I've had this blog half written for weeks and then months. I wanted to finish it. I promised you I'd finish it. Then life happened. Baby Teo was in the hospital for several days and daily life stopped. I remember this feeling from the NICU, the blinders being put on and then suddenly nothing else matters, not eating, not sleeping, just Teo. He was a champ our little guy. He's done hospitals before, he knows the drill but oh did he cry. He was in pain and there wasn't anything we could do except hold him and love him and tell him it was going to be OK. And it was. Before you worry, Teo is fine. He's healing well and I've started breathing again.
Weeks have turned into months and I keep forgetting to press the publish button. What have I been doing? Mostly parenting and finishing my book Before Baby. When's it coming out? Soon, very soon. I am self-publishing and the final steps are taking just a little longer than anticipated but I am so excited to share it with you! In the meantime, I'm giving you a follow-up on non-celiac gluten intolerance and I'm intending to be back, writing in this space.
A couple of months ago I wrote about some of the latest research bashing non-celiac gluten sensitivity (NCGS), a study which media outlets interpreted as indicating that NCGS was bunk. In most of the articles written, journalists dug up this Biesiekierski and Gibson study from 2013 as proof that NCGS doesn't exist. Biesiekierski and Gibson are credited with proving (if one study can prove or disprove anything) that NCGS existed back in 2011.
As I noted in my previous post, most studies investigating non-celiac gluten intolerance are done with people that have IBS and the myriad causes of IBS are innumerable. For example, here's a review of studies that evaluated intestinal permeability as a cause of IBS. And a review of numerous studies assessing intestinal serotonin signaling in IBS. And this review of the role of small intestine bacterial overgrowth (SIBO) in IBS, not to mention the countless studies assessing use of probiotics and elimination diets to treat IBS.
Let's look at the 2013 Biesiekierski and Gibson study in more detail: 37 participants were placed on a low FODMAP (fermentable oligo-/di-/monosaccharides and polyols; shorthand for the less-digestible sugars that can cause bloating and discomfort) diet for two weeks, and then separated into one of three groups for 1 week. Those groups consumed different quantities of proteins on a daily basis (16 g gluten, 2 g gluten and 14 g whey, or 16 g whey protein). There was then a 2 week washout period, after which 22 of the participants switched treatments and were given 16 g gluten, 16 g whey, or no additional protein for 3 days. Participants were assessed after the initial two week challenge, and again after the treatment swap period.
The results? Participants felt better on the low FODMAP diet and worse on the gluten-containing diet. The study determined that 8% of participants felt better on a gluten-free diet, but this was not statistically significant.
So, to recap: 37 people with IBS were put on a low FODMAP diet and then tested with high, low and no gluten intake. Some people felt better on the low FODMAP diet, some people felt better on a gluten free diet.
I know I keep hitting the IBS issue over the head with a hammer but to me it's the biggest flaw in all these studies about NCGS because Irritable Bowel Syndrome is by definition a collection of symptoms with no known organic cause. It's a diagnosis of exclusion, which means that all other causes (celiac, Chrohn's or colitis for example) for gas, bloating, diarrhea and/or constipation have been ruled out. So, in performing studies to demonstrate the existence or non-existence of NCGS on participants with IBS, you are assuming that there is one cause for this syndrome when that's patently not the case.
The second issue with this study is that they chose to place participants on a low FODMAP diet prior to their gluten test. FODMAPs were first articulated by researchers at Monash University, the same university where Biesiekierski and Gibson happen to be performing their research. It may not be a conflict of interest but we should note it none the less. FODMAPs are poorly absorbed by everyone, not just people with functional gastrointestinal disorders and so it seems obvious that if you remove FODMAPs from a person's diet, IBS or no, he or she will experience a decrease in gastrointestinal symptoms.
FODMAPs are made up of a collection carbohydrates and some food sources include:
Fructans: Wheat, barley, rye, onion, garlic, asparagus, beets, broccoli, brussels sprouts, cabbage, fennel and chocolate
Galactans: Beans and legumes
Polyols: Apples, apricots, blackberries, cherries, peaches, nectarines, pears, plums and watermelon
Fructose: Fruit and fruit juice, table sugar, honey, agave
Lactose: Dairy products
In practice if we suspect someone may have an issue with a FODMAP food, we eliminate all FODMAPs and then test each group individually to narrow it down and identify which FODMAP is causing the problem. Notice the first three foods listed under fructans? Wheat, barley and rye. So participants in this study felt better when they eliminated FODMAPs, a collection of foods no one digests well and the foods eliminated included wheat, barley and rye, three of the five major gluten-containing grains (the others are spelt and trickle). To me this study muddies the waters further rather than clarifying anything about FODMAPs or NCGS.
So, is the Biesiekierski and Gibson study a bad study? No, it's has it's strengths and weaknesses just like all other research. Can we determine anything definitive about non-celiac gluten sensitivity and FODMAPs from it? No, it's one study among hundreds. What the Biesiekierski and Gibson study does is add to the body of knowledge regarding functional gastrointestinal disorders and their treatment. When it comes to treatment of a collection of gastrointestinal symptoms such as IBS, each person is going to have a different cause and therefore going to require a different treatment, eliminating gluten and/or doing a FODMAP elimination and challenge being among two of the many treatments available.
The bottom line: if you feel better when you don't eat gluten, don't eat it.