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August 30, 2011

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Chocolate may lower heart risk by a third: study

Aug. 30, 2011
Courtesy of the European Society of Cardiology
and World Science staff

Eat­ing choc­o­late may be as­so­ci­at­ed with a one third re­duc­tion in the risk of de­vel­op­ing heart dis­ease, finds a study pub­lished on the Brit­ish Med­i­cal Jour­nal web­site Aug. 28.

The find­ings back up re­sults of ex­ist­ing stud­ies that gen­er­ally agree on a po­ten­tial link be­tween choc­o­late con­sump­tion and heart health. But the au­thors stress that fur­ther stud­ies are needed to test wheth­er choc­o­late ac­tu­ally causes this re­duc­tion or if it can be ex­plained by some oth­er un­meas­ured fac­tor.

Lifestyle and di­et are con­sid­ered key fac­tors in pre­vent­ing heart dis­ease. Re­cent stud­ies have found that eat­ing choc­o­late has a pos­i­tive in­flu­ence on hu­man health: the ef­fects found in­clude re­duc­ing blood pres­sure and im­prov­ing in­su­lin sen­si­ti­vity, a stage in the de­vel­op­ment of di­a­be­tes. But the ev­i­dence on how eat­ing choc­o­late af­fects your heart re­mains un­clear. So Os­car Fran­co and col­leagues at the Uni­vers­ity of Cam­bridge car­ried out a large-scale re­view of ex­ist­ing ev­i­dence.

They an­a­lysed the re­sults of sev­en stud­ies, in­volv­ing over 100,000 par­ti­ci­pants with and with­out ex­ist­ing heart dis­ease. For each stu­dy, they com­pared the group with the high­est choc­o­late con­sump­tion against the group with the low­est con­sump­tion. Dif­fer­ences in study de­sign and qual­ity were al­so tak­en in­to ac­count to min­i­mise bi­as.

Five stud­ies re­ported a ben­e­fi­cial link be­tween high­er lev­els of choc­o­late con­sump­tion and the risk of car­di­o­vas­cu­lar in­ci­dents. These found that the “high­est lev­els of choc­o­late con­sump­tion were as­so­ci­at­ed with a 37 per­cent re­duc­tion in car­di­o­vas­cu­lar dis­ease and a 29 per­cent re­duc­tion in stroke com­pared with low­est lev­els,” Fran­co and col­leagues wrote. No sig­nif­i­cant re­duc­tion was found in rela­t­ion to heart fail­ure.

The stud­ies did­n’t dis­tin­guish be­tween dark or milk choc­o­late and in­cluded con­sump­tion of choc­o­late bars, drinks, bis­cuits and desserts.

The au­thors say the find­ings need to be in­ter­preted with cau­tion, in par­tic­u­lar be­cause com­mer­cially avail­a­ble choc­o­late is very high-calorie (a­round 500 calo­ries for every 100 grams) and eat­ing too much of it could in it­self lead to weight gain, risk of di­a­be­tes and heart dis­ease. But they con­clude that, giv­en the health ben­e­fits of eat­ing choc­o­late, ini­tia­tives to re­duce the cur­rent fat and sug­ar con­tent in most choc­o­late prod­ucts should be ex­plored.

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Eating chocolate may be associated with a one third reduction in the risk of developing heart disease, finds a study published on the British Medical Journal website today. The findings confirm results of existing studies that generally agree on a potential link between chocolate consumption and heart health. But the authors stress that further studies are needed to test whether chocolate actually causes this reduction or if it can be explained by some other unmeasured factor. The World Health Organization predicts that by 2030, nearly 23.6 million people will die from heart disease. Lifestyle and diet are considered key factors in preventing heart disease. Recent studies have found that eating chocolate has a positive influence on human health: the effects found include reducing blood pressure and improving insulin sensitivity, a stage in the development of diabetes. But the evidence about how eating chocolate affects your heart remains unclear. So Oscar Franco and colleagues at the University of Cambridge carried out a large scale review of existing evidence. They analysed the results of seven studies, involving over 100,000 participants with and without existing heart disease. For each study, they compared the group with the highest chocolate consumption against the group with the lowest consumption. Differences in study design and quality were also taken into account to minimise bias. Five studies reported a beneficial link between higher levels of chocolate consumption and the risk of cardiovascular incidents and they found that the “highest levels of chocolate consumption were associated with a 37% reduction in cardiovascular disease and a 29% reduction in stroke compared with lowest levels.” No significant reduction was found in relation to heart failure. The studies didn’t distinguish between dark or milk chocolate and included consumption of chocolate bars, drinks, biscuits and desserts. The authors say the findings need to be interpreted with caution, in particular because commercially available chocolate is very high-calorie (around 500 calories for every 100 grams) and eating too much of it could in itself lead to weight gain, risk of diabetes and heart disease. But they conclude that, given the health benefits of eating chocolate, initiatives to reduce the current fat and sugar content in most chocolate products should be explored.