ScienceDaily reports that:
In a population of initially well-functioning older adults, we found a significant correlation between strong adherence to the Mediterranean diet and a slower rate of cognitive decline among African American, but not white, older adults. Our study is the first to show a possible race-specific association between the Mediterranean diet and cognitive decline.
(Score: 0) by Anonymous Coward on Monday July 21 2014, @04:25AM
I'll bet you dollars to donuts they originally ran the regression without distinguishing the two groups and didn't get a significant result.
You rarely get clear answers out of large broad datasets.