Tuesday, August 9, 2005
Chocolate maker Mars Inc. says its pipeline is full of healthful products containing compounds from the plant that gives chocolate its unique flavor. Already, the company sells one cocoa bar that it claims has "proven heart-health benefits." The Hershey Co., meanwhile, plans to launch an "extra dark" chocolate bar this September that will flaunt its potentially beneficial cocoa content. Smaller chocolatiers tout the same ingredient in a growing portfolio of products.
So: Chocolate is a proven health food?
Don't bite on that one yet. Lalita Kaul, a nutritionist at Howard University Medical School and a spokeswoman for the American Dietetic Association, says that chocolate "is a pleasure food with reduced risks" compared to many other common choices.
Chocolate makers are not using that more considered language in their product claims, of course. They are making the most of the possibility that some sweets--for example, dark chocolates made with minimal processing -- are better for you than alternative indulgences. The Food and Drug Administration has not issued a ruling regarding the health benefits of the compounds found in chocolate, so product claims have not been approved by the agency.
With its CocoaVia bar, which is partly dark chocolate, Mars says it has taken a step closer to creating a true health food. But so far, only one study has examined the bar's effects in people, and its results have been presented at an American Heart Association meeting but haven't been published in a peer-reviewed journal. Nearly all studies linking cocoa consumption to health gains have been funded by manufacturers, and few have looked at commercially available products.
Instead, most research has dealt with experimental mixtures that are rich in cocoa, a bitter extract from cacao beans, and relatively sparing with fats and sugars. An early formulation, served as a beverage, was unpopular among tasters, said Mars's chief scientist, Harold H. Schmitz.
Cocoa contains fiber and some useful minerals and vitamins, but most experts say its key constituents are its flavanols. Similar to chemicals abundant in red wine, purple grape juice and some teas, fruits and vegetables, those compounds impart the bitter taste.
Some studies suggest that flavanols have positive effects on blood vessels and that they act as antioxidants to prevent harmful changes to cells and substances in the body. See "What Can Brown Do for You? A Tantalizing Taste of Research" below. Cocoa is an ingredient in most but not all chocolates.
"Much depends on how much cocoa is in the chocolate," said Susan Moores, a nutritional consultant in St. Paul, Minn., and another spokeswoman for the dietetics association. "Dark has more [cocoa] than milk [chocolate], which has more than white, which has none." As a general rule, she said, "the darker and often the more bitter, the better."
In a recent study, U.S. Department of Agriculture researchers, supported by an industry group called the America Cocoa Research Institute, found that standard cocoa powders had the greatest concentrations of certain flavanols and of antioxidants overall among chocolate products. Baking chocolate was close behind. Dark chocolate and baking chips, as well as cocoa powders that had been treated by a method called Dutch processing, contained fewer potentially beneficial compounds. Milk chocolate -- the most widely available type for retail sale, and the love object of America's most enthusiastic chocolate consumers -- contained the fewest, about 10 percent of what's in top cocoa powders.
Even within a given type of chocolate, cocoa content varies from product to product. St. Louis--based chocolatier Bissinger's sells one dark chocolate that's 60 percent cocoa by mass, just as the upcoming Hershey's product is said to be.
Cocoa content, however, may not reflect how rich a product is in flavanols. The compounds can be destroyed at many points on the path from plantation to supermarket shelf, Schmitz said. Mars guarantees "at least 100 mg of cocoa flavanols" per bar of CocoaVia. But information that could be used to compare products' flavanol content isn't readily available.
In any case, the health claim on CocoaVia's package is based not on flavanols or anything else in chocolate but on cholesterol-blocking compounds called sterols, nearly all of them derived from soybeans, that have been added to the bar. While the Food and Drug Administration has not ruled on flavanols, it does permit claims about heart health for sterol-rich products .
CocoaVia "is more innocuous than a chocolate bar. It's a granola bar with chocolate added," said Bonnie Liebman of the Center for Science in the Public Interest, a consumer group that closely follows food issues. "Plant sterols have been shown in solid studies to lower cholesterol."
Said Moores: "If a person likes the taste of CocoaVia and is looking for a taste of chocolate that has a few extras inside, it may be the product for them. To rely on it to improve heart health, however, would likely be for naught."
Standard chocolate foods and beverages are even less likely to benefit health, scientists say, because chocolate tends to be dense with calories and saturated fats.
CocoaVia is the vanguard of Mars's efforts to "reinvent" cocoa as an ingredient in healthful, low-calorie foods, said Schmitz. "Fully capturing the potential was not going to be done through traditional cocoa-based products."
CocoaVia has a "pretty good" health profile, said cardiovascular nutritionist Penny Kris-Etherton of Pennsylvania State University, who has received funding from the American Cocoa Research Institute, which is supported by Mars and others in the candy industry. The good profile is partly because each 0.8-ounce bar contains only 80 calories. (An equivalent portion of a Mars 3 Musketeers bar has about 96 calories, though a whole bar contains 260 calories.)
Once people have met their recommended daily intake of fruit, vegetables and other nutritious foods, most of them can safely consume a small number of "discretionary calories" in any form they wish, Kris-Etherton said. But, estimating that she can permit herself no more than 200 daily bonus calories, she added, "It's especially hard for someone with low calorie needs to work in a candy bar that might have 250 calories. I can't even eat a whole candy bar or I'll exceed my discretionary allowance for the day."
Given flavanols' potential benefits, she said, "I wish there were some other ways to incorporate cocoa in our diet apart from confectionary products and desserts."
That's one area where scientists are hard at work, according to Carl L. Keen, a professor of nutrition and internal medicine at the University of California, Davis, who has collaborated with Mars. He said researchers are close to identifying specific, beneficial compounds in cocoa that could be used to enrich foods or to design medications. Mars recently announced that it's courting pharmaceutical companies interested in synthesizing cocoa constituents such as flavanols.
In the meantime, for all the promotion of chocolate's health benefits, there is virtually no definitive, long-term, gold-standard research in humans by independent researchers that demonstrate health benefits of chocolate. For now, consumers must carry on with little information about whether beneficial compounds that may be in their favorite candy bars offset all the sugar and fat that surround them. And, of course, there's the question of whether they can consume the extra calories without putting on weight.
Ah, that sticky issue of calories and weight, to which most discussions of food science eventually return.
Chocolate, said Howard University's Kaul, has "no health risks in moderation." But, she added, "If somebody takes two bars a day, I'll say, 'Can we cut it down, maybe to one initially and then a half?' " ·
Ben Harder covers health and medicine for Science News.