Two recent large epidemiological studies again suggest a beneficial effect of chocolate consumption on cardiovascular disease. One study was a prospective study in 1216 women with a follow up of 9,5 years. The frequency of chocolate consumption was categorized in three groups”: < 1 serving per week, 1-6 servings and 7 or more. Outcome was defined as plaque thickness in the carotid artery and hospitalization or death at follow up as clinical outcome. Not only were carotid plaques less prevalent in those women eating more chocolate but also those who ate more chocolate were less frequently hospitalized or death from ischemic heart disease.
In a large German study with middle aged participants of both sexes without cardiovascular disease at inclusion also an inverse relationship between chocolate consumption (at the time of enrollment in the study) and cardiovascular disease risk (myocardial infarction and stroke over the following 8 years) could be found.
in the quartile characterized by the lowest chocolate consumption (1.7 g/day) 106 myocardial infarctions and strokes occurred, whereas only 61 events occurred (combined relative risk of 0.61) in the quartile with the highest chocolate consumption (7.5 g/day). In the latter group, both systolic and diastolic blood pressure were found to be 1 mmHg lower as compared with the referent low chocolate consumption quartile.
In our quest for the optimal chocolate dose this last research adds another probable dosage that benefits our cardiovascular system namely 7,5 g/day.
Nevertheless, the problem with these large studies is the proof of a correlation, unfortunately no causation. These studies cannot provide direct proof for the existence of a cause and effect relationship. These two studies add up with two other large epidemiological studies. One in elderly Dutch men (Zutphen Elderly Study) and one in post-menopausal American women (Iowa Women’s Health Study).
Another problem is specificity. Cocoa contains other bioactive substances. Until now the beneficial effect of chocolate is attributed to it’s flavanol content. Moreover, participants might derive flavanols from other food substances such as vegetables, tea or fruit.
Originally, the positive effects of cocoa were found among the Kuna Indians living longer on islands off the coast of Panama than the mainland Panama population. But these Indians drank a cocoa drink that is consumed many times a day. This drink is something completely different from our chocolate. It’s low in calories and contains the unadulterated, unstripped cocoa, its bitterness tempered by sugar. Tried to find it’s recipe on the Internet but without any luck. Recipe anyone?
Buijsse, B., Weikert, C., Drogan, D., Bergmann, M., & Boeing, H. (2010). Chocolate consumption in relation to blood pressure and risk of cardiovascular disease in German adults European Heart Journal, 31 (13), 1616-1623 DOI: 10.1093/eurheartj/ehq068
Emma Wilkinson (2009). CardioPulse Articles European Heart Journal, 30 (24), 2951-2961 DOI: 10.1093/eurheartj/ehp485
Heiss, C., & Kelm, M. (2010). Chocolate consumption, blood pressure, and cardiovascular risk European Heart Journal, 31 (13), 1554-1556 DOI: 10.1093/eurheartj/ehq114
Lewis JR, Prince RL, Zhu K, Devine A, Thompson PL, & Hodgson JM (2010). Habitual chocolate intake and vascular disease: a prospective study of clinical outcomes in older women. Archives of internal medicine, 170 (20), 1857-8 PMID: 21059981