Coffee Drinkers, Watch That Blood Pressure

Coffee drinking to excess may increase prediabetes, hypertension risk in young adults


Coffee is a morning ritual for many people. But if you find yourself pouring too many cups too often — that could be a problem.

A new study from Italy looked at the link between coffee intake, high blood pressure, and prediabetes and found that patients who had mild high blood pressure and drank coffee heavily had an increased risk of severe high blood pressure and prediabetes.

"There is controversy surrounding the long term cardiovascular and metabolic effects of coffee consumption in patients with hypertension," said lead study author Lucio Mos, MD, a cardiologist at the Hospital of San Daniele del Friuli in Italy, in a press release. "Our study was designed to evaluate whether coffee drinking had an effect on the risk of cardiovascular events, and if the association was mediated by effects on blood pressure and glucose metabolism."

Dr. Mos and team followed 1,201 patients between the ages of 18 and 45 for about 12 years.

All of these patients had been diagnosed with stage 1 hypertension (high blood pressure). None had been diagnosed with prediabetes or diabetes.

Stage 1 hypertension is blood pressure that falls between 140/90 and 159/99. Prediabetes is a metabolic condition that precedes type 2 diabetes, in which the body becomes resistant to insulin (a hormone that allows the body to use sugar for energy).

Patients were divided into three groups by coffee intake: nondrinkers, moderate drinkers (1 to 3 cups per day) or heavy drinkers (4 or more cups per day).

Heavy coffee drinkers tended to be older and weigh more than abstainers.

The more coffee these patients drank, the higher their risk of developing severe hypertension and heart problems.

Heavy coffee drinkers also had an increased risk of developing prediabetes, with those who metabolized caffeine slowly at the highest risk.

"Our study shows that coffee use is linearly associated with increased risk of cardiovascular events in young adults with mild hypertension," Dr. Mos said. "These patients should be aware that coffee consumption may increase their risk of developing more severe hypertension and diabetes in later life and should keep consumption to a minimum."

According to Dr. Mos and team, these findings may not apply to patients without hypertension.

This study was presented Aug. 29 at the annual meeting of the European Society of Cardiology. Research presented at conferences may not have been peer-reviewed.

No funding sources or conflicts of interest were disclosed.