Health benefits of cocoa, dark chocolate
April 18, 2007
Drinking a traditional cup of cocoa at bedtime can help to lower blood pressure as effectively as prescription medications, researchers say.
Foods rich in cocoa, such as dark chocolate, also appear to improve circulation and reduce the risks of heart attacks, but drinking tea may not, an analysis of several studies suggests.
Polyphenols or flavonoids, chemicals found in cocoa and tea, are thought to lower blood pressure and reduce the risk of heart attacks and strokes.
Dirk Taubert and colleagues at the University Hospital of Cologne, Germany, conducted a meta-analysis of ten previously published trials, five of cocoa’s effects on blood pressure and five involving tea.
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The studies were either randomised trials, in which some participants were assigned randomly to drink cocoa or tea and some to control groups, or used a crossover design, in which participants’ blood pressure was assessed before and after consuming cocoa products or tea.
The findings are published to-day in the American Medical Association’s Archives of Internal Medicine.
The five cocoa studies involved a total 173 participants, including 87 assigned to consume cocoa and 86 controls, 34 percent of whom had hypertension (high blood pressure).
Four of the five trials reported a reduction in both systolic (the top number, when the heart contracts) and diastolic (the bottom number, when the heart relaxes) blood pressure, when the participants were monitored over a median period of two weeks.
Compared with those who were not consuming cocoa, systolic blood pressure was an average of 4.7 millimetres of mercury lower and diastolic blood pressure was an average of 2.8 millimetres of mercury lower. The effects are comparable with those achieved with a single course of blood pressure medications such as beta blockers, the authors note.
“At the population level, a reduction of 4 to 5 millimetres of mercury in systolic blood pressure and 2 to 3 millimetres of mercury in diastolic blood pressure would be expected substantially to reduce the risk of stroke (by about 20 per cent), coronary heart disease (by 10 per cent) and all-cause mortality (by 8 per cent),†they write.
Julie O’Sullivan, of the British Heart Foundation, said: “We should remember that chocolate is far more often part of the problem for heart health than the solution. Eating five portions of fruit and veg a day is a far better way to get the heart protective antioxidants without having to worry about the fats and sugars that go into cocoa products such as chocolate.â€
- Source: The Times, Apr. 10, 2007
