Eating chocolate two or more times per week was associated with a 66 per cent reduction in cardiac mortality, while less frequent consumption was also associated with smaller decreased risks, say the researchers in the Journal of Internal Medicine.
The study is said to be the first to assess the possible effects of chocolate consumption on the prognosis of men and women following a heart attack.
The health benefits of antioxidant-rich chocolate have received much recognition in recent years, with positive findings from a number of studies impacting on consumer awareness. Chocolate manufacturers are using high cocoa content (over 70 per cent) as a means of differentiation, and cocoa has also received attention for its potential in functional food applications.
The new study, however, did not differentiate between the different types of chocolate, be it milk or dark. “In the European Union, milk chocolate has to contain a minimum of 25 per cent of cocoa solids, dark chocolate 35 per cent,” explained the researchers. “The corresponding proportions in United States are 10 per cent and 15 per cent.
“According to the main chocolate producer (Marabou owned by Kraft Foods Sverige AB, Sweden) in the decade of the 1990s, about 90 per cent of the consumption was milk chocolate in Sweden and Swedish milk chocolate normally contains about 30 per cent cocoa solids,” they stated.
The researchers followed 1,169 non-diabetic people hospitalised after their first heart attack, and participating in the Stockholm Heart Epidemiology Program. After completing a questionnaire to assess chocolate consumption over the course of 12 months, the participants were then followed to eight years.
According to the results, consuming chocolate less than once per month, up to once per week and twice or more per week was associated with 27, 44, and 66 per cent reductions in cardiac mortality, respectively.
“Chocolate consumption generally had an inverse but weak association with total mortality and nonfatal outcomes,” said the researchers.
On the other hand, intakes of sweets and candies were not linked to any changes in cardiac or total mortality risk, added the researchers.
“Chocolate consumption was associated with lower cardiac mortality in a dose dependent manner in patients free of diabetes surviving their first acute myocardial infarction,” wrote the researchers.
“Although our findings support increasing evidence that chocolate is a rich source of beneficial bioactive compounds, confirmation of this strong inverse relationship from other observational studies or large-scale, long-term, controlled randomized trials is needed,” they concluded.
The researchers were affiliated with Karolinska Institute, Beth Israel Deaconess Medical Center, The National Board of Health and Welfare (Stockholm), and Uppsala University.
Source: Journal of Internal Medicine
Volume 266, Pages 248-257, doi: 10.1111/j.1365-2796.2009.02088.x
"Chocolate consumption and mortality following a first acute myocardial infarction: the Stockholm Heart Epidemiology Program"
Authors: I. Janszky, K.J. Mukamal, R. Ljung, S. Ahnve, A. Ahlbom, J. Hallqvist