Now you can enjoy your third daily cup of coffee and feel healthy while you do it: According to a new study, that third cup of joe may be good for your heart.
Researchers found that people who drink between three and five cups of coffee a day are likely to have less coronary artery calcium (CAC) than those who drink no coffee at all.
They also found a correlation between people who drink between one and three cups of coffee a day and a reduced prevalence of CAC, according to a paper published Monday in the journal Heart.
But try not to overdo it: Drinking more than five cups of coffee a day was associated with a higher levels of CAC, the authors report.
Calcium in the coronary artery isn't always a problem, but at high enough levels it can be an early sign of coronary heart disease.
Coronary heart disease occurs when plaque builds up in the coronary arteries, reducing the flow of blood to the heart.
The data in the study come from 28,138 men and women from the cities of Seoul and Suwon in South Korea who underwent a comprehensive health screening between March 2011 and April 2013. As part of that screening they had CT scans that measured the amount of calcium in their arteries.
They were also asked to fill out a 103-item food frequency questionnaire.
The researchers note that participants were not asked to differentiate between regular and decaffeinated coffee, but they say that decaf has not widely caught on yet in South Korea.
The prevalence of detectable CAC was 13.4% among the entire study group, and the average amount of coffee consumed was 1.8 cups a day.
The researchers found that the association between coffee drinking and CAC was U-shaped, the authors write.
Participants who drank between three and five cups of coffee a day had the lowest prevalence of CAC with a calcium ratio of .59. Those who drank less than one cup a day had a calcium ratio of .77. Those who drank one to three cups a day had a ratio of .66. And among those who drank more than 5 cups a day, the ratio was .81.
The authors write that their study adds to a growing body of evidence that the moderate consumption of coffee is good for heart health.
The study does not address why coffee seems to be good for the cardiovascular system, however, and the authors write that more research is needed to understand this relationship.