• This gluten-studying scientist deserves a lot of praise

    In 2011, Peter Gibson published a study showing that people without celiac disease could have gluten intolerance (emphasis mine):

    OBJECTIVES: Despite increased prescription of a gluten-free diet for gastrointestinal symptoms in individuals who do not have celiac disease, there is minimal evidence that suggests that gluten is a trigger. The aims of this study were to determine whether gluten ingestion can induce symptoms in non-celiac individuals and to examine the mechanism.

    METHODS: A double-blind, randomized, placebo-controlled rechallenge trial was undertaken in patients with irritable bowel syndrome in whom celiac disease was excluded and who were symptomatically controlled on a gluten-free diet. Participants received either gluten or placebo in the form of two bread slices plus one muffin per day with a gluten-free diet for up to 6 weeks. Symptoms were evaluated using a visual analog scale and markers of intestinal inflammation, injury, and immune activation were monitored.

    RESULTS: A total of 34 patients (aged 29-59 years, 4 men) completed the study as per protocol. Overall, 56% had human leukocyte antigen (HLA)-DQ2 and/or HLA-DQ8. Adherence to diet and supplements was very high. Of 19 patients (68%) in the gluten group, 13 reported that symptoms were not adequately controlled compared with 6 of 15 (40%) on placebo (P=0.0001; generalized estimating equation). On a visual analog scale, patients were significantly worse with gluten within 1 week for overall symptoms (P=0.047), pain (P=0.016), bloating (P=0.031), satisfaction with stool consistency (P=0.024), and tiredness (P=0.001). Anti-gliadin antibodies were not induced. There were no significant changes in fecal lactoferrin, levels of celiac antibodies, highly sensitive C-reactive protein, or intestinal permeability. There were no differences in any end point in individuals with or without DQ2/DQ8.

    CONCLUSIONS: “Non-celiac gluten intolerance” may exist, but no clues to the mechanism were elucidated.

    This set off a firestorm. Tons of people started blaming things wrong with their life or health on gluten. Millions gave it up, and billions of dollars were made on new diet and fads. “Gluten-free” became huge, and even lots of my friends started buying into the idea that gluten was horrible.

    It is, for people with celiac disease. But now it was bad for many, many more people as well.

    Rather than rest on his laurels, though, Peter Gibson continued to study this. He set up a better study to confirm his findings. They didn’t hold (emphasis mine):

    BACKGROUND & AIMS: Patients with non-celiac gluten sensitivity (NCGS) do not have celiac disease but their symptoms improve when they are placed on gluten-free diets. We investigated the specific effects of gluten after dietary reduction of fermentable, poorly absorbed, short-chain carbohydrates (fermentable, oligo-, di-, monosaccharides, and polyols [FODMAPs]) in subjects believed to have NCGS.

    METHODS: We performed a double-blind cross-over trial of 37 subjects (aged 24-61 y, 6 men) with NCGS and irritable bowel syndrome (based on Rome III criteria), but not celiac disease. Participants were randomly assigned to groups given a 2-week diet of reduced FODMAPs, and were then placed on 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 of at least 2 weeks. We assessed serum and fecal markers of intestinal inflammation/injury and immune activation, and indices of fatigue. Twenty-two participants then crossed over to groups given gluten (16 g/d), whey (16 g/d), or control (no additional protein) diets for 3 days. Symptoms were evaluated by visual analogue scales.

    RESULTS: In all participants, gastrointestinal symptoms consistently and significantly improved during reduced FODMAP intake, but significantly worsened to a similar degree when their diets included gluten or whey protein. Gluten-specific effects were observed in only 8% of participants. There were no diet-specific changes in any biomarker. During the 3-day rechallenge, participants’ symptoms increased by similar levels among groups. Gluten-specific gastrointestinal effects were not reproduced. An order effect was observed.

    CONCLUSIONS: In a placebo-controlled, cross-over rechallenge study, we found no evidence of specific or dose-dependent effects of gluten in patients with NCGS placed diets low in FODMAPs.

    Last month, he was part of a third study which confirmed the second.

    The jury is still out here, but the evidence is building that for many people, gluten sensitivity outside of celiac disease is less of a thing than previously thought. But I’d like to point out something that’s being overlooked in the constant argument over gluten. We have here a scientist who could have easily cashed out after his first study. He could have invented the “Gibson Diet” and gone on to make millions selling gluten-free food, and been part of the craze. He didn’t. He showed equipoise. He questioned his findings. He went back to work.

    Moreover, when he found contradictory results, he published them. He didn’t worry about being “wrong”. He presented his work for everyone to see.

    That’s something to be admired. He deserves acknowledgement.

    @aaronecarroll

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