Fiber Protects Brain Function
For years, research has demonstrated that Western-style eating patterns, typically including high levels of refined carbohydrates and saturated fats and low levels of fiber, are associated with cognitive decline, and an increased risk of dementia and Alzheimer’s disease. Researchers were interested in how the fiber from fruit and vegetables impact brain function.
Scientists investigated the impacts of five refined ingredient diets (RD), as compared to a regular diet, on young adult and old rats. Because the RDs were also low in fiber, they examined butyrate levels as well. Butyrate is a key short-chain fatty acid produced when beneficial gut bacteria ferments dietary fiber. When fiber is missing from our diet, the gut produces less butyrate. Butyrate protects the brain from damage caused by inflammation.
Aged rats exhibited significant memory deficits following RD exposure, while young adult rats did not. RD consumption led to a significant reduction in butyrate levels in both young and old rats.
Takeaway: The fiber found in fruits and vegetables produces butyrate in the digestive system that protects the brain’s cognitive function. Eat more fiber.
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Sources
Michael J. Butler, et. al, The aged amygdala’s unique sensitivity to refined diets, independent of fat or sugar content: A brain region and cell type-specific analysis - ScienceDirect, Feb. 2026.
Neuroscience News, Processed Foods Silence the Brain’s Fear Center - Neuroscience News, Feb. 19, 2026.
Photo: Fruit stand in Rome.