Gluten intolerance has been a hot topic for several years now, and medical experts are still making strides in identifying the exact cause, treatment and even the ever-increasing myriad of symptoms that come with the problem. Many people who experience a physical, or more specifically, gastrointestinal reaction to the consumption of gluten have been diagnosed with Celiac disease.
Put in simple terms, Celiac disease is an autoimmune disorder in which a person’s immune system attacks healthy cells in the body. The most easily identifiable symptoms of the disease are ones which affect the stomach, such as abdominal bloating, diarrhea, constipation, vomiting and stomach pain. Even more common symptoms, which aren’t usually identified as being related to Celiac disease, include psychological and emotional issues, including anxiety, fatigue, headaches and depression.
With only 1% of the population having been diagnosed with Celiac disease, many more have opted to adhere to a gluten-free diet simply because it feels better, even if they’ve tested negative for the disease. This brings the scientific community to consider a non-celiac gluten sensitivity (NCGS), leading researchers to consider the impact gluten may play on parts of the body other than the gastrointestinal system.
A recent study published in a paper titled “Gluten May Cause Depression in Subjects With Non-Coeliac Gluten Sensitivity” featured in Alimentary Pharmacology & Therapeutics, focused on the psychological effects of gluten, particularly how it may or may not affect depression.
With research contributed by Dr. Jessica Biesiekierski and author Dr. Simone Peters, the study features 22 patients assigned one of three diets: either supplemented with gluten, whey, or nothing (placebo group.) Their various states of mental health were measured with a survey called State Trait Personality Inventory (STPI), which was filled out by individual participants on the third day of each dietary challenge. Salivary cortisol levels were also measured in order to indicate stress, and gastrointestinal symptoms were recorded throughout the process through a questionnaire.
All 22 participants were fed the same gluten-free diet for three days, all low in fermentable oligo, di-, mono-saccharides and polyols (FODMAPS), and dairy products were restricted. After this “baseline” period, patients were randomly assigned one of the three diets mentioned above, which were followed for three days. They were then allowed a “washout” period of 3-14 days before being assigned a new diet, which all 22 participants did complete.
After the research was examined, STPI scores did indicate a significant difference in depression levels between patients given a gluten diet versus those on the placebo diet, with those consuming gluten experiencing higher levels of depression. A slight difference in depression levels between gluten diets and whey diets was also measured, though not enough to be considered significant for the purpose of the study.
Considering their findings, the authors of the study project the possibility that gluten-free diets may feel better for those not diagnosed with Celiac disease because gluten might be affecting their mental health, as opposed to strictly physical. The way gluten may affect these changes are still unknown, though researchers have a few theories.
They were almost immediately able to dismiss the possibility that gluten may affect the production of cortisol, as no change in the cortisol levels of participants was measured. Next, they looked at the possibility that gluten may affect serotonin, a neurotransmitter which directly influences one’s mood, and is primarily found in the gastrointestinal tract. This theory may offer a connection between how what we eat may be directly affecting our mental health, though there is currently little research out there to help determine this claim.
A third possibility could be attributed to “exorphins,” which unlike endorphins that occur within the body, enter from outside the body, in this case, in the form of gluten. As endorphins and exorphins are opioid peptides created by the pituitary gland and central nervous system, some find it plausible that this may affect the mental processes, assuming the peptide were to cross the blood brain barrier.
The final explanation offered by the researchers comes down to bacteria found within the gut. As those diagnosed with Celiac disease are already believed to have an imbalance of certain necessary bacterias which live in the intestine that ceases to yield painful symptoms once gluten is removed from the diet, it is possible that gluten is what is causing this imbalance in the first place. The relationship between the gut and the mental processes have been widely researched, and the link between probiotics and brain activity in adult women has also been published, suggesting that the connection between what we eat and how we feel may be more apparent than we’ve previously considered.