- Category: Miscellaneous Health News
- Published on Friday, 08 June 2012 00:00
- Written by Liz Highleyman
Daily consumption of dark chocolate could significantly reduce the risk of cardiovascular events such as heart attacks, and would be cost-effective with a price tag of about $40 per person per year, according to estimates from a mathematical model reported in the May 31, 2012, British Medical Journal. The researchers stressed, however, that these benefits depend on good adherence.
Dark chocolate, made from cocoa beans, is rich in polyphenols, specifically flavonoids, that have been shown to have anti-oxidant, anti-inflammatory, and anti-thrombotic (reducing blood clots) effects, all of which may contribute to its protective effect against cardiovascular disease. Some studies have also found that cocoa helps lower blood pressure, perhaps by stimulating production of nitric oxide to dilate blood vessels. Short-term trials indicate that dark chocolate can potentially reduce systolic blood pressure by 5 mm Hg and total cholesterol level by 0.21 mmol/L.
Ella Zomer and Christopher Reid from Monash University in Melbourne, Australia, and colleagues modeled the long-term effectiveness and cost-effectiveness of dark chocolate consumption in a population with a high prevalence of metabolic syndrome (characterized by abdominal obesity, insulin resistance, abnormal blood lipid levels, and elevated blood pressure) and at high risk for cardiovascular disease.
The analysis included 2013 people in the Australian Diabetes, Obesity and Lifestyle study who had metabolic syndrome but so far had no history of heart disease, did not currently have diabetes, and were not receiving drugs to control blood pressure.
Using data on the beneficial effects of dark chocolate derived from published meta-analyses, the researchers generated a Markov model to estimate the number of cardiovascular events that would be expected to occur with and without daily chocolate consumption. They also used the cost of cardiovascular events and their treatment to determine if dark chocolate therapy would be considered cost-effective.
- Assuming 100% adherence, the model predicted that daily consumption of dark chocolate with a polyphenol content equivalent to 100 g could prevent 85 cardiovascular events per 10,000 people over a 10-year period:
o 70 non-fatal heart attacks or strokes;
o 15 fatal heart attacks or strokes.
- Given this best-case scenario, it would be cost-effective to spend US$42 per person per year on dark chocolate for prevention.
"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," the study authors concluded. "Daily dark chocolate consumption could be an effective cardiovascular preventive strategy in this population."
"Chocolate benefits from being by and large a pleasant, and hence sustainable, treatment option," they added.
The $42 per person per year could be spent on education campaigns, advertising, or directly subsidizing the provision of dark chocolate, they suggested. Evidence to date suggests that only dark chocolate with a cocoa percentage of at least 60%-70% -- not milk chocolate or "white chocolate" -- is likely to have a protective effect. 100 g would be roughly equivalent to 1 premium-quality bar containing at least 70% cocoa.
"We're not suggesting that the high-risk group use dark chocolate as their only preventative measure, but in combination with sensible choices, such as exercise," Zomer said in a Monash University press release.
E Zomer, A Owen, DJ Magliano, D Liew, and CM Reid. The effectiveness and cost effectiveness of dark chocolate consumption as prevention therapy in people at high risk of cardiovascular disease: best case scenario analysis using a Markov model. British Medical Journal 344:e3657. May 31, 2012.
Monash University. A Dark Chocolate a Day Keeps the Doctor Away. Press release. June 1, 2012.