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.