

Berry Good Food for the Brain By Judy
McBride April 8, 1997Diets high in antioxidant foods appear to protect the brain
against oxidative damage, if rat studies by Agricultural Research Service and
University of Denver scientists are any
indication. Oxidative damage is thought to lead to age-related dysfunctions
such as loss of memory or motor coordination. In the studies, rats that ate extracts of strawberries,
blueberries or spinach as part of their daily diet fared far better on brain
cell function tests than the animals getting chow alone. The fruit and
vegetable extracts offered at least as much protection as vitamin E against
oxidative damage, an ARS scientist said yesterday at the Experimental Biology
97 meeting in New Orleans. Earlier, these foods scored highest among commonly eaten fruits
and vegetables in a test-tube assay of total antioxidant capacity. The next
step was to assess their protective power in animals. So the scientists added
either strawberry extract, vitamin E or nothing to the rats normal diet
for eight weeks. Then they put the animals in chambers under 100 percent oxygen
for two days. They later repeated the study using blueberry and spinach
extracts. High oxygen exposure alters brain function in young rats in a
manner similar to the aging process. In both cases, brain cells are less
sensitive to neurotransmitters, such as dopamine or norepinephrine, that prompt
them to send or stop sending information. The scientists measured responses of three different types of
brain function controlling memory, movement and growth of nerve cells. In all
three cases, decline in these functions due to oxygen exposure was
significantly--often dramatically--reduced by strawberry extract as well as by
vitamin E. Preliminary data indicates that blueberry extract provides even
more protection to rats brains. If this finding holds up, it supports the
usefulness of the chemical assay--known as ORAC--for identifying
health-promoting foods because blueberries had the highest antioxidant capacity
of the fruits and vegetables tested. Scientific contact: James A. Joseph,
Jean Mayer USDA Human Nutrition Research
Center on Aging at Tufts, Boston, Mass., phone (617) 556-3178,
[email protected].  U.S. Department of Agriculture | |