Many different types of flour: What do they do to our intestines and body?

Wheat is most often used for baking. Barley, which is both healthy and produced in Norway, is most often used as animal feed.

It's not entirely coincidental – but perhaps a bit unfair. Barley actually contains something you'd like to have in your body.

So which types of flour do researchers highlight as the healthiest? And why do we use so much wheat?

Bitter and heavy barley

“One of the challenges with barley is that it tastes a bit bitter,” says Simon Ballance, a senior researcher at the food research institute Nofima.

But it's not just the taste that makes us choose something other than barley from the flour shelf most of the time.

“You can’t just make products with 100 per cent barley flour, for example. You have to do other things with barley to make it rise, so it doesn't become like a rock,” he says.

Barley contains different proteins than wheat. That means it doesn't rise as well.

Wheat has a huge advantage

Wheat is the only type of grain that can produce light and airy yeast bread on its own.

“Wheat gluten is completely unique in that regard. That's why so much wheat is used for bread,” says Shiori Koga, a researcher who also works at Nofima.

The gluten network traps the gas bubbles in wheat dough. In a short time, the dough goes from being a dense lump to an airy bread dough.

That doesn't necessarily mean that wheat flour is the best for your body.

Benefits of oats and barley

“I give a thumbs-up to oats and rolled oats,” Eli Anne Myrvoll says about this versatile grain.

She is a clinical nutritionist and associate professor at the University of Agder.

Oats are good both as groats and as flour.

“We can use it in rolls or bread, breakfast cereals, or oatmeal with milk. It is many times healthier than wheat," says Myrvoll.

She also points to barley, which together with oats is rich in the soluble fibre beta-glucan.

“Beta-glucans can carry some cholesterol out of the intestine, so the cholesterol in the blood may become lower. Beta-glucans can also form a gel-like mass in our intestines that slows down the absorption of glucose and carbohydrates, which can lead to a slower rise in blood sugar,” Myrvoll says.

“It's also positive that we can grow oats and barley in Norway,” she adds.

Contains fibre and protein

Oats are in many ways a super grain, Ballance and Koga say.

Dietary fibre such as beta-glucan does an important job of keeping digestion working properly. It binds water and keeps stool soft. Fibre also acts as a filler – it fills you up, says Ida Rud, who studies food and intestinal flora at Nofima.

“We know from social media that protein has been in focus. Now people are starting to talk about fibre again. The fibre trend is coming back. That's good,” says Ballance.

But that said, the gluten in bread is a protein.

“Grain-based foods, such as bread, can be a good daily source of protein,” says Rud.

Different types of fibre in flour

Different types of grain contain different kinds of dietary fibre. Ida Rud's advice is to vary what you eat.

Oats are rich in beta-glucan, which is a type of fibre. Wheat contains a lot of arabinoxylan, which is another type of fibre, says Rud. Barley contains about equal amounts of both.

She recommends taking a look at the ingredient list. Check and compare the fibre content in the bread or flour bag.

“Most people in Norway consume too little fibre,” she says.

You can certainly have problems if you consume a lot of fibre without drinking enough. And if your digestive system is not used to that much fibre, you may experience some initial difficulties and gas pains when you increase the amount. The trick is to increase the amount of fibre gradually.

Science Norway asks what kind of flour people should choose for health reasons. But the answer is a little more complex in real life.

“We have to remember that no one eats flour on its own. It has to be processed, so the products are mainly bread or baked goods,” says Ballance.

Shiori Koga advises that we consume as many whole-grain products as possible.

This is the most important thing, according to the researchers

“In terms of health, the most important thing is that people eat mostly whole grains, regardless of whether it's wheat, oats, or barley,” says Koga.

Myrvoll agrees:

“When you grind away all the outer layer of the grain and are left with the kernel, you miss out on everything that's in this external layer. You get less dietary fibre and somewhat fewer minerals, vitamins, antioxidants, and plant compounds that sit in the outer layer of the grain,” she says.

“Fibre is also important for good gut health, since it's the most important nutrient for the intestinal flora,” says Ida Rud.

“Barley and oats are more beneficial than wheat because these grains have a high content of beta-glucan,” says Ballance.

He also advises people to eat whole grains.

“If you eat porridge made from whole grains, it usually takes longer for the body to digest it. That slows the absorption of sugar. Bread, which is usually made from flour, is digested faster,” he says.

If you bake your own bread, you can make it just as coarse as you want without unwanted additives. And if you mix wheat and oats in the bread, there is one thing you should be careful about, based on Simon Ballance's research.

Don't destroy the beta-glucan!

Something can happen to the beta-glucan in oats if you make dough with wheat flour.

If you are going to make bread with half oats and half wheat flour, you should make two separate doughs, explains Ballance.

“These should be mixed together as shortly as possible before baking,” he says. 

Wheat flour contains enzymes that can break down beta-glucan. Then you lose some of the beneficial effects of beta-glucan, according to Ballance.

Doing it this way can also help you get an edible bread that is not too compact.

What's the deal with spelt?

Spelt is found in many products. It's a form of wheat. But what’s the difference, and why is it marketed as something special?

Spelt is often described as an ancient grain and as a relative of modern wheat.

“It has been bred less than wheat, but some spelt varieties have nevertheless been bred to improve baking quality, for example,” says Koga. “Several studies have shown that spelt contains less fructans than wheat, but the difference is not that great and sometimes overlaps.”

Fructans are a type of carbohydrate that is found in large quantities in vegetables such as onion, garlic, broccoli, and cabbage. They are also found in wheat. What they have in common is that they often worsen the symptoms of people with irritable bowel syndrome (IBS).

However, wheat contains less fructans than the aforementioned vegetables. But since many people eat a lot of wheat, the intake of fructans from wheat can become high.

Baking with sourdough has also been shown to be beneficial for breaking down fructans.

Sourdough is not necessarily healthier

Eli Anne Myrvoll still cannot say that sourdough baking is generally better than regular yeast baking.

“I cannot say that one is healthier than the other,” she says.

Myrvoll says the advantage of sourdough is that the bread gets more time to rise. This makes certain nutrients more readily available for absorption in the intestines.

“You can also do this with regular yeast bread, that is, let it rise for a long time," she says.

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Translated by Nancy Bazilchuk

Read the Norwegian version of this article on forskning.no

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