Apr 10 2007
Chocolate, in particular the cocoa-rich dark variety is in the news again because of it's apparent health benefits.
According to a new study dark chocolate and other cocoa-rich products may be better at lowering blood pressure than tea.
Both cocoa and tea are rich in a class of antioxidants known as polyphenols which are considered to have a beneficial effect by protecting against heart disease and high blood pressure.
This latest research however maintains that the polyphenols found in cocoa may be more effective at lowering blood pressure.
Researchers the University Hospital of Cologne, in Germany carried out a review of studies done on the blood pressure-lowering effects of cocoa and tea and found that eating cocoa-rich foods was linked to an average 4.7-point lower systolic blood pressure reading and 2.8-point diastolic blood pressure reading.
No such effect was found among any of the studies on black or green tea.
The systolic number is the top one in a blood pressure reading while the diastolic is the bottom number.
People with high blood pressure are as a rule advised to eat a diet rich in fruits and vegetables, which are also high in polyphenols as these compounds are thought to have beneficial effect on protecting against heart disease and high blood pressure.
However as the researchers point out current recommendations for people at risk for high blood pressure or heart disease are not advised to include polyphenol-rich cocoa and tea products in their diet.
The researchers reviewed five previous studies on the effects of cocoa-rich products, such as dark chocolate or specially formulated polyphenol-rich milk chocolate, and blood pressure, with a total of 173 participants which lasted on average for two weeks.
They also reviewed another five studies on black and green tea and blood pressure involving a total of 343 participants for an average of four weeks.
All the studies were published between 1966 and 2006.
The review revealed that four of the five cocoa studies reported a reduction in both systolic blood pressure and diastolic blood pressure and that reduction was an average of 4.7 points systolic and 2.8 points diastolic.
The researchers say such effects are similar to those found using one-drug therapy with common blood pressure-lowering medications such as beta-blockers and ACE inhibitors.
Of the five studies on green or black tea none were associated with any significant reduction in blood pressure.
According to the researchers when these figures are applied to the population as a whole, they estimate that the blood pressure-lowering effect associated with cocoa would be expected to reduce the risk of stroke by about 20%, coronary heart disease by 10%, and death from all causes by 8%.
However, they do caution against their findings being used as an excuse to over-indulge in chocolate and say a reasonable approach would be to substitute a slice of cheesecake for a polyphenol-rich piece of dark chocolate and any dietary advice should take into account the high sugar, fat and calories existing in most cocoa products.
Researcher Dr. Dirk Taubert, says a rational approach might be to include cocoa products as part of a dietary guide to lowering a hypertension risk.
The research is published in the Archives of Internal Medicine, a publication of the American Medical Association.