New findings from the Framingham Heart Study show an association between high serum levels of brain-derived neurotrophic factor (BDNF) and a reduced risk of dementia in certain sectors of the population. Among women, people aged ≥80 years and individuals with college degrees, the risk of dementia was reduced by over 50% in those with BDNF levels in the top quartile compared with the bottom quartile. The results suggest a possible role for BDNF in dementia prevention, at least in selected subgroups.