Researchers in the Mayo Clinic Study of Aging asked whether physical and mentally stimulating activities relate to how Alzheimer's brain-imaging markers change over time. They followed adults aged 50+ who were cognitively unimpaired or had mild cognitive impairment, using amyloid PET, tau PET and FDG-PET (glucose metabolism). People reporting more total or moderate-to-vigorous physical activity showed a slower decline in brain glucose metabolism. Those reporting more cognitive activity showed both slower metabolic decline and a smaller increase in amyloid. No link emerged with tau accumulation. The effects were small and may not be clinically meaningful, and the observational design cannot establish cause and effect.
