Eating high levels of chocolate could reduce the risk of coronary heart disease and stroke, according to a review of previous research.

Data from 114,009 patients suggested risk was cut by about a third, according to a study published on the BMJ website.

But the researchers warned that excessive consumption would result in other illnesses.

The British Heart Foundation said there were better ways to protect the heart.

The analysis, conducted by scientists at the University of Cambridge, compared the risk to the brain and heart in groups of people who reported eating low levels of chocolate, fewer than two bars per week, with those eating high levels – more than two bars per week.