Researchers from the University of Newcastle have found that only 16 per cent of people with self-reported (non-coeliac) gluten intolerance have symptoms that are reproducible in a double-blinded trial (when they don't know if they are eating gluten or a placebo).
The media response has not been kind to the other 84 per cent.
Gluten is a protein found in wheat, barley, rye and oats, and in the past week people who avoid it without an official diagnosis of coeliac disease – the relatively rare immune disorder in which permanent organ damage can result if gluten is consumed – have been called "delusional", told they are "fooling themselves", and have been chastised by everyone from Gizmodo to Yahoo7 for being fad dieters, spending exorbitant money on trendy food.
"Here we go again," I can't help but think. Another round of condescending eye-rolling to endure for choosing the gluten-free option, because I am one of those people who has not been diagnosed with coeliac disease but still forks out for the gluten-free gnocchi, pizza bases and cake, because too much wheat gives me tummy rumbles.
I've had irritable bowel syndrome (IBS) for as long as I can remember, and way back in 2003 decided it was worth cutting out gluten just to see what would happen. What followed was a miraculous discovery of the joys of regular bowel movements and a belly that no longer blew itself up like a balloon.
It was an improvement, but I still had some (ahem) issues, and over time discovered more and more foods to cut from my diet – dairy, onions, leeks, cabbage, apples, beans, cauliflower – all of which made a positive difference. Admittedly, I became a nightmare for friends trying to cater – "What are you, allergic to life?!" – but my insides were thanking me, and that was the important thing.
Meanwhile at Monash University, researchers were busy developing a new diet for people with IBS. They did not cite gluten as the culprit, but found that certain short-chain carbohydrates, collectively known as fermentable oligosaccharides, disaccharides, monosaccharides and polyols (or "FODMAPs" if you prefer something pronounceable), were contributing to IBS symptoms in about one-in-seven people.
Examples of FODMAPs are lactose (the sugar found in dairy products), fructose (found in many fruits, vegetables and honey) and sugar alcohols such as xylitol (sometimes sold as a low-calorie sweetener).
People with IBS may have varying sensitivity to FODMAPs, so an individualised diet can be designed (ideally with your doctor) through trial and error, depending on what is tolerated.
Last year, after testing positive for fructose malabsorption, I was directed towards the Monash Low FODMAP App, designed to help manage the diet (yes, there's an app for that), and trawling through the impressive database of foods helpfully matched to their FODMAP content I realised that finally (finally!), the puzzle pieces had fallen into place.
But why had I felt better avoiding gluten, if gluten was not my problem? Coincidentally, three common grains containing gluten – wheat, barley and rye – are also high in FODMAPs, hence my ongoing enthusiasm for the gluten-free section of the supermarket.
Having the right diagnosis was important though, because a gluten-free label is no guarantee of a low FODMAP product. Chickpea flour, for example, is a popular high FODMAP ingredient found in many gluten-free alternatives. Some foods made with gluten, such as soy sauce, are very low in FODMAPs.
So where does this leave us on the issue of "delusional" people opting for unnecessary, expensive "fad food"?
Well, first of all, I'd personally like to thank them for helping make wheat-free alternatives readily available in restaurants. Good job on that!
But, more seriously, it's important to remember that 16 per cent of self-reported gluten-intolerant people did react badly to gluten in the double-blinded studies, so there's always the possibility that your non-coeliac friend who won't eat the bread is right about her own body.
The review was also focused quite specifically on responses to gluten. Doing their due as good scientists, the reviewers acknowledged the role of FODMAPs in IBS, but had no way to retrospectively determine if study participants who didn't react to gluten might still have been benefiting from the consequentially lowered FODMAPs in their diet.
Another study on people with self-reported gluten sensitivity conducted at Monash University found that "In all participants, gastrointestinal symptoms consistently and significantly improved during reduced FODMAP intake" while "gluten-specific effects were observed in only 8 per cent".
This suggests a high rate of misdiagnosis (or a lack of diagnosis, since many patients, like myself, are being left to guess at it themselves), and shows it might be beneficial for people with self-diagnosed gluten sensitivity to raise the question of FODMAPs with a doctor or dietician.
Dismissing people who have taken their health into their own hands with moderate success as "delusional", however, might not be as conducive to their good health as some seem to think.