Can cutting back on whole grains be bad for your gut and deadly to your health? Though some popular diets promote the elimination of grains, a recent report from the American Institute for Cancer Research suggests this may be ill-advised.
Researchers say 47 per cent of colorectal cancers can be prevented with lifestyle changes, such as adding whole grains to your diet and exercising more. Eating three daily servings of whole grains reduces the risk of colorectal cancer by 17 per cent, the report says.
But the link between whole grains and cancer may be confusing. After all, the major benefit of whole grains is fibre, and fibre is fibre, right?
Here’s the paradox about fibre: Americans have increased their consumption of fibre, including whole grains. In spite of that, bowel cancer is still one of the most common types of cancer. Not all fibre is alike. Understanding how whole grains and their fibre types go to work in the gut may hold the key to reducing the risk of colorectal cancer.
A new kind of super-grain
First, we turn to the humble barley grain. It may be on the verge of a big moment. Australian researchers spent 30 years breeding a variety of barley that contains more of the properties believed to reduce colon cancer. The result is a so-called super-grain called Barleymax.
What’s special about Barleymax? This non-GMO grain has twice the fibre as most other whole grains, including wheat. It’s also chock-full of a unique type of fibre called resistant starch. Scientists believe resistant starch plays an important role in keeping the gut environment healthy. Barleymax has four times as much resistant starch as wheat and oats, and scientists believe it’s this resistant starch that may be the key link to fighting colorectal cancer.
What do resistant starches do?
Why did the Australian researchers want to develop a grain that was high in resistant starches? Dr David Topping, who headed the research team, points to previous research showing the link between diet and colorectal cancer.
Africans have a lower fibre intake compared to Americans and Australians, yet their bowel cancer rates are much lower, he reports. On the surface, this appears to diminish the role of fibre. Here’s the kicker: The African diet is much higher in resistant starches and fermentable fibres than American and Australian diets. According to Topping, that highlights the key determinant of better bowel health and fighting cancer is that we eat enough of the right fibre types, from whole grain sources, rather than to focus only on the amount of fibre we eat.
How do resistant starches work?
We’ve all heard about how important it is to make sure the gut is inhabited by the right kinds of bacteria. But it’s not as simple as taking a probiotic supplement or eating yoghurt for breakfast. Gut bacteria need food to thrive, and that’s where resistant starches come in.
In the gut, resistant starches are a food source for healthy gut bacteria, and these bacteria keep the gut environment healthy. When diets are low in resistant starches, it creates a “hungry gut bacteria population.” But increasing the availability of fermentable fibre-rich whole grains that feed the gut microbiota can potentially make us healthier.
Good sources of good fibre
It’s exciting to hear that boosting your intake of resistant starches can have such a profound effect on your well-being and health. Getting the right foods that “feed” your gut has been tricky because, frankly, many are not appealing to American tastes.
Green bananas are a prime example. Although resistant starches are abundant in foods like cooked and cooled potatoes, barley, and oats, these have to be eaten cold to get the full benefits, because these starches break down when heated.