In 2002, heart disease caused more than 16.7 million deaths worldwide, and this figure is likely to rise in future. The American Health Association stresses the importance of diet on the prevention of heart disease, and recommends the consumption of more fruits and vegetables, which are rich in antioxidants. Consumption of cacao and chocolate has been linked to a reduced risk of cardiovascular disease. The cacao bean contains high levels of flavonoids and stearic acid, which are responsible for this action.
The purpose of this study was to analyse 136 publications regarding the influence of cacao or chocolate and its components (flavonols, flavonols, catechins, epicatechins and procynadins) on the risk for cardiovascular disease.
Most feeding trials suggest that cacao and chocolate may have a beneficial effect on cardiovascular risk. Cacao and chocolate seem to lower the blood pressure, reduce inflammation, reduce platelet formation, increase HDL (good cholesterol) and reduce oxidation of LDL cholesterol. Cacao is a very rich source of flavonoids (catechins, epicatechins and procyanidins) and polyphenols, even more than tea and red wine. Dark chocolate contains more polyphenols and flavonoids than milk chocolate. Catechins and epicatechins have antiplatelet action. A study by Innes AJ and colleagues entitled 'Dark Chocolate Inhibits Platelet Aggregation' and published in Platelets (2003) showed that dark chocolate had considerably more effect on platelet reduction than white or milk chocolate. Dark chocolate is a better source for flavonoids than milk chocolate, because milk components reduce the intestinal absorption of flavonoids. Cacao polyphenols have an anti-inflammatory effect, thereby protection against heart disease. Most publications about the effect of cacao and cardiovascular disease mortality show that the intake of flavonoids may be protective against cardiovascular disease mortality.
The influence of stearic acid on cardiovascular disease is not conclusive. Stearic acid, a saturated fat also found in diary and meat, has been considered as an unhealthy fat but recent studies indicate that stearic acid has no effect on cholesterol levels.
Eric L Ding and his colleagues concluded that stearic acid may have no effect and flavonoids may be protective against heart disease mortality. The studied publications mainly involved short-term feeding studies. In future larger studies have to be established to investigate the long term effects.
Source: Eric L Ding, Susan M Hutfless, Xin Ding and Saket Girotra. Chocolate and Prevention of Cardiovascular Disease: A Systematic Review. Nutrition and Metabolism (London) 2006; 3: 2.