People who drink three to five coffees a day are less likely to develop clogged arteries that could lead to heart attacks, a study has shown.
The effects of coffee consumption on cardiovascular health have led to much debate, and despite earlier concerns about a potential increase in heart disease risk, researchers found that people who drank a moderate amount a day had the least risk of coronary calcium in their arteries.
The international team examined the association between drinking coffee and the presence of coronary artery calcium (CAC), an early indicator of coronary atherosclerosis - a potentially serious condition where arteries become clogged up by fatty substances known as plaques or atheroma. This can cause the arteries to harden and narrow, leading to blood clots which can trigger a heart attack or a stroke.
They studied a group of more than 25,000 Korean men and women with an average age of 41, who had no signs of heart disease.
Their coffee consumption was categorised as none, less than one cup a day, one to three cups a day, three to five cups per day and five or more per day.
They found the prevalence of detectable CAC was 13.4% amongst the whole group while the average amount of coffee drunk was 1.8 cups per day.
Their findings showed the calcium ratios were 0.77 for people who had less than one cup per day, 0.66 for those having one to three cups every day, 0.59 for those consuming three to five cups per day, and 0.81 for people having at least five cups or more every day compared with non-coffee drinkers.
The U-shaped findings meant that those who drank one to three coffees a day had the second least prevalence of arteries that had clogged up.
The research, led by the Kangbuk Samsung Hospital in Seoul, South Korea, is published o nline in the journal Heart.
The authors concluded: "Our study adds to a growing body of evidence suggesting that coffee consumption might be inversely associated with CVD (cardiovascular disease) risk.
"Further research is warranted to confirm our findings and establish the biological basis of coffee's potential preventive effects on coronary artery disease."
Victoria Taylor, senior dietitian at the British Heart Foundation, said: "While this study does highlight a potential link between coffee consumption and lower risk of developing clogged arteries, more research is needed to confirm these findings and understand what the reason is for the association.
"We need to take care when generalising these results because it is based on the South Korean population, who have a different diet and lifestyle."