Gluten free diets are being hailed for their role in weight loss, and much, much more... 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 Part 2: Why else go Gluten free? Beyond the conditions discussed in Part 1 of this monthly myth bust, gluten has been branded as the cause of weight gain, general feelings of lethargy, poor health, and inflammation which underpins 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? As we’ve seen so far the evidence for specifically avoiding gluten beyond Celia Disease is limited and yet ordering from the gluten free menu seems to be the new “I’ll just have a salad …” Weight loss is quiet possibly the biggest preoccupation of our modern western society and of course we would just love to find something to ‘blame’ for our population-wide weight worries (other than poor dietary choices, limited physical activity and generally being immersed in an obesogenic environment) – enter Gluten. We’ve tried blaming carbohydrates, we’ve tried blaming fat and we’ve tried blaming sugar, next on the chopping block is gluten. The underlying mechanism by which gluten is blamed for weight gain is inflammation, which is also said to be the reason it causes heart disease, diabetes etc. There is evidence to support the inflammatory effect of gluten in people with Celiac Disease, as is to be expected, and even a little for those with NCGS, despite no clinical markers currently being accepted. (1) But within the general population the evidence is (again) limited. The one and only study which seems to be quoted as the ultimate ‘evidence’ that gluten causes weight gain in subjects without Celiac Disease or NCGS, claims that removing gluten from the diet of mice reduced inflammation, insulin resistance and adiposity (fatness), compared with mice fed a high fat diet (61% of energy from fat), comprising 4.5% gluten, however this diet is hardly reflective of the typical Western human diet, or even the recommended diet (e.g The Australian Dietary Guidelines), so the beneficial effects of a gluten-free diet as claimed by this research, seems a bit of a stretch (but of course more research is warranted). (2) The benefits of a gluten free diet in the general population is further questionable given that another study on human subjects with hyperlipidaemia, reported that increasing wheat gluten on a weight maintenance diet reduced triglyceride levels by 13% independent of fibre content, suggesting that gluten may in fact have some benefit in improving lifestyle related conditions. (3) Of course, we could then consider the plethora of data to support the beneficial role of whole grains, including wheat and other grains containing gluten, in type 2 diabetes, heart disease, some forms of cancer and weight management. (4) The fact is there is insufficient data to support any of the widely made claims the gluten causes weight gain, hampers weight loss, or causes inflammation, diabetes or heart disease within the general population. So despite a few mice seemingly benefiting from removing gluten from the diet, do I think cutting gluten from your diet should be the first lifestyle modification made to aid weight loss or improve lifestyle related conditions? Umm, No… Ultimately if people have lost weight by ‘going gluten free’, more than likely they have just cut their carbs, which we know results in short term “weight loss” largely from water losses. We know that a low carb diet results in no greater weight loss after 6 months than other dieting methods (such as low fat, high protein etc) and is difficult for many to sustain long term. So if you are stocking the pantry with gluten free products simply to lose weight you are wasting your time, your money and could actually be risking your health. Negative Consequences of avoiding Gluten Resistant starches in grains like wheat (which we know contains gluten) creates healthy gut bacteria shown to reduce the risk of some cancers, inflammatory conditions, and cardiovascular disease. (3) Given the dependence on wheat in the western diet a significant portion of resistance starch comes from wheat consumption and as such following a gluten free diet unnecessarily could have adverse effects on gut health. Conversely positive changes in gut health as a consequent of including whole grains in the diet have been seen within as little as 3 weeks. (3) Conclusion Despite the hype around gluten there certainly is no reason for the general population (outside of having a gluten related disorder) to jump on board this movement. Cutting gluten from your diet to improve your overall health, prevent disease or aid weight loss is not substantiated by current research and in fact, gluten could in fact have some health benefits. Although the research to support this is far from definitive, the role of grains in good health is definitely well understood. Of course branching out from wheat, irrespective of gluten, adds nutritional variety to the diet and assists to increase crop biodiversity so by all means enjoy a variety of grains, gluten free or otherwise, within your diet too. Summary - Celiac’ s must adhere to an exclusively gluten free diet
- Our understanding of NCGS, and specifically the role of gluten in this condition, is very primitive - There is insufficient evidence to say that a gluten free diet has any positive effect on conditions such as MS, schizophrenia, dementia or autism - There is similarly little evidence to say that a gluten free diet causes any harm in these conditions - There is insufficient evidence to say a gluten free diet has an effect on weight loss, obesity, inflammation, insulin sensitivity or diabetes - The gluten free food industry is cashing in on processed products that are equally energy dense and nutrient deficient as their gluten containing counter parts - Whole grains are good for us and many of them just happen to be gluten free This is a really great fact sheet that guides you through the spectrum of gluten related disorders including symptoms and appropriate diagnostic protocol. (open fact sheet)
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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? 'Gluten Allergy' 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) Gluten Sensitivity 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. |
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