For the study, researchers examined the diets of 8,085 men and women over
the age of 65 who did not have dementia at the beginning of the study. Over
four years of follow-up, 183 of the participants developed Alzheimer's
disease and 98 developed another type of dementia.
The study found people who regularly consumed omega-3 rich oils, such as
canola oil, flaxseed oil and walnut oil, reduced their risk of dementia by
60 percent compared to people who did not regularly consume such oils.
People who ate fruits and vegetables daily also reduced their risk of
dementia by 30 percent compared to those who didn't regularly eat fruits and
vegetables.
The study also found people who ate fish at least once a week had a
35-percent lower risk of Alzheimer's disease and 40-percent lower risk of
dementia, but only if they did not carry the gene that increases the risk of
Alzheimer's, called apolipoprotein E4, or ApoE4.
"Given that most people do not carry the ApoE4 gene, these results could
have considerable implications in terms of public health," said study author
Pascale Barberger-Gateau, PhD, of INSERM, the French National Institute for
Health and Medical Research, in Bordeaux, France. "However, more research is
needed to identify the optimal quantity and combination of nutrients which
could be protective before implementing nutritional recommendations."
In addition, the study found people who did not carry the ApoE4 gene and
consumed an unbalanced diet characterized by regular use of omega-6 rich
oils, but not omega-3 rich oils or fish were twice as likely to develop
dementia compared to those who didn't eat omega-6 rich oils, which include
sunflower or grape seed oil. The study did not find any association between
consuming corn oil, peanut oil, lard, meat or wine and lowering risk of
dementia.
"While we've identified dietary patterns associated with lowering a person's
risk of dementia or Alzheimer's, more research is needed to better
understand the mechanisms of these nutrients involved in these apparently
protective foods," said Barberger-Gateau.
The study was supported by the National Agency for Research in France.
The American Academy of Neurology, an association of more than 20,000
neurologists and neuroscience professionals, is dedicated to improving
patient care through education and research. A neurologist is a doctor with
specialized training in diagnosing, treating and managing disorders of the
brain and nervous system such as Parkinson's disease, ALS (Lou Gehrig's
disease), dementia, West Nile virus, and ataxia.
