9–11 SNS reactivity is already enhanced in patients with borderline hypertension 10 as well during mental stress in normotensive offspring of hypertensive parents, 12 which suggests that intermittent activation of the SNS may in the long run lead to persistent increases in BP.Ĭoffee contains several hundred different substances, 13 but its effects on hemodynamics and on the SNS have been mainly related to caffeine. Indeed, sympathetic overactivity is a well-established pathogenetic mechanism in hypertension. The sympathetic nerve system (SNS) plays an important role in the regulation of BP. 5 Similarly, the role of coffee in the development of hypertension is also controversial, inasmuch as coffee drinking has been linked to both elevated 6 and reduced 7 blood pressure (BP) and has even been shown to have no effect on BP. 3,4 Interestingly, a beneficial effect of coffee was reported recently in the Scottish Heart Health study. Coffee drinking has been associated with increased cardiovascular morbidity and mortality in some 1,2 but not all prospective and epidemiological studies. Although its taste is a factor, many consume it for its stimulant properties.
Because decaffeinated coffee also increases BP and MSA in nonhabitual drinkers, ingredients other than caffeine must be responsible for cardiovascular activation.Ĭoffee is one of the most popular beverages, consumed in a large amount all over the world. Nonhabitual coffee drinkers showed similar activation of MSA and BP after caffeine infusion, coffee, or decaffeinated coffee.Ĭonclusions- Acutely, coffee and caffeine induced comparable increases in MSA and BP in nonhabitual coffee drinkers, whereas habitual coffee drinkers exhibited lack of BP increase despite MSA activation to coffee. Habitual and nonhabitual coffee drinkers demonstrated similar changes in MSA and BP after intravenous caffeine, whereas coffee drinking increased BP in nonhabitual drinkers only, despite comparable increases of MSA and plasma caffeine levels. A similar significant time effect was found for coffee drinking (54.1☒2.5% total activity). There was a significant time × condition interaction for the intravenous caffeine and placebo conditions for MSA, with caffeine showing a significant increase in MSA at 60 minutes (53.2☑4.1% total activity) and the placebo group showing no effect. Methods and Results- In 15 healthy volunteers (6 habitual and 9 nonhabitual coffee drinkers) arterial blood pressure (BP), heart rate, and muscle sympathetic nervous activity (MSA) were continuously recorded before and after drinking a triple espresso or a decaffeinated triple espresso or after intravenous administration of caffeine (250 mg) or placebo (saline) in the same subjects. Activation of the sympathetic nervous system by coffee may enhance cardiovascular risk however, it is unclear whether this effect of coffee is related to caffeine or other substance(s) also contained in decaffeinated coffee. Possible health hazards have been related to its main ingredient, caffeine. However, its cardiovascular safety remains controversial.
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