It was a trip to the supermarket where junk food was masquerading as health food with a “gluten-free” label, it was the conversation with a woman who’s on a gluten-free diet to lose weight, it was the e-newsletter telling me that quitting gluten would help me to cure my autoimmune disease. This week I’ve reached peak “gluten-free” and although I’m wary, I’ve decided to wade in to the treacherous waters of this micro-nutrient diet-debate.

As someone living with an autoimmune disease known as Sjogren's syndrome, I can tell you that I am very motivated to look after myself and explore any evidence that may point to a cause or cure for my illness. I’m also convinced that eating a healthy diet and avoiding junk-food is one of the keys to staying well. But after deep-diving into the research, I’m not convinced that there is currently a compelling case that we should all quit gluten.

Don’t get me wrong. Coeliac disease is definitely real. It’s a significant medical condition that damages the lining of the small intestine and affects about 0.5 – 1 percent of the population. I’ve been tested. I don’t have it.

What I’m talking about here is the wholesale argument that gluten is the proven cause of all manner of ailments ranging from gut troubles, to metabolic imbalances, autoimmune diseases and even to mental illness.

Before you ask, yes, I’ve read Grain Brain and Wheat Belly, and yes I know that many popular health gurus say that gluten might be killing us. And, yes, there are some studies that have found that gluten causes gut problems in people even if they don’t have coeliac disease.

I get it. The arguments presented by the anti-gluten campaigners are convincing. Generally the theory is that gluten (gluey proteins found in wheat, barley, and rye) wreaks havoc in your gut. Bloating, wind, diarrhoea? It’s gluten. Constipation, cramping, pain? It’s gluten. The theory goes on to propose that gluten causes a permeable or “leaky” gut, which allows nasty things to escape into your blood stream and sends your immune system bonkers. Aches, pains, arthritis? It’s gluten. Low mood, anxiety, depression? It’s gluten.

Often, the gluten-free campaign is bolstered by studies showing, for example, that it's associated with fibromyalgia, type 1 diabetes, multiple sclerosis, and depression. Even autism and ADHD are linked to gluten. This is all true. There are also small, clinical trails in which gluten is found to significantly increase symptoms in people with self-identified gluten intolerance.

On the back of all this evidence, it’s little wonder that the gluten-free cause has become big business. By 2020, the market for gluten-free food products, cook books and Online Health-Revolution-Cleanse-Courses is projected to be valued at 7.59 billion U.S. Dollars.

Unfortunately what those with a stake in the gluten-free game don’t tell you is that if you weigh up the evidence investigating if gluten causes gut problems, there's actually more evidence showing that gluten isn’t the problem. For example, in a recent placebo-controlled, cross-over study (considered very high-quality as far as nutritional research goes) researchers found that gluten did not cause gastrointestinal symptoms. Gluten may also help to prevent type 2 diabetes. A recent review concluded that the evidence "is neither robust nor convincing. In fact, gluten avoidance may be associated with adverse effects in patients without proven gluten-related diseases." The latest position paper, bearing the names of 24 international nutrition experts states, “Without a confirmed diagnosis, a gluten-free diet is unjustified and not recommended.”

So what if you’re one of the 30 percent of people who avoid gluten because it makes you feel better, despite not being diagnosed with coeliac disease?  What other explanations could there be?

One recent, very well-done double-blind, crossover study demonstrated that in people with self-diagnosed gluten sensitivity, it was fructan, rather than gluten that caused their gut problems. Fructan lurks in a wide variety of common foods such as watermelon, bananas, beetroot, garlic, onions, and in grains including rye and interestingly, wheat. This may go a long way towards explaining why people stop eating wheat and feel better, but their symptoms don’t completely resolve. I recommend you look into research being done at Monash University if you'd like to know more about this line of investigation. I spoke to some of the researchers there a few years ago when I was researching the chapter in my book on diet and was fascinated that they originally started out investigating gluten, but moved on because they weren't convinced by their own findings.

Another explanation being explored by scientists is the nocebo effect. You might be having symptoms because you think gluten is a problem. As I've written about previously, this is a very real physiological response.

In conclusion, I don’t doubt that there is an association between gut problems and autoimmune disease and that the science on the leaky-gut theory is definitely something to watch closely. But there are many reasons that you might have tummy troubles that don’t have billion dollar industries driving public appetite.

For example, when I investigated the impact of junk food on our health, I learned that our friendly gut microbes don’t like substances like the emulsifiers, preservatives, and artificial sweeteners found in processed foods. It's been shown that when mice are fed junk, the animals’ gut barriers become notably more permeable, allowing toxins to leak into the bloodstream.

My regular readers will know that although I’m committed to providing health information to people looking for a reliable map to navigate their way through this crazy, confusing world of ours, I tend to avoid writing about specific micro-ingredients in diets. This is because good nutrition journalism is fraught with intricacy and detail that requires in-depth consideration before any conclusive takeaways can be made. I know the gluten-free debate stirs strong emotions. I may well live to regret coming out publicly about why I don't buy into the gluten-free industry.

Ultimately any diet that makes you feel better is worth sticking to and as I wrote in my piece How To Be Healthy When Everyone Around You Is Not, in an age when junk is called “party food,” when “if you snooze, you lose” is the mantra of those we revere, and when the ancient practices of mindfulness and meditation are considered “new age” hippie ju ju, I know that sticking your head up and doing things differently can be really hard. But I guess, the point of this blog is to challenge assumptions and to invite critical thinking before you hand over your hard earned money to something that may be doing more harm than good.