It seems like chocolate is good for the heart as researchers have said that consuming chocolate at least once a week is linked with a reduced risk of heart disease.The study, published in the European Journal of Preventive Cardiology, suggests that chocolate helps keep the heart's blood vessels healthy.In the past, clinical studies have shown that chocolate is beneficial for both blood pressure and the lining of blood vessels."I wanted to see if it affects the blood vessels supplying the heart (the coronary arteries) or not. And if it does, is it beneficial or harmful?" said study lead author Chayakrit Krittanawong from Baylor College of Medicine in the US.The researchers conducted a combined analysis of studies from the past five decades examining the association between chocolate consumption and coronary artery disease (the blockage of the coronary arteries).The analysis included six studies with a total of 336,289 participants who reported their chocolate consumption.During a median follow-up of nearly nine years, 14,043 participants developed coronary artery disease and 4,667 had a heart attack.Compared with consuming chocolate less than once a week, the findings showed that eating chocolate more than once a week was associated with an eight per cent decreased risk of coronary artery disease."Chocolate contains heart-healthy nutrients such as flavonoids, methylxanthines, polyphenols and stearic acid which may reduce inflammation and increase good cholesterol (high-density lipoprotein or HDL cholesterol)," Krittanawong said.The research team noted that the study did not examine whether any particular type of chocolate is more beneficial and whether there is ideal portion size."Chocolate appears promising for prevention of coronary artery disease, but more research is needed to pinpoint how much and what kind of chocolate could be recommended," the study authors wrote.While it's not clear how much chocolate is optimal, the study researchers warned against overeating."Moderate amounts of chocolate seem to protect the coronary arteries but it's likely that large quantities do not," they said."The calories, sugar, milk, and fat in commercially available products need to be considered, particularly in diabetics and obese people," the research team concluded.