A study came out in Gastroenterology (1), that I find to be nicely timed with my most recent post on the need for controlled studies surrounding issues like gluten. I am in no way saying this is the be all end all for the gluten-free fad, but this is a scientific step in the right direction for understanding the role of gluten, if any, in medical conditions.
A lot of people are avoiding gluten for a number of reasons - they think it causes weight gain, it's 'toxic', causes GI discomfort, skin problems, etc etc. Much of the information that pushes gluten-free diets is anecdotal, and doesn't control for confounding factors - when it comes to food, there are hundreds of food components/chemicals to consider, at both the macro and micronutrient levels, as well as the many interactions between said components.
I must admit a pretty non-scientific sentiment- I've always been a bit skeptical of the scientific community's acceptance of gluten sensitivity. Not that people have symptoms or not, but rather, that some other change could account for the issues being experienced - I can think of a number, be it changes in the microbiota, mineral deficiencies, etc. A lot of vegetarian 'meats' are made of wheat gluten (seitan) and there's a pretty widespread consumption of gluten-based meat alternatives by American vegetarians and in the past, by Vietnamese Buddhists. One would think the people consuming concentrated forms of gluten daily would've been experiencing a number of similar problems the anti-gluten crowd attributes to gluten. Alas, maybe it's something else?
This study in Gastroenterology looked at 37 individuals with non-celiac gluten sensitivity and irritable bowel syndrome - first off, this is not a huge cohort, so we don't wanna draw too many overwhelming conclusions, and it's mostly female (only 6 males). The study participants could not have diagnosed celiacs disease. This study utilized a double blind cross over placebo design (a gold standard in study design) to measure the effects of gluten on individuals placed on a low FODMAPs diet - a diet low in Fermentable Oligo, Di, Monosaccharides And Polyols. There's a growing body of research on this diet, and individual's sensitivity to these fermentable carbohydrates, rather than the current culprits of gluten, food chemicals, etc. (2,3,4).
The studies endpoints looked mostly at measurements on a visual analogue scale, while also measuring biomarkers of protein metabolism, gluten specific T-cell response, fatigue and GI symptoms. The FODMAPs diet was naturally free of gluten/dairy, and low in chemicals (salicylates, MSG, benzoate, other preservatives).
The results of the study were quite interesting. Figure 2 of the study looked at overall symptoms and diet type. Interestingly, high-gluten diets had less negative effects on overall symptoms, though all diets showed symptoms progressively worsened during the first week challenge. Low gluten diets significantly worsened bloating and tiredness. 6 individuals did have worsened symptoms on the high gluten diet, 3 of which tested positive for HLA-DQ2 (a high risk factor for celiacs). Across the 3 day rechallenge, all symptoms varied, irrespective of diet. Reduction of FODMAPs in the diet universally reduced GI symptoms and fatigue.
Compared to past studies showing an effect of gluten, this study controlled for the diet, beyond the treatment, much better. These past studies added supplements to the habitual diet, which wouldn't account for the effect of other dietary factors or random changes in the diet - their lack of FODMAPs control is a particularly strong confounding factor. Ultimately, a larger study design, reproducing these effects, is necessary to conclude that gluten does not have any effect. The fact that the whey placebo induced some GI distress also warrants further investigation. An interesting thought I had while reading the study that the authors mention at the end is 'what are the synergistic effects of FODMAPs and gluten/whey'. If you read this blog, you're probably sick of me saying this but nutrients, as well as non-nutritive food components, don't work in isolation - if gluten is 'bad' for you, in what environment, in synergy with what other dietary components?
Overall, this study is a shot in the knee caps to the title of Non-Celiacs Gluten Sensitivity, but won't be killing it anytime soon. For more information on FODMAPs, I'd check out http://candidrd.com/ - her blog has a lot of great recipes, and since she follows a low-FODMAPs diet herself, she's a great resource.
For the sake of objectivity, it's important to mention that this study only talks about gluten in relation to IBS. Gluten has been implicated (both anecdotally and scientifically) in many pathologies that gluten in this sense does not relate to. I hope to cover gluten in autoimmune diseases/allergens/intestinal permeability/zonulin in the future.
