Effects of cereal bran consumption on cardiometabolic risk factors: A systematic review and meta-analysis

Aims: Cardiovascular disease is a prevalent worldwide disease, and cardiometabolic risk factors (CMRFs) include hyperlipidemia, hypertension, diabetes, and adiposity. Healthy diets are the critical factor in controlling these CMRFs risks, especially cereal bran which contains many beneficial substances. However, there are still contradictions in the indicators of improving CMRFs by bran from different grain sources or even the same grain source. Therefore, this study aimed to investigate the effects of cereal bran consumption on CMRFs. Data synthesis: Eligible randomized controlled studies were searched in PubMed, Embase, Scopus, the Cochrane Library and Web of Science until February 2023. The random-effects model was used to calculate overall effect sizes of weighted mean difference (WMD) and 95% confidence interval (CI). Finally, 22 studies were included in the present meta-analysis. Compared to the control, cereal bran consumption had no significant effect on high-density lipoprotein cholesterol, triglycerides, waist circumference, and body mass index, but could reduce systolic blood pressure (WMD: -1.59; 95% CI: -2.45 to -0.72), diastolic blood pressure (WMD: -1.96; 95% CI: -3.89 to -0.04), total cholesterol (WMD: -0.19; 95% CI: -0.34 to -0.04), low-density lipoprotein cholesterol (WMD: -0.21; 95% CI: -0.38 to -0.04 ), and fasting blood glucose (WMD: -0.13; 95% CI: -0.24 to -0.01). Additionally, oat bran can lower blood lipids in individuals with lipid diseases and blood pressure in obese or hypertensive patients. Conclusions: Cereal bran could significantly reduce blood pressure, total cholesterol, low-density lipoprotein cholesterol, and fasting blood glucose in individuals with CMRFs, and oat bran had the most obvious effect. (c) 2023 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.