Beta glucan is one form of soluble dietary fiber that’s strongly linked to improving cholesterol levels and boosting heart health. Like many fibers, it’s available in supplement form. You can also find it in whole grains, oats, bran, wheat, and barley. Baker’s yeast and some types of fungi, such as maitake and reishi mushrooms, contain beta glucan as well.
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.
The majority of people have never heard of beta glucan, but there are nearly 13,000 peer-reviewed articles talking about it in scientific journals. It’s surprising that beta glucan hasn’t hit the “mainstream” supplement market yet because the health benefits are outstanding.
Beta glucans belong to a group of physiologically active compounds called biological response modifiers. They are naturally occurring sugars that act as highly conserved structural components of cell walls in, fungi, seaweed, and yeast. (1)
For the past eight years, health claims for beta-glucan–containing foods have been allowed in the United States, Canada, Sweden, Finland, and the United Kingdom. The health claims approved by the FDA and the European Food Safety Authority are based on research showing that consuming 3 g of beta-glucans per day, from either oats or barley, can lower blood cholesterol levels by 5% to 8%.3 Clients or patients with high cholesterol levels likely will see the greatest benefit. However, it isn’t clear whether beta-glucans can lower triglyceride levels.
β-glucans are healthy fibers that humans cannot digest, but that can be digested by some species of our gut bacteria. They are special types of sugars that are found in the cell walls of certain microbes, as well as in oats and barley. β-glucans are used clinically against diabetes, cancer, and high cholesterol, as well as to boost the immune systems of people whose immunity has been compromised by radiation, chemotherapy, stress, and other conditions.
Still, few people understand why and how the benefits of beta glucan work. Czech researchers state it the best:
“Despite almost 150 years of research, the exact mechanisms of their action remain unclear.” (6)
More information about glucans has recently been added to the mystery: The number and type of glucans seem limitless. The University of Louisville, Department of Pathology states, “The number of individual glucans is almost as great as the number of sources used for their isolation.” (7)
Although there isn’t a single magic bullet when it comes to eliminating disease, scores of research shows that adding beta glucans to your daily diet—either in the form of supplements or foods that contain the compound—can play a significant role in helping your body fend off not only the common cold and respiratory infections but also more serious diseases, including cancer.
1. Beta glucan can lower LDL cholesterol and reduce your heart disease risk.
The evidence is so strong that this fiber is one of the few natural substances the Food & Drug Administration (FDA) allows manufacturers to make a health claim about. In 1997, they approved a health claim that the beta glucan from oats definitively helps to reduce cholesterol levels and, in turn, reduce the risk of heart disease. Basically, when you consume oats, research suggests your bad cholesterol should go down between 5-7 percent overall. (2)
2. Beta glucan fiber may improve gut health.
It’s no surprise that a type of soluble fiber like beta glucan would be good for the gut, and research backs this up.
In general, prebiotic supplements and foods, like those containing beta glucan, are beneficial to the health of your gut microbiome. This delicate balance of bacteria is where 70-80 percent of your immune system lives, so keeping it fully operational is a big deal for the health of your entire body.
3. A beta glucan gel improves the time wounds take to heal.
Like many substances used in medicine today, various forms of beta glucan were tested in lab and animal studies to find out the extent of its benefits.
One of the most remarkable of these was the way a gel made from beta glucan seemed to speed the healing of wounds. In rats, this nanofiber wound dressing resulted in much faster healing compared to the control group. (6)
Then, the experiment was moved into a human trial. The volunteers had to fit into a very challenging category: they needed to have wounds that, after four weeks, had stopped getting better. Normally, these are the most frustrating wounds for doctors to treat.
But the beta glucan gel did not disappoint. After six months, the patients within the study had experience between two and four times the normal rate of healing after using beta glucan gel.
4. Beta glucan supplements may reduce the frequency of respiratory infections.
One compound used in beta glucan supplements, Wellmune, has been put through a large number of human clinical trials for its effects on infections of the respiratory tract.
When taken daily, Wellmune seems to significantly reduce the number and severity of upper respiratory tract infections (URTI) and common cold in multiple circumstances.As in some of the other studies, beta glucan was not tested on its own. In this study in China, the beverage given to the children in the study also contained omega-3s, other prebiotics, zinc, vitamin A, and iron. It’s important to be careful, therefore, about how these results are interpreted.
5. Consuming beta glucan may improve allergies.
Two studies have found improvements in allergy symptoms after supplementing with beta glucan.
In the first, 250 milligrams of Wellmune beta glucan was given for four weeks and resulted in better results all around. Participants not only found they had less severe allergic reactions to ragweed than before but also that they felt less stressed out and more content in life. (21)
Similar beta glucan benefits were found when children between one and three were given beta glucan supplements.
Healthcare providers sometimes give beta-glucans by IV (intravenously) or by injection into the muscle to treat cancer and to boost the immune system in people with HIV/AIDS and AIDS-related conditions. Beta-glucans are also given by IV to prevent infection in people after surgery.
In manufacturing, beta-glucans are used as a food additive in products such as salad dressings, frozen desserts, sour cream, and cheese spreads.
In essence, the main “side effect” of beta glucan is that it assists your body to heal from sickness and disease.
The majority of clinical trials conducted on animals and humans have not uncovered any adverse effects related to taking beta glucans whatsoever. (9)
For example, a 13-week clinical trial uncovered that when a maximum deliverable oral dose was administered to rats, there were no harmful effects measured whatsoever.
When people take them orally, they are well tolerated and are considered by the FDA to be generally regarded as safe (GRAS).
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 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.
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.
The Mayo Clinic recommends that men and women ages 50 and under eat 38 grams (g) and 25 g per day, respectively. Men and women ages 51 and over should get 30 g and 21 g per day. Teenagers may need 30 to 35 g a day.
For high cholesterol: 7.5 grams of beta-glucans made from yeast has been added to juice and taken twice daily for 7-8 weeks. 3-10 grams of beta-glucans made from barley or oat have also been taken daily for up to 12 weeks.