Eating six chocolate bars a week is good for your heart, study says
Eating up to six bars of chocolate a week could reduce the risk of a potentially heart condition by almost one quarter, a study by Harvard University suggests.
The research on more than 50,000 people found strong links between regularly eating the treat and a reduced risk of suffering a heart flutter.
The strongest association was found among men eating between two and six portions of chocolate a week - with a portion classified as 30g, which is a small bar.
Those doing so had a 23 per cent lower risk of developing atrial fibrillation, compared with those avoiding such treats.
Among women, the effect was linked to eating just one portion a week, which was linked to a 21 per cent lower risk.
But other experts said the group eating the least chocolate were unhealthier in other ways - meaning it might not be the daily treats that explained the better health of those who liked to indulge.
More than 1.5 million people in the UK suffer from atrial fibrillation, with one in four likely to develop it over a lifetime.
The condition, also known as a heart flutter, doubles the risk of dying from other cardiac conditions, including stroke, heart attacks and heart failure.
It occurs when electrical impulses in the heart become jumbled, so that blood is pumped less effectively, increasing the chance of strokes and heart attacks.
Chocolate has previously been linked to other aspects of cardiac health.
It is thought it may have an anti-inflammatory effect, because it is high in flavonoids.
However, previous studies have focused on dark chocolate, which contains less fat and sugar than milk chocolate.
The new research did not ask participants to specify which type of chocolate they ate, but took place in Denmark, where milk varieties are more commonly eaten.
The study involved 55,502 participants, aged between 50 and 64, from the Danish Diet, Cancer and Health Study. Their health was then tracked for an average of 14 years, using national registry data on episodes of hospital treatment and deaths.
By the end of the study, 3346 new cases of atrial fibrillation were diagnosed.
Those who ate more chocolate had far lower rates of the condition, when compared with those eating less than one serving a month.
The researchers said: "Despite the fact that most of the chocolate consumed in our sample probably contained relatively low concentrations of the potentially protective ingredients, we still observed a robust statistically significant association."
However, researchers cautioned that the research was observational and did not prove cause and effect.
Those who were eating more chocolate were thinner, healthier in other ways, and more highly educated, experts noted.
Lead author Elizabeth Mostofsky, instructor in the Department of Epidemiology at Harvard Chan School, said: "Our study adds to the accumulating evidence on the health benefits of moderate chocolate intake and highlights the importance of behavioral factors for potentially lowering the risk of arrhythmias."
Too much chocolate would fuel other health problems, she said.
"Eating excessive amounts of chocolate is not recommended because many chocolate products are high in calories from sugar and fat and could lead to weight gain and other metabolic problems. But moderate intake of chocolate with high cocoa content may be a healthy choice," she said.
Researchers said the study could not establish why women with the lowest risk of heart flutters had just one portion of chocolate a week while for men it was between two and six portions.
But they said it was possible that men were protected by the fact they could eat more total calories each day without putting on weight.
Dr Gavin Sandercock, reader in clinical physiology from the University of Essex, said the group eating the least chocolate - less than one portion a month - were far less healthy than all the others, making comparisons misleading.
"They had the highest blood pressure, were most likely to have hypertension, most likely to have high cholesterol and were twice as likely to already have heart disease. They were fatter than all the other groups despite eating the least calories overall, which tells us they were the least active as well.
"In short, they were the unhealthiest group in the whole study - which means that almost any other group will seem healthier than them," he said.
Victoria Taylor, Senior Dietician at the British Heart Foundation, urged caution in adding chocolate to a daily diet.
She said: "Chocolate, or rather, the cocoa it contains, has previously been linked to a variety of cardiovascular benefits and in this case, people who ate more had a lower risk of developing atrial fibrillation.
"However, although this is a large study, it is only observational and so other factors could also be responsible for the effects seen.
"If you eat chocolate, keep your portions small and go for dark chocolate with the highest cocoa content."