The effect of flaxseed on lipid profile in healthy individuals: A systematic review and dose-response meta-analysis of clinical trials

Introduction: Findings on the effects of flaxseed on the lipid profile in healthy individuals are conflicting. The current comprehensive systematic review and meta-analysis aimed to summarize available evidence in this regard. Methods: After a systematic search in the online databases, we included the randomized controlled trials (RCTs) investigating the effect of flaxseed on the lipid profile [total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), Apolipoprotein -A (apo-A) and Apolipoprotein -B (apo-B)] in healthy individuals. Results: Altogether, 16 studies with a total sample size of 1000 were included in the analysis. Combining 17 effect sizes from 16 RCTs, we found a significant lowering effect of flaxseed on serum levels of TG (weighted mean difference (WMD): <0.001, 95 % CI: - 0.05-0.05 mmol/L; p = 0.996), TC (WMD: 0.23 mmol/l; 95 % CI: -0.34 to -0.13; p & l; 0.001), LDL-C (WMD): -0.15 mmol/l; 95 % CI: -0.26 to -0.05; p = 0.003), HDL-C (WMD): -0.05 mmol/l; 95 % CI: -0.09 to -0.02; p = 0.001), apo-A (WMD): 0.16 g/l; 95 % CI: - 0.26-0.58; p= 0.465) and apo-B (WMD): -0.06 g/l; 95 % CI: - 0.15-0.02; p = 0.131). Conclusion: The present study demonstrates the beneficial effects of flaxseed on TC, HDL-C, and LDL-C in healthy people.