In a new study, researchers say a connection between high blood pressure and coffee drinking has been discussed for decades, but no studies have actually established this link. Previous research has shown that coffee temporarily increases blood pressure immediately after consumption, but the body quickly adapts to that effect. Other studies have hinted that there might be a more persistent relationship between coffee drinking and the risk of developing high blood pressure over time.
In this study, which appears in the March 25 Archives of Internal Medicine, researchers tracked the coffee intake and blood pressure of a group of male medical school graduates for 33 years. They found that drinking one cup of coffee a day led to small increases in blood pressure, but long-term coffee drinking did not significantly increase the risk of developing high blood pressure.
People who didn't drink coffee were less likely than coffee drinkers to have high blood pressure, but there was no progressive increase in risk associated with higher levels of coffee intake, according to the researchers.
Researchers say the impact of coffee on the heart and blood vessels may also vary according to how the coffee is prepared. For example, passing boiled coffee through a paper filter removes compounds that have been shown to raise cholesterol levels.
The authors note that studies have shown that stopping coffee drinking can lower blood pressure in people who already have high blood pressure, and the results of this study may not apply to that group of people.