Madrid: Filtered coffee does not raise the risk of heart disease, a new study by scientists at the universidad Autonoma de Madrid has found.

The research project, which followed 128,000 men and women for as long as 20 years, showed drinking filtered coffee – not percolated or French-style brews – did not raise the risk of heart disease.

Heavy coffee drinkers did tend to smoke and drink alcohol more often and those two factors clearly do raise heart risk, the researchers report in the journal Circulation.

But another recent study from the Harvard School of Public Health in Boston has said that the association between coffee consumption and the risk of heart disease in small groups of people cannot be excluded. The study published last month in the Journal of the American Medical Association showed that those men and women with a ‘slow’ version of a particular liver enzyme gene had a higher risk of heart disease if they drank more coffee, compared to those with a fast-metabolising version. Liver enzymes metabolise coffee and many other compounds.

Other studies have shown a link with heart disease and copious drinking of French press coffee, made using a mesh filter instead of a paper drip filter, or percolated coffee.

Volunteers in both studies fill out periodic questionnaires about their diet, exercise and other health habits and undergo regular physical exams.

The researchers found more than half the women and 30 percent of men who drank six or more cups of coffee a day were also more likely to smoke cigarettes, drink alcohol and use aspirin. They were also less likely to drink tea, exercise or take vitamin supplements.

But once these factors were accounted for, there was no difference in heart attack risks between the very light and heavy coffee drinkers.

A study published last November found no link between coffee drinking and high blood pressure, but there was an apparent association with drinking caffeinated fizzy drinks.