Question:
I read that oats can improve gut health. Is this true? I know they’re good for lowering cholesterol levels, but I am not sure about these latest claims.
Answer:
If ever a food deserved the title of “superfood”, it would be the humble oat. But for some reason, oats never make the Hollywood list for best-dressed foods each year. This is a shame, because oats lower blood-cholesterol levels, stabilise blood-sugar levels, and promote bowel regularity. Furthermore, emerging research suggests they also actively improve gut health by positively influencing our gut microbiota.
Rolled oats have a unique composition of fibre, fats and bioactive compounds that are likely responsible for their health effects. As with most whole grains, oats are a rich source of dietary fibre, antioxidants, resistant starch, vitamins and folic acid, which is why nutritionists recommend wholegrain and wholemeal bread, breakfast cereals, pasta, crackers and rice over refined versions. Sadly, the processing of whole grains results in much of their bran and some of the germ being removed, resulting in dietary fibre, vitamin and mineral losses. Refined products have a longer shelf life, but they are nutritionally inferior.
Whole oats are particularly special because they contain a type of dietary fibre not found in most other whole grains. Beta-glucan is responsible for the cholesterol-lowering effects of oats, and it also helps with bowel regularity. And now, emerging research suggests beta-glucan may also boost our gut health. A review published in 2020 found evidence in humans that oats had beneficial effects on gut health.
In particular, consuming enough oats to provide 2.5-2.9g of beta-glucan a day decreased faecal pH and altered bowel bacteria. Higher faecal pH is associated with an increased risk of colon cancer, so by lowering the pH, the beta-glucan in oats may be helping to reduce colon-cancer risk.
Similarly, the review also found people who ate between 40g and 100g a day of oat bran had increased short-chain fatty-acid production in their lower gut and increased bacterial mass in their bowel motions. The good bacteria in our gut produce short-chain fatty acids that promote immunity and suppress inflammatory responses in the intestine and other organs. So again, this is another way oats can improve the health of our gut.
Oat bran differs from rolled oats in its composition, because the oat groats are rolled more and sifted to separate the oat bran from the flour. The resulting oat bran contains more fibrous material than rolled oats: ½ cup of oat bran contains 9.2g of fibre, whereas ½ cup of rolled oats contains 5.5g. Still, both oat varieties make a healthy contribution to our daily fibre requirements: men 30g a day and women 25g. Oat bran has slightly more B vitamins per serve than rolled oats, but both are valuable sources. Oat bran, rolled oats and oatmeal also contain some potassium, calcium, iron, zinc and selenium, although the fibre in oats limits the absorption of some of these minerals.
Harraways’ New Zealand-grown rolled oats contain 3.2g of the precious beta-glucan fibre per 100g. Henc, so a half-cup of rolled oats (weighing about 65g) would provide nearly 2.1g of beta-glucan. If you want to boost your beta-glucan intake further, Harraways’ Oat-activ products contain more beta-glucan, at 4.2g per 100g. A 65g serving of this would provide 2.73g of beta-glucan, falling within the range indicated by research to improve gut-health markers. To boost beta-glucan further, a little oat bran can always be added to the top of your oats.
So, whether you choose rolled oats, oatmeal or oat bran, they’re all terrific options and packed with the unique beta-glucan fibre. By choosing a nutritious, enjoyable breakfast with one or more of those ingredients, you can improve cholesterol levels, stabilise blood-glucose levels, promote bowel regularity and potentially improve your gut health, too.
