Coffee seems to be a steaming hot topic in health news these days. Last week we wrote about a study that associated high levels (six cups) of daily coffee intake with reduced risk for multiple sclerosis. And this week, according to a new South Korean study, moderate coffee consumption was associated with a decreased risk of high coronary artery calcium (CAC). Calcium in the walls of the coronary arteries can be an early sign of coronary heart disease.
The study, published in Heart, included over 28,000 young and middle-aged Korean adults with an average age of about 41 years old. The majority of the participants were male (over 83 percent). All of the participants showed no clinical signs of cardiovascular disease.
The participants underwent a comprehensive health screening between March 2011 and April 2013 at the Kangbuk Samsung Hospital Total Healthcare Centers in Seoul or Suwon, South Korea. Part of the screening included CT scans that measured CAC prevalence. They also completed a food frequency questionnaire.
The association between coffee consumption and CAC was U-shaped: The researchers found that those who drank the least amount of coffee and the most amount of coffee had the highest prevalence of CAC. Moderate coffee drinkers (who drank between three to less than five cups per day) had the least amount of CAC.
The multivariate-adjusted CAC score ratios when comparing coffee consumption were as follows:
- Less than 1 cup/day: 0.77
- 1 to < 3 cups/day: 0.66
- 3 to < 5 cups/day: 0.59
- ¥ 5 cups/day: 0.81
The authors point out limitations of their study, including that coffee consumption was self-reported. Syed T. Ahsan, MD, a cardiologist at Henry Ford Hospital in Detroit who was not involved in the study, said that another limitation is that Korea is traditionally not associated [with] a high clinical burden of coronary artery disease as compared to the Western countries. The study results should therefore not be generalized.
The researchers conclude, our study adds to a growing body of evidence suggesting that coffee consumption may be inversely associated with [cardiovascular disease] risk. However, they note that the study does not address why moderate coffee consumption appears to reduce CAC prevalence, and more research needs to be done to understand this relationship.