http://www.realclearscience.com/blog/20 ... exist.html
Non-Celiac Gluten Sensitivity May Not Exist
Subjects would be provided with every single meal for the duration of the trial. Any and all potential dietary triggers for gastrointestinal symptoms would be removed, including lactose (from milk products), certain preservatives like benzoates, propionate, sulfites, and nitrites, and fermentable, poorly absorbed short-chain carbohydrates, also known as FODMAPs. And last, but not least, nine days worth of urine and fecal matter would be collected. With this new study, Gibson wasn't messing around.
37 subjects took part, all with self-reported gluten sensitivity who were confirmed to not have celiac's disease. They were first fed a diet low in FODMAPs for two weeks, then were given one of three diets for a week with either 16 grams per day of added gluten (high-gluten), 2 grams of gluten and 14 grams of whey protein isolate (low-gluten), or 16 grams of whey protein isolate (placebo). Each subject shuffled through every single diet so that they could serve as their own controls, and none ever knew what specific diet he or she was eating. After the main experiment, a second was conducted to ensure that the whey protein placebo was suitable. In this one, 22 of the original subjects shuffled through three different diets -- 16 grams of added gluten, 16 grams of added whey protein isolate, or the baseline diet -- for three days each.
Analyzing the data, Gibson found that each treatment diet, whether it included gluten or not, prompted subjects to report a worsening of gastrointestinal symptoms to similar degrees. Reported pain, bloating, nausea, and gas all increased over the baseline low-FODMAP diet. Even in the second experiment, when the placebo diet was identical to the baseline diet, subjects reported a worsening of symptoms! The data clearly indicated that a nocebo effect, the same reaction that prompts some people to get sick from wind turbines and wireless internet, was at work here. Patients reported gastrointestinal distress without any apparent physical cause. Gluten wasn't the culprit; the cause was likely psychological. Participants expected the diets to make them sick, and so they did.
I, of course, would have been equally sick on the placebo diet which included whey protein. They claimed their placebo was lactose free, but I understand whey protein to be relatively high in lactose too. And shifting the diet every 3 days, or even weekly, would not be enough to calm the symptoms caused by the original gluten insult (for me). I'm not sure whether they used pure gluten, or whole wheat, but perhaps people with some forms of NCGS are reacting to the wheat germ agglutenin or other wheat proteins and not the gluten?
What's a good rebuttal for this research?