1. http://www.ncbi.nlm.nih.gov/pubmed/23648697
2. http://www.ncbi.nlm.nih.gov/pubmed/24076059
3.http://www.ncbi.nlm.nih.gov/pubmed/20659225
4.http://www.ncbi.nlm.nih.gov/pubmed/22778791
A lot of people are avoiding gluten for a number of reasons - they think it causes weight gain, it's 'toxic', causes GI discomfort, skin problems, etc etc. Much of the information that pushes gluten-free diets is anecdotal, and doesn't control for confounding factors - when it comes to food, there are hundreds of food components/chemicals to consider, at both the macro and micronutrient levels, as well as the many interactions between said components.
I must admit a pretty non-scientific sentiment- I've always been a bit skeptical of the scientific community's acceptance of gluten sensitivity. Not that people have symptoms or not, but rather, that some other change could account for the issues being experienced - I can think of a number, be it changes in the microbiota, mineral deficiencies, etc. A lot of vegetarian 'meats' are made of wheat gluten (seitan) and there's a pretty widespread consumption of gluten-based meat alternatives by American vegetarians and in the past, by Vietnamese Buddhists. One would think the people consuming concentrated forms of gluten daily would've been experiencing a number of similar problems the anti-gluten crowd attributes to gluten. Alas, maybe it's something else?
This study in Gastroenterology looked at 37 individuals with non-celiac gluten sensitivity and irritable bowel syndrome - first off, this is not a huge cohort, so we don't wanna draw too many overwhelming conclusions, and it's mostly female (only 6 males). The study participants could not have diagnosed celiacs disease. This study utilized a double blind cross over placebo design (a gold standard in study design) to measure the effects of gluten on individuals placed on a low FODMAPs diet - a diet low in Fermentable Oligo, Di, Monosaccharides And Polyols. There's a growing body of research on this diet, and individual's sensitivity to these fermentable carbohydrates, rather than the current culprits of gluten, food chemicals, etc. (2,3,4).
The studies endpoints looked mostly at measurements on a visual analogue scale, while also measuring biomarkers of protein metabolism, gluten specific T-cell response, fatigue and GI symptoms. The FODMAPs diet was naturally free of gluten/dairy, and low in chemicals (salicylates, MSG, benzoate, other preservatives).
The results of the study were quite interesting. Figure 2 of the study looked at overall symptoms and diet type. Interestingly, high-gluten diets had less negative effects on overall symptoms, though all diets showed symptoms progressively worsened during the first week challenge. Low gluten diets significantly worsened bloating and tiredness. 6 individuals did have worsened symptoms on the high gluten diet, 3 of which tested positive for HLA-DQ2 (a high risk factor for celiacs). Across the 3 day rechallenge, all symptoms varied, irrespective of diet. Reduction of FODMAPs in the diet universally reduced GI symptoms and fatigue.
Compared to past studies showing an effect of gluten, this study controlled for the diet, beyond the treatment, much better. These past studies added supplements to the habitual diet, which wouldn't account for the effect of other dietary factors or random changes in the diet - their lack of FODMAPs control is a particularly strong confounding factor. Ultimately, a larger study design, reproducing these effects, is necessary to conclude that gluten does not have any effect. The fact that the whey placebo induced some GI distress also warrants further investigation. An interesting thought I had while reading the study that the authors mention at the end is 'what are the synergistic effects of FODMAPs and gluten/whey'. If you read this blog, you're probably sick of me saying this but nutrients, as well as non-nutritive food components, don't work in isolation - if gluten is 'bad' for you, in what environment, in synergy with what other dietary components?
Overall, this study is a shot in the knee caps to the title of Non-Celiacs Gluten Sensitivity, but won't be killing it anytime soon. For more information on FODMAPs, I'd check out http://candidrd.com/ - her blog has a lot of great recipes, and since she follows a low-FODMAPs diet herself, she's a great resource.
For the sake of objectivity, it's important to mention that this study only talks about gluten in relation to IBS. Gluten has been implicated (both anecdotally and scientifically) in many pathologies that gluten in this sense does not relate to. I hope to cover gluten in autoimmune diseases/allergens/intestinal permeability/zonulin in the future.
1. http://www.ncbi.nlm.nih.gov/pubmed/23648697
2. http://www.ncbi.nlm.nih.gov/pubmed/24076059
3.http://www.ncbi.nlm.nih.gov/pubmed/20659225
4.http://www.ncbi.nlm.nih.gov/pubmed/22778791
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