Dark Chocolate Good for heart ?
Good news for chocolate lovers, chocolate may a lower heart attack risk. This is the outcome according to a new U.S. study that fulfills the dreams of chocoholics everywhere.
In a study of aspirin's effect on blood clotting in which abstinence from chocolate was required, a large proportion of participants broke the rules. Their 'offence' led to what is believed to be the first biochemical evidence that a few squares of chocolate a day can almost halve the risk of heart attack by decreasing the tendency of platelets to clot in narrow blood vessels.
"What these chocolate offenders taught us is that the chemical in cocoa beans has a biochemical effect similar to aspirin in reducing platelet clumping, which can be fatal if a clot forms and blocks a blood vessel, thus causing a heart attack," said Diane Becker from Johns Hopkins University in Maryland, USA, who led the study.
Becker cautions that this discovery should not become an excuse to indulge in large amounts of chocolate frequently, since chocolate also contains high amounts of sugar, butter and cream. However, just a few squares of dark chocolate - the purest form - may be just what the doctor ordered.
For almost 20 years researchers have known that chemicals called flavonoids, most common in dark chocolate, help blood flow and lower blood pressure.
This new finding, presented at the American Heart Association's annual scientific sessions in Chicago in mid-November, identifies the effect of everyday doses of chocolate found in regular foods such as hot chocolate or chocolate bars. This differs from previous studies that have examined the effects of eating unrealistic doses of flavonoids, equivalent to several pounds of chocolate a day.
"Eating a little bit of chocolate or having a drink of hot cocoa as part of a regular diet is probably good for personal health, as long as people don't eat too much of it, or too much of the kind with lots of butter and sugar," said Becker.
In the study, 139 chocolate offenders were disqualified from a larger experiment that aimed to examine the effects of aspirin on blood clotting. Before the study began, all participants were instructed to follow a strict exercise and diet regime and to refrain from smoking or partaking of foods and drinks known to affect platelet activity, like caffeinated drinks, wine, grapefruit juice and, of course, chocolate. Those who gave in to temptation were a diverse bunch who got their fix from a variety of sources including chocolate bars and drinks, black or green tea, or grapes and strawberries. Although the offending group was evicted from the aspirin study, Becker's team examined their blood results for chocolate's effect on blood platelets.
Platelet samples from both groups (offenders and non-offenders) were run through a mechanical blood vessel system designed to time how long it takes for platelets to clump together. Chocolate lovers' samples were found to clot more slowly, on average taking 130 seconds to block the system. Platelets from those who stayed away from chocolate clotted faster, taking an average of 123 seconds. Participants in the study ranged in age from 21 to 80. Of the chocolate offenders, none had any history of heart problems, such as heart attack, but all were considered to be at a slight risk of heart disease due to family history.
"These results really bring home the point that a modest dietary practice can have a huge impact on blood and potentially on the health of people at a mildly elevated risk of heart disease," said study co-author Nauder Faraday, also from John Hopkins University.
"But we have to be careful to emphasize that a single healthy dietary practice cannot be taken alone, but must be balanced with exercise and other healthy lifestyle practices that help the heart," she said.
Why dark chocolate is different
Not all chocolates are created equal. Dark chocolate contains a lot more cocoa than other forms of chocolate. Furthermore, the standard chocolate manufacturing process destroys up to half of the flavonoids, but chocolate companies have now learned to make dark chocolate that keeps up to 95% of its flavonoids.