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Clinical Question:
What is the effect of coffee on hypertensive habitual alcohol
drinkers?
Bottom Line:
Coffee intake of more than 3 cups per day in hypertensive and
prehypertensive men who regularly consume alcohol lowers blood pressure.
Reference:
Hypertens Res. 2005 Jun;28(6):521-7.Effect of coffee intake on
blood pressure in male habitual alcohol drinkers.Funatsu K, Yamashita T,
Nakamura H.
Study Design:
Randomized Controlled Trial
Synopsis:
Many cross-sectional epidemiological studies have revealed that alcohol
consumption is closely related to an increase in blood pressure, which is
known to be associated with an elevated serum gamma-glutamyltransferase (GGT)
level, rather than to the volume of alcohol consumed. Since recent studies
showed that coffee intake is inversely related to serum GGT, we investigated
the effect of coffee on blood pressure in habitual alcohol drinkers. A total
of 42 male hypertensive or prehypertensive volunteers who consumed alcohol
and coffee daily completed this randomized controlled crossover trial. After
a 2-week baseline period, these participants were randomly assigned to
either a coffee-drinking group or a non-coffee-drinking group for the first
4 weeks. The situation was then reversed for the next 4 weeks. All
participants continued their usual alcohol consumption. Blood pressure was
measured once a week and compared between the two groups. After 1 week of
coffee intake of more than 3 cups per day, the systolic and diastolic blood
pressure began to fall slowly, and cessation of coffee intake raised the
blood pressure. Systolic blood pressure was lowered by 7-10 mmHg, and
diastolic pressure by 3-7 mmHg in 4 weeks. Alcohol consumption of more than
60 ml per day was maintained and there were no lifestyle changes in the
participants of either group throughout the study period. Analyses of urine
electrolytes and urea nitrogen indicated that there were no significant
dietary changes. |