Seafood types and age-related cognitive decline in the Women's Health Study.

BACKGROUND: Seafood consumption may prevent age-related cognitive decline. However, benefits may vary by nutrient contents in different seafood types. We examined associations between total seafood consumption and cognitive decline and whether these associations differ by seafood types.

METHODS: We conducted a prospective cohort study of 5,988 women (mean age, 72 years) from the Women's Health Study who self-reported seafood intake at Women's Health Study baseline and also participated in telephone assessments of general cognition, verbal memory, and category fluency administered 5.6 years after Women's Health Study baseline and 2 and 4 years thereafter. Primary outcomes were standardized composite scores of global cognition and verbal memory.

RESULTS: After adjusting for potential confounders, different amounts of total seafood consumption were not associated with changes in global cognition (p = .56) or verbal memory (p = .29). Considering seafood types, however, compared with women consuming less than once-weekly tuna or dark-meat finfish, those with once-weekly or higher consumption had significantly better verbal memory (0.079 standard units; p < .01) after 4 years-a difference comparable to that for women 2.1 years apart in age. There was also a statistically nonsignificant suggestion of better global cognition (p = .13) with once-weekly or higher tuna or dark-meat fish consumption. No significant associations were observed for light-meat finfish or shellfish.

CONCLUSIONS: The relation of seafood to cognition may depend on the types consumed. Total consumption levels of seafood were unrelated to cognitive change. However, consumption of tuna and dark-meat fish once weekly or higher was associated with lower decline in verbal memory for a period of 4 years.