April 22, 2011

Links Between Blood Pressure And Coffee Use Overblown?

New research published in The American Journal of Clinical Nutrition, points out that there is little conclusive evidence comparing blood pressure increases with enhanced intakes of coffee and caffeine. High blood pressure has been linked to heart disease, stroke, and a shorter life expectancy. Some scientists have long suggested that coffee might be exacerbating the condition, Reuters Health is reporting.

Results from six previous studies that included more than 170,000 people in total were pooled and examined. For each study, spanning a total of 33 years, scientists surveyed the participants to find out how many cups of coffee they drank each day -- from less than one to more than five.

Only slightly more than one in five participants eventually developed symptoms of high blood pressure according to the findings. The chance, however, of being diagnosed with the condition was no different between people who drank more than five cups of coffee per day to those who drank a minimal amount of coffee.

Dr. Liwei Chen, from the Louisiana State University School of Public Health in New Orleans, said more data would be needed to draw a firm conclusion, the report "is not saying there's no risk." One result that researchers could not explain was show that people who drank between one and three cups per day had a slightly higher risk of high blood pressure than those who drank less.

Dr. Lawrence Krakoff, studies high blood pressure at the Mount Sinai Medical Center in New York, and explains that question about the effects of coffee drinking "keeps popping up" among both his patients and fellow doctors. Answers however, are not readily apparent said Krakoff, who was not involved in the recent study.

"I don't think of coffee as a risk factor for high blood pressure," he told Reuters Health. However, "If people are drinking 12 cups a day and aren't sleeping, I assume that that's an important issue."

"There may be other adverse effects to (drinking) large amounts of caffeine," explains Dr. Gary Curhan, of Brigham and Women's Hospital in Boston, who worked on one of the studies. Based on the existing data however, he said there is no reason to believe that drinking coffee itself would lead to high blood pressure.

The research did not compare the effect of drinking caffeinated versus decaffeinated coffee, as some of the studies they analyzed had participants report both together or only asked about caffeinated coffee.

Further complicating the results is the possibility that caffeine doesn't work the same way in everyone, she said. "People with a different genetic background may react to coffee differently," Chen said. "For some people maybe it's safe to drink a lot of coffee, but not for other people."


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