February 22, 2009
Tea And Coffee Cut Stroke Risk

Black or green, either way you cut your risk of stroking out of life. Don't want to have half your face drooping when the nerves that instruct it die? Don't want to become a drooler or become confined to a wheelchair? Really you should think about these gruesome outcomes and change your behavior accordingly.

Drinking at least three cups of green or black tea a day can significantly reduce the risk of stroke, a new UCLA study has found. And the more you drink, the better your odds of staving off a stroke.

The study results, published in the online edition of Stroke: Journal of the American Heart Association, were presented Feb. 19 at the American Heart Association's annual International Stroke Conference in San Diego, Calif.

The UCLA researchers conducted an evidence-based review of all human observational studies on stroke and tea consumption found in the PubMed and Web of Science archives. They found nine studies describing 4,378 strokes among nearly 195,000 individuals, according to lead author Lenore Arab, a professor of medicine in the division of general internal medicine and health services research at the David Geffen School of Medicine at UCLA.

"What we saw was that there was a consistency of effect of appreciable magnitude," said Arab, who is also a professor of biological chemistry. "By drinking three cups of tea a day, the risk of a stroke was reduced by 21 percent. It didn't matter if it was green or black tea."

And extrapolating from the data, the effect appears to be linear, Arab said. For instance, if one drinks three cups a day, the risk falls by 21 percent; follow that with another three cups and the risk drops another 21 percent.

This effect was found in tea made from the plant Camellia sinensis, not from herbal teas.

What I want to know: If one eats a lot of berries and other fruits does one get equivalent compounds (e.g. flavonoids) from them that provide the same benefits?

Since coffee may provide a similar (though perhaps smaller) reduction of stroke risk..

But after considering factors such as cigarette and alcohol consumption, van Dam and his colleagues found that healthy women who consumed two to three cups of caffeinated coffee a day had, on average, a 19 percent lower risk for any kind of stroke than did women who drank less than one cup a month. Drinking four or more cups a day lowered risk by 20 percent.

Women who drank five to seven cups of coffee a week were 12 percent less likely to have a stroke than were those who downed just one cup a month, the study found.

But among women who do not smoke the stroke risk reduction from coffee rivals that from tea.

When the results were stratified by smoking status, women who had never smoked or who had quit and drank four cups of coffee or more had a 43% reduced risk of stroke (RR 0.57, 95% CI 0.39 to 0.84).

Tea is just one element in a total stroke risk-reducing lifestyle.

The study involved 20,040 men and women aged 40-79 years old who were taking part in the European Prospective Investigation into Cancer Study (EPIC). Between 1993 and 1997, participants completed a detailed health and lifestyle questionnaire and underwent a thorough health examination by trained nurses.

Participants scored one point for each of four healthy behaviours: current non-smoking, physically not inactive, moderate alcohol intake (1-14 units per week) and blood vitamin C levels of 50 µmol/l or more, indicating fruit and vegetable intake of at least five servings a day.

An individual could therefore have a total health behaviour score ranging from zero to four, with a higher score indicating more protective behaviour.

Participants were then followed for an average of 11 and a half years. Strokes were recorded using death certificates and hospital discharge data.

There were a total of 599 incident strokes during the follow-up period. After adjusting for other factors that may have affected the results, the risk of stroke was 2.3 times greater in those with a score of zero compared to those with a score of four.

A significantly higher percentage of women scored four compared to men.

The risk of stroke increased in linear fashion with every point decrease in health behaviour score. So, for example, those with a score of two were one and a half (1.58) times more likely to have a stroke than those with a score of four, while those with a score of just one were just over twice (2.18) as likely to have a stroke.

Also, number of fast food restaurants in a neighborhood correlates with stroke risk.

Share |      Randall Parker, 2009 February 22 02:27 PM  Aging Diet Heart Studies


Comments
TTT said at February 22, 2009 6:56 PM:

It is best to mix both, I think. Coffee in the morning, green tea in the afternoon.

David Govett said at February 22, 2009 8:59 PM:

"number of fast food restaurants in a neighborhood correlates with stroke risk"
Positively or negatively?
Do residents have higher stroke risk because the restaurants are located there? Or because they eat the food disproportionately? Or could it be that such restaurants are more likely to locate in low-cost neighborhoods already more prone to strokes?
Reminds me of the story about the man who drowned in a river that averaged 1 foot deep.

Lou Pagnucco said at February 23, 2009 9:09 AM:

Impressive results.

But I wonder if consuming too much high fluoride tea might result in fluorosis - especially in areas with fluoridated water - or in areas where vegetables are absorbing fluoride from industrial fertilizers.

A quick web search leads me to believe that taking tea with calcium or magnesium supplements, or anti-acid tablets, might reduce the bioavailability of fluoride. Also, green tea appears to contain more fluoride than black tea.

If anyone has more information, I would be interested.

Bob Badour said at February 23, 2009 2:47 PM:

Skeletal fluorosis is most usually associated with brick teas, which are not generally the kinds of tea consumed in North America, and with highly fluoridated water from very deep wells. It is a very rare condition in the US; although, it is common in some other countries.

I suspect you are more likely to get fluorosis from an accidental mismeasurement down at the water treatment plant than by increasing your tea consumption. The risk of either is very small.

Allan said at February 23, 2009 3:57 PM:

Caffeine drains calcium out of the body ... be very, very careful ... especially women.

Lou Pagnucco said at February 25, 2009 7:46 AM:

A cautionary note -

It is possible that tea, having a high theophylline content, may worsen the condition of people with congestive heart failure. See:

"Differential Effects of Theophylline on Sympathetic Excitation, Hemodynamics, and Breathing in Congestive Heart Failure"
http://circ.ahajournals.org/cgi/content/full/110/15/2157

BTW, another popular supplement, turmeric/curcumin, may also adversely affect heart failure according to animal experiments. Probably only in large doses, and possibly not in humans, but it is noteworthy that the rate of heart failure in India, where turmeric is consumed liberally, is high.

Probably, megadosing on any of the latest fad foods is a bad idea.

Lou Pagnucco said at February 25, 2009 7:53 AM:

...and I forgot to add that tea consumption in India is high as well.

It would interesting to know if statistics between nations show a negative correlation between tea consumption and stroke incidence.

Randall Parker said at February 25, 2009 7:35 PM:

Lou,

I hesitate to go in for pharma-foods in a big way. Tea, coffee, and chocolate all strike me as too much pharma-foods. They are too pharmacologically active (caffeine, theobromine) for my taste. I worry about the side effects. Fruits seem a safer bet.

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