Niki Bezzant: Grains of truth

Research suggests modern strains of wheat do not contain more gluten than historical strains. Photo / 123RF

Just in time for Coeliac Awareness Week came a study busting one of the commonly accepted wisdoms about wheat.

I'm sure you've heard this one: more and more of us are having problems with gluten intolerance and coeliac disease because modern wheat has been selectively bred to contain higher gluten content than in the past.

It sounds "truthy", right? It makes sense that since wheat was first domesticated 10,000 years ago, man has been fiddling around with the best ways to grow it, and in the past century or so, the agricultural industry been breeding wheat that works better in modern processed foods.

The nebulous "they" have been messing with our food supply, making our bread less healthy than the lovely loaves our grandparents and great-grandparents ate.

It turns out this is probably not the case. A study recently published in Food Chemistry has found that modern wheat is no higher in coeliac-inducing factors than historical wheat - the proteins that cause problems have always been there.

Previous work has also reported similar findings. A 2013 article in the Journal of Agricultural and Food Chemistry concluded it had "not found clear evidence of an increase in the gluten content of wheat in the United States during the 20th century, and if there has indeed been an increase in coeliac disease … wheat breeding for higher gluten content does not seem to be the basis".

The author of that article hypothesised that perhaps the increase in coeliac disease might be to do with a straightforward increase in consumption of gluten overall - because gluten itself is often used as an additive quite apart from wheat, humans are on the whole consuming more of it.

It could be that at some point the amount of gluten in the diet tips the immune system over into a reaction. That theory, as scientists like to say, needs more study.

Another common wheat theory is that sourdough bread is more digestible than regular bread.

There is some basis for this. Traditionally made sourdough bread is fermented for many hours, and uses wild yeast from the local environment, rather than added quick-rising commercial yeast.

This long fermentation allows for bacteria to degrade some of the potentially harmful gluten proteins, making it easier to digest.

There has been surprisingly little research on this, although one interesting small study 15 years ago found a specially made sourdough bread to be tolerated by its trial coeliac patients. Scientists are cautious about this, though. People with coeliac disease still definitely need to avoid all wheat-containing foods, fermented or not.

Where sourdough could be useful is for those who don't have coeliac disease, but who do have problems with wheat. Those with non-coeliac gluten sensitivity or irritable bowel syndrome can both experience this; sourdough can be digestible for both groups.

Head to a bakery or make your own, though - supermarket sourdough is unlikely to be the real thing.

• Niki Bezzant is the editor-at-large for Healthy Food Guide www.healthyfood.co.nz