While there is “no scientific basis” behind this theory, the belief that a gluten-free diet will help you lose weight and improve your health - even if you don’t have celiac disease - continues to gain momentum as more celebrities promote gluten-free diets, said Cureton.
But she added: “There is no evidence that gluten is harmful in healthy people without a gluten-related disorder."
And as for weight management, she said: "People on gluten-free diets often gain weight as many gluten-free foods are quite calorie dense. Gluten-free diets are often higher in fat and lower in vitamin B12, zinc, iron and folate.”
As for top athletes, several of whom are now advocating gluten-free living, she said: “There is no evidence that a gluten-free diet will increase sports performance.”
There is no biomarker for gluten sensitivity
It is also important to stress that gluten sensitivity or intolerance, which is believed to affect 6-7% of Americans, is not the same as celiac disease, which is an auto-immune disorder which causes damage to the gut wall if not diagnosed, she said.
“People will gluten sensitivity will often have faster and more violent symptoms or reactions to gluten than celiacs, but they do not have the intestinal damage associated with celiac disease.
Meanwhile, contrary to popular belief, “there is no [validated] biomarker for gluten sensitivity”, she said.
“We’re trying to find one, but there is a lot of misinformation out in the public about this.”
Why is the prevalence of celiac disease rising?
As regards celiac disease, just under 1% of the US population is estimated to have it, although less than 10% of these people are diagnosed, she said.
“What we do know is that true prevalence of celiac disease is increasing, and this is not just because more people are getting diagnosed. Why this is, we still don’t know.”
There are lots of hypotheses, exploring everything from changes in bread-making processes, plant-breeding techniques and wheat varieties, to caesarian births, breastfeeding trends, the ‘hygiene hypothesis’, increasing use of antibiotics and changes to the gut microbiome, she said.
Gluten-free market: What’s the size of the prize?
According to SPINS data presented by sales director Bobbi Leahy at the conference, sales of gluten-free products were up 19% in the year to September 2012 in natural and conventional channels combined (excluding Walmart, Trader Joe’s, Whole Foods Market), with 80% of sales coming from the food, drug and mass merchandise channel.
Meanwhile, the number of new product launches featuring gluten-free claims rose from around 600 in 2007 to more than 1,600 in 2011, she said.
The conviction that gluten-free products are generally healthier is the top motivation for purchase of these products...
Her comments came as a new report from Packaged Facts was published revealing that the market for gluten-free foods and beverages has continued to grow "even faster than anticipated", and is set to reach $4.2bn in 2012 and $6.5bn in 2017.
Meanwhile, an August 2012 consumer survey by Packaged Facts suggested that 18% of adults are buying or consuming food products tagged as gluten-free, up from 15% in October 2010, said research director David Sprinkle.
And the primary reason? Because they think they are better for you, he said.
"The conviction that gluten-free products are generally healthier is the top motivation for purchase of these products."
Asked why they buy gluten-free products, 35% said gluten-free products are "generally healthier", 27% said "to manage my weight", 21% said that gluten free products are "generally low-carb" and 15% said a member of the household has a gluten or wheat intolerance.
Just 7% said they were buying them because a household member has celiac disease.
Do gluten intolerant shoppers and wheat avoiders represent a huge market opportunity?
While this data suggests that the gluten-free market is going from strength to strength, ConAgra Mills’ director of consumer research David Sheluga PhD told FoodNavigator-USA it is important to put the numbers into context, however.
For example, if celiacs represent less than 1% of Americans, and less than 10% of celiacs actually know they have the disease, this equates to a relatively small number of diagnosed celiacs actively seeking out gluten-free products, he claimed.
But what about all those gluten-sensitive consumers and shoppers avoiding gluten for lifestyle or health reasons?
This group is often cited as a huge market opportunity for manufacturers, he said, but they are not all buying gluten-free products.
Many of them are simply cutting down on or avoiding bread or gluten-containing products altogether rather than switching to gluten-free replacements, he speculated.
Meanwhile, although the number of products making gluten-free claims is increasing, and the value of the gluten-free category is clearly growing rapidly, many ‘new’ gluten-free claims are coming from large manufacturers that are slapping gluten-free labels on products that are inherently gluten-free, which they have been selling for years, he said.