Beta-glucans
OTHER NAME(S): β-glucans, beta-glucan, beta-glucans
Overview
Beta-glucans are a type of soluble fiber available over the counter in dietary supplements. They are also found in many foods, including oats, barley, mushrooms, and seaweed. Beta-glucans are used to improve heart and digestive health. Common side effects include constipation, diarrhea, bloating, and gas. Before taking beta-glucans, make sure to tell your health care provider about any health conditions you have or medicines you are taking.
Uses
What are beta-glucans used for?
Beta-glucans, usually derived from oats or barley, are commonly used to improve heart and digestive health. Their benefits for other uses are not well defined.
Note: The FDA has not reviewed beta-glucans for safety and effectiveness. Learn more about dietary supplements here.
How do beta-glucans work (mechanism of action)?
Beta-glucans are a form of soluble fiber found in many common foods, such as oats, barley, and seaweed. They are also present in many types of mushrooms, including shiitake, reishi, and oyster mushrooms. The beta-glucans from grains, mushrooms, and seaweed are not identical and may have slightly different effects in the body. Most dietary supplements that contain beta-glucans are made from either yeast or seaweed.
Soluble fibers are considered an important and healthy part of the diet. They can help reduce the amount of cholesterol your body absorbs from the foods you eat and can also make you feel more full after a meal. As a result, beta-glucans are often used to improve heart health. Although beta-glucans do not seem to help with weight loss, research shows that they can help lower cholesterol levels. At least 3 grams of beta-glucans from either foods or supplements must be taken each day to help lower cholesterol levels, which could in turn help reduce the risk of heart disease. Learn more about the health benefits of dietary fibers here.
Soluble fibers such as beta-glucans can also help with digestive health by keeping bowel movements regular and increasing the growth of healthy bacteria in your gut. Because of this, beta-glucans are sometimes used to help manage constipation and diarrhea. But it is not clear how much beta-glucans are needed to help with these problems, and they are not expected to help with severe constipation or diarrhea.
How should I store beta-glucans?
You should store beta-glucans according to the product label. Most dietary supplements should be kept in a cool, dry location that is out of the reach of children and pets and not in direct sunlight.
Side Effects
What are the most common side effects of beta-glucans?
The most common side effects of beta-glucans are listed below. These side effects may vary depending on the dose you are taking or the specific product you are using. Tell your health care provider if you have any of these side effects that bother you.
- Bloating or gas
- Constipation or diarrhea
There may be other side effects of beta-glucans that are not listed here. Contact your health care provider if you think you are having a side effect of a supplement. In the U.S., you can report side effects to the FDA at www.safetyreporting.hhs.gov or by calling 888-SAFEFOOD (888-723-3366). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.
What are the serious side effects of beta-glucans?
While less common, the most serious side effects of beta-glucans are described below, along with what to do if they happen.
Severe Allergic Reactions. Beta-glucans may cause allergic reactions, which can be serious. Stop taking beta-glucans and get help right away if you have any of the following symptoms of a serious allergic reaction.
- Breathing problems or wheezing
- Racing heart
- Fever or general ill feeling
- Swollen lymph nodes
- Swelling of the face, lips, mouth, tongue, or throat
- Trouble swallowing or throat tightness
- Itching or skin rash
- Bumps on the skin called hives that can be red, pink, white, or brown depending on your skin tone
- Nausea or vomiting
- Dizziness, feeling lightheaded, or fainting
- Stomach cramps
- Joint pain
Precautions
Who should not use beta-glucans?
Allergies to Ingredients. People who are allergic to any of the following should not take beta-glucans.
- Beta-glucans
- Any of the ingredients in the specific product
Your pharmacist can tell you all of the ingredients in the specific beta-glucan products they stock.
What should I know about beta-glucans before using it?
Beta-glucan is a dietary supplement. It cannot be marketed to treat or cure a disease.
Read and follow the directions on the specific product you are using, or use it as recommended by your health care provider.
Keep beta-glucans out of the reach of children.
If you are taking beta-glucan powder, use an appropriate measuring device to measure the powder, such as the device included with the product. Read the label carefully, and mix the powder with the amount of fluid stated on the label. Taking beta-glucans with food may help reduce the risk of side effects.
The FDA has not tested beta-glucan products to confirm that they contain the ingredients stated on their labels. Some dietary supplements have been tested by third-party organizations to confirm that they contain the ingredients listed on their labels and do not contain any harmful chemicals. Learn more about how to choose a safe dietary supplement product here.
What should I tell my health care provider before using beta-glucans?
Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know if beta-glucan is right for you.
In particular, make sure that you discuss any of the following.
Yeast Allergy.Some beta-glucan supplements are made from yeast (Saccharomyces cerevisiae). If you have a yeast allergy, you may be at higher risk for an allergic reaction to these products. However, you may be able to take beta-glucan supplements that are made from algae (seaweed). Read the product label carefully, and speak with your health care provider before taking beta-glucan supplements that are made from yeast.
Other Medicines and Supplements.Beta-glucans may interact with other medicines and supplements. Before taking beta-glucans, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.
Pregnancy. It is not known if or how beta-glucans could affect pregnancy or harm a fetus. Tell your health care provider if you are pregnant or plan to become pregnant.
Breastfeeding. It is not known if beta-glucans pass into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed.
Interactions
Do beta-glucans interact with foods or drinks?
There are no known interactions between beta-glucans and foods or drinks, but taking beta-glucans with food may help reduce the risk of side effects.
It is unknown if drinking alcohol will affect beta-glucans.
Do beta-glucans interact with medicines (drug interactions)?
Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.
Beta-glucans may affect the absorption of some medicines. Tell your health care provider about all medicines that you take or have recently taken.
The interactions between beta-glucans and medicines are not fully understood. As with most dietary supplements, the research on drug interactions with beta-glucans is incomplete. Always check with your health care provider before taking beta-glucans with any medicines.
Dosing
What should I do if I accidentally use too much beta-glucans?
If you or someone else has used too much beta-glucans, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.
Beta-glucans are available in many different foods and in a powder or capsule form. Read the product label closely, and speak with a health care provider about how to take beta-glucans safely. Do not take double or extra doses, even if you miss a dose.
References
- EFSA Journal: “Beta‐glucans from oats or barley and reduction of postprandial glycaemic responses: modification of an authorised health claim pursuant to Article 13(1) of Regulation (EC) No 1924/2006 following a request in accordance with Article 19 of Regulation (EC) No 1924/2006,” “Scientific opinion on the substantiation of health claims related to beta glucans and maintenance or achievement of normal blood glucose concentrations (ID 756, 802, 2935) pursuant to Article 13(1) of Regulation (EC) No 1924/2006,” “Scientific opinion on the safety of ‘yeast beta‐glucans’ as a Novel Food ingredient,” “Scientific opinion on the substantiation of a health claim related to barley beta‐glucans and lowering of blood cholesterol and reduced risk of (coronary) heart disease pursuant to Article 14 of Regulation (EC) No 1924/2006.”
- Frontiers in Nutrition: “β-glucans: a potential source for maintaining gut microbiota and the immune system.”
- Journal of Fungi: “β-glucan metabolic and immunomodulatory properties and potential for clinical application.”
- National Institutes of Health Office of Dietary Supplements: “Dietary Supplements for Weight Loss, Fact Sheet for Consumers,” “Dietary Supplements for Weight Loss, Fact Sheet for Health Professionals.”
- FDA: “Food Labeling: Health Claims; Soluble Dietary Fiber From Certain Foods and Coronary Heart Disease.”