The pros and cons of drinking coffee on a regular basis have been the subject of research for many years, with countless studies producing controversial results. A new study suggests that coffee may reduce the risk of clogged arteries, and therefore the risk of heart attacks.

Yuni Choi, Kangbuk Samsung Hospital and Sungkyunkwan University, Seoul, South Korea, and colleagues conducted a study with over 25,000 men and women (mean age 41) without any signs of cardiovascular disease. The individuals were questioned about their smoking habits, alcohol, food and coffee consumption, and underwent CT scans to determine their coronary artery calcium (CAC) score. The score indicates the amount of calcium accumulated in the arteries, which may indicate a predisposition to the formation of blood clots in the coronary arteries and, potentially, to heart attacks. Comparing the CAC scores, they found that moderate coffee consumption of one to four cups a day was associated with less calcium deposits in the coronary arteries, while both very low and very high consumption of coffee was associated with higher CAC scores.

These findings suggest that drinking coffee at moderate levels may help reduce the risk of potentially life-threatening coronary heart disease. However, it remains unclear how coffee may cause this beneficial effect.

• Coffee consumption and coronary artery calcium in young and middle-aged asymptomatic adults,
  Y. Choi, Y. Chang, S. Ryu, J. Cho, S. Rampal, Y. Zhang, J. Ahn, J. A. C. Lima, H. Shin, E. Guallar,
  Heart 2015.
  DOI: 10.1136/heartjnl-2014-306663