Plant-based oestrogen holds potential for menopausal cardiovascular health

Phytoestrogen supplementation improves blood lipids and endothelial function in postmenopausal women, yielding modest effects on cardiovascular disease (CVD) risk factors, according to the results of a meta-analysis.

Researchers searched five electronic databases for randomized controlled trials (RCTs) that assessed the effects of phytoestrogen supplementation on CVD risk factors, including serum lipids, homocysteine, fibrinogen, markers of inflammation, oxidative stress, endothelial function, and carotid intima-media thickness (CIMT), after menopause.

Fifty-six RCTs were included in the meta-analysis, with the total population comprising 4,039 postmenopausal women. There was substantial heterogeneity in quality across studies. Quality was poor in 26 RCTs (46 percent), and there was evidence of publication bias for some of the biomarkers.

Pooled data showed that the use of phytoestrogens produced reductions in serum total cholesterol (mean difference [MD], −0.27 mmol/L, 95 percent confidence interval [CI], −0.41 to −0.13), low-density lipoprotein cholesterol (MD, −0.25 mmol/L, 95 percent CI, −0.37 to −0.13), triglycerides (MD, −0.20 mmol/L, 95 percent CI, −0.28 to −0.11), and apolipoprotein B (MD, −0.13 g/L, 95 percent CI, −0.23 to −0.03), as well as an increase in serum apolipoprotein A-1 (MD, 0.04 g/L, 95 percent CI, 0.02–0.07).

There also were decreases in serum intercellular adhesion molecule 1 (MD, −18.86 ng/mL, 95 percent CI, −30.06 to −7.65) and E-selectin (MD, −2.32 ng/mL, −4.05 to −0.59). No significant effect was observed for other parameters examined.

However, phytoestrogen use was associated with an increase in CIMT (MD, 9.34 μm, 95 percent CI, 0.39–18.29).

The findings indicate that while phytoestrogen supplementation seems to modestly improve the CVD risk profile of postmenopausal women, a harmful effect on CIMT progression may be present, which could have adverse consequences in women with an increased risk of atherosclerosis, the researchers noted.

Given the limited quality and the heterogeneous nature of the current evidence, more studies are needed to explore the role of phytoestrogens in menopausal cardiovascular health.