For example, Kris-Etherton's studies involved feeding subjects as little as 16 g (about half an ounce) of cocoa powder. An ounce or two is the common amount tested in many of the human trials, and a small study recently conducted at the Hippokratian Hospital at the University of Athens found eating about 3.5 ounces daily (100 g) of dark chocolate improved blood vessel function in healthy young adults for three hours or longer.
The study was a follow-up to an American study, published in the June 2004 Journal of the American College of Nutrition, that found that flavanoids appeared to increase dilation of blood vessels. That study looked at samples of cocoas with varying flavonoid levels, with the samples provided by the American Cocoa Research Institute. A healthy increases in vascular dilation usually means better circulation and fewer chances of clot formation, protecting the body against thrombosis, stroke and cardiac incidents.
A February 2003 review in the Journal of the American Dietetic Association regarding potential health aspects of flavonoids found in cocoa and chocolate described a variety of beneficial actions, such as antioxidant protection and blood flow regulation.
Positive benefits to cardiovascular health also were reported for other constituents in cocoa. Although chocolate is high in fat, cocoa butter is about one-third stearic acid, a fat known to positively influence blood cholesterol levels. The association also noted cocoa and chocolate contribute needed trace minerals, especially those critical to vascular tone. The ADA review concluded "multiple components in chocolate, particularly flavonoids, can contribute to the complex interplay of nutrition and health."
For processors, adding these healthy flavonoids to foods may pose a problem due to their characteristic bitterness. But scientists found adding flavonoids to foods at beneficial levels may not necessarily increase bitterness and even could improve the taste of some products. The antioxidant ability of flavonoids acts as a protector of flavor for foods that are heat-treated.
At a recent meeting of the American Chemical Society, several successful experiments with epicatechin (one flavonoid found in chocolate) were described. In one, ultrapasteurized milk containing the compound was protected from developing an off, "overcooked" flavor, and taste testers could not detect a difference in flavor of pasteurized milk with added epicatechin.
Another experiment discussed at the meeting described how in a granola bar the flavonoid inhibited formation of negative flavors associated with processing without any increase in bitterness. In a third study presented at the meeting, epicatechin was added to unroasted cocoa, which was then heat processed. The addition of epicatechin halved the formation of two known negative flavor elements. The scientists concluded these flavonoids can be included during food processing without increased bitterness, allowing processors to make healthier, tasty foods.
For more information on the functional compounds in chocolate and other foods, check out the International Food Information Council's functional foods comprehensive information update at http://ific.org/nutrition/functional/index.cfm.
|MEDICINE OR OPIATE?
Neuropharmacologists searching for the chemistry behind the universal passion for chocolate discovered marijuana-like compounds, called cannabinoids, in the confection, plus related chemicals that could help in the treatment of depression and other ailments.
At the University of Michigan, Adam Drewnowski, director of human nutrition, determined chocolate may possess natural analgesic properties, and eating chocolate may trigger the brain's production of natural opiates.
In a study reported in Nature, researchers identified several compounds in chocolate that act independently of fat and sugar in their ability to enhance the sense of pleasure and well-being. Based on evidence that nerve cells in the brain produce anandamide — a chemical that activates the same cellular receptors as THC in marijuana — the research group found n-oleoylethanolamine and n-linoleoylethanolamine in trace amounts in chocolate.
In in vitro trials, these chemicals were shown to delay anandamide's breakdown. This suggested an ability to prolong the pleasurable sensations derived from the body's own natural production of anandamide.