Liver Enzyme Reverses Brain Aging

Researchers at University of California, San Francisco have identified a biological process explaining how exercise benefits brain health, offering new avenues for protecting against neurodegenerative diseases like Alzheimer s disease. The study, published in the journal Cell, reveals that exercise prompts the liver to release an enzyme called GPLD1. This enzyme travels to the blood vessels surrounding the brain and removes a harmful protein, TNAP, from the surface of cells forming the blood-brain barrier. As people age, TNAP builds up, weakening the barrier and increasing leakiness, which leads to inflammation and cognitive decline. By reducing TNAP levels, GPLD1 helps restore the barrier's integrity, decrease inflammation, and improve memory. Experiments in older mice showed that reducing TNAP levels improved memory and cognitive function, suggesting potential therapeutic interventions even in later life. This discovery highlights a surprising body-to-brain pathway and could inspire new Alzheimer s disease therapies beyond traditional brain-focused strategies.