09/19/2013 04:26 EDT | Updated 11/19/2013 05:12 EST

Cost of gluten-free food falling as diet becomes more popular

New Canadian research suggests gluten-free products are getting cheaper as gluten-free diets become more popular.

Celebrities such as Jennifer Esposito and Ryan Phillipe have touted the benefits of a diet free of gluten, a protein found in wheat, barley and rye, for improved health. And the book Wheat Belly promotes a gluten-free diet as a way of losing weight.

That’s made gluten-free diets increasingly popular, even for those without health concerns related to wheat.

Now brands such as Robin Hood and Betty Crocker offer gluten-free alternatives, at a lower price than earlier products on the market.

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Dr. Mohsin Rashid, a gastroenterologist based in Halifax and an expert on celiac disease, did a cost comparison study on the cost of gluten-free products in 2008, finding they were 242 per cent more expensive than comparable, regular products.

But in a new study to be presented next week, Dr. Rashid found that difference has shrunk. Gluten-free flours, baked goods and prepared foods are now 162 per cent more than regular products, he told CBC News.

"What we found was gluten-free foods are still significantly more expensive, but the price difference, differential, seems to have narrowed down a bit,” he said.

Between 2005 and 2010, the number of gluten free products grew by nearly 80 per cent. Larger-scale food manufacturers have economies of scale that smaller companies cannot achieve.

They’ve been attracted because of the response to books like Wheat Belly, which have turned gluten-free eating into a weight loss fad.

A small number of people eat gluten-free out of necessity, among them people with celiac disease, an autoimmune disorder triggered by gluten, and people who have non-celiac gluten-sensitivity. Those with gluten sensitivity suffer from digestive issues and frequent illness that seems to be corrected by giving up gluten, Dr. Rashid says.

Michelle Fenwick, who owns Good Bye Gluten, a 100 per cent gluten-free grocery and bakery in Toronto, has noticed the cost of gluten-free products coming down.

Gluten-free products tend to cost more, because every ingredient must be free from contamination all the way from the field through the packaging plant, she says.

"The more it goes mainstream, the more larger companies start to make things, like Robin Hood or Post or Betty Crocker. I mean they are able to do things on a much larger scale than has generally been out there,” Fenwick said.