Flaxseed supplementation reduces plasma lipoprotein(A) levels: A meta-analysis

Context • Elevated levels of lipoprotein (a) [Lp(a)] are an independent risk factor for premature cardiovascular disease (CVD). Flaxseed (Linum usitiatissimum L.) is a rich source of alpha-linolenic acid, phytoestrogens, and lignans and has been shown to improve several cardiovascular risk factors, although the overall effect on Lp(a) is unknown. Objective • The study intended to assess the impact of flaxseed on plasma Lp(a) levels through a meta-analysis of the results of randomized controlled trials (RCTs). Design • PubMed-Medline, Scopus, Embase, and Google Scholar databases were searched using the following search terms in titles and abstracts: flaxseed OR Linum usitatissimum OR lignin OR linseed AND lipoprotein(a) OR lipoprotein (a) OR Lp(a) OR Lp (a). Results • Of the 48 RCTs, 6 were eligible for inclusion, and the results suggested a significant decrease in plasma Lp(a) levels—standardized mean difference:-0.22, 95% confidence interval:-0.41 to-0.04, P= .017—following supplementation with flaxseed-containing products. Conclusions • This finding highlights the potential clinical significance of flaxseed supplementation for patients who are at risk of a high residual CVD despite intensive statin therapy, patients with hyperliporoteinemia(a), and patients who prefer natural remedies for CVD prevention in the context of a healthy lifestyle. Further RCTs are needed to establish the role of flaxseed-containing products on lowering Lp(a). (Altern Ther Health Med. 2021;27(3):50-53).