While we’ve been aware of how gluten can negatively impact the digestive tract and body mass, New Zealand scientists have now identified for the first time that it can also cause brain inflammation.
On a study with mice, the scientists found that animals consuming a 4.5% gluten diet experienced inflammation in the hypothalamic region of the brain, an area that plays an integral role in metabolic functions such as blood sugar regulation.
“Mice are an excellent model to study human physiology,” said lead researcher Alex Tups, an associate professor at the University of Otago. “They 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.”
It’s estimated that 20 million Americans have a gluten sensitivity, and conservative numbers suggest around 1% of the population suffers from the serious celiac disease, a genetic autoimmune condition that can be incredibly debilitating and for which there is no cure besides avoiding gluten and potential contaminants altogether.
“The brain has two types of immune cells similar to macrophages in the blood,” Tups said. “These are called astrocytes and microglia. We found that gluten as well as HFD (high fat diet) increases the number of those immune cells. The effect of gluten added to [a] normal diet increased the cell number to the same extent as if mice were fed a HFD. When gluten was added to the HFD, the cell number went up even further.”
The researchers don’t know why this inflammation is occurring, but it does seem to be linked to an extreme immune system response like what’s seen in celiac disease.
“This is entirely new and so we don't know yet why it is the case,” Tups said. “It could be that digestion resistant components of gluten can lead to an immune response as seen in celiac patients that then manifests in the brain.”
Tups cautions that this discovery is very preliminary and more studies are needed. But it underpins how complex gluten sensitivity is and how far-reaching the health implications are.
“If gluten led to hypothalamic inflammation in humans and therefore brain damage, it can be bad in the long run, such as increase in body weight and impaired blood sugar regulation,” he said. “If these effects became persistent they might exacerbate the risk of, for example, impaired memory function, which is linked to disturbed blood sugar regulation.”
However, some good news: there’s no reason to ban the bread if you have no issues with digesting gluten.
“We are not saying that gluten is bad for everyone,” Tups said. “For gluten-tolerant people to go entirely gluten free may have health implications that may outweigh potential benefits. Often people don’t consume wholefoods, and highly processed gluten-free products are often low in fiber and high in sugar.”
The research was published in the Journal of Neuroendocrinology.
Source: University of Otago