Does flaxseed supplementation affect apo- lipoproteins? A GRADE-assessed systematic review and meta-analysis.

Several studies indicated the ameliorating effects of flaxseed supplementation on
apolipoproteins, although others have conflicting results. Therefore, the present research was
conducted in order to accurately and definitively understand the effect of flaxseed on
apolipoproteins in adults. All articles published up to Juan 2024 were systematically searched
through PubMed, Scopus, Embase, and Web of Science to collect all randomized clinical trials
(RCTs). A random effects model was used to measure the combined effect sizes. Also,
standardized mean difference (SMD) and 95 % confidence interval (CI) were used to report the
combined effect size. Our results showed that flaxseed supplementation significantly reduced
apo-BI (SMD: -0.57; 95 % CI: -0.95, -0.19, p = 0.003; I 2  = 83.2 %, heterogeneity p < 0.001) and
lipo(a) decreased (SMD: -0.34; 95 % CI: -0.59, -0.09, p=0.007; I 2 =30.3 %, heterogeneity
p=0.197). However, flaxseed did not change apo-AI levels (SMD: -0.37; 95 % CI: -0.87, 0.13, p
= 0.146; I 2  = 89.2 %, p-heterogeneity < 0.001). This meta-analysis has shown that flaxseed
supplementation may have beneficial effects on apolipoproteins. Future high-quality, long-term
clinical trials are needed to confirm our results.