The very low incidence of cardiovascular disease of the Kuna Indians of the San Blas Islands off the coast of Panama is believed to be due to their high use of chocolate products. Cocoa beans are a rich source of flavanols and the cocoa tree is Theobroma cacao.
Flavanols reduce vascular damage because of their antioxidant activity and their ability to increase the availability of nitric oxide (NO). Increased NO availability improves glucose uptake and relaxes vascular tone. The flavanols are mainly epicatechin, catechin and procyanidins. NO is necessary for the normal relaxation of blood vessels.
The goal of this study was to compare dark chocolate with high levels of flavanols with white chocolate with no flavanols. The study, done on healthy people, had subjects ate a 100 g. dark chocolate bar daily for 15 days or a 90 g. white chocolate bar for 15 days. The dark chocolate bars contained 500 mg. polyphenols, the class of chemicals to which flavanols belong. The white chocolate bars contained no polyphenols; but, they did contain cocoa butter.
Blood pressure was checked, and oral glucose-tolerance tests were given to determine insulin sensitivity and resistance during this study.
The results were that the patients eating dark chocolate bars showed less insulin resistance than those eating white chocolate bars. Those on dark chocolate also showed a reduction of their blood pressure, which was still within normal limits. Those on white chocolate showed no such reduction in blood pressure.
CONCLUSION: “Dark, but not white, chocolate decreases blood pressure and improves insulin sensitivity in healthy persons.”
NOTE: Improved insulin sensitivity is needed in diabetes. It would be interesting to see a study about the results of the use of use of cacao nibs in people with type II diabetes to see if it increases their insulin sensitivity. Read about cacao as a “super-food.”
PMID: 15755830.
Summary #179.
