People who drink three to five cups of coffee a day may have a lower risk of heart attack as they are less likely to develop clogged arteries, a major new study has claimed.
Despite earlier concerns about a potential increase in heart disease risk associated with drinking coffee, a recent meta-analysis of 36 studies showed that moderate coffee consumption was associated with a decreased risk of heart disease.
An international team of researchers led by the Kangbuk Samsung Hospital, Seoul, set out to examine the association between coffee consumption and the presence of coronary artery calcium (CAC).
CAC is a early indicator of coronary atherosclerosis – a potentially serious condition where arteries become clogged up by fatty substances known as plaques or atheroma and which 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 25,138 men and women – average age of 41 – who had no signs of heart disease, attending a health screening examination.
Researchers estimated the CAC score ratios associated with different levels of coffee consumption compared with no coffee consumption and took potential confounders into account such as education level, physical activity level, smoking status, BMI, alcohol consumption, among others.
The researchers found the prevalence of detectable CAC was 13.4 per cent amongst the whole group of people and the average consumption of coffee was 1.8 cups per day.
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.
Participants drinking three to five cups per day had the lowest prevalence of arteries that had clogged up, researchers found.
Possible explanations for the findings, said the researchers, were that chronic coffee consumption had a possible link to reduced risk of type 2 diabetes, a strong risk factor for atherosclerosis, and that coffee drinking might improve insulin sensitivity and beta-cell function.