You're not alone drinking that morning cup of coffee. Around
85% of Americans drink caffeine daily in the form of coffee,
tea, or soft drinks. People take caffeine because it is a
stimulant - our bodies respond to caffeine essentially the
same as they do to stress - but its effects may last longer
than you might expect, based on a recent study in Psychosomatic
Forty-seven healthy, habitual coffee drinkers were followed
for three days to monitor blood pressure, heart rate, and
hormonal changes based on caffeine consumption. The individuals
were monitored through a normal day of drinking coffee; a
day when given caffeine pills twice (total equivalent to four
cups of coffee); and a day when only given placebo pills containing
Caffeine significantly raised both diastolic and systolic
blood pressures and increased levels of epinephrine (a stress
hormone) in the body by 32%, which in turn increased feelings
of stress. Also, although all caffeine pills were given prior
to 1 p.m., their effects lingered until bedtime.
eight hours after caffeine consumption, one-quarter of the
amount consumed remains in your body. Stress reactions and
higher blood pressure caused by caffeine may be dangerous,
so try to limit yourself to one cup of coffee or tea each
morning, and avoid caffeine altogether in the afternoon and
Lane JD, Pieper CF, Phillips-Bute BG, et al. Caffeine affects
cardiovascular and neuroendocrine activation at work and home.
Psychosomatic Medicine 2002:64, pp. 595-603.
Other nutrition studies can be found at http://www.chiroweb.com/find/archives/nutrition.