Effects of brewer's yeast on blood pressure and serum lipoproteins in type-2 diabetes mellitus patients

The increasing trend of prevalence of diabetes mellitus, a diet-related chronic disease has prompted research to find ways to control it. Brewer's yeast may have a potential role because its glucose tolerance factor (GTF) may have beneficial effects on insulin receptors in diabetic patients. This study was conducted to investigate the effects of brewer's yeast supplementation on serum lipoproteins and blood pressure in patients with type-2 diabetes mellitus (T2DM) patients. In a randomized double-blind controlled clinical trial 84 adults (21 men and 63 women, 46.3 ± 6.1 years old) with T2DM were recruited and divided randomly into 2 groups of 42 subjects each, one receiving brewer's yeast (six 300-mg capsules/day, total 1800 mg) and one (control group) receiving a placebo (6 capsules/day) for 12 weeks. Body weight, height, body mass index (BMI), food consumption (based on 24-hour food recall), fasting serum lipids and lipoproteins (total cholesterol, triglyceride, LDL-c and HDL-c), and systolic and diastolic blood pressure were measured before and after the intervention. Data analysis was performed using the Statistical Package for Social Sciences (SPSS-Ver 18.0), the statistical tests being the independent t-test, paired t-test, Kolmogorov-Smirnov test, and analysis of covariance. Brewer’s yeast supplementation brought about statistically significant reductions in diastolic and systolic blood pressures (5.7±0.6 mm Hg, p=0.001 and 4.1±1.5 mm Hg, p=0.007, respectively) after 12 weeks. Changes in LDL-c, HDL-c, triglycerides and total cholesterol were no-significant. Further analysis of the data showed significant differences between the brewer’s yeast and control groups with regard to diastolic (p<0.03) and systolic (p<0.05) blood pressure at the end of the period. Dietary supplementation with brewer's yeast can reduce systolic and diastolic blood pressure in type-2 diabetes mellitus patients.