-progesterone replacement in hypercholesterolemic menopausal women.
METHODS: Twenty-five menopausal patients with total cholesterol greater than 6.2 mmol/L (240 mg/dL), a cholesterol/high-density lipoprotein-cholesterol ratio greater than 4.5 and triglycerides less than 3.5 mmol/L (310 mg/dL) after a 4-month diet, were randomized to add 40 g/day of crushed flaxseed to their diet or to take daily 0.625 mg of conjugated equine estrogens alone (hysterectomy, n = 10) or combined with 100 mg of micronized progesterone (intact uterus, n = 15). After 2 months of treatment, both groups continued the diet alone during a 2-month washout period before crossing over to the alternate treatment for 2 more months. RESULTS: Differences were found between hormone replacement therapy and flaxseed respectively for decrease of low-density lipoprotein cholesterol (3.8 +/- 0.2 versus 4.4 +/- 0.2 mmol/L) (148 +/- 8 versus 170 +/- 8 mg/dL) (P =.10), increase of high-density lipoprotein cholesterol (1.6 +/- 0.04 versus 1.3 +/- 0.03 mmol/L) (62 +/- 1 versus 50 +/- 1 mg/dL) (P =.001), and increase of apolipoprotein A-1 (1.71 +/- 0.07 versus 1.42 +/- 0.05 g/L) (P =.003). These changes were not related to modifications in diet, exercise, or anthropometric measurements evaluated in parallel. Both treatments produced similar decreases in menopausal symptoms and in glucose and insulin levels. Only hormone replacement therapy as compared with flaxseed induced an elevation of sex hormone binding globulin (P =.004), lowered fibrinogen (P =.08), and plasminogen activator inhibitor type 1 (P =.01). CONCLUSION: Although 40 g of flaxseed is as effective as oral estrogen-progesterone to improve mild menopausal symptoms and to lower glucose and insulin levels, only hormone replacement therapy significantly improves cholesterol profile in hypercholesterolemic women and favorably modifies markers related to cardiovascular health.