MEDICAL MATTERS:New study is great news for chocaholics, writes MUIRIS HOUSTON
FEELING GUILTY about your intake of Easter eggs over the past few days? Don’t be: the strongest evidence to date that chocolate is good for your heart has just been published.
Until now, much of the research into chocolate and heart health has focused on those eating the equivalent of 100g of chocolate a day for short periods. But the latest research looks at people with a regular chocolate “habit” over an eight- to 10-year period – more typical of us “chocaholics” who need our daily “fix”.
The German researchers followed almost 20,000 people aged 35-65. They received medical checks, including blood pressure, height and weight measurements at the start of the study between 1994 and 1998, and they also answered questions about their diet, lifestyle and health.
They were asked how frequently they ate a 50g bar of chocolate, and they could say whether they ate half a bar, or one, two or three bars. They were not asked if the chocolate was white, milk or dark chocolate; however, the researchers asked a sub-set of 1,568 participants to recall their chocolate intake over a 24-hour period and to indicate which type of chocolate they ate.
This gave an indication of the proportions that might be expected in the whole study. In this sub-set, 57 per cent ate milk chocolate, 24 per cent dark chocolate and 2 per cent white chocolate.
In follow-up questionnaires, sent out every two or three years until December 2006, the study participants were asked whether they had had a heart attack or stroke – information which was subsequently verified by a check on medical records. Death certificates from those who had died were also used to identify heart attacks and strokes.
The results, published in the European Heart Journal, are striking. Those who ate the most chocolate – about 7.5g a day – had lower blood pressure and had a significantly lower risk of having a heart attack or stroke than those who ate the least chocolate.
Lead author Dr Brian Buijsse of the German Institute of Human Nutrition summarised the results succinctly: “People who ate the most chocolate were at a 39 per cent lower risk than those with the lowest chocolate intakes.
“To put it in terms of absolute risk, if people in the group eating the least amount of chocolate [of whom 219 per 10,000 had a heart attack or stroke] increased their chocolate intake by 6g a day, 85 fewer heart attacks and strokes per 10,000 people could be expected to occur over a period of about 10 years.
“If the 39 per cent lower risk is generalised to the whole population, the number of avoidable heart attacks and strokes could be higher because the absolute risk in the general population is higher.”
The study found that people with the highest blood pressures had a 48 per cent reduction in the risk of stroke and a 27 per cent reduction in the risk of having a heart attack.
So what is the magic ingredient in chocolate? Almost certainly it is the flavanols present in cocoa that can take the credit for the health benefits.
The cocoa link would also explain why dark chocolate – with its higher proportion of cocoa – has a more potent effect.
“Flavanols appear to be the substances in cocoa that are responsible for improving the availability of nitric oxide from the cells that line the inner wall of blood vessels,” Buijsse says.
“Nitric oxide is a gas that, once released, causes the smooth muscle cells of the blood vessels to relax and widen; this may contribute to lower blood pressure. Nitric oxide also improves platelet function, making the blood less sticky.”
A couple of squares of dark chocolate a day would seem the ideal dose for heart health based on this latest research.
Just don’t forget to subtract the equivalent amount of calories from your diet in order to avoid weight gain.
And the ubiquitous T-shirt logo – “just hand over the chocolate and no one gets hurt” – now has a certain ring of truth about it.