The Summary
In a double-blind, placebo-controlled crossover trial, 18 older, overweight men consumed a ketone monoester (KME) drink or a placebo. Researchers measured brain insulin responsiveness using MRI to track cerebral blood flow after nasal insulin administration, and evaluated cognitive function. The ketone drink successfully induced ketosis, modestly improved attention and psychomotor speed (reducing reaction times by 9 milliseconds), and altered brain insulin responsiveness by lowering insulin-induced cerebral blood flow in ten specific brain regions. It also reduced resting whole-brain blood flow and improved various cardiometabolic markers.
Why this is interesting
As we age, our brains become less efficient at processing glucose, leading to cognitive decline. Ketones offer an alternative energy source. This study is exciting because it shows that a single dose of ketones can rapidly change how the brain responds to insulin, mimicking a younger, healthier profile. By lowering insulin-induced cerebral blood flow and speeding up reaction times, this research suggests that ketone supplements could be a fast-acting tool to help preserve mental sharpness and combat age-related cognitive sluggishness without requiring strict ketogenic diets.