Drinking more than one cup of coffee a day increases the risk of heart disease, a Greek study shows.
Men and women in the UK both drink more than a cup a day on average
University of Athens and Harokopio University researchers found drinking more than one cup increased the chances of cardiovascular inflammation.
They studied 3,000 people and found those who drank more than 200ml tested higher for a variety of indicators of inflammation.
Britons on average drink more than a cup of coffee a day.
Men drink 1.7 cups while women drink 1.5 cups and in total £630m is spent on coffee in the UK each year.
These figures are based on a cup containing 150ml - but the quantities still add to more than 200ml.
Report co-author Professor Antonis Zampelas, of the department of nutrition and dietetics at Harokopio University, said he was surprised by the findings.
"We did not expect the results for such low amounts of coffee but they are intriguing.
"Our results show that coffee drinkers are at higher risk of cardiovascular inflammation and what we need now is clinical trials into this.
"I would not go as far to say people should stop drinking coffee but I personally have cut down the amount I drink."
The study, published in the American Journal of Clinical Nutrition, took blood samples from 3,000 people, about half men and half women, while they were fasting.
The participants were also asked about their coffee drinking habits.
It found men who drank more than 200ml of coffee a day had 30% higher levels of C-reactive protein (CRP) and 3% higher white blood cell counts - both indicators of cardiovascular inflammation - than those who did not drink coffee.
Women had 38% higher CRP and 4% higher white blood cell counts.
The report did not identify which coffee ingredients caused the increased risk but Prof Zampelas said the suspicion was that cafestol and kahweol, found in unfiltered coffee, were to blame.
Cafestol and Kahweol have been linked to high cholesterol levels.
Dr Jeremy Pearson, associate medical director at the British Heart Foundation, said people with high blood pressure are advised to reduce their intake of coffee.
But he said the increased risk revealed in the study was "modest" and unlikely by to raise the risk of heart disease significantly.
He added: "Cutting down on coffee is less likely to help people protect their heart health than other measures, such as taking regular exercise and eating a healthy, balanced diet."
And Zoe Wheeldon from the British Coffee Association, said: "While this new study is very interesting it should be taken in context and the overwhelming scientific evidence shows that coffee drinking in moderation, four to five cups per day, is perfectly safe for the general population and may confer health benefits."