Flaxseed reduces plasma cholesterol and atherosclerotic lesion formation in ovariectomized Golden Syrian hamsters

Background: Dietary modification contributes significantly in reducing cardiovascular disease (CVD) risk factors including lowering cholesterol and atherosclerosis. The purpose of this study was to investigate the effects of flaxseed, a rich source of lignans, α-linolenic acid and soluble fiber mucilage, on the prevention of ovariectomy-induced rise in total cholesterol and atherosclerotic lesions. Methods: Seventy-two 6-month-old female Golden Syrian hamsters were either ovariectomized (ovx) or sham-operated (sham) and randomly assigned to six groups (n=12): sham, ovx, or ovx plus either 17β-estradiol (E2, 10 μg/kg body weight) or semi-purified diet adjusted for macronutrients and fiber to contain one of the three doses of flaxseed (7.5, 15, or 22.5%) for 120 days. Results: Ovariectomy significantly elevated plasma total-, HDL-, and free-cholesterol concentrations. Similar to estrogen, all doses of flaxseed were effective in preventing the ovx-induced rise in plasma total cholesterol. Triglyceride concentrations were significantly higher in the flax-fed hamsters. There were no significant differences in plasma non-HDL- and esterified-cholesterol among the treatment groups. Ovariectomy also increased the number of hamsters with lesions and the aortic fatty streak area. All three doses of flaxseed reduced the fatty streak area and the incidence of lesions to levels similar to the sham group. Conclusion: The findings of this study show that flaxseed is beneficial in reducing plasma cholesterol and plaque formation induced by ovarian hormone deficiency.