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5/2/15 Cover


Food for Thought

Janet Raloff
Food for Thought

Chocolate-science news

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Make no mistake: Chocolate is not a health food. Indeed, most portions are loaded with empty calories from sugar and saturated fats.

Several studies in recent years, however, have demonstrated that among sweets, chocolate may possess a few nutritional advantages over most calorie-rich alternatives. The latest of these good-news findings is a report that milk chocolate contains tiny amounts of conjugated linoleic acid, or CLA–a relatively low-profile fat that has been winning some big kudos.

Most trans fats–ones containing a structural feature that make them solid at room temperature–have a bad reputation. Not only do they physically resemble saturated fats in their solidity, but studies have suggested that the trans may also pose much the same risk to heart health that sat fats do.

CLA, however, is different. Studies in animals have long shown this trans fat to fight cancer and to combat atherosclerosis (see "The good trans fat" at http://www.sciencenews.org/20010303/bob1.asp). Indeed, notes Peter Yurawecz of the Food and Drug Administration in Washington, D.C., the functional biochemical distinctions of CLA have prompted his agency to exempt it from a proposed new rule that would require manufacturers of grocery foods to label their products trans fat content.

In a new study of chocolate, W. Jeffrey Hurst and his colleagues at Hershey Foods, analyzed six different types of candy. Not surprisingly, all were commercially available Hershey chocolates. The company wont divulge which types, other than to acknowledge that the group included its trademark kisses.

Each tested chocolate contained tiny amounts of CLA. The richest candy–denoted only as sample 1–contained a mere 0.3 milligrams of this fat per gram of chocolate. The findings are due to appear soon in the Journal of Agricultural & Food Chemistry.

Recent studies have suggested that humans may need to consume at least 3 grams or so of CLA for it to provide much benefit. To get the benefit from milk chocolate would require more than a little overindulgence, the new data suggest. One would need considerably in excess of 10 pounds of the candy per day!

Moreover, the new data likely hold little relevance to dark chocolate because the CLA in Hersheys samples comes from the milk integral to its light (milk) chocolate recipes.

Earlier, in the dark. . .

Last month, dark-chocolate chemistry made news, thanks to a study by the Nestlé Research Center. Scientists there found a way to make that companys dark candy a tad more healthful, without affecting its taste.

They replaced table sugar equal to 2.5 percent of the candys weight with an identical amount of calcium carbonate, the stuff of chalk. Then, every day for 2 weeks, they gave two 50-gram snacks of either the modified or the unmodified chocolate to 10 male volunteers. After waiting another 2 weeks, they repeated the experiment, this time giving each man the other chocolate.

During the weeks they ate the calcium-fortified confection, the men excreted roughly twice as much fat as in weeks when they downed regular dark chocolate, note Yasaman Shahkhalili and her colleagues in the February American Journal of Clinical Nutrition. Virtually all of the extra fat was of saturated types characteristic of cocoa butter. Because of the fats' excretion and the slight reduction in the candy's sugar, the modified candy provided 9 percent fewer calories than the unaltered chocolate did.

More importantly, the men's low-density-lipoprotein (LDL) cholesterol, the so-called bad cholesterol, fell by 15 percent during the period when they ate the calcium-fortified chocolate but remained at baseline levels when they ate the unmodified candy.

These new data offer a yummy example of "plain old fat chemistry," observes Margo Denke of the University of Texas Southwestern Medical Center in Dallas.

Manufacturers make soaps by combining calcium and fats. In the new study, she says, the gut similarly combined ingredients of the modified chocolate to form a soap that washed out in the feces. Indeed, Denke notes that, unlike the fatty molecules in a burger, the type and structure of chocolate's fat make it ideal for this transformation.

Alas, dark-chocolate aficionados, Nestlé has announced no plans to calcium fortify its chocolate morsels. If it ever does, I might be able to offer yet another putative benefit of Janets Chocolate Medicinal Mousse Pie (see Chocolate Therapies (with recipe for Janet’s Chocolate Medicinal Mousse Pie)).

Citations

Margo A. Denke

Department of Internal Medicine

University of Texas Southwestern Medical Center at Dallas

Dallas, TX 75235-9052

W. Jeffrey Hurst

Technical Center

Hershey Foods Corp.

P.O. Box 805

1025 Reese Avenue

Hershey, PA 17033-0805

Web site: [Go to]

Yasaman Shahkhalili

Nestlé Research Center Lausanne

P.O. Box 44

Vers-chez-les-Blanc

CH-1000 Lausanne 26

Switzerland
Further Reading

Denke, M.A., M.M. Fox, and M.C. Schulte. 1993. Short-term dietary calcium fortification increases fecal saturated fat content and reduces serum lipids in men. Journal of Nutrition 123:1047.

Raloff, J. 2001. The good trans fat. Science News 159(March 3):136. Available at [Go to].

_____. 2000. Chocolate hearts. Science News 158(Sept. 30):188. Available at [Go to].

_____. 2000. Chocolate therapies (with recipe for Janet's Chocolate Medicinal Mousse Pie). Science News Online (Sept. 30). Available at [Go to].

______. 1999. Better butter? This one may fight cancer. Science News 156(Dec. 11):375.

Raloff, J. 1996. Prescription-strength chocolate. Science News Online (Oct. 12). Available at [Go to].

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