Calcium supplements for chocolate.

Chemists have found a way to make dark chocolate a tad more healthful--without affecting its taste.

Scientists at the Nestle Research Center in Lausanne, Switzerland, replaced table sugar equal to 2.5 percent of the candy's 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 of the men the other chocolate.

The men excreted roughly twice as much fat during the weeks they ate the calcium-fortified confection as during the weeks they downed regular dark chocolate, note Yasaman Shahkhalili and her colleagues in the February AMERICAN JOURNAL OF CLINICAL NUTRITION. Virtually all the extra fat was of the saturated varieties 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 about the same when they ate the unmodified candy.

The finding is 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, unlike the fatty molecules in a burger, the type and structure of chocolate's fat make it ideal for this transformation.