Common questions about beta-glucans

How do beta-glucans work?

Beta-glucans exert their multiple beneficial effects via different modes of action in different parts of
the body.

Beta-glucan forms a highly viscous solution that slows down the absorption of cholesterol, fatty acids, bile acids and glucose, resulting in lower levels in the blood. In response to lower blood glucose levels, insulin levels are also reduced. In this way, viscosity in the small intestine mediates the cholesterol-lowering and glucose-lowering properties of beta-glucan.

In the large intestine, beta-glucan is a prebiotic, which stimulates the growth of desirable bacteria and limits the growth of potentially harmful organisms. Beneficial bacteria ferment beta-glucan to produce volatile fatty acids, which are used by the cells lining the intestine to protect against
bowel disease.

Beta-Glucan is also a potent stimulator of the immune system, via its ability to bind and activate specialised cells involved in immune response. These cells (macrophages and natural killer cells) operate over the entire body, as part of the humoral immune system. By activation of the immune response, beta-glucan boosts the body’s ability to fight infections and limit cancers.

How much beta-glucan should I take?

A daily intake of 3 g barley beta-glucan is recommended for recognised health benefits. The US Food and Drug Administration allow a health claim to be made for foods containing 0.75g soluble fibre (beta-glucan) per serving. Foods containing this level of beta-glucan can claim to reduce the risk of heart disease, if eaten as part of a diet low in saturated fats and cholesterol.

What is molecular weight?

Molecular weight(MW) is a measure of the size of beta-glucan polysaccharides and is expressed in units called kiloDaltons(kDa). Large polysaccharides have a high MW. The “native” beta-glucans present in whole grains tend to have a higher MW (up to 5400 kDa) (26), than the beta-glucans in foods as food preparation breaks down large beta-glucans. In foods, beta-glucans of less than 150 kDa are commonly found (7).

Are high MW beta-glucans better?

High MW beta-glucans are not “better” than moderate MW beta-glucans. Clinical trials have shown that beta-glucans with high or moderate MW are equally effective in reducing blood cholesterol (22) and blood glucose and insulin levels (5). Although higher MW beta-glucans are more viscous outside the body, viscosities in the intestine, where they work, are similar for beta-glucans of differing MW (15,16). This is consistent with the evidence that beta-glucans are partially broken down in the intestine to produce molecules of reduced MW. These moderate MW beta-glucans appear to be responsible for increased intestinal viscosities.

Are more viscous beta-glucans better?

The viscosity of a beta-glucan extract outside the body (ie. in the laboratory) does not reflect its viscosity in the intestine, where it works. Beta-glucan extracts with differing viscosities outside the body have been shown to give similar viscosities inside the body (15,16) and to have similar biological effects (5,22).

Highly viscous beta-glucan extracts are difficult to incorporate into food formulations. Glucagel is a highly pure/concentrated, moderate MW beta-glucan extract, with improved solubility that is easier to incorporate into functional foods.

Are barley beta-glucans better?

Barley is the richest cereal source of beta-glucans, with grain kernels containing about 3-11% by weight, compared to 3-7% in oats and less than 1% in wheat. beta-glucans from high-producing strains of barley have been shown to be more effective at lowering blood glucose than
oat beta-glucans.

Why is purity important?

Glucagel™ is the highest purity (75%) commercially available cereal beta-glucan. This means Glucagel™ has significantly less of the cereal starch and lipid fractions that contribute to the taste and palatability problems of other beta-glucan extracts. Highly concentrated Glucagel™ can be simply incorporated into new or existing food products, without requiring significant formulation alterations. Only 1 g Glucagel™ is needed to deliver the recommended 0.75 g beta-glucan
per serving.