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Vis
tegen Alzheimer.*
Het
jarenlang en regelmatig eten van vis en speciaal vette vis met veel DHA en
omega-3 vetzuren lijkt in muizenstudies de kans op Alzheimer met 70% te
verminderen. En dat is niet weinig zeker als men weet dat deze muizen genetisch
voorbestemd waren om Alzheimer te ontwikkelen.
Fish
Oil Holds Promise In Alzheimer's Fight
--
Even our grandmothers told us fish was "brain food"--and now
scientists have evidence to back the claim.
Researchers
with the Department of Veterans Affairs (VA) and the University of California at
Los Angeles (UCLA) found that a diet high in docosahexenoic acid, or DHA--an
omega-3 fatty acid found in relatively high concentrations in cold-water fish--dramatically
slowed the progression of Alzheimer's disease in mice. Specifically, DHA cut the
harmful brain plaques that mark the disease. The results appear in the online
edition of the Journal of Neuroscience.
Senior
author Greg M. Cole, Ph.D., a neuroscientist at the Greater Los Angeles VA
Healthcare System and UCLA, said that unlike many studies with mice, this one
points to the benefits of a therapy that is easily available and already touted
for other medical conditions. DHA--either from food sources such as fish and soy,
or in fish-oil supplements--is recommended by many cardiologists for heart
health, based on scores of previous studies.
"The
good news from this study is that we can buy the therapy at a supermarket or
drug store," said Cole. "DHA has a tremendous safety profile--essentially
no side effects--and clinical trial evidence supports giving DHA supplements to
people at risk for cardiovascular disease."
The
new study involved older mice genetically altered to develop Alzheimer's disease.
The researchers fed one group of the mice DHA-fortified chow. The control mice
ate a normal or DHA-depleted diet.
After
three to five months--the equivalent of several years in human biology--the
high-DHA group had 70-percent less buildup of amyloid protein in the brain. This
sticky protein makes up the plaques, or patches, that are a hallmark of
Alzheimer's.
A
similar study by Cole's group published in Neuron last fall showed that DHA
protected against damage to the "synaptic" areas where brain cells
communicate and enabled mice to perform better on memory tests.
The
studies, say the scientists, suggest that even people who are genetically
predisposed to the disease may be able to delay it by boosting their DHA intake.
Omega-3
fatty acids, typically deficient in the American diet, are essential for human
health. DHA in particular is vital to proper brain function, as well as eye
health and other body processes. In recent years epidemiologists have tied
fish-rich diets to a lower incidence of Alzheimer's disease and homed in on DHA
as the preventive factor. Omega-3 fatty acid supplements are now being tested in
clinical trials with early-stage Alzheimer's patients in the United States,
Canada and Sweden to see if the therapy really slows the disease.
Food
sources of omega-3 fatty acids include fish such as salmon, halibut, mackerel
and sardines, as well as almonds, walnuts, soy, and DHA-enriched eggs. Concerns
about mercury contamination in fish have helped popularize purified DHA
supplements based on fish oil or algae. Last year, Cole's team identified
another nutrient that appears to combat Alzheimer's plaques in mice: curcumin,
the yellow pigment in turmeric, one of the spices that make up curry powder.
Researchers became interested in curcumin's potential to prevent or treat
Alzheimer's disease after noting the low prevalence of dementia among the
elderly in India, where curry is a staple.