For Heart Health, Chocolate is a Girl's Best Friend

Posted on Sep 7, 2010 in Cardiovascular Health

by Rachel Stockton

Who cares about diamonds, chocolate is a girls’ best friend!  Chocolate’s silky rich ooey-gooey-ness is far less expensive, allowing indulgence on a weekly basis.

Before you stock up though, there are a few guidelines regarding the type and of chocolate and how much you should consume for maximum heart benefit.

Chocolate is a significant source of flavonoid antioxidants.  Several short-term clinical trials revealed it to be beneficial to cardiovascular health by lowering blood pressure, reducing incidence of stroke and acute myocardial infarction (AMI), lowering the incidence of deaths from coronary heart disease and lowering mortality in patients surviving their first AMI.

Evidence supports the hypotheses that chocolate might have long-term protective effects on cardiovascular events.  Population-based studies have found that chocolate consumption is associated with lower cardiovascular mortality among postmenopausal women and elderly men free of known coronary heart disease. 

Long-term effects of chocolate consumption among patients with established coronary heart disease is unknown, as is the association between chocolate consumption and prognosis in AMI survivors. 

“Despite clinical trials showing the effect of chocolate on blood pressure and the strong relationship between blood pressure and heart failure, no prior studies have examined the association between chocolate intake and heart failure,” the authors noted.

Murray A. Mittleman, MD, DrPH, of Beth Israel Deaconess Medical Center in Boston, and colleagues, investigated the long-term prospective relationships between chocolate consumption and total mortality, cardiac mortality as well as recurrent AMI, hospitalization for heart failure and stroke among patients surviving their first AMI in a population-based study of AMI.

According the study published in the Journal of Internal Medicine, researchers “followed 1169 non-diabetic patients who were hospitalized with a confirmed first AMI between 1992 and 1994 in Stockholm County, Sweden, as part of the Stockholm Heart Epidemiology Program (SHEEP). Participants self-reported usual chocolate consumption over the preceding 12 months with a standardized questionnaire distributed during hospitalization and underwent a health examination 3 months after discharge. Participants were followed for hospitalizations and mortality with national registries for 8 years.”

Researchers wrote, “Chocolate consumption was associated with lower cardiac mortality both amongst men and women, in patients below or equal to 60 years and in those older than that, amongst physically active and inactive subjects, amongst never-, current- and former smokers, amongst hypertensive patients and patients without hypertension and amongst patients having high school/college degree and lower education. Chocolate consumption was also associated with lower cardiac mortality for patients with a BMI value below 30 kg, but not for those above this BMI.

The two components of chocolate particularly relevant to the findings:
    **Fat in chocolate is especially high in stearic acid (around 30% of all fatty acids).  The effect of stearic acid on cardiovascular health remains controversial, but a recent systematic review concluded that stearic acid has beneficial or neutral effects on blood pressure and clotting parameters and does not adversely affect traditional lipid risk factors.
    **Chocolate is a very rich source of flavonoid antioxidants

Mittleman’s team reported in Circulation: Heart Failure that women who ate European chocolate once or twice a week had a 32% lower heart failure risk compared to those who didn’t regularly eat chocolate.

The adjusted rate ratio of heart failure among the study cohort was 1.09 for those who had three to six servings of chocolate per week (95% CI 0.74 to 1.62), compared with no consumption, and 1.23 for  daily consumption (95% CI 0.73 to 2.08) compared with no regular intake of chocolate.

In an interview, Linda Van Horn, PhD, RD, of Northwestern University in Chicago and a spokesperson for the American Heart Association said, “Dark chocolate in the U.S. is not necessarily the same as chocolate in Europe, therefore, one cannot assume the darkness of the chocolate is the potency of the isoflavone content.”

While people can, and perhaps should, indulge in this antioxidant and flavonoid-rich treat, Van Horn suggests choosing chocolate with a 70% or higher cocoa content, and warns that too much indulgence is potentially harmful due to the saturated fat intake which may lead to weight gain negating the heart benefits of this treat.

It is worth noting, that more than one serving daily of chocolate increases the risk of heart failure by 23% compared to no regular intake. 

Finally, a reason to buy the “good” chocolate.