The Right Chocolate for your heart

Chocolate is made from the seeds of the cacao tree. These seeds are rich in flavonoids (aka bioflavonoids), a class of antioxidant polyphenol. Along with some flavonols like quercetin, cacao seeds contain a lot of flavanols like catechin and short chains of flavanols called Proanthocyanidins (aka procyanidins).

Researchers soon concluded that cocoa flavanols (catechins and proanthocyanidins) are responsible for the Kuna peoples' apparant immunity to high blood pressure and began measuring the flavanol content of many foods. Cinnamon (8%), cocoa(.7%-5%), sorghum bran(4%), and grapeseed(3.5%) turn out to be the foods with the most flavanols, with baking chocolate(1.6%) not far behind. Dark (.2%) and milk (.1%) chocolate, with less than one tenth the flavanol content of cocoa, are a bit further down the list.

So it can matter which chocolate you choose.... Different varieties of cacao plant make beans with different amounts of flavanols. Cocoa flavanols are destroyed when the cacao beans are fermented, roasted, or processed with alkali (as in "dutched" cocoa), and when chocolate is "conched", or milled smooth. Some foods combined with cacao products might make it hard for you to absorb the flavanols. Natural cocoa powders contain 3-5% flavanol, while dutched cocoas are about 1% flavanol. Unsweetened (100% cacao) chocolates vary from about 1.9% to 2.5% flavanol, and are about 50% cocoa butter. Dark chocolates vary from about .85% to about 2.0% flavanols.

It is hard to know exactly what any off-the-shelf product contains, unless you happen to have access to some very expensive lab equipment and sophisticated software. Several chocolate companies supported studies to analyze their products via the American Cocoa Research Institute, but will not reveal which values belong to their products. Other companies, not part of the ACRI, may or may not have had their products analyzed, but are not supplying flavanol content information in any case. They may be trying to avoid making illegal health claims for their products.

I've contacted Hershey, Nestle, Baker's Chocolate, and Ghirardelli, asking if they can give minimum values for some products (natural cocoas and 100% cacao bars). The big companies simply chose to email me their answers to slightly different questions, while Ghirardelli told me plainly that they do not measure the flavanol content of their products. Mars promises a minimum of 200mg of flavonols per serving of its CocoaVia(TM) products, which contain proprietary high-flavanol CocoaPro(TM) process cocoa. Barry Callebaut has developed an ACTICOA(TM) process, which is said to preserve 70% of cocoa flavanols, but is not marketing any of its products directly to consumers.

• Hollenberg et al. Cocoa, Flavanols and Cardiovascular Risk. Br J Cardiol 11(5):379-386, 2004
  
• Liwei Gu et al. Concentrations of Proanthocyanidins in Common Foods and Estimations of Normal Consumption. J. Nutr. 134:613-617, March 2004


• Gu, L et al. Procyanidin and catechin contents and antioxidant capacity of cocoa and chocolate products. J Agric Food Chem. 2006 May 31;54(11):4057-61.