Flaxseed reverses atherosclerotic lesion formation and lowers lipoprotein (a) in ovarian hormone deficiency.

Key Findings:

Previous reports by these authors showed that flaxseed (7.5%, 15%, and 22.5%) decreased aortic fatty streak area compared to control. Fatty streak area was reduced by 80%. Their clinical studies showed that flaxseed significantly lowered TC, lipoprotein(a) (Lp(a)), and Apo B concentrations without altering HDLC in postmenopausal women. Hypocholesterolemic effects of flaxseed were noted in ovx hamsters, an animal model used to mimic lipid changes that occur in women after menopause. Flaxseed prevented atherosclerotic lesion formation by decreasing fatty streak area and the severity of atheromatous plaques in animal models.   In this study, whole flaxseed lowered serum Lp(a), Apo B, and TG, and reversed atherosclerotic lesion formation as found by the number of animals with lesions in the heart and aorta.  The animal and human data compiled by this group demonstrates the efficacy of flaxseed in decreasing CVD-related risk factors in postmenopausal women.

ABSTRACT:

Objective: The incidence of cardiovascular disease dramatically increases during menopause, and postmenopausal women seek natural alternatives to hormone therapy. Flaxseed can slow the progression of atherosclerotic lesion formation; however, it is not known whether it can reverse formation that has already occurred. Methods: Seventy-two female Golden Syrian hamsters were randomly divided into six groups, sham operated (sham) or ovariectomized (ovx), and kept on the same diet for 120 days to allow for atherosclerotic lesion development. After this 120-day period, whole flaxseed was introduced to the diets of hamsters in three of the groups: group 1 (sham + casein); group 2 (ovx + casein); group 3 (ovx + 7.5% flaxseed); group 4 (ovx + 15%flaxseed); group 5 (ovx + 22.5% flaxseed); and group 6 (ovx + 17A-estradiol). This diet was maintained for an additional 120 days. Lesion regression was examined histologically, and serum was analyzed for total cholesterol, triglyceride, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, Apo A, Apo B, and lipoprotein(a). Results: Results showed that 15% and 22.5% flaxseed, compared with ovx animals, significantly reduced lipoprotein(a) (4.4 mg/dL [ovx] vs 2.15 mg/dL [15% flaxseed] and 0.3 mg/dL [22.5% flaxseed]; P < 0.05) and Apo B (2.8 mg/dL [ovx] vs 2.4 mg/dL [15% flaxseed] and 2.5 mg/dL [22.5% flaxseed]). Flax reduced by 67% the number of animals with aortic arch lesions. Conclusions: All three doses of flax reduce the severity of lesion formation compared with ovx controls. These results support the efficacy of flaxseed in reducing cardiovascular disease risk. (Authors abstract)