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 > > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ To unsubscribe/subscribe or view archives of postings, go to the Gambia-L Web interface at: http://maelstrom.stjohns.edu/archives/gambia-l.html To contact the List Management, please send an e-mail to: [log in to unmask] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~