What Are Beta Glucans?

Beta glucans are sugar compounds found in bacteria, yeast, fungi, algae and plants such as oats and barley.

They are a source of soluble fiber, and research suggests they may reduce high cholesterol and improve skin conditions such as eczema, bedsores, wounds and radiation therapy burns.

Potential benefits include:

  • Supporting the immune system to fight bacterial infections.
  • Enhancing the activity of natural killer cells, a part of the immune system that recognizes and attacks cancer cells.

Beta glucans are also prebiotics, which are food for the healthy bacteria in the human digestive system. The collection of bacteria in the gut are collectively referred to as the microbiome.

People diagnosed with mesothelioma who are considering beta glucan should consult with their oncologist first to discuss potential drug interactions, side effects and dosage.

How Does Beta Glucan Work?

Beta glucans don’t attack cancer directly, but they indirectly stimulate the immune system to attack cancer cells.

Beta glucans are first absorbed in the small intestine and broken into smaller parts. These substances then enter into circulation where they interact with bone marrow and various parts of the immune system.

Once they are in the immune system, researchers believe beta glucans:

  • Enhance immune activation, which translates into anti-cancer activity.
  • Spur immune cells to produce anti-cancer compounds called cytokines, which regulate inflammation and help the immune system fight diseases such as cancer.

Research on Beta Glucans and Cancer

Researchers have not studied the effects of beta glucan in mesothelioma, but they have studied other types of cancers, including lung cancer.

Studies on Beta Glucans and Cancer

  • A 2021 systematic review of studies on fungal beta glucans as an adjuvant for cancer patients found most studies reported reduced immune system depression and better recovery of white blood cell counts in patients receiving chemotherapy or radiation. It also found studies that reported no difference with beta glucan use, prompting researchers to suggest further research.
  • Epidemiological studies suggest diets containing beta glucans may prevent or slow the development of cancer, including breast cancer and gastric cancer, according to a 2019 review published in Critical Reviews in Food Science and Nutrition.
  • Most cancer research on beta glucan has been conducted in test tubes and mice studies, with few trials conducted in humans, according to a 2013 review published in Anti-Cancer Agents in Medicinal Chemistry. Human trials have been conducted outside of the U.S., and they reported a positive impact on patient survival and quality of life.
  • A 2012 study published in the journal Surgery Today shows that Japan approved a mushroom-derived beta glucan for use with chemotherapy to treat gastric cancer and colorectal cancer, and to prolong remission among patients with small-cell lung cancer.
  • Several studies show beta glucans may boost the immune system in patients with late-stage cancers, according to a 2009 review published in the Journal of Hematology and Oncology. One study in the review found a beta glucan extract shrunk tumors in more than 60% of participants with lung, liver and breast tumors, but the validity of the study was questioned by an independent researcher. Another study in late-stage lung cancer patients found beta glucan had inconclusive and mixed effects on the immune system.

More research needs to be conducted in the United States to reach a consensus on the benefits of beta glucans in cancer care.

Two elderly people exercising together
Expert Q&A: Exercise During Mesothelioma Treatment
Join us on Dec. 6 to discover which exercises can help you feel better and recover faster throughout mesothelioma treatment.

Foods Containing Beta Glucan

Doctors and dietitians generally recommend people eat foods containing beta glucan such as mushrooms and seaweed to get these nutrients through their diet rather than taking a supplement. However, beta glucan supplements are available and generally considered safe and well tolerated.

Edible plants and fungi that contain beta glucan include:

  • Oats, barley, wheat, rye and sorghum grains
  • Seaweed
  • Algae
  • Brewer’s and baker’s yeast
  • Reishi, shiitake and maitake mushrooms

Barley and oats have the highest amount of beta glucans per serving. One cup of cooked barley provides 2.5 grams of beta glucans, while a cup of oatmeal has 2 grams of this healthy fiber.

Incorporating beta glucan-rich foods into your diet regularly is a good option for gaining the potential health benefits of this substance.

Couple using the Nutrition Guide from the Mesothelioma Center
Free Mesothelioma Nutrition Guide
Eating the right diet throughout mesothelioma treatment can ease your symptoms.

Potential Side Effects of Beta Glucan

Consuming a recommended amount of beta glucans through dietary choices may not cause side effects, but taking a beta glucan supplement carries potential side effects and risks including: diarrhea, back and joint pain and skin rashes. 

Side effects may differ depending on whether a patient takes the supplement orally or intravenously.

Possible side effects of beta glucan supplements include:

  • Diarrhea
  • Nausea
  • Vomiting

Possible side effects of intravenous beta glucan include:

  • Back and joint pain
  • Fever and chills
  • Excessive urination
  • Diarrhea
  • Changes in blood pressure
  • Skin rashes
  • Swollen lymph nodes

While beta glucan supplements have a good record of safe use, they may not be safe for everyone. These products could worsen gastrointestinal side effects of cancer treatment and interfere with certain medications.

If you want to take beta glucan or use any type of complementary therapy, talk to your oncologist first to make sure it is OK for you to use these products.