Beta-glucan

What is beta glucan?

Beta glucan is a soluble fiber that occurs naturally in foods such as brown rice, whole grains, oats, bran, wheat, barley, yeast and some types of mushrooms such as maitake and reishi. Beta glucan is also available in concentrated form as a supplement. Beta glucan is a large carbohydrate molecule that is made up of several sugar compounds and therefore belongs to the polysaccharide class. In the human body, beta glucan acts as a prebiotic that helps to keep the intestinal flora healthy. Beta glucan has long been used in the field of alternative medicine for everything from aiding weight loss, preventing diabetes and lowering cholesterol levels, to treating immune-related conditions such as multiple sclerosis.

Potential health benefits of beta glucan

Beta glucan can be beneficial to the body in many ways, including supporting heart health and immune system function. Some of the benefits of beta glucan have been well studied and documented scientifically, while others are less certain. In the following sections we will separate the hard scientific facts, including human studies, from less certain research. So what is fact and what is fiction? We'll find out.

5 beta glucan benefits that have been scientifically confirmed

Beta glucan can lower LDL cholesterol levels and reduce the risk of heart disease When it comes to lowering the risk of heart disease, eating foods rich in beta glucan could be helpful. According to studies, beta glucan foods can help lower levels of 'bad' LDL cholesterol in people with mild to moderately elevated cholesterol levels (1). The evidence for this is so compelling that dietary fiber is one of the few substances that the U.S. Food and Drug Administration (FDA) allows to be advertised as having health benefits. In 1997, the claim that beta glucan from oatmeal helps to lower cholesterol levels and consequently the risk of heart disease was officially approved. Scientific research suggests that eating oats can reduce bad LDL cholesterol levels by 5 to 7% (2). Although the benefits of beta glucan do not go so far as to increase levels of "good" cholesterol, beta glucan is a powerful cholesterol-lowering fiber.

Dosage: At least 3 grams per day to reduce cholesterol levels.

Beta glucan could improve digestive health

It's not surprising that a type of soluble fiber like beta glucan would be good for the digestive tract - and scientific research supports this. Prebiotic supplements and foods such as those containing beta glucan have a positive effect on the health of the intestinal flora. The delicate balance of these bacteria is crucial for the immune system to function properly, which is why maintaining a healthy gut flora is very important for the health of the whole body. In one study, scientists observed that subjects who ate beta glucan-rich foods produced more short-chain fatty acids in their digestive tract. These fatty acids are an important marker of digestive health and an increase in levels of these fatty acids suggests that beta glucan aids digestion (4). A 2017 study review looked at the effects of a mixture of beta glucan and other digestive nutrients on patients suffering from irritable bowel disease. This type of inflammatory bowel disease is a very painful and treatment-resistant condition. Although this mixture did not improve all symptoms of irritable bowel syndrome, significant relief of several symptoms was observed in patients taking this mixture over a 4 week period. These included (5):

Less bloating
Less bloating
Less abdominal pain
A better general sense of well-being.

However, two things are important at this point. Firstly, an improvement in some symptoms does not mean that beta glucan is a cure for IBS. Secondly, the supplement used in this study contained inositol and digestive enzymes in addition to beta glucan. Since beta glucan was not tested on its own, we cannot say with certainty how much of the overall effect can be attributed to beta glucan and how much to the other ingredients.

Dosage: Unknown based on currently available data.

A beta glucan gel can accelerate wound healing

As with many substances used in medicine today, various forms of beta glucan have been tested in the laboratory and in animal studies to determine the full range of possible benefits. One of the most surprising of these effects was the way in which a gel made from beta glucan accelerated wound healing. In studies conducted with rats, this nanofiber wound healing gel resulted in much faster wound healing compared to a placebo (6). The next step was a human study. The subjects were patients with wounds whose healing had not progressed after four weeks. These types of wounds are often a frustrating challenge for doctors. But the beta glucan gel did not disappoint in this study either. After 6 months, patients experienced a 2 to 4 times faster rate of wound healing after using the gel. The scientists also noted that this faster healing could serve to save both doctors and patients money (7). However, even though this study was well designed and conducted with a sufficient number of subjects, the results still need to be confirmed by further studies to determine the exact effects of beta glucan on wound healing. The results are promising, but so far there is no consensus on the optimal dosage.

Beta glucan supplements could reduce the incidence of respiratory diseases

A beta glucan supplement called Wellmune has been studied in a large number of human clinical trials for its effects on respiratory tract infections. When taken daily, Wellmune appears to significantly reduce the number and severity of upper respiratory tract infections and colds in several circumstances:

High-intensity activities

Studies have found that taking 250 mg of Wellmune resulted in fewer infections and fewer missed training days in marathon runners and hardcore athletes. One of the reasons for this appears to be related to the fact that beta glucan helps to prevent a weakening of the immune system, which can often be observed after hard training sessions (8, 9, 10). This appears to be the case not only in competitive athletes, but also in people who are only moderately athletic (11, 12). In addition to reducing the risk of respiratory disease, beta glucan also helped improve some psychological markers in marathon runners, including mood, stress levels and aggression levels (13). Firefighters experience high-intensity activities every day. Beta glucan suppressed symptoms of upper respiratory tract infections in firefighters during a two-week study and also improved their overall health (14).

