According to the experts, eating fish can keep your mentally sharp. In
a recent study, researchers found elderly people who eat fish at least
once per week had the mental functioning of a person three years
younger than their chronological age. Those eating fish twice or more
weekly functioned at four years their younger. Fish is high in
omega-3 fatty acids, one of which is DHA. DHA is essential for brain
development early in life and may be beneficial later in life as well.
However, a separate analysis of omega-3 fatty acid consumption did not
find it affected cognitive function. Researchers felt this could have
been because their information may not have been precise enough. The
researchers have since launched another study to look specifically at
the effect of these nutrients on mental function. In any event, the
findings do suggest eating fish protects the brain, either through its
own fatty acid content or by knocking foods high in saturated fat, like
red meat, off the menu.
Source: Archives of Neurology. December 2005.