Good for the heart, beta glucan (β-glucans) foods and supplements help everything from brain function to cancer prevention. Beta glucan is found in plants such as oats and barley. It comes from the cell walls of bacteria, fungi, yeasts, algae, and lichens. Beta glucan can be taken orally as a supplement, or form part of a whole-foods diet. Studies show that beta glucan yeast products help lower cholesterol, especially "bad" low-density lipoproteins (LDL).
Fibers and polysaccharides from mushrooms, yeasts, and cereals are beta glucan nutrients with proven antitumor, anti-microbial, anti-allergic, and immune-modulating effects. They can reduce the risk of cardiovascular disease.
Beta glucan has shown significant antimicrobial (stops the growth of microorganisms), anticancer, anti-diabetic, and anti-hypercholesterolemic (controls cholesterol levels) properties in countless clinical trials.
Beta glucan can act as an immune system activator and cell response modifier. The binding of beta glucan to specific receptors can cause a cellular response that’s especially helpful in chemo- and radiotherapy-induced immunosuppression and depleted hematopoiesis, the process through which the body manufactures blood cells.
Beta glucan also plays an important role in promoting the activity of lymphocytes, white blood cells known as Th1 and Th2 effectors. Th1 lymphocytes control immunity against intracellular parasites, while Th2 effectors control immunity against extracellular pathogens. Disruptions in the balance of these cells may cause an autoimmune response. Autoimmune responses occur when your immune system attacks healthy cells which can lead to serious problems.
Antitumor and Cancer Response
Extracted and/or purified β-glucans have been used in clinical cancer treatment. Beta glucan acts as an immunomodulating agent (helps fight disease) through the activation of innate immune cells. This activation sets off adaptive immune cell responses, inhibiting tumor growth and metastasis (when cancer spreads to a different body part from where it started).
Beta glucan has demonstrated anti-osteoporotic activities in clinical trials. More studies into the effects on humans is needed. Osteoporotic fractures occur when people have osteoporosis, a disease in which bones are fragile due to low bone mass or deterioration.
β-glucans also mobilize murine progenitor cells from bone marrow and enhance murine hematopoietic recovery following bone marrow injury.
Blood Pressure Management
Beta glucan can reduce hypertension (high blood pressure). In a study in rats with spontaneous hypertension, a diet containing 5% shiitake (Lentinus edodes) or maitake (Grifola frondosa) mushroom caused a decrease in mean systemic blood pressure.
In addition, a clinical trial with foods containing oat β-glucans resulted in reduced blood pressure in subjects with a body mass index (BMI) above median (31.5 kg/m2).
Beta glucan’s cholesterol effects have been largely studied. Oat bran, which contains β-glucans, was the first-ever cholesterol-reducing food registered by the US Food and Drug Administration. When polysaccharide glucans are included in a meal, carbohydrate and lipid absorption slow down, modifying alimentary hormone and lipid responses. Along with carbohydrates and proteins, lipids are the main constituents of plant and animal cells.
Diabetes and Weight Control
The anti-diabetic and anti-obesity effects of beta glucan have been proven in many animal- and human-based clinical trials.
With regard to weight management, the satiating capacity (ability to make you feel full after eating) of beta glucan is likely tied to short-chain fatty acid generation through colonic fermentation. Short-chain fatty acids control the release of appetite-regulating hormones, such as peptide YY (PYY), glucagon-like peptide-1 (GLP-1), and ghrelin, a hormone in the gastrointestinal tract.
There are possible gastrointestinal side effects to taking beta glucan, including:
- Flatulence (gas)
- Abdominal cramping
Beta glucan may also have adverse effects when combined with other medications. Consult your doctor if you are taking any other medicines. Avoid beta glucan if you take certain blood pressure medicines, drugs that suppress the immune system, or certain non-steroidal medicines, unless instructed by your doctor.
Studies on mice found that intestinal damage may result from a combination of beta-glucan and most non-steroidal and anti-inflammatory drugs (NSAIDs) including aspirin.
Amounts and Dosage
Beta glucan is found in several edible plants. For example, oat or barley products containing 3.6 grams of soluble fiber can be included in your daily diet for heart disease prevention.
Dosages of b eta g lucan depend on several factors, including how they’re delivered and what you’re treating. Studies have shown that 3 to 250 milligrams of high-quality beta glucan is an effective biological response modified (substances that modify immune responses).
Short-term studies have used 3 to 15 grams of beta glucan daily to improve blood sugar control in patients with diabetes. Additional research on the long-term effects of beta glucan in diabetes management is needed.
Beta glucan therapy can cause some discomfort. To help relieve discomfort, it’s recommended that you take beta glucan at the start of your meal and split the daily recommended dosage across three meals a day.