Normal stress levels

It is impossible to live a stress-free life. However, chronic stress can become a challenge for the body and immune system. Chronically stressed people are therefore more likely to fall ill and also heal less well. Women who were exposed to chronic stress were given Wellmine for 12 weeks as part of a study. It was observed that this supplement reduced their risk of respiratory tract infections and also improved their response to stress (15). This is particularly interesting as beta glucan is found in large quantities in some medicinal mushrooms that act as adaptogens. Adaptogens are foods that improve the body's response to stress.

Older people

The older we get, the harder it is for our bodies to fight infections. A 90-day study conducted on subjects aged 50 to 70 found that supplementation with Wellmune resulted in an improved immune response. This supplement appeared to be an effective way to reduce the frequency and duration of upper respiratory tract infections in the subjects who took Wellmune (16).

Children

In China, a 12-week study was conducted with 174 children with the aim of finding out what effects beta glucan may have on the risk of infections. It was observed that Wellmune helped to reduce the number of respiratory tract infections with very few side effects (17). As with some other studies, beta glucan was not tested on its own. In the Chinese study, the drink given to the children also contained omega-3 fatty acids, other prebiotics, zinc, vitamin A and iron. It is therefore important to be cautious when interpreting the results of this study. This study was replicated for a period of 28 weeks with children aged three to four years with similar results. It was also observed that the children treated with Wellmune required less antibiotics (18).

Healthy adults

Finally, Wellmune beta glucan also appears to be effective against respiratory tract infections in healthy adults, at least to some extent (19, 20).

Beta glucan could alleviate allergies

Two studies have observed an improvement in allergy symptoms after supplementation with beta glucan. In the first study, administration of 250 mg Wellmune resulted in improvements in several respects. Not only did the subjects have less severe allergic reactions to mugwort, but they also felt generally less stressed and happier (21). Similar benefits of beta glucan have been observed in children between the ages of one and three (17).

Possible benefits of beta glucan that require further investigation

From this point, we consider some preliminary indications of possible benefits of beta glucan for a wide range of conditions. It should be kept in mind that these are not proven effects, so the study results presented here should be interpreted with caution.

Cancer

Beta glucan molecules are not only helpful in their own right - they also act as transporters for other important compounds (22). It is believed that with the right approach, it is possible that beta glucan could transport anti-cancer nutrients into diseased cells. In a study conducted with animals, beta glucan acted as an antioxidant that counteracted the carcinogenic effects of TCDD, an environmental toxin (23). Beta glucans - particularly the beta 1, 3-D glucan molecule - have been shown to be biological response modifiers. Another way in which beta glucan may be effective against cancer is the way in which it suppresses some cells that normally promote cancer growth. These special white blood cells, known as macrophages, are repolarized by beta glucan, making them more dangerous to tumor cells than would otherwise be the case. This effect has been observed in both human and animal cancer cells (24, 25, 26). This type of effect leads some scientists to believe that beta glucan could be a good way to increase the effectiveness of other cancer treatment methods. One laboratory study found that beta glucan molecules from oats had a cytotoxic effect on several cancer cell lines without damaging normal cells (27). This type of result is important for any potential cancer treatment, as the major drawback of most conventional cancer treatments is that they kill healthy cells as well as cancer cells. A first human study has already been conducted using beta glucan in combination with conventional cancer treatment in patients with lung cancer. Although the cancer had already reached an advanced stage, beta glucan helped to improve the effectiveness of the cancer treatment. At the same time, beta glucan made the treatment more tolerable for the patients (28).

Infections after surgery

Among the most problematic complications of surgery are infections that occur while the patient's immune system is weakened by surgery. This can lead to serious infections known as sepsis. In the laboratory, scientists have discovered that beta D glucan can help prevent sepsis by binding to a specific cell receptor. The scientists believe this would be most effective in patients who are at the highest risk for infection, such as trauma patients in critical condition (29).

Mouth ulcers

Initial research suggests that a small dose of beta glucan taken daily may help to relieve mouth ulcers.

One study review looked at beta glucan and many other methods used to reduce the duration and symptoms of mouth ulcers. Although this review concluded that many of these methods are commonly used, the authors of the study were unable to say whether beta glucan supplements on their own can make a big difference (30).

Dosage: 10 mg per day until the mouth ulcers have healed.

