Wheat-based foods may pose a threat to brain health, according to a medical warning. Gluten contained in everyday foods such as noodles and bread damages the intestinal lining and triggers brain inflammation through that pathway.
According to the medical community on Wednesday, Kim Sung-bo, a neurologist and clinic director, said, "The food I most urgently and persistently urge patients to give up in the consultation room is wheat flour." The core of the problem is gliadin, a protein component of gluten. When gliadin enters the intestine, it stimulates the secretion of a protein called zonulin, which loosens the tight junction structure of the intestinal lining. A healthy intestine maintains a dense defensive barrier that prevents external toxins and bacteria from penetrating into the bloodstream, but excessive zonulin secretion creates cracks in this barrier. This is the so-called state of "increased intestinal permeability," or leaky gut syndrome. Research findings have also been published showing that gliadin increases intestinal epithelial permeability.
Through the breached intestinal wall, undigested protein fragments and toxins produced by gut bacteria flow into the bloodstream. These harmful substances circulate throughout the body, reach the brain, and trigger inflammation in the nervous system. As a result, symptoms such as brain fog (a hazy mental state), unexplained headaches, chronic fatigue, anxiety, and depression can appear. The neural circuits of the brain itself are affected. A study published in 2023 also presented findings that gluten can induce brain inflammation.
The connection between the gut and the brain has recently drawn attention in dementia research as well. A team led by Professor Mook In-hee at Seoul National University identified that the vagus nerve, which directly connects the gut and the brain, plays a critical role in degenerative brain diseases such as Alzheimer's. Signals originating in the gut can travel along the vagus nerve to the brain through the "gut-nerve-brain axis," potentially allowing neurodegenerative substances to migrate to the brain.
As a countermeasure, the priority is to limit refined carbohydrates, sugar, and processed foods to suppress the growth of harmful gut bacteria. Bone broth rich in collagen and gelatin, fermented foods that supply beneficial bacteria, and healthy fats such as olive oil and avocado help restore the intestinal lining. However, when inflammation has accumulated over a long period, dietary adjustments alone have their limits. Experts recommend that if symptoms persist, patients should consult a neurologist and combine treatment with neuromodulation therapy.
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