I am not a fan of food hyperbole. The idea of superfoods or miracle ingredients can be a potentially harmful message when it comes to health, distracting us from the need to eat a balanced and varied diet. But there are some foods that seem to be almost unreservedly great from a health perspective. There’s a good case for pulses and legumes. Oily fish. Perhaps a bit fermented dairy. Generally speaking however, we do well not to idolise or revile any food in particular.

But if we are going to call anything a superfood, perhaps the best case to be made is for beta glucans. Found in oats and barley, this type of fibre comes with a huge amount of evidence to suggest that we should be eating plenty of it every day. But what exactly are beta glucans? And is the story quite as simple as is made out?

Beta Glucans are a type of carbohydrate found within the cell walls of oats and barley. They are similar to cellulose, comprising of long chains of glucose molecules, but beta glucans have a particular type of chemical bond every three or four carbons along that gives them an irregular structure. This means that beta glucans do not form insoluble networks like cellulose but instead have a more complex, open structure that strongly binds water and likes to form gels. As a result, beta glucans are far more soluble than cellulose and also behave very differently in the human digestive system.

Cellulose is fairly indigestible making it useful for bulking stools and helping intestinal transit, but the ability of beta glucans to form gels gives them a host of different benefits. In the stomach they can delay gastric emptying and increase feelings of satiety, meaning that calorie consumption tends to fall. They can also reduce absorption of nutrients from the gut, including glucose, meaning that they lower our glycaemic response to foods.

Perhaps even more importantly, beta glucan gels are thought to bind bile salts and help them move through our digestive tract. This stimulates the production of more bile salts, a process that uses up cholesterol. For this reason, beta glucans come with an allowable heart health claim as they are proven to help manage blood cholesterol levels.

In short, beta glucans from oats and barley can help us eat less, feed our microbiome, prevent heart disease and lower glucose spikes. They have the potential to address some of the most significant health issues facing our food system, and they are readily available in cheap and easily consumed foods.

There is no doubt that eating more oats and barley would be hugely beneficial to most people’s diets. But before we get too carried away, it is worth hearing one or two caveats. Firstly, there are a few uncertainties regarding the ideal types of beta glucans. They can vary dramatically in the length of their carbon chains, sometimes by a factor of 1000, and that length is influenced by many things including crop variety, growing conditions, processing, cooking, freezing and storage. Really short beta glucan chains don’t form gels easily, but really long ones don’t either, meaning that there is probably an optimum length. To date, it is currently uncertain what the ideal length is for gelling in the stomach and gut, meaning that more research is needed to optimise the types we are eating.

It is also the case that lots of other substances form gels in our guts and probably have significant impacts. Beta glucans are relatively easy to categorise and study, and there is an argument that this drives a lot of the focus on them. Although eating beta glucans is certainly positive, it should not be done at the expense of other healthy foods.

There should always be caution about idolising anything as a superfood, but that does not alter the fact that oats and barley contain some substances that are really beneficial for our health. Beta glucans are also available in extracted forms, and these can be added to a variety of food formulations with the promise of health benefits and allowable claims.

Heart health claims in particular can be very motivating for older consumers, and in this case, there are very few reservations that those claims are valid. What’s even better is that oats and barley are cost effective ingredients used in many commonly eaten foods, meaning that including them in recipes is realistic and achievable, helping to create a healthier food system for everyone.