Does flaxseed improve blood lipids and liver enzymes in nonalcoholic fatty liver disease? Original paper

In this meta-analysis of randomized controlled trials, supplementing with flaxseed improved some blood lipid and liver enzyme measurements in participants with nonalcoholic fatty liver disease.

The effect of supplementing with flaxseed on blood lipids and liver enzymes in the context of nonalcoholic fatty liver disease (NAFLD).

The outcomes assessed were total cholesterol, LDL-C, HDL-C, triglycerides, ALT, and AST.

A total of 296 men and women with NAFLD.

A meta-analysis of 5 randomized controlled trials was performed. Three studies were conducted in Iran, 1 study in Japan, and 1 study in Ukraine. The dosage of flaxseed ranged from 100 mg per day to 30 grams per day, and the intervention duration was 12 weeks in 4 studies and 8 weeks in 1 study. Flaxseed was compared to a placebo in 4 studies, and in the other study, the control was sunflower oil.

Subgroup analyses were performed to determine whether the dose of flaxseed (≥20 grams per day vs. lower amounts) influenced the results.

Compared to the control, flaxseed reduced triglycerides (−31 mg/dL), total cholesterol (−16 mg/dL), LDL-C (−11 mg/dL), and ALT (−5 U/L), and increased HDL-C (+2 mg/dL). The only potentially clinically meaningful improvement was for triglycerides. The reported effects did not clearly differ between higher and lower doses of flaxseed.

Two studies had a high risk of bias, 2 had some concerns, and 1 had a low risk of bias.

The small number of studies included and their questionable quality limits our confidence in the results.