Eating fish associated
with
slower cognitive decline
Newswise — Consuming fish at least
once a week was associated with a 10 percent per year slower rate of
cognitive decline in elderly people, according to a new study posted
online today from Archives of Neurology, one of the JAMA/Archives
journals. The study will be published in the December print edition
of the journal.
Fish is a direct source of omega-3
fatty acids, which have been shown to be essential for
neurocognitive development and normal brain functioning, according
to background information in the article. Fish consumption has been
associated with lower risk of dementia and stroke and recent studies
have suggested that consumption of one omega-3 fatty acid in
particular, docosahexaenoic acid (DHA), is important for memory
performance in aged animals.
Martha Clare Morris, Sc.D., of
Rush University Medical Center, Chicago, and colleagues analyzed six
years of data from an ongoing study of Chicago residents, 65 years
and older, first interviewed between 1993 and 1997 and every three
years in two follow-up interviews. Interviews included four
standardized cognitive tests and dietary questions on the frequency
of consumption of 139 different foods, as well as questions of daily
activities, exercise levels, alcohol consumption and medical
history.
“Dietary intake of fish was
inversely associated with cognitive decline over six years in this
older, biracial community study,” the researchers report. “The rate
of decline was reduced by 10 percent to 13 percent per year among
persons who consumed one or more fish meals per week compared with
those with less than weekly consumption. The rate reduction is the
equivalent of being three to four years younger in age.” The
researchers examined whether overall dietary consumption patterns
accounted for the association of cognitive decline and fish
consumption, but the rate differences did not change after adjusting
for consumption of fruit and vegetables.
“Cognitive decline is common among
older people and is very much associated with advancing age,” the
authors write. “Our data offer no insight as to whether this
cognitive decline is pathological or the result of a normal aging
process. Nonetheless, data from the United States and other
countries indicate that it is a widespread and increasing public
health problem.”
“This study suggests that eating
one or more fish meals per week may protect against cognitive
decline associated with older age,” the authors conclude. “More
precise studies of the different dietary constituents of fish should
help to understand the nature of the association.”