Eat weed. Like people in Asian countries (Himalayas region, Golden Triangle, etc.).
Active ingredient in cannabis protects aging brain cells
Cannabinoids and Neurogenesis: The Promised Solution for Neurodegeneration?
Studies also show that it can regenerate brain cells.
Marijuana might cause new cell growth in the brain
Why hasn't this news been publicized widely? Maybe most news outlets are run by conservatives who do not want to indirectly promote marijuana use?