Flaxseed Improves Lipid Profile without Altering Biomarkers of Bone Metabolism in Postmenopausal Women

Abstract

The risk of cardiovascular disease and osteoporosis drastically increases at the onset of menopause. Phytoestrogens have been suggested to inhibit bone loss and protect the cardiovascular system, in part by improving lipid profiles. The purpose of the present study was to examine the effects of flaxseed, a rich source of the phytoestrogens called lignans, on lipid metabolism and biomarkers of bone turnover in postmenopausal women. Postmenopausal women who were not on hormone replacement therapy were assigned to one of two treatment groups in a double-blind randomized study. Women were asked to consume 40 g of either ground flaxseed or wheat-based comparative control regimen daily for 3 months. In addition, all subjects received 1,000 mg calcium and 400 IU vitamin D daily. Flaxseed supplementation lowered (P < 0.05) both serum total cholesterol and non-high-density lipoprotein cholesterol by 6%, whereas the comparative control regimen had no such effect. Flaxseed regimen reduced serum levels of both low-density- and high-density-lipoprotein cholesterol by 4.7% and triglyceride by 12.8%, albeit not statistically significant. Serum apolipoprotein A-1 and apolipoprotein B concentrations were significantly (P < 0.005) reduced by 6 and 7.5%, respectively, by the flaxseed regimen. Markers of bone formation and resorption were not affected by either of the treatments. The findings of this study indicate that flaxseed supplementation improves lipid profiles but has no effect on biomarkers of bone metabolism in postmenopausal women.

Flaxseed enhances the beneficial effect of low-dose estrogen therapy at reducing bone turnover and preserving bone microarchitecture in ovariectomized rats

“…In the few clinical and animal trials that have examined the effects of FS on bone turnover, mixed findings have been reported (Abdelkarem et al 2011;Babu et al 2000;Brooks et al 2004, Farmer et al 2007Griel et al 2007;Lucas et al 2002;Ward et al 2001aWard et al , 2001b. Our finding that FS alone did not impact serum markers of bone turnover is in agreement with most previous data reporting little or no effect on BMD, bone strength, and bone turnover (Brooks et al 2004;Dodin et al 2005;Farmer et al 2007;Lucas et al 2002;Sacco et al 2009). However, it is difficult to compare our current findings with these previous studies since they were conducted in various clinical populations (e.g., healthy postmenopausal women, middle-aged men) and animal models (e.g., growing rats and gilts), and they were of varying durations (6 weeks-12 months).…”

“…The 10% FS level was chosen for the present study because it is attainable in the human diet, representing an intake of 25-50 g or 2½-5 tablespoons of FS per day. Moreover, 10% FS represents a level that has been shown to reduce tumour growth, serum, or plasma cholesterol, and atherosclerosis in animal and clinical models (Chen et al 2007;Dupasquier et al 2007;Lindahl et al 2011;Lucas et al 2002;Thompson et al 2005). The sham-operated group was fed the BD and was included as a positive control group (POS).…”

“…Since postmenopausal bone loss is linked to low levels of circulating 17␤-estradiol and increased production of proinflammatory cytokines, there is biological plausibility that through its components, FS may exert protective action against postmenopausal bone loss as well as increase the effectiveness of estrogen replacement therapy. However, intervention with FS alone did not protect areal bone mineral density (aBMD) in healthy postmenopausal women (Brooks et al 2004;Dodin et al 2005;Lucas et al 2002) or bone strength in ovariectomized (OVX) rats (Sacco et al 2009), the established preclinical model of postmenopausal osteoporosis (Thompson et al 1995). A 10% FS diet has been shown to enhance the effect of low-dose estrogen therapy (LD) on bone health in OVX rats (Sacco et al 2009) by preventing the loss of aBMD and strength at the lumbar vertebrae (LV), but not in long bones, compared with either treatment alone (Sacco et al 2009).…”

The application of probiotics and flaxseed promotes metabolism of n-3 polyunsaturated fatty acids in pigs

“…Other plasma lipid parameters were not changed significantly. Many studies are focused on the effect of either probiotics (reduction in TG, TC, LDL and HDL cholesterol levels; Jin et al 1998;Wang et al 2009) or flaxseed (no effect; Lemay et al 2002;Lucas et al 2002) on lipid metabolism in animals. Several authors discussed the effect of synbiotics on cholesterol levels (Liong et al 2007), who observed decrease in HDL cholesterol, but in hypercholesterolaemic pigs.…”

Formulation and organoleptic evaluation of flaxseed globs as a functional food

“…Flaxseed being a rich source of plant lignan precursors for enterolactone might provide cardiovascular benefits [6]. Investigations into the health effects of whole flaxseed or flaxseed products (for example, defatted flaxseed meal, flaxseed extracts) in human clinical trials and animal models have shown beneficial changes in blood lipid profiles [7,8] and protection against some types of cancer [9,10].…”