Diabetes

Although some of the significant research with beta glucan has been done on the benefits in heart disease with diabetic patients, it is unclear what effects beta glucan might have on diabetes itself. Some studies have observed no results, while others have concluded that beta glucan supplementation may help lower blood glucose levels and improve insulin sensitivity. Together with exercise, beta glucan appears to be able to alleviate the metabolic symptoms of diabetes. This has been shown most clearly in studies conducted with animals (31). According to recent studies, beta glucan does not help children with type 1 diabetes.

High blood pressure

Although we know that beta glucan is good for heart health in many ways, its effects on blood pressure are still unclear. Oats rich in beta glucans, for example, have been shown to lower blood pressure in overweight patients and patients with mild to moderate hypertension (32, 33). The main reason that scientists have not yet confirmed the benefits of beta glucan for high blood pressure may be that pure beta glucan supplements have not yet been tested for this effect.

Weight loss

In animals, beta glucan from oats appears to be effective in reducing body weight (34). There is also evidence that consuming foods rich in beta glucan may help reduce the incidence of metabolic syndrome, symptoms of which include overweight and obesity (35). Other research that originally seemed to suggest that beta glucan may promote satiety is equivocal. According to one study, it took at least two grams of beta glucan in food to achieve a feeling of satiety in overweight women (36).

Inflammation

Certain receptors to which beta glucan molecules bind are involved in the body's normal inflammatory process. Laboratory studies have found that these receptors can activate defense mechanisms against certain disease-causing pathogens (37, 38).

Basically, this means that beta glucan could help influence the way the body deals with inflammation. A certain amount of inflammation is important for the immune system to function properly, so it's important that the body's cells have regulators like beta glucan to keep inflammation under control while still being able to use that inflammation to protect against bacteria.

Can beta-glucans be consumed naturally in the form of food?

Beta glucans can be found in certain mushrooms, cereal products such as oats and barley, and brewer's yeast.

What about beta glucan supplements?

As there were not many beta glucan supplements available at the time this article was published, it is difficult to find studies on their effects. One review that looked at these supplements looked at different dosages for specific applications where beta glucan is used (39).

The best-studied beta glucan product for medical use is probably Wellmune, whose effects are supported by several clinical studies.

Recommended intake

Optimal dosages of beta-glucans have not yet been determined. Supplement ingredients and their quality can vary greatly from manufacturer to manufacturer. This makes it difficult to determine a standard dosage. Beta-glucans have been taken orally in studies investigating their effects in people with high cholesterol levels and diabetes. Studies in people with AIDS or serious infections have used injectable forms of beta-glucans. In studies with people who had suffered burns, beta-glucans were applied to the skin.

Risks and side effects

Soluble forms of beta-glucans produced from yeast or fungi appear to be safe and harmless when taken orally. In the many human studies conducted with beta glucan, the benefits outweighed the rare side effects. Some mild side effects that can occur with oral administration of high doses include stomach upset, flushing, rashes and headaches (40). For most people, even high doses (up to three grams per day) are safe and have relatively few side effects. In some cases, doctors also administer beta-glucans intravenously. Side effects can include back pain, changes in blood pressure, chills, diarrhea, dizziness, excessive urination, fever, rash, joint pain, nausea, vomiting and swollen lymph nodes. It is not known whether beta-glucans are safe for pregnant or breastfeeding women. Some types of beta-glucans may not be considered safe and harmless if you have certain medical conditions such as AIDS, ARC, diabetes and high blood pressure. In these cases, the use of beta-glucans should be discussed with your doctor. In addition, beta-glucans can influence the effect of some medications, which is why their use should be discussed with your doctor.

Beta glucan can interact with the following medications or increase their effect

Medication to suppress the function of the immune system
Blood pressure-lowering medication
steroids

Beta-glucans should not be combined with non-steroidal anti-inflammatory drugs or aspirin, as such a combination can seriously damage the stomach and digestive tract. HIV/AIDS patients may suffer from skin calluses on hands and feet known as keratodermatosis during the first two weeks of beta-glucan supplementation, which should disappear within 2 to 4 weeks.

Conclusion

Beta glucan is an exciting new area of research for many scientists, as this compound could positively impact many systems of the body, ranging from the heart to the digestive tract. Although much of this research is still in its infancy, the initial results are promising. Beta glucans are polysaccharides that can influence how the immune system functions and transport compounds into the cells of the body. This makes beta glucans a promising compound in the treatment of cancer and immune system problems.

References

Further sources

Murphy, E.A. Current Opinion in Clinical Nutrition and Metabolic Care, November 2010; vol 13: pp 656-661.
Asano, T. Biophysical and Biophysical Research Communications, April 6, 2012; vol 420: pp 444-449.
Cloetens, L. Nutrition Review. August 2012; vol 70: pp 444-458.
Volman, J.J. Molecular Nutrition and Food Research, February 2010; vol 54: pp 268-276.
Jesenak, M. Allergologia et Immunopathologia, Dec. 17, 2012.