Gluten may cause brain inflammation, suggests study on mice.

Gluten may cause brain inflammation, suggests study on mice.

Research in mice suggests that wheat gluten in the diet may contribute to brain inflammaton. Image credit: Maren Caruso/Getty Images.

In a groundbreaking study conducted in New Zealand, researchers have observed that wheat gluten can cause brain inflammation in mice. Their recent work showed that gluten added to a low- or high-fat diet triggered inflammation in the brain’s hypothalamic region, which regulates metabolism. This finding raises important questions about the potential impact of gluten on brain health and its implications for human physiology.

Gluten is a protein present in wheat, barley, rye, and other widely consumed grains. It is also added to many processed foods. Previous research has suggested that gluten could contribute to peripheral inflammation in the gastrointestinal tract and enteric nervous system. However, according to University of Otago researchers in New Zealand, wheat gluten may also trigger central inflammation in the brain.

In their study, the team fed male mice either a low-fat diet or a high-fat diet, later adding gluten. Associate professor Dr. Alexander Tups, the lead author, explained that the addition of gluten to either diet “led to a marked increase in the number of microglia and astrocytes in the arcuate nucleus (ARC) of the hypothalamus, a key brain region for metabolic control.” These findings, which have been published in the Journal of Neuroendocrinology, suggest a link between gluten consumption and brain inflammation.

Astrocytes and microglia are two types of immune cells in the brain that play a part in inflammation. The brain’s hypothalamic region is responsible for regulating metabolic functions that control weight and blood sugar. The researchers hypothesized that gluten-induced hypothalamic inflammation could lead to brain damage, body weight gain, impaired blood glucose regulation, and increased risk of impaired memory function.

While this study was conducted in mice, Dr. Tups noted that mice and humans share several common physiological factors. “Mice […] have a very similar circulatory, reproductive, digestive, hormonal, and nervous system. So, it is quite possible that the same inflammation we found in mice could happen in humans,” he explained.

To investigate the effects of gluten on brain inflammation, the researchers fed male mice either a low-fat diet with 10% fat or a high-fat diet with 60% fat, with or without 4.5% wheat gluten. The gluten-enriched diets contained 4.5% gluten, equivalent to a human’s average daily gluten consumption. The researchers observed that gluten added to the low-fat diet increased C-reactive protein levels, a marker of inflammation.

Regardless of whether it was added to a low- or high-fat diet, gluten drove a significant increase in the number of astrocytes and microglia in the hypothalamus. The scientists stated that their study reported for the first time that gluten-induced astro- and microgliosis indicates the “development of hypothalamic injury in rodents.” This research confirms the team’s hypothesis that dietary gluten increases markers of hypothalamic inflammation.

But how does gluten trigger inflammation? Medical News Today discussed the study’s findings with Dr. Heather Sandison, a specialist in brain health. She explained that gluten ingestion can trigger the production of zonulin, which creates a “leaky gut” and allows large molecules to cross from the gut into the bloodstream, triggering a body-wide inflammatory response. Additionally, gut microbiota and gut-derived bacterial toxins called lipopolysaccharides may enter the bloodstream, leading to an “inflammatory cascade.”

It is important to note the limitations of this study. Firstly, it only included male mice, while women make up over half of individuals with celiac disease. However, Dr. Tups emphasized that this choice was made to keep the sample size low for ethical reasons. Future studies should include female mouse models. Dr. Sandison mentioned that she did not have a solid reason to believe that females would have a different inflammatory response to gluten than males.

The study authors also acknowledged that the high-fat diet they used primarily contained long-chain saturated fats from lard, which may have produced different results from a high-fat diet containing polyunsaturated fats with anti-inflammatory potential. Further research is needed to explore the dose-response relationship between gluten and its effects. Additionally, while this study suggests that a gluten-enriched diet may lead to dysbiosis and inflammation in the brain, more research is required to confirm this.

Designing controlled clinical trials for humans presents challenges due to the different texture of gluten-free food. This might explain the scarcity of empirical evidence for excluding gluten for individuals without gluten sensitivities. The researchers emphasized the need for future studies to reveal whether their findings in male mice are applicable to humans and how gluten-induced astro- and microgliosis may develop in gluten-sensitive individuals.

In conclusion, the groundbreaking study conducted in New Zealand provides insights into the potential negative effects of wheat gluten on brain health. By observing brain inflammation in mice exposed to gluten, the researchers have shed light on the possible impact of gluten consumption on metabolic control and overall brain function. While more research is needed to confirm these findings in humans, it is important to consider the possible implications of gluten on inflammation and brain health. Nonetheless, it is essential to remember that the study does not suggest that everyone should stop eating gluten. Dr. Tups emphasized the need for a balanced approach, as highly processed gluten-free products are often low in fiber and high in sugar.