People who drink a moderate amount of coffee daily – defined as three to five cups a day – are less likely to develop clogged arteries that could lead to heart attacks, suggests South Korean research.
The authors of the new study, from Kangbuk Samsung Hospital in Seoul, highlighted that there had been much debate over the effect of coffee consumption on cardiovascular health.
“Our study adds to a growing body of evidence suggesting that coffee consumption might be inversely associated with CVD risk”
They noted that, 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.
Coffee consumption has been associated with improved insulin sensitivity and reduced risk of type 2 diabetes, but it has also been linked to increased cholesterol concentrations and heightened blood pressure, they said online in the journal Heart.
The researchers set out to examine the association between coffee consumption and the presence of coronary artery calcium (CAC), an early indicator of coronary atherosclerosis, which can cause the arteries to harden and narrow, leading to blood clots that can trigger a heart attack or stroke.
They studied a group of 25,138 men and women, with an average age of 41, who had no signs of cardiovascular disease.
Participants were attending a routine health screening examination – common in Korea. The examination included a food frequency questionnaire and a multidetector cardiac CT for diagnostic imaging to determine levels of CAC scores.
The researchers estimated the CAC score ratios associated with different levels of coffee consumption, compared with no coffee consumption.
They categorised coffee consumption as none, less than one cup a day, one to three cups a day, three to five per day and at least five or more per day.
The researchers found the prevalence of detectable CAC was 13.4% among 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.
The association was U-shaped, with participants drinking three to five cups per day having the lowest prevalence of arteries that had clogged up.
“More research is needed to confirm these findings and understand what the reason is for the association”
Possible explanations for the findings, said the researchers, were that coffee consumption was linked to reduced risk of type 2 diabetes – a strong risk factor for atherosclerosis – and that coffee drinking might improve insulin sensitivity and β-cell function.
The researchers said: “Our study adds to a growing body of evidence suggesting that coffee consumption might be inversely associated with CVD risk.
“Further research is warranted to confirm our findings and establish the biological basis of coffee’s potential preventive effects on coronary artery disease,” he added.
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 different diet and lifestyle habits to people in the UK,” she said.