Green Tea, Black Coffee
By ANDREW WEIL, M.D.
Tuesday, Sep. 19, 2006
Coffee or tea? There's a growing body of research to suggest that both are probably good for you.
We've heard a lot about the health benefits of tea, especially
green tea. It is high in polyphenols--compounds with strong antioxidant
activity that in test-tube and animal models show anticancer and
heart-protective effects. Good clinical studies are few, however, and
although I and other physicians tell our patients to drink green tea,
there hasn't been any definitive proof of the value of that advice.
That's why I was so interested in a report last week in the
Journal of the American Medical Association. A team of Japanese
researchers was able to link green-tea consumption with decreased
mortality from all causes--including cardiovascular disease. The
researchers tracked 40,530 healthy adults ages 40 to 79 in a region of
northeastern Japan where most people drink green tea, following them
for up to 11 years. Those who drank five or more cups of green tea a
day had significantly lower mortality rates than those who drank less
than one cup a day. There were also fewer deaths from cardiovascular
But no such association was seen with deaths from cancer. Nor
was consumption of oolong or black tea correlated with any decrease in
mortality. Those teas are more oxidized in processing, which not only
darkens the color of the leaves and changes their flavor but also
reduces their polyphenol content.
Japanese people have access to better-quality green tea than do
most North Americans. If you want the good stuff (like gyokuro or
matcha, the powdered tea used in Japanese tea ceremonies), go to the
nearest specialty-tea shop, Asian grocery store or the Internet (try
japanesegreenteaonline com inpursuitoftea.com or matchaandmore.com)
Coffee is more complicated. It has received both gold stars and
black marks in the medical literature. It too contains antioxidants,
although they are less well studied than tea polyphenols. Evidence for
the health benefits of coffee is growing, however. In the August issue
of the European Journal of Clinical Nutrition, for example, a group of
investigators from Finland, Italy and the Netherlands report that
coffee seems to protect against age-related cognitive decline. The
scientists studied 676 healthy men born from 1900 to 1920 and followed
them for 10 years, using standardized measures of cognitive function.
Their conclusion: the men who consumed coffee had significantly less
cognitive impairment than those who didn't. Three cups a day seemed to
provide maximum protection.
Population studies like those help us form hypotheses about
relationships between dietary habits and long-term health. We still
have to test our suppositions in controlled conditions and measure the
effects of coffee and tea on various systems of the body.
In the meantime, enjoy your tea and coffee, get the best
quality you can, and know that they are probably doing you more good
HOW BROWN SEAWEED BURNS OFF FAT
Chemists in Japan have found that brown seaweed, widely used in
Asian cuisine, contains a compound, fucoxanthin, that may promote
Fed to obese rats and mice, fucoxanthin promoted the loss of
abdominal fat by targeting a protein that increases the rate at which
fat is burned. The chemists got their fucoxanthin from wakame, a tasty
seaweed available in dried form in Asian groceries and natural-food
stores. I like it in cucumber salad and soups. But don't expect to lose
weight by simply adding wakame to your diet; you would have to eat a
great deal of it to make any difference. Wait for further developments;
the chemists say their research could lead to novel medications that
may someday help people shed unwanted pounds.