The positive effects of exercise, sleep, and moderate alcohol consumption on our brains and on cognition is real and measurable. The exact mechanisms for these positive effects is less clear, but the connection to the glymphatic system gives us at least some explanation for why they work.
Older adults with mild cognitive impairment (MCI) who engaged in moderate physical activity had greater hippocampal volume. Atrophy of the hippocampus is a hallmark of Alzheimer's, therefore these results suggest that exercise can help to stave off Alzheimer's.
Individuals at higher risk for Alzheimer's who engaged in little to no physical activity lost 3% of their hippocampal volume after only 18 months. Those who did moderate physical activity showed no change in the volume of the hippocampus.
UCLA reversed dementia in 9 human subjects using a combination of exercise, diet, brain games, and a dietary supplement.