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Fruits
and Veggies Boost Memory
July 16, 2002 -- Eating more fruits and vegetables has always been smart, but
new research now shows it can boost your memory and your ability to learn. Two
new animal studies have found that antioxidants in fruits and vegetables can
improve learning and memory, and they minimize the effect of aging on the brain.
Certain foods do a better job of this, the studies show, because they have higher
levels of antioxidant activity.
Antioxidants
can undo cell damage caused by renegade "free
radical" molecules, and previous studies
have shown they can prevent disease and improve
mental functioning, among other things.
"What
we have done is focus on the fruits and vegetables
high on the U.S. Department of Agriculture
(USDA) list of antioxidants," says Paula
Bickford, a senior career scientist at the
James A. Haley Veterans Hospital in Tampa
and lead author of both studies, just published
in the Journal of Neuroscience.
The
USDA ranks foods by their antioxidant content.
Spinach, spirulina (an algae often sold in
capsule form in health food stores) and apples
were particularly beneficial for learning
and memory, Bickford says.
In
the first study, the researchers fed a group
of rats a diet rich in spinach, while another
group got regular rat chow, all for six weeks.
The rats were then measured for their performance
on a traditional learning test: They were
exposed to a tone, then exposed to a puff
of air to the eye. The researchers studied
how long it took rats in each group to learn
to blink to avoid the air puff.
"The
ones on spinach learned to make the association
with fewer trials," Bickford says. "By
the third day, they were at their learning
maximum. It took the [other] rats five or
six days to learn.
"We
think that what we are experiencing [in the
rats] is an improvement in neuron functioning.
Because we improve the ability of the neurons
to communicate, it is easier for the animals
[on the spinach-enriched diets] to learn," she
adds.
In
the second study, the researchers compared
three types of diets, again fed to rats: one
group got a diet enriched with spirulina (high
in antioxidants), another group got apples
(moderate in antioxidant activity), and a
third got cucumber, which is low in antioxidants.
"Initially,
I was amazed," Bickford says. "We
were seeing effects within two weeks with
the apple and spirulina diets." When
the rats' brain functioning was evaluated,
the researchers found the accumulation of
inflammatory substances in the brain that
typically occurs with age had been reversed
in those on the apple and spirulina diets,
and that they had better neuron functioning.
The
amount of apple in the apple-enriched diet,
for instance, was about 1 percent of the diet,
Bickford says, which translates to about an
apple a day.
Bickford
can't say the study applies to humans, but
she thinks it might.
"I've
always eaten a lot of fruits and vegetables," she
says. Since the study results, she's boosted
her intake even more, she adds.
Another
antioxidant researcher says the study is interesting,
but not yet reason enough to change your diet. "We
have done similar studies," says Raj
Sohal, a professor of molecular pharmacology
and toxicology at the University of Southern
California School of Pharmacy in Los Angeles.
In one instance, Sohal and his team gave animals
supplements of the antioxidant vitamin E and
found it improved memory in up to 15 percent
of the animals.
The
unanswered question, he says, is, "to
what extent are we correcting a deficiency?" When
and if that is the case, he adds, someone
who already gets the recommended amounts of
antioxidants may not benefit by taking even
higher amounts.
SOURCE:
Journal of Neuroscience, July 15, 2002. For
information about other natural memory boosting
elements, click here: Cognition
For information about Dr. Hansen’s High Potentcy Antioxidant Rich Multi-Vitamin,
click here:
PeakAdvantage.
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