WELL & GOOD

LEARNING TO EAT WITHOUT WHEAT IS COMMON. BUT WHY? AND IS GOING GLUTEN-FREE REALLY NECESSARY?

Is going gluten- free really necessary?

PEOPLE WITH COELIAC disease can’t eat foods containing gluten. But there are some who, despite testing negative, have digestive symptoms that disappear if they avoid it.

“Gluten sensitivity” is the 10th-ranking health search for females older than 25; for girls under six it probably would be “unicorns”. Debates rage about the existence of both. Since 2010, sales of gluten-free alternatives have doubled, with 54 per cent of younger consumers opting for at least one glutenfree product.

Estimates are that between 60,000 and 70,000 New Zealanders are coeliacs (one in 70), but up to 80 per cent are unaware of it.

Coeliac disease is a permanent intestinal reaction to dietary gluten — when the cells lining the small bowel (intestine) become damaged and inflamed. This causes flattening of the tiny, finger-like projections called villi that line the inside of the bowel, and when the villi become flat, the surface area of the bowel decreases, which interferes with nutrient absorption.

Although coeliac disease is a specific and sometimes debilitating condition, people without the illness can also have autoimmune reactions to grains and gluten. The tests for the disease don’t identify those with a condition called “non-coeliac gluten sensitivity” (NCGS), even though they may react to even smaller amounts of gluten than those with coeliac. About five per cent of the non-coeliac population experience significant gut symptoms after eating gluten.

So what is gluten and how did it become the villain? Gluten is a protein complex found in wheat (and all wheat relatives such as spelt, emmer, einkorn, kamut and farro), rye and barley. There is also a type of gluten found in oats called avenin, to which some react.

People may respond to all gluten proteins (gliadin in wheat, secalin in rye, hordelin in barley and avenin in oats). Or they may only react to some, depending on their particular intolerance. Oats will never be entirely glutenfree as they will always contain avenin even if they are described as gluten-free (free from gliadin). About 20 per cent of people with coeliac disease react to avenin in oats.

How can we explain why people around the world might be increasingly wheat sensitive when humans have been cultivating wheat for about 10,000 years? The wheat that the west now consumes is, almost exclusively, common wheat ( Triticum aestivum). This cultivar contains chromosomes from all the ancient relatives selectively bred for easier harvesting.

But this complex genetic structure has new elements that might trigger reactions in the immune system. It also may explain why some people react adversely to common wheat and yet can eat spelt or emmer bread without issues. Common wheat now has a glycaemic index similar to sugar and a greater tendency to raise blood sugar than ancient varieties.