No evidence coffee ups risk of high blood pressure

NEW YORK Fri Apr 22, 2011 7:52am EDT

Latte art is displayed during the finals of the German Barista Championships in Hamburg April 17, 2011. REUTERS/Morris Mac Matzen

Latte art is displayed during the finals of the German Barista Championships in Hamburg April 17, 2011.

Credit: Reuters/Morris Mac Matzen

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NEW YORK (Reuters Health) - Despite earlier concerns, downing lots of coffee doesn't seem to increase the risk of high blood pressure, according to a new report -- but the evidence isn't conclusive.

High blood pressure has been linked to heart disease, stroke, and a shorter life expectancy, and some scientists have suggested that coffee might fuel the problem.

The new report pools data from six previous studies that included more than 170,000 people in total. For each study, scientists surveyed the participants to find out how many cups of coffee they drank each day -- from less than one to more than five -- and then followed them for up to 33 years.

Just more than one in five participants eventually developed high blood pressure, according to the findings, which appear in The American Journal of Clinical Nutrition.

But the chance of being diagnosed with the condition was no different between people who said they chugged more than five cups of coffee per day and those who drank very little.

Still, the report "is not saying there's no risk" to drinking lots of java, Dr. Liwei Chen, who worked on the study, told Reuters Health.

Chen, from the Louisiana State University School of Public Health in New Orleans, said more data would be needed to draw a firm conclusion.

What's more, people who drank between one and three cups per day had a slightly higher risk of high blood pressure than those who drank less -- a result the researchers couldn't explain.

Dr. Lawrence Krakoff, who studies high blood pressure at the Mount Sinai Medical Center in New York, said that the question about coffee's effects "keeps popping up" among both his patients and fellow doctors.

But it has yet to be answered completely, said Krakoff, who was not involved in the new work.

"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."

Dr. Gary Curhan, who worked on one of the studies Chen and her colleagues looked at, agreed.

"There may be other adverse effects to (drinking) large amounts of caffeine," Curhan, of Brigham and Women's Hospital in Boston, told Reuters Health.

But based on the existing data, he said there is no reason to believe that drinking coffee would lead to high blood pressure.

Chen's team could 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.

And the relationship between coffee drinking and blood pressure is further complicated by the possibility that it 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."

SOURCE: The American Journal of Clinical Nutrition, online March 30, 2011.

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Comments (4)
Gulfstate wrote:
I could share a personal anecdote. Someone I know has chronic high blood pressure–it was so bad that this person was on the max medication that could be taken. We were watching a news report on TV that said it was linked to caffeine. The next day, she quit drinking coffee. Soon after that, her blood pressure dropped so low that she had to be hospitalized for a day until it stabilized. She was then able to establish a lower level of meds, but only with lower caffeine intake.

Apr 22, 2011 10:23am EDT  --  Report as abuse
Rudeasp wrote:
I hadn’t had a cup of coffee in a couple of months then I drank one due to a craving. My blood pressure jumped to hypertension stage 2 from normal. I’d say do more research.

Apr 22, 2011 10:45am EDT  --  Report as abuse
GCN wrote:
Regardless, I couldn’t care less what the study said about contracting chronic hypertension. It’s not really the point. When I drink a cup of coffee or any other caffeinated beverage, my systolic and diastolic blood pressure goes up 20 points. Yes, it comes back down. However, if I were to drink caffeinated beverages from morning to night like so many folks do, I’d have over 16 hours per day of hypertension. That can’t be good. Could it? Really!

If one had atherosclerosis, just one cup of one’s favorite vasoconstrictor could ruin your day. Many middle aged folks have atherosclerotic adhesions and the average age for a heart attack in males is 44 years old. Why push the odds by drinking multiple cups all day long?

Apr 22, 2011 10:50am EDT  --  Report as abuse
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