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Mediterranean Diet, Exercise May Lower Alzheimer's
Risk
Reported August 13, 2009
(Ivanhoe Newswire) -- Elderly people who ate lots of fruits,
vegetables, legumes, cereal and fish and generally avoided red meat and
poultry and who were physically active had a lower risk of Alzheimer
disease, according to a new study. In a second study, adherence to a
Mediterranean diet was associated with slower cognitive decline, but was not
associated with a decreased risk of dementia.
Nikolaos Scarmeas, M.D., of Columbia University Medical Center, New York,
and colleagues examined the combined association of physical activity and
dietary habits on the risk of Alzheimer disease (AD) or dementia. The study
included two groups consisting of 1,880 elderly residents of New York City
who did not have dementia at the start of the study. Diet and physical
activity information was available for all participants. Standardized
neurological and neuropsychological measures were administered approximately
every 1.5 years from 1992 through 2006.
The participants were measured for their adherence to a Mediterranean-type
diet and their physical activity. Higher diet scores were awarded for
greater consumption of fruits, vegetables, legumes, cereals, and fish, lower
consumption of meat and dairy products, and a higher ratio of
monounsaturated fats to saturated fats and mild to moderate alcohol
consumption.
During the average follow up period of 5.4 years, 282 developed AD. The
researchers found that more physical activity was associated with lower risk
for AD. "Compared with physically inactive individuals, report of some
physical activity was associated with a 29 to 41 percent lower risk of
developing AD, while report of much physical activity was associated with a
37 to 50 percent lower risk," the authors wrote.
When considered simultaneously, both physical activity and Mediterranean
diet adherence were significantly associated with AD incidence. "Belonging
to the middle diet adherence tertile was associated with a 2 percent to 14
percent risk reduction,” Researchers were quoted as saying, “while belonging
to the highest diet adherence tertile was associated with a 32 percent to 40
percent reduced risk. Similarly, compared with individuals with no physical
activity, individuals reporting some physical activity had a 25 percent to
38 percent lower risk for AD, while individuals reporting much physical
activity had a 33 percent to 48 percent lower risk for AD."
In a related article, researchers found while adherence to a
Mediterranean-type diet is linked to lower risk for mortality and chronic
diseases, its association with cognitive decline has been unclear.
Catherine Féart, Ph.D., of the Université Victor Ségalen Bordeaux 2,
Bordeaux, France, and colleagues examined whether adherence to a
Mediterranean diet was associated with change in cognitive performance and
with lower risk of dementia or Alzheimer disease. The study included 1,410
individuals age 65 years or older from Bordeaux. Participants were
re-examined at least once over 5 years. The authors were quoted as saying
that a Mediterranean-type diet "might also have protective effects against
cognitive decline in older individuals, because it combines several foods
and nutrients potentially protective against cognitive dysfunction or
dementia, such as fish, monounsaturated fatty acids, vitamins B12 and folate,
antioxidants (vitamin E, carotenoids, flavonoids), and moderate amounts of
alcohol."
"The Mediterranean diet pattern probably does not fully explain the better
health of persons who adhere to it, but it may contribute directly. A
Mediterranean diet also may indirectly constitute an indicator of a complex
set of favorable social and lifestyle factors that contribute to better
health. Further research is needed to allow the generalization of these
results to other populations and to establish whether a Mediterranean diet
slows cognitive decline or reduces incident dementia in addition to its
cardiovascular benefits," the authors conclude.
In an accompanying editorial, David S. Knopman, M.D., of Mayo Clinic,
Rochester, Minn., commented on the two studies. "The findings . . . fit into
a larger and potentially optimistic view of prevention of late-life
cognitive impairment through application, at least by midlife, of as many
healthy behaviors as possible, including diet. Based on these two studies,
diet may play a supporting role, but following a healthy diet does not occur
in isolation."
SOURCE: Journal of the American Medical Association ( JAMA), August 12, 2009 |
