For my fellow coffee lovers, please read.
> <A HREF="http://www.americanheart.org/">American Heart Association</A>
>
> New buzz on coffee: It's not the caffeine that raises blood pressure
>
DALLAS, Nov. 19 – People who enjoy the occasional decaf latte may be getting
> more of a lift than they know, scientists report in today's rapid access
> issue of Circulation: Journal of the American Heart Association. Swiss
> scientists studying caffeine's effects in a small group of people report
> markedly elevated blood pressure and increased nervous system activity when
> occasional coffee drinkers drank a triple espresso, regardless of whether
> or not it contained caffeine. Surprisingly, people who drank coffee on a
> regular basis showed increased stimulation of sympathetic nerve pathways –
> but no increase in blood pressure. This is the first time such disparities
> in reactions to coffee have been reported, says lead researcher Roberto
> Corti, M.D., a cardiologist at University Hospital in Zurich. The results
> suggest that some unknown ingredient or ingredients in coffee – not
> caffeine – is responsible for cardiovascular activation, he explains.
> Coffee contains several hundred different substances. "Until now we have
> attributed the cardiovascular effects of coffee to caffeine, but we found
> non-coffee drinkers given decaffeinated coffee also display these effects,"
> Corti says. "This demonstrates how little we know about the effects of one
> of our most popular beverages and the most abundantly consumed stimulant
> worldwide. "Coffee's cardiovascular safety remains controversial," he says.
> "The possible health hazards have been related to its main ingredient –
> caffeine." The researchers measured blood pressure, heart rate and muscle
> sympathetic nervous system activity (MSA) in 15 healthy volunteers (ages 27
> to 38) – six habitual coffee drinkers and nine who either abstained or
> drank coffee only occasionally. Measurements were recorded before, during
> and after participants consumed a triple espresso, a decaf triple espresso
> or intravenous administration of the equivalent amount of caffeine, or a
> placebo. None of the subjects knew whether they were receiving caffeine.
> Sympathetic nervous system activity plays an important role in the
> regulation of blood pressure and over-activation has been linked with high
> blood pressure. The non-habitual or occasional coffee drinkers had systolic
> blood pressure (the top number in a blood pressure reading) increases of 12
> millimeters of mercury (mm Hg) after 60 minutes. No significant change was
> observed in habitual drinkers' blood pressure. MSA increased in both
> caffeine and decaffeinated coffee groups by 29 percent after 30 minutes and
> 53 percent after 60 minutes, with almost identical activation times. In
> non-habitual coffee drinkers given decaffeinated espresso, systolic blood
> pressure increased despite no increase in blood concentrations of caffeine.
> MSA activity was only marginally increased, and heart rate and diastolic
> blood pressure remained unchanged. "Recent epidemiological studies have
> revealed a possible beneficial effect on cardiovascular disease and deaths
> in habitual coffee drinkers," he says. "But our study strongly supports the
> hypothesis that ingredients other than caffeine are responsible for the
> stimulating effects of coffee on the cardiovascular system." The lack of
> blood pressure elevation in coffee drinkers suggests the effects may be
> mediated through increased tolerance, the researcher notes. However,
> sympathetic nerve activation occurred in both groups when caffeine was
> administered intravenously, and habitual drinkers' MSA increased after
> drinking caffeinated espresso, both of which suggest tolerance to coffee
> does not appear to be related to caffeine. He concludes that the potential
> adverse effects attributed to coffee could be less hazardous in regular
> consumers with normal blood pressure. In such people, especially those
> without a hereditary predisposition to hypertension, coffee drinking can't
> be considered a risk factor for hypertension. What remains to be seen is
> whether people with hypertension should be advised to avoid decaffeinated
> coffee as well, Corti says. The American Heart Association says studies
> investigating a direct link between caffeine, coffee drinking and coronary
> heart disease have produced conflicting results. However, moderate coffee
> drinking (one – two cups per day) doesn't seem harmful. ###
> Co-authors include Christian Binggeli, M.D.; Isabella Sudano, M.D.; Lukas
> Spieker, M.D.; Edgar Hänseler, M.D.; Frank Ruschitzka, M.D.; William F.
> Chaplin, Ph.D.; Thomas F. Lüscher, M.D.; and Georg Noll, M.D. NR02-1212
> (Circ/Corti) CONTACT:
For journal copies only,
please call: 214-706-1396
> For other information, call:
> Carole Bullock: 214-706-1279
> Bridgette McNeill: 214-706-1135
>
>
>
>
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