Scientists have named the dietary habit that accelerates memory loss

# Just Three Days Without Fiber: Scientists Reveal Unexpected Threat to Memory in Older Adults **Researchers from Ohio State University have made an alarming discovery: the absence of fiber in the diet can deal a blow to memory in older adults in just a matter of days — even before the first signs of weight gain appear.** As reported by **TUT.AZ**, the results of the study have been published in the authoritative journal Brain, Behavior, and Immunity (BBI). During the experiment, scientists observed young and older rats that were kept for three days on either a regular diet or one of five "refined" diets with varying ratios of fat and sugar. The key feature of all experimental diets was the complete absence of fiber. This component of plant-based food cannot be broken down by digestive enzymes, yet it serves as genuine "fuel" for beneficial gut bacteria. The results of behavioral tests proved telling: in older animals, regardless of the amount of fat and sugar, long-term emotional memory was noticeably impaired — the amygdala is responsible for this type of memory. Meanwhile, the hippocampus, which controls spatial and episodic memory, showed particularly significant "decline" on a high-fat, low-sugar diet. Blood and gut analysis revealed a sharp drop in butyrate levels — a short-chain fatty acid produced by the microbiota when processing dietary fiber. Scientists had previously established that butyrate has anti-inflammatory properties and can cross the blood-brain barrier. Its deficiency apparently triggers inflammatory processes in the brain. At the cellular level, specialists recorded mitochondrial damage in microglia — the immune cells of the brain. Young animals were able to adapt to the changes, while in older animals the cellular energy "power plants" functioned with significant disruptions. The researchers particularly note: the negative consequences manifested in just a few days and were in no way associated with weight gain. The main culprit, in their opinion, is specifically the fiber deficiency and, consequently, the drop in butyrate levels. The next step will be to test the hypothesis: can enriching the diet with fiber or butyrate reverse age-related memory decline.