Gluten-free diets

The last few years have brought an increased awareness of the presence of gluten in our diets. In line with this, the Daily Mail recently ran an article headlined “Could going gluten-free boost your brain power? Landmark study reveals diet ‘reduces fatigue and increases energy levels’”.

breadThe article in question was published on the Mail Online. In it they report on a study that links a gluten-free diet to decreased fatigue, flatulence and bloating. There is so much wrong with the piece it’s difficult to know where to begin, so I’ll start with the most concerning issue: that the study was funded by Genius Gluten Free Foods.

That’s right, this “Landmark” study was funded by the very people who will benefit most from its result. This fact alone throws up big red flags, but reading further brings up some other major issues.

The study has not been published, neither online or in a peer-reviewed journal. I contacted the University of Aberdeen, The Rowett Institute and authors of the study, to try to get my hands on the data (or the press release the journalist was working from), but to no avail. From the article in the Daily Mail, I can say that the study itself had fewer than 100 people in it, far too small a sample size to say anything concrete unless the study used extremely stringent criteria (which it did not).

Furthermore, the article itself points out that the participants ate a healthier diet while on the study, making it entirely possible (and likely) that the effects seen were not as a result of the gluten-free diet, but as a result of eating better in general.

I could go on all day, but I’ll leave it at that. The article is clearly rubbish, but it does highlight the recent popularity of gluten-free diets however, and this is a topic about which there is a lot of controversy.

Removing gluten from the diet has become big business. According to the BBC, 29% of American adults (70 million people) say they are trying to cut back on gluten. This results in a gluten-free market in the US of almost $9 billion. Here in the UK, sales of gluten-free foods were around £184 million in 2014, which shows just how common it has become.

It is safe to say that there are certainly people who do benefit hugely from a gluten-free diet. These are people with coeliac disease, an autoimmune disorder that results a decrease in the ability of the intestine to absorb the nutrients it needs. It is thought that around 1% of the population have some level of coeliac disease, so it is a relatively common disorder. Additionally, most of that 1% are undiagnosed, so it is certain that a gluten-free diet can improve the symptoms of some people.

Another group that may benefit from the diet are those with non-coeliac gluten sensitivity, but this is controversial, as it has not yet been shown that gluten sensitivity actually exists. The most definitive study into this (in 2013) showed that gluten was not causing the symptoms of the patients in their study. They laid the blame at the door of a group of carbohydrates known as FODMAPs (which are partially eliminated in a gluten-free diet). Other research has blamed ATIs, plant proteins that are common in grains. Regardless, diet clearly influences the symptoms in these people.

With the caveat in mind that going gluten-free will help some people, it must be pointed out that the large majority of people trying to reduce the gluten in their diets have no need to. Studies have shown that at least two-thirds of people who claim they have non-coeliac gluten sensitivity cannot tell if they have been exposed to gluten or not. The design of that study also makes us confident that this is an underestimation. The same study showed that symptoms often got worse if the subjects thought they were eating gluten, suggesting that the nocebo effect plays a large role in their symptoms (I’ve previously written about the nocebo effect here. Put simply, it is an ill effect caused by the suggestion or belief that something is harmful).

gluten free“Gluten-free” is a fad diet, albeit an extremely popular one. Gluten is widely perceived to be unhealthy, a contention for which there is little evidence. Celebrities (Gwyneth Paltrow, Miley Cyrus) and sport stars (Novak Djokovic) have further propagated this myth, leading to the boom in sales we have seen recently.

The problem is that there are risks attached. It is known that some foods that are free from gluten are actually less healthy than the original variety because they may contain more fat or sugar and thus more calories. In order to attain the same texture and consistancy, starches and binding agents are often added. It has also been shown that avoiding wheat products can lead to deficiencies in nutrients such as folate.

The majority of people who are gluten-free do it because they are under the impression that it is better for you. In reality, they are spending more money on products for no real benefit, and feeding an industry that encourages people to unnecessarily buy more expensive foods. Eating more fruit and vegetables is a much wiser investment.

As I’ve already pointed out, there are people who benefit from a gluten-free diet. However, that is not the case for the majority. I’ll leave the final word to Dr. Ruth Kava, who is a Senior Nutrition Fellow at the American Council on Science and Health. She commented that “The bottom line is that if you don’t really need to go gluten-free, don’t bother. And to determine if you do, consult a gastroenterologist, not a celebrity diet guru.” Well said.

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