Gut-Friendly Diets Boost Brain Power in Older Adults.

In 2025, Changhu Sun and a team from Chengdu University of Traditional Chinese Medicine looked at data from 2,207 older adults in the US from the National Health and Nutrition Examination Survey (2011-2014). They created a score called the Dietary Index for Gut Microbiota to see how foods that help good gut bugs—like fruits, veggies, whole grains, beans, yogurt, and fish—affect thinking skills. They tested memory and focus with simple tasks and adjusted for things like age, weight, and exercise.

Higher scores on this gut-friendly diet linked to better brain scores: for every point up, thinking improved by 0.012-0.022 points. A U-shaped pattern showed that moderate intake (not too little or too much) gave the best results, with up to 15-20% better cognition in some groups. Foods like berries and nuts seemed to help the most by feeding helpful gut bugs that fight brain fog.

Eat more fruits, yogurt, and fish daily to support your gut and keep your mind sharp as you age.