The Health Benefits of Beta-Glucan

Dried mushrooms in a jar
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Beta-glucan is a soluble fiber found naturally cereal grains, yeast, and certain mushrooms and sold as a supplement. A polysaccharide—a large molecule made up of multiple sugar molecules—beta-glucan may offer a number of health benefits, including lowering cholesterol, improving blood sugar management, and boosting the immune system.

As a soluble fiber, beta-glucan itself is not digested, however, it slows food transit in the intestines. As a result, carbohydrates are absorbed slower, resulting in more steady blood sugar. In addition, it moves slowly through the digestive tract, taking cholesterol with it.

In alternative medicine, proponents claim that beta-glucan supplements may help with the following health conditions:

Beta-glucan is also purported to strengthen the immune system and, in turn, fend off colds, flu, and even cancer. Additionally, beta-glucan is said to increase the body's defense against the harmful effects of stress.

Health Benefits

So far, scientific support for the benefits of beta-glucan is limited. Here's a look at some key study findings on the possible health benefits of beta-glucan:

Cholesterol

The beta-glucan found in oats may help keep cholesterol in check, according to a 2011 report from Nutrition Reviews. Looking at studies conducted over the previous 13 years, the report's authors determined that oat-derived beta-glucan may significantly reduce levels of total and LDL ("bad") cholesterol. On average, the authors note, daily oat consumption is associated with 5 percent and 7 percent reductions in total and LDL cholesterol levels, respectively.

A 2014 meta-analysis published in the American Journal of Clinical Nutrition found similar results. The researchers focused on studies that included at least 3 grams of beta-glucan daily and found it reduced total cholesterol and LDL cholesterol, but did not impact HDL cholesterol levels or triglycerides.

Diabetes

Beta-glucan may help manage diabetes, a 2008 research review from Vascular Health and Risk Management suggests. Analyzing previous research on beta-glucan and diabetes, the review's authors found that dietary intake of beta-glucan may help protect against diabetes-related complications by controlling blood sugar levels, lowering cholesterol, and keeping blood pressure in check.

A 2014 literature analysis confirmed these results but noted that beta-glucan alone was not enough to achieve normal blood-sugar readings in patients with diabetes, and it should be used as an adjunct to standard treatment.

Cancer

Preliminary research indicates that beta-glucan may activate a number of cells and proteins that fight cancer (such as T-cells and natural killer cells). What's more, tests on animals have shown that beta-glucan may inhibit the spread of cancer cells. However, a 2009 report in the Journal of Hematology and Oncology cautions that there are "no good quality clinical trial data" for the effectiveness of beta-glucan in treating cancer.

Immunity

Currently, there is a lack of clinical trials supporting the claim that beta-glucan can rev up the immune system and stave off colds, flu, and other types of infection. However, some preliminary research suggests that beta-glucan may strengthen the immune system and knock out viruses.

In a 2004 study from Medicine and Science in Sports and Exercise, for instance, tests on mice revealed that beta-glucan may offset the negative effects of exercise-induced stress and increase the immune system's defense against upper respiratory tract infections.

Possible Side Effects

Although beta-glucan is generally considered safe, there's some concern that it may lower blood sugar. Therefore, people with hypoglycemia or anyone taking medications to reduce blood sugar should consult a physician before using beta-glucan.

People who eat a low-fiber diet should add beta-glucan gradually to their diet. Like all fibers, it may cause gastric distress, bloating, and gas if taken in larger than a normal dosage. The side effects should wear off over time, but slowly adding more fiber to your diet can ease stomach discomfort.

Supplements haven't been tested for safety and due to the fact that dietary supplements are largely unregulated, the content of some products may differ from what is specified on the product label.

Also keep in mind that the safety of supplements in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications has not been established. Get additional tips on using supplements.

Dosage and Preparation

There is no standard dose for beta-glucan. Research has shown various levels to be effective and it differs based on the source of beta-glucan. For instance, beta-glucans made from yeast may lower cholesterol at 7.5 grams of beta-glucans taken twice daily for 7 to 8 weeks, while beta-glucans made from barley or oat have been shown effective at levels between 3 gram to 10 grams daily for up to 12 weeks.

What to Look For

Beta-glucan supplements are widely available for purchase online and are also sold in many natural-food stores and in stores specializing in dietary supplements.

Many beta-glucan supplements source their beta-glucan from substances like baker's yeast. Others contain medicinal mushrooms like shiitake and maitake (both found to be rich in beta-glucan). While research on the health effects of medicinal mushroom supplements is somewhat limited, a number of studies suggest that they can help boost immunity.

Supplements are not regulated by the U.S. Food & Drug Administration. Look for brands tested by a trusted, independent third party, such as U.S. Pharmacopeia, NSF International, or ConsumerLab.

Food Sources

Beta-glucan is a soluble fiber found primarily in cereal grains like oats, barley, and wheat. It is also in baker's yeast and certain fungi like maitake, shiitake, and reishi mushrooms.

Beta-glucan is most abundant in food in their raw and natural state, however, grains require cooking to be edible. in addition, any processing done to the grains will reduce the amount of beta-glucan. Look for whole grains in as close to their natural states as possible, such as choosing steel-cut oats over instant oatmeal or oat flour, and pearl barley over barley flour.

A Word From Verywell

Although it's too soon to recommend beta-glucan supplements for health purposes, increasing your beta-glucan intake (by including oats, barley, and medicinal mushrooms in your diet) may help enhance your overall health.

If you're considering using beta-glucan supplements, talk to your doctor to weigh the potential risks and benefits. Keep in mind that alternative medicine should not be used as a substitute for standard care. Self-treating a condition and avoiding or delaying standard care may have serious consequences.

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Article Sources

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  1. Bashir KMI, Choi JS. Clinical and Physiological Perspectives of β-Glucans: The Past, Present, and FutureInt J Mol Sci. 2017;18(9):1906. doi:10.3390/ijms18091906

  2. Martin SS, Blumenthal RS, Miller M. LDL cholesterol: the lower the better. Med Clin North Am. 2012;96(1):13-26. doi:10.1016/j.mcna.2012.01.009

  3. Kalra S, Mukherjee JJ, Venkataraman S, et al. Hypoglycemia: The neglected complicationIndian J Endocrinol Metab. 2013;17(5):819–834. doi:10.4103/2230-8210.117219

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