Oat-Based Beta-Glucans Improve Lipid Profile in Patients with High Cholesterol

by | May 11, 2020 | 2020, Blood Lipids, Cardiovascular Health, Fiber, Mediterranean Diet

Written by Angeline A. De Leon, Staff Writer. This study evaluates the effect of oat-based beta-glucans on lipid profiles in a mildly hypercholesterolemic population that adheres to the Mediterranean diet.

fiberBeta-glucans are sugars found in the cell wall of grains and cereals, like oats and barley 1. Growing research on the beneficial role of nutraceuticals in heart health suggests that beta-glucans from oat fibers can effectively protect against cardiovascular disease (CVD) by improving low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), and other lipid parameters 2. One meta-analysis reports a significant dose-response relationship between fiber intake and total serum cholesterol, such that each gram of dietary fiber was associated with a mean reduction of 0.045 moll/L in total cholesterol (TC) 3. While the mechanisms associated with the lipid-lowering effects of fiber are still under investigation 4, it is hypothesized that the binding of dietary fiber to cholesterol particles inside the small intestine may help inhibit the transportation of cholesterol into the bloodstream 5,6. Beta-glucans may also reduce LDL-C by modulating gut microbiota 7. While clinical trials have examined the effects of beta-glucan supplementation, these studies have typically employed relatively shorter study periods and smaller sample sizes 8,9. In 2020, a study 10 published in Nutrients examined the relationship between oat-based beta-glucan intake and fasting plasma lipids in subjects with mild hypercholesterolemia.

A total of 83 subjects (35 men, 48 women; mean age = 52.3 +/- 4.4 years) with moderately high levels of TC (TC ≥ 5.17mmol/L and ≤ 6.2mmol/L) and LDL-C (LDL‐C ≥ 3.36mmol/L and ≤ 4.91mmol/L) were enrolled in a randomized, double-blind, placebo-controlled, cross-over trial. Subjects followed a standardized diet for 4 weeks prior to being assigned to ingest 3 g of either a proprietary oat-based beta-glucan formulation or matching oat-based placebo daily for 4 weeks. A 4-week washout period was observed prior to crossing over to the second arm of the study, and throughout the treatment period, subjects were instructed to follow a Mediterranean diet. A food diary was maintained, and at regular intervals throughout the study period, subjects were assessed for anthropometric measurements, blood pressure readings, and lipid profile based on fasting blood samples.

Compared to placebo, beta-glucan supplementation was found to reduce mean LDL-C by 12.2% (95% Confidence Interval: -15.4 to -3.8) from baseline to Week 4 and by 15.1% (95% CI: -17.8 to -5.9) from baseline to Week 8 (p < 0.01 for both). For the beta-glucan group, relative to placebo, mean TC levels were reduced by 6.5% (95% CI: -10.9 to -1.9) (p < 0.05) from baseline to Week 4, and non-HDL-C levels were reduced by 11.8% (95% CI: -14.6 to -4.5) (p < 0.01). After 8 weeks, the beta-glucan group, relative to placebo, also showed a reduction of 8.9% in TC (95% CI: -12.6 to -2.3) (p < 0.05) and a reduction of 12.1% in non-HDL-C (95% CI: -15.6 to -5.3) (p < 0.01).

General results point to the clinical efficacy of oat beta-glucans in safely reducing LDL-C, TC, and non-HDL-C in adults with elevated cholesterol levels. Researchers noted that TC and LDL-C levels quickly returned to their basal values following supplement discontinuation, suggesting that the lipid-lowering effects of beta-glucans are effective in the medium-term, but may require regular maintenance to achieve longer-term efficacy. Future studies are needed to address this and to explore the null findings observed regarding fasting blood glucose and the other metabolic parameters in the present study. It would also be valuable to replicate findings in patients with more severe cases of hypercholesterolemia and to examine the therapeutic effects of beta-glucan supplementation outside of a plant-based diet like the Mediterranean diet. Potential study limitations relate to the lack of clinical markers of intestinal absorption and failure to account for changes in gut microbiota composition.

Source: Cicero AFG, Focaccia F, Veronesi M, et al. A randomized placebo-controlled clinical trial to evaluate the medium-term effects of oat fibers on human health: the beta-glucan effects on lipid profile, glycaemia, and intestinal health (BELT) study. Nutrients. 2020; 12: 686. DOI: 10.3390/nu12030686.

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access Article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

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Posted May 11, 2020.

Angeline A. De Leon, MA, graduated from the University of Illinois at Urbana-Champaign in 2010, completing a bachelor’s degree in psychology, with a concentration in neuroscience. She received her master’s degree from The Ohio State University in 2013, where she studied clinical neuroscience within an integrative health program. Her specialized area of research involves the complementary use of neuroimaging and neuropsychology-based methodologies to examine how lifestyle factors, such as physical activity and meditation, can influence brain plasticity and enhance overall connectivity.

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