The MIND diet was not an intervention in this study, however; researchers looked at what people were already eating. Participants earned points if they ate brain-healthy foods frequently and avoided unhealthy foods. The one exception was that participants got one point if they said olive oil was the primary oil used in their homes.
The study enlisted volunteers already participating in the ongoing Rush Memory and Aging Project (MAP), which began in 1997 among residents of Chicago-area retirement communities and senior public housing complexes. An optional "food frequency questionnaire" was added from 2004 to February 2013, and the MIND diet study looked at results for 923 volunteers. A total of 144 cases of AD developed in this cohort.