Dark chocolate reported to reduce risk of cardiovascular disease
According to a new study, being a chocaholic might be a component of a healthy lifestyle. Furthermore, it might be a money-saving healthcare strategy for reducing the risk of cardiovascular disease, particularly in high-risk individuals. Researchers in Melbourne, Australia published the results of their research online on May 31 in the BMJ.
The authors noted that short term clinical trials have reported that dark chocolate consumption can potentially reduce systolic blood pressure by 5 mm Hg and total cholesterol concentration by 0.21 mmol/L. To build on current research, the investigators conducted a long-term study to evaluate the potential health benefits and cost-effectiveness of daily dark chocolate consumption in a high risk population.
The study group was comprised of 2,013 individuals with hypertension (high blood pressures) who met the criteria for metabolic syndrome and had no history of cardiovascular disease and were not taking antihypertensive medication. (Metabolic syndrome is a collection of conditions (elevated blood pressure, high blood sugar level, excess body fat around the waist, and abnormal cholesterol levels) that occur together; thus, increasing the risk of cardiovascular disease and diabetes.) They employed a statistical method known as a Markov model. A Markov model is a useful statistical tool for evaluating a risk that is continuous over time, when the timing of events is important, and when important events may happen more than once.
The authors note that cardiovascular disease is the leading cause of death worldwide; the 2004 death rate was estimated at 17.5 million individuals. The metabolic syndrome is becoming increasingly prevalent because of rising rates of obesity and diabetes as well as an aging population. Lifestyle changes such as dietary modifications and behavioral adaptations constitute first line treatment in the prevention of diseases associated with the metabolic syndrome. Dietary modifications that increase the intake of vegetables, fruit, and grains as well as decrease the intake of saturated fats and refined sugars are recommended. It is believed that the high content of polyphenolic antioxidants in some fruit, vegetables, whole grains, nuts, and tea may contribute to their cardioprotective effects. Dark chocolate, derived from cocoa beans, is rich in polyphenols, specifically flavonoids. Flavonoids exhibit antihypertensive, anti-inflammatory, antithrombotic, and metabolic effects, all of which may contribute to their cardioprotective effect.
The authors reviewed published meta-analyses to evaluate the treatment effects associated with dark chocolate consumption. (A meta-analysis is a review of similar studies on the same topic to establish whether similar results were obtained.) The data were used to determine the absolute number of cardiovascular events with and without treatment with dark chocolate. The costs associated with cardiovascular events and treatments were applied to determine the potential amount of funding required for dark chocolate therapy to be considered cost-effective.
The researchers found that daily consumption of dark chocolate (polyphenol content equivalent to 100 grams (3.5 ounces) of dark chocolate) can reduce cardiovascular events by 85 per 10,000 individuals treated over 10 years. The cost of the chocolate was estimated to be $42 per person per year. The noted that these projected results assume 100% compliance and represent a best case scenario.
The authors concluded that the blood pressure and cholesterol lowering effects of dark chocolate consumption are beneficial in the prevention of cardiovascular events in a population with metabolic syndrome. They noted that daily dark chocolate consumption could be an effective and cost-effective cardiovascular preventive strategy in this population.
Take home message:
Although this study focused on dark chocolate, it actually is a testimonial to the benefits of a healthy diet rich in flavonoids. Chocolate is available without added sugar; this form of the product might not be as tasty but it is far healthier.