April 12, 2010 -- A low-fat diet with a lot of salad dressing, nuts,
poultry, and certain fruits and vegetables may help
prevent Alzheimer's disease, according
to a new study.
Researchers say evidence is mounting on which foods may prevent Alzheimer's
disease. But because foods are not eaten in isolation and may work together to
prevent disease, more information is needed on dietary patterns that reduce the
risk of Alzheimer's disease.
In the study, published in the Archives of Neurology, researchers
analyzed the dietary patterns of 2,148 people aged 65 and older living in New
York. The participants gave information about their diets and were evaluated
for signs of Alzheimer's disease
and dementia every year and a half
over a four-year period.
Researchers analyzed dietary intake for seven nutrients that have been shown
in previous studies to be associated with dementia risk: saturated fatty acids,
monounsaturated fatty acids, omega-3 fatty acids, omega-6 fatty acids, vitamin
E, vitamin B12, and folate.
By the end of the study, 253 participants developed Alzheimer's disease. In
particular, the study showed one particular dietary pattern was associated with
a lower risk of Alzheimer's disease. The diet included low amounts of high-fat
dairy products, red meat, organ meat, and butter. Foods in this diet that
appeared to fight Alzheimer's disease were salad dressing, nuts, fish, poultry,
tomatoes, fruits, and cruciferous and dark and green vegetables.
Researchers say the combination of nutrients and foods in this particular
dietary pattern may fight Alzheimer's in a variety of ways.
"For example, vitamin B12 and folate are homocysteine-related vitamins that
may have an impact on Alzheimer's disease via their ability of reducing
circulating homocysteine levels, vitamin E might prevent Alzheimer's disease
via its strong antioxidant effect, and fatty acids may be related to dementia
and cognitive function through atherosclerosis, thrombosis,
or inflammation via an effect on brain development and membrane functioning or
via accumulation of beta-amyloid," write researcher Yian Gu, PhD, of Columbia
University and colleagues.