Gluten free diets are a hot topic and apparently they're not just for Celica's
There was a lot of ground to cover in this month’s myth bust, so it will be coming to you in a two part instalment. Part 1 clears up some background information about what gluten is and why people might avoid it for medical reasons while Part 2 looks at those other reasons people are avoiding gluten, like for weight loss and general health - enjoy
We know that for people medically diagnosed with Celiac Disease a strict gluten free diet is necessary to prevent damage to the villi which line the small intestine wall. Along with gastrointestinal distress, the damage caused to the villi by Celiac Disease can lead to malabsorption, nutrient deficiencies and secondary conditions such as osteoporosis.
But, for the other 99% of the population (yep, only about 1% of people are Celiac) is there any reason to jump aboard the gluten free movement? (1)
Food fashions and fads come and go and it seems at the moment ‘going gluten free’ is in style. Celebrities are doing it, all the trendiest restaurants and cafes feature gluten free options, it’s a hot topic in the media, and a multimillion dollar industry (which far exceeds the needs of Celica’s), has emerged almost overnight.
What is Gluten?
There seems to be a huge amount of confusion around what gluten actually is and consequently the myths about why people should avoid it. So let’s clear that up to start with.
Gluten is a protein found in wheat, rye, barley, triticale and oats (controversially) but its uses within the food supply spreads far and wide as along with being found in products that use these grains it acts as a great thickening agent in many sauces, condiments and processed meats. Clearly avoiding all of these foods in order to ‘go gluten free’ is quiet a commitment and requires an extensive diet overhaul.
Fortunately, there are many foods that are naturally gluten free that can be appropriately substituted into the diet, including amaranth, arrowroot, buckwheat, cornflour and meal, millet meal, polenta, psyllium, quinoa, rice, sago, sorghum and tapioca. Of course many specifically developed gluten free products are available too.
So in the absence of Celiac disease, why are people going gluten free?
More than likely you may have come across someone with a “gluten allergy,” this however is a complete myth – or at least a bit of a misunderstanding on what may actually be a wheat allergy, Celiac Disease, gluten sensitivity, or another gluten related aetiology.
A wheat allergy is an immune mediated reaction to wheat itself and there is no question it is legit (estimated to affect 0.1% of the population); Celiac disease is an autoimmune disease, which like many autoimmune diseases, presents with mixes aetiology (over 300 symptoms have been reported!), it has an accepted diagnostic protocol and common clinical markers; Gluten sensitivity or intolerance however, is a bit of a phantom condition that is still under a lot of investigation. (2)
In the absence of Celiac Disease or a wheat allergy there is a sub-population who report being gluten sensitive or intolerant (often referred to as non-celiac gluten sensitivity; NCGS). Unlike Celiac Disease or wheat allergies, NCGS is far less understood which makes diagnosis and even recognition of the condition difficult, however it has very crudely been estimated that 20% of the population believe they are gluten sensitive or intolerant – many of them self-diagnosed (rightly or wrongly). (3)
NCGS as a condition has only really been validated in the last few years, it often comes with similar symptoms as Celiac Disease (abdominal pain, diarrhoea, bloating and excessive wind, as well as lethargy, poor concentration and general aches and pains), however does not result in the same villi damage as Celiac Disease and as yet has no accepted clinical markers.
Much research (with much funding from the gluten free food industry), has been done into this condition in an effort to uncover and legitimise it, too little prevail. (3,5) It is largely thought that NCGS generally occurs from a heightened immunological response to gluten in genetically susceptible people, although this isn’t universally accepted (6). Regardless of this, for people with this phantom condition removing gluten from their diet seems to alleviate the symptoms.
Interestingly however, recent research has suggested that in the case of NCGS, gluten may not be the culprit at all.
A double blinded cross over trial of 37 patients with NCGS were placed on a low FODMAP diet (fermentable, oligo-, di-, monosaccharides, and polyols; Short chain carbohydrates which are hard to digest, leading to fermentation in the gut hence boating, wind and discomfort), for 2 weeks then placed on either a high-gluten (16 g gluten/d), low-gluten (2 g gluten/d and 14 g whey protein/d), or control (16 g whey protein/d) diets for 1 week, followed by a washout period for 2 weeks. Several months later twenty-two of the participants then crossed over to another protocol group for a further 3 days. The researchers found that all participants’ symptoms improved on the low FODMAP diet and only 8% of participants had gluten specific responses. (4)
This is only one small study and obviously a lot more research is needed but the results suggest that people who are “gluten sensitive” may feel improvements in gastrointestinal problems consequently as a gluten free diet is also low in FODMAPs.
This study again raises questions of the legitimacy of NCGS and questions the appropriateness of treatment with a gluten free diet. FODMAPs are found in many foods, including fruits and vegetables and can affect people differently, so simply removing foods which contain gluten may not be appropriate. (For this reason it is important not to self-diagnose or simply choose gluten free without seeking medical advice.)
Similarly, another recent review suggested that other constitutes of grains, particularly wheat, may be the underlying issue in NCGS and not in fact gluten. (5)
Gluten Free for other conditions
Further to this, gluten free diets have been used for the treatment/management of schizophrenia, multiple sclerosis, dementia and a bunch of other diseases, but unfortunately the actual benefits of this treatment/management protocol remains ‘alleged’ with insufficient evidence to support a medical benefit from a gluten free diet in these conditions. (6, 9)
Regrettable, autism one of the many ‘other’ conditions to have insufficient evidence to support any benefit of a gluten free diet. (7, 8) Fortunately though, no harm has been reported either.
The conditions mentioned are highly complex with multiple aetiology and comorbidities, much is still unknown about them and despite current limitations in evidence much support remains for trialling a medically supervised elimination diets. (9)
Why else avoid Gluten?
Beyond these conditions gluten has been branded as the cause of weight gain, general feelings of lethargy, poor health, and inflammation which is said to underpin heart disease, diabetes, cancer, and arthritis, amongst other things. Consequently, the hyped reasoning to avoid gluten includes increased energy levels, aiding weight loss, and a general “healthy” or “lighter” option.
With this impressive health resume, does a gluten free diet live up to the hype - Should we all be avoiding gluten? – Stay tuned for part 2 of this monthly myth bust.
The Monthly Myth Bust
Using research and evidence to bust and debunk all those Nutrition and Fitness myths you've been wondering about.