Eating Fish Associated With Slower Cognitive Decline

Fish is adirect source of omega-3 fatty acids, which have been shown to beessential for neurocognitive development and normal brain functioning,according to background information in the article. Fish consumptionhas been associated with lower risk of dementia and stroke and recentstudies have suggested that consumption of one omega-3 fatty acid inparticular, docosahexaenoic acid (DHA), is important for memoryperformance in aged animals.

Martha Clare Morris, Sc.D., of RushUniversity Medical Center, Chicago, and colleagues analyzed six yearsof data from an ongoing study of Chicago residents, 65 years and older,first interviewed between 1993 and 1997 and every three years in twofollow-up interviews. Interviews included four standardized cognitivetests and dietary questions on the frequency of consumption of 139different foods, as well as questions of daily activities, exerciselevels, alcohol consumption and medical history.

"Dietary intakeof fish was inversely associated with cognitive decline over six yearsin this older, biracial community study," the researchers report. "Therate of decline was reduced by 10 percent to 13 percent per year amongpersons who consumed one or more fish meals per week compared withthose with less than weekly consumption. The rate reduction is theequivalent of being three to four years younger in age." Theresearchers examined whether overall dietary consumption patternsaccounted for the association of cognitive decline and fishconsumption, but the rate differences did not change after adjustingfor consumption of fruit and vegetables.

"Cognitive decline iscommon among older people and is very much associated with advancingage," the authors write. "Our data offer no insight as to whether thiscognitive decline is pathological or the result of a normal agingprocess. Nonetheless, data from the United States and other countriesindicate that it is a widespread and increasing public health problem."

"Thisstudy suggests that eating one or more fish meals per week may protectagainst cognitive decline associated with older age," the authorsconclude. "More precise studies of the different dietary constituentsof fish should help to understand the nature of the association."

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(Arch Neurol. 2005; 62: 1-5. Available pre-embargo for the media at www.jamamedia.org)

Editor's Note: This study was supported by grants from the National Institutes of Health, Bethesda, Md.