Coffee Is Safe, HSPH Study Says

There is no long-term link between coffee consumption and increased blood pressure in women, a joint study by the Harvard School of Public Health and Brigham & Women’s Hospital has found.

The team, headed by Dr. Wolfgang Winkelmayer, sent out questionnaires every two years to 238,371 female nurses, asking for medical histories and lifestyle information—including coffee consumption. These were compared with incidence of physician-reported and self-reported high blood pressure.

The study, published last Wednesday in the Journal of the American Medical Association, found a “modest inverse U-shaped relation” between coffee consumption and hypertension after controlling for other factors such as diet and smoking.

While not disputing the short-term increase in blood pressure and stress hormones found by other studies, one of the authors of the report, Dr. Gary C. Curhan, suggests people who drink a large amount of coffee develop some sort of resistance over time.

The study backs up a similar investigation by Johns Hopkins Bloomberg School of Public Health published in 2002, which found similar results for men.

Decaffeinated coffee was found to have very similar results to caffeinated coffee, while the results for tea were inconclusive.

The study did find a link between hypertension and drinking caffeinated soft drinks.

“There’s a suggestion that, if you’re increasing your cola intake, there may be a slight increase in the risk of high blood pressure,” Curhan explained, adding that the team suspected this was due to some compound found in the drinks other than caffeine. The results were true for caffeinated and decaf varieties.

However, Dr. Soheyla D. Gharib of the Center for Wellness and Health Communication at Harvard University Health Services was cautious about this particular finding.

“I wouldn’t put a lot of weight on it,” she said. “The news here is that it’s safe to drink coffee.”

“It would be nice if this could be further investigated,” Curhan added.

In the meantime, Gharib suggests little change to the old adage “everything in moderation.”

A couple of cups of coffee a day is safe, she said, but much more will raise the risk of other problems including jittery hands, disruption to the sleep cycle and palpitations, not to mention stained teeth.

Some students say the study is unlikely to change their behavior.

“I probably won’t drink any more coffee because of [the study],” said Pamela C. Chan ‘07. “There are still other reasons not to drink coffee.”

But not all students are as health conscious. Brandon P. Geller ‘08 said he drinks a large amount of coffee regardless of warnings not to overindulge.

“It all sits at the back of my mind but I don’t do a lot about it,” he said.