Beta-Glucan Health Benefits and More

A soluble fiber source that reduces blood sugar and more

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Beta-glucan is a soluble fiber found naturally in oats, barley and other cereals, yeast, and certain mushrooms. It is also sold as a supplement.

As a soluble fiber, beta-glucan is not digested but can slow food transit in the intestines. As a result, carbohydrates are absorbed more slowly, resulting in more steady blood sugar. In addition, it may help remove cholesterol.

This article explains the uses and benefits of beta-glucan.

Oats, barley, and wheat
Verywell / Anastasia Tretiak

In the United States, the Food and Drug Administration (FDA) does not regulate supplements like it regulates prescription drugs. That means some supplement products may not contain what the label says. 

When choosing a supplement, look for third-party tested products and consult a healthcare provider, registered dietitian nutritionist (RD or RDN), or pharmacist.

What Is Beta Glucan?

Beta-glucan is a type of soluble fiber found in certain plants and other organisms. Since beta-glucan increases the amount of time it takes for your body to digest food and move through the intestines, it makes you feel full for longer.

Beta-glucan helps reduce your body's absorption of cholesterol as it moves through your digestive system, so it may also contribute to improved heart health and reduced cholesterol levels.

What Does Beta-Glucan Do?

Soluble fiber is a type of dietary fiber that dissolves in water. It forms a gel-like substance as it passes through the digestive system. Beta-glucan and other types of soluble fiber help slow food down in the intestines, reducing the absorption of sugar and cholesterol and contributing to reduced blood sugar and cholesterol levels.

Sources of Beta-Glucan

Beta-glucan is found in various types of food, and can also be obtained from supplements.

Food Sources of Beta-Glucan

Beta-glucan can be obtained from grains like:

  • Wheat
  • Oats
  • Barley
  • Rye
  • Maize
  • Sorghum
  • Rice

Beta-glucan is most abundant in raw foods, but consuming grains in this state is not possible due to processing and cooking needs, which reduce their beta-glucan content.

Instead, look for whole grains that are as close to their natural states as possible. For example, choose steel-cut oats over instant oatmeal or oat flour, and pearl barley over barley flour.

Some mushroom varieties are also a good source of beta-glucan, such as oyster and shiitake mushrooms. Beta-glucan is also present in foods made from yeast and in nutritional yeast.

Beta-Glucan Supplements

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

Many manufacturers source their beta-glucan from substances like baker's yeast. Others use medicinal mushrooms like shiitake and maitake, which are rich in beta-glucan.

When shopping for supplements, look for brands tested by a trusted, independent third party, such as the U.S. Pharmacopeia (USP), the National Science Foundation (NSF), or ConsumerLab.

Uses of Beta-Glucan

Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian nutritionist (RD or RDN), pharmacist, or healthcare provider. No supplement is intended to treat, cure, or prevent disease.

The FDA has approved health claims for certain soluble fibers, including beta-glucan. This means manufacturers can claim that certain types of soluble fiber (such as beta-glucan) in recommended amounts per serving can reduce the risk of heart disease in conjunction with a diet low in saturated fat and cholesterol.

The adequate intake for fiber recommendations is 14 g of fiber/1,000 calories of intake. The Institute of Medicine (IOM) also issues daily intake recommendations for fiber. It ranges from 21–26 grams (g) of fiber daily for women and 30–38 grams daily for men, depending on their age.

Cholesterol

Beta-glucan may prevent cholesterol absorption from food, helping to lower blood cholesterol levels.

A meta-analysis published in 2016 found that oat beta-glucan reduced LDL cholesterol. Doses of about 6 grams daily for four weeks had a statistically significant effect on reducing LDL cholesterol levels.

A larger meta-analysis assessed 59 clinical trials comparing an oat supplement intervention to a control group. The results showed an overall reduction in total cholesterol, LDL cholesterol, blood glucose, body weight, body mass index, and waist circumference.

Though the differences were statistically significant, the question of clinical significance remains. For example, those in the oat supplementation group lost about 1 kilogram (kg) more weight (about 2 pounds). This underscores the importance of overall diet modification for reducing heart disease risk, which you can achieve in addition to adding beta-glucan food sources.

Diabetes

Beta-glucan has also been studied for its role in blood sugar and blood pressure management in people with diabetes and hypertension, respectively.

Research suggests that beta-glucan may help manage diabetes by controlling blood sugar levels when incorporated into the diet.

A recent meta-analysis found that long-term beta-glucan intake of an oat beta-glucan supplement at 5 g per day improved metabolic control, including blood sugar, in people with type 2 diabetes.

Overall, beta-glucan may be helpful to use in conjunction with prescribed treatment and diet modifications. However, it should never replace standard medical care.

