PNAS: Diet regulates human brain stability

Epidemiological studies have shown that insulin resistance accelerates the progression of cognitive dysfunction in old age, while neuroimaging studies have linked it to low glucose metabolism in the brainas an input to the cell's energy, the ketone sinton increases the Gibbs free energy change of ATP by 27% compared to glucoserecently, by changing the brain's main dietary fuel from glucose to ketone diet, researchers tested whether dietary changes regulate continuous functional communication (network stability) between brain regionsresearchers first established network stability as a biomarker of brain aging, using two large-scale (n - 292, ages 20 to 85; n s 636, ages 18 to 88) 3T functional magnetic resonance imaging (fMRI) data setsTo determine whether diet could affect the stability of the brain network, the researchers scanned an additional 42 adults, ages 50, using ultra-high field (7T) ultra-fast (802 ms) fMRI-optimized detection sensitivity for single participant levelsresearchers scanned a queue on a standard diet, overnight fasting and ketogenic dietTo isolate the effects of fuel types, an independent overnight fasting queue was scanned before and after the intake of calorie-matched glucose or exogenous ketones (D-beta-hydroxybutylater)brain network instability is associated with decreased brain activity and cognitive acuity throughout its life cycleThe effects occur at age 47 and the fastest degeneration at age 60The brain network can be destroyed by glucose and stabilized by the ketone body, regardless of whether the ketone diet or exogenous ketoneest sits reach the ketosis statetherefore, these results suggest that instability in the brain network may reflect early signs of dementia-related metabolic declineKetonodiet diet interventions increase the amount of energy available, potentially demonstrating the potential to protect the aging brain