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Is Green Tea Good For the Brain?
Can green tea prevent
or ease Alzheimer’s disease, that devastating disease that can rob you
of your ability to learn, reason, communicate, remember and carry out
daily activities? Well, no one’s saying that yet. But recent studies of
the effects of green tea’s catechins on animal brains are intriguing.
These studies have found that the catechins can:
Delay brain aging
A study of mice
genetically programmed to age rapidly found that taking in green tea
catechins on a daily basis prevented oxidative damage to the DNA in
their brain cells, slowed memory loss and delayed brain aging.1
Reverse mental deterioration
Another study of
rapidly-aging mice measured the extent of their brain degeneration over
time.2 Mice that received green or oolong tea as their sole
source of drinking fluid for 16 weeks reduced degenerative changes to
their brains and actually reversed their mental deterioration.
(These mice actually got smarter!)
Improve memory-related learning
Long term
administration of green tea catechins to young rats lowered levels of
damaging free radicals in a part of the brain that’s vital to memory
processing.3 The catechin-consuming rats also experienced
improved memory-related learning ability, compared to those that didn’t
receive the catechins.
Lessen the buildup of plaque
Finally, mice
specially bred to develop Alzheimer’s disease developed up to 54%
less beta-amyloid buildup in their brains when they were given daily
injections of the green tea catechin EGCg.4 Beta-amyloid
plaques are believed to be a major cause of the brain cell death and
tissue loss seen in Alzheimer’s disease.
Of course, the big
question still looms: Does green tea have
the same effects in humans as it does in mice and rats?
While few human studies of green tea’s effects on brain function exist,
one published in the American Journal of Clinical Nutrition in
2006 offers hope.5
Researchers
gathered information from 1,003 Japanese men and women age 70+, measured
their cognitive function, and tallied the frequency of their green tea
consumption.
After analyzing the
data, the researchers concluded that, "A higher consumption of green tea
is associated with a lower prevalence of cognitive impairment in
humans." In other words, the more green tea they drank, the less likely
they were to have problems related to thinking and memory. So have
another cup of tea!
Click
here for a simplified look at the studies of green tea's effects
on brain health.
Footnotes:
1)
Unno K, Takabayashi F, Yoshida H, et al. Daily consumption of green tea
catechin delays memory regression in aged mice. Biogerontology
2007;8(2):89-95.
2)
Chan YC, Hosoda K, Tsai CJ, Yamamoto S, et al. Favorable effects of tea
on reducing the cognitive deficits and brain morphological changes in
senescence-accelerated mice. Journal of Nutritional Science and
Vitaminology (Tokyo) 2006;52(4):266-73.
3)
Haque AM, Hashimoto M, Katakura M, et al. Long-term administration of
green tea catechins improves spatial cognition learning ability in rats.
Journal of Nutrition 2006;136(4):1043-47.
4)Rezai-Zadeh
K, Shytle D, Sun N, et al. Green tea epigallocatechin-3-gallate (EGCG)
modulates amyloid precursor protein cleavage and reduces cerebral
amyloidosis in Alzheimer transgenic mice. Journal of Neuroscience
2005;25(38):8807-14.
5)
Kuriyama S, Hozawa A, Ohmori K, et al. Green tea consumption and
cognitive function: a cross-sectional study from the Tsurugaya Project
1. American Journal of Clinical Nutrition 2006:83)2):355-61.
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Nadine Taylor, M.S., R.D. presents
GreenTeaLibrary.com,
the most comprehensive collection of scientific information
describing the health benefits of green tea. |
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