Weight Management

Some research has suggested that beta-glucan might help reduce body weight and BMI. There are a few possible reasons why this might happen.

Beta-glucan may help increase feelings of fullness and slow the rate at which the stomach empties, which can help discourage overeating. It may also have an effect on hormones and microbiota in the digestive system. The effect seems to be greatest for high-fiber foods made from oat and barley.

Cancer Treatment and Prevention

Beta-glucans have been studied for their use as cancer-preventatives and adjunct therapies for people with cancer. 

A 2017 study found that beta-glucans derived from oats have anti-tumor properties, and a 2020 study suggested that the antioxidant properties of beta-glucan might help prevent cancer. In the 2020 study, the researchers also suggested that beta-glucan could be used to help deliver anti-cancer drugs directly to tumors.

Although this research is promising, more work is needed before we will know how and if this might be able to help people with cancer.

Blood Pressure

Dietary fiber intake may help lower blood pressure. The Dietary Approaches to Stop Hypertension (DASH) diet, which includes the intake of fruits, vegetables, and high-fiber foods, is often recommended for blood pressure management.

A meta-analysis published in 2018 evaluated studies looking at the effect of fiber on blood pressure. Overall, fiber was found to reduce systolic and diastolic blood pressure. However, it's important to note that they looked at several types of fiber, not just beta-glucan. In fact, only psyllium lowered systolic blood pressure (SBP).

Additionally, the reduction in blood pressure was small, and adding fiber should not be the only method for managing high blood pressure.

Bone Health

Beta-glucans may also play an important role in bone metabolism, the process where the body removes old bone and replaces it with new bone. There is some evidence that beta-glucans may help protect bone resorption, which may mean they could be used as a therapy for protecting against bone diseases like osteoporosis. 

This research is still in its infancy, so more studies will need to confirm the role of beta-glucans in bone metabolism before they can be recommended as a potential therapy for these conditions.

Immune Support

Beta-glucan is sometimes recommended for "immune support." The idea of boosting your immune system can be misleading, however.

Researchers have studied beta-glucan for its role in helping the body fend off upper respiratory infections like colds and flu. Some studies have also looked at the role of beta-glucan in increasing defenses against the harmful effects of stress. However, there is very little scientific support for these suggested benefits.

You can support a healthy immune system by getting enough sleep, exercising, eating a healthy diet, and generally taking care of yourself. Specific nutrients won't boost your immune system but can play a role in keeping it healthy. Therefore, beta-glucan taken alone will not boost your immune system.

What Are the Side Effects of Beta-Glucan?

Although beta-glucan is generally considered safe, there may be a few side effects. Consuming too much fiber can cause gas, bloating, and flatulence. Be sure to drink enough water when increasing your fiber intake or adding beta-glucan.

People who eat a low-fiber diet should start with a lower dose of beta-glucan and increase it gradually. Like all sources of fiber, it may cause gastric distress, bloating, and gas if taken in larger-than-normal doses. The side effects should wear off over time, but slowly introducing it can help prevent this.

Dosage: How Much Beta-Glucan Should I Take?

Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs.

There is no standard dose for beta-glucan, and the required amount differs based on the source.

Doses taken in studies range from 2–6 g orally daily for up to 12 weeks for oat beta-glucan. Doses ranging from 250–500 milligrams (mg) once daily for up to 12 weeks have been taken for beta-glucan derived from yeast. According to the FDA, 3 g daily of beta-glucan is the amount needed to make a health claim that the food can help lower cholesterol.

Similar Supplements

Psyllium is another form of soluble fiber that is sold as a supplement. Psyllium comes from a shrub-like herb called Plantago ovata. It is used as a bulk-forming laxative in over-the-counter products such as Metamucil (psyllium).

Summary

Beta-glucan is one type of soluble fiber. This fiber can be found in oats, barley, and some mushrooms, or as a supplement.

In general, most people don't get enough fiber in their diet. Incorporating high-fiber foods is advisable. Though a food-first approach for fiber intake is preferable, supplementation is also an option. As always, discuss your supplements with a healthcare provider.

Although it's too soon to recommend beta-glucan supplements for health purposes, increasing beta-glucan in your diet may help enhance your overall health. Remember that alternative medicine should never serve as a substitute for standard care. Self-treating a condition and avoiding or delaying standard care may have serious consequences.

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Bio headshot for Jennifer Lefton

By Jennifer Lefton, MS, RD/N, CNSC, FAND
Jennifer Lefton, MS, RD/N-AP, CNSC, FAND is a Registered Dietitian/Nutritionist and writer with over 20 years of experience in clinical nutrition. Her experience ranges from counseling cardiac rehabilitation clients to managing the nutrition needs of complex surgical patients.

Originally written by Cathy Wong