β-glucan, also known as Beta-polydextrose, has different health effects according to different conformations, and is a functional food raw material (common brands are Epicor and Wellmune).
What are the benefits of β-glucan in empirical medicine? Are there any side effects of β-glucan? See text analysis for details
What is β-Glucan?
β-Glucan is a polysaccharide widely found in the cell walls of bacteria, fungi, algae, and plants such as barley and oats, and is joined together by several different types of beta-glycosidic bonds to form linear or branched structures.
For example, cereals (oats and barley) have (1,3/1,4) ligenation patterns, while β-glucans from fungal origin (mushrooms, yeast, reishi) have (1,3/1,6) lignes patterns, each with varying degrees of sidechain branches attached to the trunk.
The number and length of side chain branching has been shown to be important for biological activity, in general, the higher the degree of branching, the stronger the biological activity, often claimed effects are: immune enhancement, antitumor, antibacterial, antiviral and wound healing etc.
What are the proven benefits of β-glucan?
1. Beneficial for upper respiratory tract infections
Upper respiratory tract infections are the most common diseases, including rhinitis, sinusitis, tonsillitis, pharyngitis, laryngitis, and the common cold, mainly caused by influenza viruses, adenoviruses, rhinoviruses, respiratory syncytial viruses and other viruses.
Symptoms include nasal congestion, runny nose, cough, sore throat, headache, body aches, chills, fever, etc. In some countries, upper respiratory tract infections are one of the most common causes of antibiotic misuse. Therefore, it is important to prevent its occurrence.
A systematic literature review and meta-analysis (13 relevant randomized controlled trials) suggested that yeast β-glucan significantly reduced the incidence, mean number of episodes, shortened duration, and improved symptom severity compared with placebo. Note 1
In addition, yeast β-glucan is well tolerated and generally safe.
*Conclusion: Oral yeast β-glucan may be a positive help for the prevention of upper respiratory tract infection, but limited by the small sample size and high heterogeneity of the included studies, more high-quality studies are needed to further validate
2. Beneficial for diabetic blood sugar control
Diabetes mellitus is a metabolic disorder caused by insufficient insulin secretion or insulin action, leading to chronic hyperglycemia and its complications such as vascular changes, myocardial infarction, nephropathy, retinopathy and neuropathy.
It is estimated that 5% of deaths worldwide are caused by diabetes complications, and by 2030, there will be more than 3 million people living with diabetes worldwide.
A systematic literature review and meta-analysis (4 randomized controlled trials, 350 people with type 2 diabetes) suggested that intake of oat β-glucan (daily dose of 2.5 g to 3.5 g) for 3 to 8 weeks significantly improved glycaemic control, such as reducing fasting plasma glucose and glycosylated hemoglobin (HbA1c) concentrations. Note 2
*Conclusion: Medium-term oat β-glucan intake (between 3 to 8 weeks) may be beneficial for glycaemic control in patients with type 2 diabetes, but limited by small sample sizes, more studies are needed to further validate
3. Beneficial blood lipid regulation
Cholesterol levels above normal reference values are the main risk factor for the development of cardiovascular disease. A 40 mmol/L reduction in total cholesterol in adults aged 49 to 1 years reduces the risk ratio for ischaemic heart disease by 56%.
Treatment of dyslipidemia includes dietary and lifestyle interventions, surgery, and lipid-lowering drugs. These drugs include statins, fibric acid derivatives, bile acid-binding tree esters, nicotinic acids, omega-3 fatty acids, etc.
A systematic literature review and meta-analysis (21 randomized controlled trials, 1120 participants with mild hypercholesterolemia) suggested that intake of β-glucan (daily dose≥3 g for at least 3 weeks) reduced total cholesterol (-0.27 mmol/L) and LDL cholesterol (-0.26 mmol/L) compared with controls. Note 3
In addition, subgroup analysis further showed that food matrices that combine “solid products” and “liquid products” together are considered the best way to exert their beneficial properties.
*Conclusion: For mild hypercholesterolemia, intake of β-glucan may confer positive help, but more high-quality studies are needed to further validate due to the heterogeneity of the included studies
4. Assist in weight loss
Obesity, an abnormal accumulation of body fat (often more than 20% of normal ideal weight) to the point where it can adversely affect health, affects about 11% of men and 15% of women globally and poses a serious challenge to healthcare systems.
Adipose tissue has a unique structure that can accumulate activated macrophages that are essential for inflammation, in part by releasing cytokines such as tumor necrosis factor α (TNF-α), interleukin-6, when excess adipose tissue often leads to increased inflammation, often associated with the development of chronic diseases, including metabolic syndrome, type 2 diabetes, hypertension, and cardiovascular disease.
A systematic literature review and meta-analysis (12 randomized controlled trials) found that intake of products containing β-glucans reduced body weight and body mass index (BMI) in the intervention group compared with the control group. Note 4
In addition, subgroup analysis showed that total energy intake increased when the daily dose exceeded 4 grams.
*Conclusion: Intake of β-glucan may have a positive effect on assisted weight loss, but limited by the small sample size, more long-term trials are needed to further validate
5. Adjuvant cancer therapy
Clinically, chemotherapy in cancer patients is usually based on the indications of the drug, recommended dose, duration of treatment, and adverse effects (such as nephrotoxicity and hepatotoxicity), and adverse reactions occur during treatment with chemotherapy drugs that are sometimes difficult to prevent.
The purpose of adding natural compounds to cancer chemotherapy is to increase the therapeutic window of chemotherapy drugs and reduce the occurrence of chemotherapy resistance, and the synergistic effect refers to the increased efficacy of the combined components compared to a single component.
A systematic review (16 clinical trials with 1650 cancer patients) suggests that β-glucans given concurrently with chemotherapy or radiation therapy can reduce treatment-induced immunosuppression or accelerate recovery of white blood cell counts. Note 5
However, some studies did not observe statistical differences between β-glucan-treated and control groups.
*Conclusion: Due to the low quality of the available evidence, there are no clear conclusions on the use of β-glucan for adjuvant cancer therapy
Are there any side effects of β-glucan?
Oral β-glucan is safe in most adults, with possible side effects or adverse effects such as diarrhea, nausea, and vomiting.
Possible side effects or adverse reactions when injected are: chills, fever, pain at the injection site, headache, back pain, joint pain, nausea, vomiting, swollen lymph nodes, diarrhea, dizziness, high or low blood pressure, flushing, rash, fatigue, leukopenia, and increased urine.
Safety precautions (5 contraindications to use)
1. Do not use by pregnant and lactating women (due to unknown safety)
2. Patients with AIDS or AIDS-related syndromes should use with caution, patients who have developed keratoderma on the palms and soles of the feet after intravenous injection of soluble glucans. This condition may occur within 2 weeks of treatment and then disappear 2 to 4 weeks after discontinuation. Note 6
3. Please avoid using immunosuppressants, because some β-glucan has the effect of strengthening the immune system, which may affect the efficacy of the drug, common related drug names are: azathioprine (imidazolthiopine), basiliximab, cyclosporine, daclizumab, muromonab-CD3, Mycophenolate, tacrolimus, sirolimus, prednisone, corticosteroids
4. Patients with diabetes or taking related hypoglycemic drugs, please use with caution, because β-glucan may have a hypoglycemic effect
5. Patients with high blood pressure or taking related blood pressure lowering drugs, please use with caution, because β-glucan may have a blood pressure lowering effect