A long-running study involving 8225 adults found that self-reported diet during midlife (mean age 50) was not significantly associated with subsequent risk for dementia.
Dietary intake was assessed in 1991-1993, 1997-1999, and 2002-2004, with follow-up for incident dementia until March 31, 2017. Diet quality was assessed using the Alternate Healthy Eating Index (AHEI), an 11-component diet quality score (score range, 0-110), with higher scores indicating a healthier diet.
There were 344 cases of incident dementia developed in the study period. 69.1% of participants were male.
(2019). Association of Midlife Diet With Subsequent Risk for Dementia.
JAMA. 321(10), 957 - 968.