Flaxseed supplementation significantly reduces HbA1c in patients with type 2 Diabetes

Flaxseed is a functional food owing to its high content of dietary fibres, lignans, alpha-linolenic acid, and other substances that may be beneficial to improve cardiometabolic parameters in type 2 diabetes patients. Huihui Xi, School of Nursing, Jilin University, Changchun, Jilin, China, and colleagues hypothesized that flaxseed supplementation would improve cardiometabolic parameters in T2DM patients; however, clinical trials have yielded conflicting results. Therefore, the authors performed a systematic review and meta-analysis to determine the impact of flaxseed supplementation in type 2 diabetes mellitus (T2DM) patients.

For this purpose, the team systematically searched the online databases for randomized controlled trials until 25 March 2022. In total, 13 studies were included.

The study revealed the following findings:

· Flaxseed supplementation significantly reduced hemoglobin A1c (HbA1c) in participants with T2DM compared with the control group. In contrast, it had no effects on body weight, body mass index, blood pressure, fasting blood glucose (FBG), homeostatic model assessment for insulin resistance, quantitative insulin sensitivity check index, and lipid parameters.

· In the subgroup analyses, FBG was significantly reduced with flaxseed supplementation in participants with baseline FBG ≥8.0 mmol/L or baseline HbA1c ≥7.0%. And a significant decrease in HbA1c in participants with baseline HbA1c ≥7.0% after flaxseed supplementation.

· Subgroup analyses indicated that whole flaxseed supplementation significantly increased high-density lipoprotein cholesterol and reduced total or low-density lipoprotein cholesterol in participants with T2DM.

To conclude, flaxseed supplementation remarkably reduced HbA1c in patients with type 2 diabetes, particularly those with poorly controlled blood sugar levels.

"Larger scale studies with better designs are needed to confirm insignificant and ambiguous findings," the researchers wrote.

Reference:

Xi, H., Zhou, W., Sohaib, M., Niu, Y., Zhu, R., Guo, Y., Wang, S., Mao, J., Wang, X., & Guo, L. (2023). Flaxseed supplementation significantly reduces hemoglobin A1c in patients with type 2 diabetes mellitus: A systematic review and meta-analysis. Nutrition Research, 110, 23-32. https://doi.org/10.1016/j.nutres.2022.12.008