Archive | December, 2012

Good news for chocolate lovers everywhere…

3 Dec

By: Natasha Sheikh

SANYO DIGITAL CAMERA

With the holiday season just around the corner, thoughts turn to family gatherings, holiday parties and baking. It is almost guaranteed that you will come face-to-face with the toughest treat to resist, i.e. chocolate. But can our love/hate relationship with this decadent treat finally be put to rest? It turns out, that incorporating a moderate amount of dark chocolate into your diet to prevent or manage heart disease may be a good idea.

So, what makes dark chocolate so special? Research indicates that dark chocolate is superior to white chocolate in lowering one’s risk of cardiovascular disease due to its higher polyphenol content (Grassi et al., 2005; Taubert et al., 2007). More specifically, intervention studies have found that a subclass of polyphenols, known as flavanols in chocolate can improve cardiovascular health through improving endothelial function, lowering blood pressure and modulating cholesterol levels (Grassi et al., 2005; Taubert et al., 2007; Jia et al., 2010).

You may be asking yourself, how exactly how do these flavanols produce such remarkable health effects? Although a variety of mechanisms may be involved, the beneficial effects of flavanol intake are most often attributed to an increase in nitric oxide bioavailability (Ried et al., 2012; Hollenberg et al., 2004). Nitric oxide is a powerful vasodilator, believed to be responsible for improving endothelial function and for the blood pressure-lowering effects associated with chocolate consumption (Hollenberg et al., 2004; Ried et al., 2012; Monahan et al., 2012).

It’s also interesting to note that cocoa flavanols appear to elicit similar blood pressure-lowering effects in healthy individuals and those with high blood pressure. For instance, Grassi et al. (2005) demonstrated a significant reduction in systolic blood pressure with the administration of 100g/day of dark chocolate over 15 days in individuals with high blood pressure in comparison to 90g/day of white chocolate. In another study, the same intervention was found to lower blood pressure, within a normal range, in healthy persons (Grassi et al., 2005).

While few studies have looked at the effects of chocolate consumption on lipid profiles, an analysis of eight trials including 215 participants at risk for cardiovascular disease demonstrated that cocoa consumption was associated with a significant reduction in LDL-cholesterol or what is known as “bad” cholesterol in these individuals (Jia et al., 2010).

Now you may be wondering, how much chocolate can I indulge in guilt-free? One study following 31, 823 middle-aged and elderly Swedish women discovered that 1 – 2 servings (19 – 30g) / week of chocolate was associated with lower incidences of hospitalization and death due to heart failure (Mostofosky et al., 2010). Meanwhile, another study found that 6.3g/day (~1-2 squares/day) of dark chocolate over an 18-week period lowered blood pressure in individuals with high blood pressure (Taubert et al., 2007).

Of course, chocolate lovers should also take note of the high fat and sugar content found in many chocolates.  Choose chocolate with at least 70% dark cocoa most often.  And before haphazardly diving into a box of chocolates, remember that less may be more, even when it comes to chocolate.

REFERENCES:

Grassi, D., et al. (2005). Cocoa Reduces Blood Pressure and Insulin Resistance and Improves Endothelium-Dependent Vasodilation in Hypertensives, Hypertension, 46, 398-405.

Grassi, D., et al. (2005). Short-term administration of dark chocolate is followed by a significant increase in insulin sensitivity and a decrease in blood pressure in healthy persons, Am J Clin Nutr, 81, 611-614.

Hollenberg, N.K., et al. (1997). Aging, Acculturation, Salt Intake, and Hypertension in the Kuna Panama. Hypertension, 29, 171-176.

Jia, L., et al. (2010). Short-term effect of cocoa product consumption on lipid profile: a meta-analysis of randomized controlled trials, Am J Clin Nutr, 92, 218-225.

Monahan, K.D. (2012). Effect of cocoa/chocolate ingestion on brachial artery flow-mediated dilation and its relevance to cardiovascular health and disease in humans, Arch Biochem Biophys, 527, 90-94.

Mostofsky, E., et al. (2010). Chocolate intake and incidence of heart failure: a population-based prospective study of middle-aged and elderly women, Circ Heart Fail, 3(5), 612-616.

Ried K., et al. (2012). Effect of cocoa on blood pressure. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD008893. DOI: 10.1002/14651858.CD008893.pub2.

Taubert, D., et al. (2007). Effects of Low Habitual Cocoa Intake on Blood Pressure and Bioactive Nitric Oxide. JAMA, 298(1), 49-60.