Some studies have suggested dark chocolate might be good for the heart. But just how much chocolate would you have to eat to reap the benefits? A new study claims to have figured it out.
Researchers in Australia have calculated that eating about 100 grams of dark chocolate every single day for at least 10 years would lead to "significant" benefits for high-risk heart patients and could prevent heart attacks and strokes.
But a number of researchers question the findings, and say it doesn't account for the risk of eating chocolate every day – mainly, the risk of developing obesity, a strong risk factor for heart attacks in itself.
For the study, which is published in the British Medical Journal, a team of researchers from Melbourne's Monash University used a mathematical model based on the Framingham Heart Study. That's a large, ongoing study that began in 1948 and is responsible for much of our understanding about how diet, exercise, and medications such as ASA affect our risk for heart attacks.
They used the model to predict the long-term health effects of daily chocolate consumption on 2,013 people who were already at high risk of heart disease.
All the participants had high blood pressure and met the criteria for "metabolic syndrome" a groups of risk factors that are known to raise the risk of heart attacks and stroke, such as high cholesterol and high blood pressure. None of the participants had a history of heart disease or diabetes, nor were any on blood pressure medications.
The researcher calculated what would happen if each of them ate a small amount of dark chocolate with a 70 per cent or higher cocoa content, every day.
They calculated that in the best case scenario, with 100 per cent compliance, the daily dark chocolate habit could avert 15 fatal heart attacks and strokes, and 70 non-fatal heart events per 10,000 people treated, over 10 years.
If compliance fell to 80 per cent, 10 fatal events and 55 non-fatal events could be averted per 10,000 people treated over 10 years.
The authors point out that only non-fatal stroke and non-fatal heart attack were assessed in their analysis; the risks of other cardiovascular events, such as heart failure, weren't calculated.
The researchers don't believe that milk chocolate or white chocolate would have any effect. That's because it's dark chocolate that has the highest level of flavanoids, which are thought to be heart-protective because they can reduce blood pressure and lipid levels in the blood.
The authors of this study conclude that dark chocolate "could represent an effective and cost effective strategy for people with metabolic syndrome (and no diabetes)."
But they concede that their study relied heavily on the Framingham algorithm, which may underestimate risk in a high-risk population such as those with metabolic syndrome.
