A study in the May 2016 issue of Neurology shows that eating seafood protects against declines in specific aspects of cognition, especially in individuals who have the APOE4 gene, a genetic risk factor for developing Alzheimer’s. The investigation was conducted in 915 men and women with an average age of 81 who were followed for about five years, during which they periodically underwent cognitive assessments with a battery of tests. Investigators collected dietary information with a food frequency questionnaire.
Analysis showed that whether or not participants ate seafood did not affect how much overall cognition declined over time. However, semantic memory (long-term memory related to ideas, meanings, and concepts) and perceptual speed (ability to carry out simple tasks) declined more slowly in those who had one or more seafood meals each week than in those who did not.
In addition to experiencing these benefits, those with the APOE4 gene—but not those without the gene—who ate seafood regularly also showed slower rates of decline in other cognitive areas, including overall cognition. A strength of this study is that it was prospective and measured cognition over time. This makes the results more meaningful.
These findings suggest that you should be sure to include at least one meal with seafood in your weekly meal plans. Fish high in n-3 fatty acids, such as salmon, mackerel, cod, and tuna, are your best bets.