June 15, 2015

expert reaction to study on chocolate consumption and risk of cardiovascular disease

A number of types of food have been suggested to have beneficial effects on health, and a team publishing in the journal Heart have investigated an association between chocolate consumption and cardiovascular disease. Based on a meta-analysis, the researchers report that higher intake of chocolate was associated with a lower risk of future cardiovascular events. A Before the Headlines analysis accompanied this Roundup.

Prof. Aedin Cassidy, Professor of Nutrition at the University of East Anglia (UEA), said:

“Although the findings are not new, they add to the evidence that intake of chocolate may reduce the risk of heart disease and stroke compared to non-consumers.

“When they divided chocolate intake into quintiles they showed that those in the top 20% intake group had a 12% reduction in risk for heart disease and 23% for stroke compared to the lowest 20% (who didn’t eat chocolate). Intake in the top ranging between 16-99g/d suggesting modest intakes have these health benefits. A couple of squares of chocolate would be around 16g and an average choc bar is around 50g.

“They infer that since most of the chocolate came from milk chocolate that it is unlikely that the flavonoids present in cocoa (called flavan-3-ols) are unlikely to explain their results- however although it is true that dark chocolate in general contain more flavan-3-ols than milk, the levels present are entirely depended on manufacturing processes and some milk chocolate contains high levels of these bioactive compounds too. If these flavonoids are important there are many other sources in the diet, including tea, apples, wine.

“This is an observational study and although thorough to really determine if chocolate is good for your heart we need robust long-term trials and to date most of the trials (which have shown beneficial effects on biomarkers of heart disease including blood pressure, blood flow and cholesterol levels) have been short term (3-4 months in length). Chocolate also contains fat and sugar so only moderate intakes should be recommended as part of a healthy diet rich in fruits and vegetables(an average chocolate bar (50g) provides about 230 kcal and 10% daily energy intake therefore high intake has the potential to affect weight, an important risk factor for heart disease.

“We need long term trials to further understand the importance of chocolate for heart health.”

Dr Tim Chico, Reader in Cardiovascular Medicine and Consultant Cardiologist at the University of Sheffield, said:

“This study adds to the evidence that people who consume chocolate tend to have lower rates of cardiovascular disease, although such studies cannot say whether the chocolate is the cause of this protective effect.

“There is evidence from other studies that have randomised people to be given chocolate that this can have effects that might reduce cardiovascular disease, such as a reduction in blood pressure. “These studies taken together suggest that there might be some health benefits from eating chocolate. However, it is also clear that chocolate has the potential to increase weight, which is unequivocally bad for cardiovascular health.

“The message I take from this study is that if you are a healthy weight, then eating chocolate (in moderation) does not detectibly increase risk of heart disease and may even have some benefit. I would not advise my patients to increase their chocolate intake based on this research, particularly if they are overweight.”

‘Habitual chocolate consumption and risk of cardiovascular disease among healthy men and women’ by Chun Shing Kwok et al. published in Heart on Monday 15^th June 2015. 

Declared interests

None declared