Coffee lovers who are in good health may have little reason to cut back, at least as far as their blood pressure is concerned. Because the caffeine in coffee and other foods can cause a short-term spike in blood pressure, there's been concern that coffee drinking may over time raise the risk of high blood pressure. Studies, however, have come to inconsistent conclusions. Researchers from the University Medical Center Utrecht, Netherlands, did an 11-years follow-up of nearly 6,400 men and women who were 40 years old, on average, at the study's start. Participants completed detailed questionnaires on their diet, including coffee drinking, as well as other lifestyle habits, education and family medical history. It was found that healthy women who drank more than six cups of coffee per day were no more likely than abstainers to develop high blood pressure over the next decade. On the other hand, women who drank coffee occasionally or in moderation - reporting anywhere from zero to three cups a day - had a higher risk of developing high blood pressure than the heavy coffee drinkers or the abstainers. For men, the risk of high blood pressure did not significantly increase or decrease, regardless of how much coffee they drank each day. However, men who abstained did have a lower risk than any coffee drinkers. Still, the effect was relatively small. A possible reason for the findings is that people who drink several cups of coffee every day develop a tolerance to the transient blood-pressure-raising effects of caffeine, while those who drink less coffee, less often, may remain sensitive. Even if coffee drinking contributes to raised blood pressure in some people, studies have failed to show that it actually increases the risk of heart disease in healthy people. There is no evidence for healthcare workers to advise against coffee drinking in healthy people. However, the findings do not apply to people with high blood pressure or other risk factors that increase their odds of heart disease.
American Journal of Clinical Nutrition,
March 2007