What do beta-glucans do?
Beta glucans have many protective effects against risk factors for heart disease and stroke. Within the EU, the European Food Safety Authority have authorised health and nutrition claims that:
- Beta-glucans contribute to the maintenance of normal blood cholesterol levels with a daily intake of 3g of beta-glucans from oats, oat bran, barley, barley bran, or from mixtures of these beta-glucans.
- Beta-glucans from oats or barley, as part of a meal, contributes to the reduction of the blood glucose rise after that meal for food which contains at least 4g of beta-glucans from oats or barley per 30g of available carbohydrates.
- Barley and oat beta-glucans have been shown to lower/reduce blood cholesterol with a daily intake of 3g oat or barley beta-glucans.
The results from 58 trials show that a daily dose of 3.5g oat beta-glucans can significantly lower LDL-cholesterol and a harmful type of protein, known as apoB, which is found within LDL particlesi. Barley beta glucans also lower cholesterol levelsii, as can yeast beta-glucans which reduced total cholesterol concentrations by 6% to 8% in people with high cholesterol levels. iii
Data from 18 studies show that a diet rich in beta glucans can reduce blood pressure by an average of 2.9/1.5mmHg at an intake of around 4g daily.iv
Oat beta glucan helps to lower fasting blood glucose levels in people with type 2 diabetes, and lower the peak rise in blood glucose that occurs after a meal. v
Yeast beta glucans stimulate the activity of immune cells, and are used by elite athletes to help ward off colds and other viral infections. One study assessed the immune effects of yeast beta-glucan against placebo in 182 men and women undergoing intense training for a marathon. Those taking yeast beta glucan experienced 37% fewer cold and flu symptom in the days after the marathon than those taking placebo. In 60 athletes undertaking strenuous cycling training, the level of protective salivary antibodies (secretory IgA) was 32% higher in those taking yeast betaglucans (250 mg per day) for ten days, compared with those given placebo. This suggests that yeast beta glucans can reduce upper respiratory tract symptoms in athletes undergoing intensive training by boosting their levels of protective salivary antibodies. vi Other studies have shown that yeast beta glucans (250mg per day) also boost the activity of immune cells and their production of protective cytokines such as anti-viral interferon.vii
Getting beta-glucans from your diet
Beta-glucans are found in plant foods, and are also added to thicken products such as salad dressings and frozen desserts.
There are no significant safety concerns from taking oral beta glucans.
Yeast beta-glucans for immunity:The usual dose is 250mg yeast beat glucans per day to boost immunity. Beta glucans may be combined with other beneficial ingredients such a s co-enzyme Q10, vitamin C, zinc and French maritime Pine Bark Extract.
Oat or barley beta-glucans: Beneficial effects in lowering cholesterol and glucose are seen at daily intakes of 3g to 4g per day.
- i https://www.ncbi.nlm.nih.gov/pubmed/27724985
- ii https://www.ncbi.nlm.nih.gov/pubmed/21470820
- iii https://www.ncbi.nlm.nih.gov/pubmed/10426696?dopt=Abstract
- iv https://www.ncbi.nlm.nih.gov/pubmed/25668347
- v https://www.ncbi.nlm.nih.gov/pubmed/26771637
- vi https://www.ncbi.nlm.nih.gov/pubmed/23927572
- vii https://www.ncbi.nlm.nih.gov/pubmed/22575076