Coffee May Combat High Blood Pressure
Chemicals in Coffee Appear to Combat Blood Vessel Aging, Researchers Say
Sept.1, 2010 (Stockholm, Sweden) -- Older people with high blood pressure who drink one to two cups of coffee a day have more elastic blood vessels than people who drink less or more, Greek researchers report.
As we age, our blood vessels get stiffer, and that's thought to increase the risk of high blood pressure. The new findings suggest moderate coffee drinking may counteract this process.
Previous research has shown conflicting results as to whether coffee is good or bad for the heart.
The new study involved 485 men and women, aged 65 to 100, who live on a small island called Ikaria, in the Aegean Sea, where more than a third of people live to celebrate their 90th birthday.
"We were aiming to evaluate the secrets of the long-livers of Ikaria," says study head Christina Chrysohoou, BSc, of the University of Athens.
She presented the findings at the European Society of Cardiology Congress.
Coffee Improves Blood Vessel Elasticity
Participants, all of whom had high blood pressure, underwent imaging scans to measure the stiffness of their blood vessels.
Of the total, 33% of participants drank no coffee or less than one cup of coffee a day, 56% drank one to two cups, and 11% drank three or more cups a day.
People who drank one to two cups of coffee a day had about a 25% greater elasticity in their major blood vessels than people who drank less coffee or none at all.
Their blood vessel elasticity was about five times greater than people who drank three or more cups a day.
The analysis took into account factors that can affect blood vessel aging -- age, gender, smoking, education, physical activity, body weight, blood pressure, nutritional habits, and diabetes.
The study also showed that people who drank one to two cups of coffee a day were less likely to have diabetes, high cholesterol, cardiovascular disease, or to be overweight, compared to people who drank more coffee or less coffee, Chrysohoou says.
Nutrients in Coffee Credited for Fighting Blood Vessel Aging
Most of the men and women drank traditional Greek coffee in small, espresso-sized cups.
Greek coffee is considerably stronger, with more caffeine, than espresso, Chrysohoou tells WebMD.
She credits compounds, including flavonoids, magnesium, potassium, niacin, and vitamin E, for combating blood vessel aging by blocking the damaging oxidation process and reducing harmful inflammation. Oxidation reactions can produce free radicals. This, in turn, can start chain reactions that damage cells.
Traditional Greek coffee contains more of these chemicals than most other types of coffee as it is unfiltered and boiled, Chrysohoou says.
"We recommend hypertensive patients drink coffee in moderation, just one to two cups a day, as it seems that it may improve arterial aging," Chrysohoou says.
One limitation of the study is that participants drank their coffee in cafes with friends or with family at home, in a relaxed atmosphere. Therefore, the psychological benefits of socializing on heart health may help explain the findings.
American Heart Association spokesman Ray Gibbons, MD, tells WebMD that he is skeptical of the results.
"I'm concerned whether this finding could be reproduced," he says.
Other factors in the Greek lifestyle, such as the heart-healthy Mediterranean diet, could explain the results, Gibbon says.
This study was presented at a medical conference. The findings should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.