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CMA Public Statement on Chocolate Products and Flavonoids

Overview:

Flavonoids are polyphenolic compounds of plant origin; evidence for their potential health benefits (e.g., the reduction of risk factors related cardiovascular disease (CVD)) is emerging. They can be found - in varying levels - in most chocolate and cocoa products. Those found in cocoa and chocolate appear to have potent antioxidant activity and may have health-promoting benefits; white chocolate does not contain significant amounts of these compounds.

Background:

Flavonoids share a common structure consisting of 2 aromatic rings bound together by 3 carbon atoms that form an oxygenated heterocycle (Arts, 1999: Hammerstone, 1999; Osakabe, 2002). There are flavonoid subclasses based on the type of heterocycle involved: flavonols, flavones, isoflavones, flavanones, anthocyanidins, proanthocyanidins and flavanols (Manach, 2004).

The main flavonoids in cocoa and chocolate are flavanols, specifically, the flavan-3-ol class of flavonoids, and proanthocyanidins (which are flavanol units linked together)(Murphy, 2003).

In addition to containing (-)-epicatechin, (+)-catechin and proanthocyanidins, cocoa and chocolate contain other flavonoids, including other catechins and the flavonol quercetin and its glycosides (Lazarus 1999; Zhu, 2002). Collectively, these flavonoids are known as cocoa flavonoids or cocoa polyphenols (Steinberg, 2003).

(from Murphy, K., et al. 2003)   (from Osakabe, N., Yasuda, A., Natsume, M., and Takizawa, T., 2002)

The cocoa flavonoids appear to have potent antioxidant activity (Arteel, 1999; Lee, 2003) and may have health-promoting benefits (Waterhouse, 1996; Raloff, 2000; Steinberg, 2003 and Mursu, 2004).

Cocoa flavonoids have been shown to inhibit the oxidation of low - density lipoprotein (LDL or 'bad') cholesterol (Kondo, 1996). The oxidation of LDL is thought to be a crucial event in the pathogenesis of atherosclerosis. In one in vitro study, three types of cocoa-based product (cocoa powder, baking chocolate, dark and milk chocolate) demonstrated ability to inhibit the oxidation of LDL-cholesterol (Vinson, 1999); additional research correlates consumption of cocoa polyphenols with lowered blood pressure (Taubert, 2003).

Results published to date suggest that consuming food high in flavonoid content may be linked with reduced risk for cardiovascular disease (Kris-Etherton, 2002). Effects observed in healthy adult subjects include increases in plasma antioxidant capacity and reductions in platelet reactivity, both of which are heart risk - lowering factors (Schramm, 2001; Wan, 2001).

In one study, small daily doses of flavonoid-rich dark chocolate eaten over a two-week period significantly improved blood vessel function, without increasing blood cholesterol levels (Engler, 2004). This is likely due to stearic acid, a major form of fat in chocolate; previous research draft dietary guidance has inferred that stearic acid, a saturated fat, is "cholesterol-neutral" when consumed in moderate amounts (Sanders, 2001).

More research is needed regarding the pharmacokinetics of cocoa flavonoids in humans, which appear to be partially absorbed (Wan 2001; Manach, 2004).

Conclusions:

• Research published to date demonstrates that the cocoa bean is a rich source of flavonoids. These flavonoids are found in cocoa powder, baking chocolate and milk chocolate, among other foods.
• Cocoa flavonoids, in early-stage research, show potential health benefits (e.g., the promotion of cardiovascular health, and other possible health benefits).
• Chocolate needs to be consumed responsibly, in moderation, due to the potential of high-caloric consumption to increase weight.
• More research is needed to further understand physiological effects of cocoa flavonoids.

Selected References:

Arteel, G., and Sies, H. 1999. Protection against peroxynitrite by cocoa polyphenol oligomers. Federation of European Biochemical Societies (FEBS) Letters 462:167.

Arts, I., Hollman, P., and Kromhout, D. 1999. Chocolate as a source of tea flavonoids. Lancet 354:488.

Hammerstone, J., et al. 1999. Identification of procyanidins in cocoa (Theobroma Cacao) and chocolate using high-performance liquid chromatography/mass spectrometry. Journal of Agricultural and Food Chemistry 47:490.

Engler, M. et al. 2004. Flavonoid-Rich Dark Chocolate Improves Endothelial Function and Increases Plasma Epicatechin Concentrations in Healthy Adults J. Am. Coll. Nutrition 23: 197.

Kondo, K. et al. 1996. Inhibition of LDL oxidation by cocoa. Lancet 348:1514.

Kris-Etherton, P., and Keen, C. 2002. Evidence that the antioxidant flavonoids in tea and cocoa are beneficial for cardiovascular health. Current Opinion in Lipidology 13: 41.

Lazarus, S., Hammerstone, J. and Schmitz, H. 1999. Chocolate contains additional flavonoids not found in tea. Lancet 354:1825.

Lee, K., Kim, Y., Lee, H., and Lee, C. 2003. Cocoa has more phenolic phytochemicals and a higher antioxidant capacity than teas and red wine. Journal of Agricultural and Food Chemistry 51: 7292.

Mursu J. et al. 2004. Dark Chocolate Consumption Increases HDL Cholesterol Concentration and Chocolate Fatty Acids May Inhibit Lipid Peroxidation in Healthy Humans. Free Radical Biology and Medicine 37 (9): 1351-1359.

Osakabe, N., Yasuda, A., Natsume, M., and Takizawa, T., 2002. Catechins and their oligomers linked by C4 C8 bonds are major Cacao polyphenols and protect low-density lipoprotein from oxidation In Vitro. Experimental Biology and Medicine 227:51.

Sanders, T., Oakley, F., Cooper, J. and Miller, G. 2001. Influence of a stearic acid-rich structured triacylglycerol on postprandial lipemia, factor VII concentrations, and fibrinolytic activity in healthy subjects. Am. J. Clinical Nutrition 73: 715.

Schramm, D. 2001. Chocolate procyanidins decrease the leukotriene-prostacyclin ratio in humans and human aortic endothelial cells. Am. J. Clinical Nutrition 73: 36.

Taubert, D., Berkerls, R., Rosen, R., and Klaus, W. 2003. Chocolate and Blood Pressure in Elderly Individuals With Isolated Systolic Hypertension. Journal of the American Medical Association. 290: 1029 - 1030.

Vinson, J., Proch, J., and Zubik, L. 1999. Phenol antioxidant quantity and quality in foods: cocoa, dark chocolate and milk chocolate. Journal of Agricultural and Food Chemistry 47:4821.

Wan, Y. 2001. Effects of cocoa powder and dark chocolate on LDL oxidative susceptibility and prostaglandin concentrations in humans Am. J. Clinical Nutrition 74: 596.