By Katrina Woznicki

      When you tear into that heart-shaped box and bite into a luscious piece of rich chocolate, don't feel guilty about what you might be doing to your waistline. Instead, think about what you may be doing for your health.
      A growing body of scientific evidence suggests that chocolate may not be the devil's food after all. Studies from Europe and the United States, two regions known for their inhabitants' love of chocolate, find that this candy may provide a variety of benefits, from increasing longevity to reducing the risks of heart disease and -- no surprise here -- improving mood.
      Naturally occurring compounds in chocolate have attracted the attention of chemists who say chocolate is loaded with antioxidants, molecules that protect cells from disease and damage.
      "Think about chocolate in its pure state, not with caramel and nuts, but as something that comes from the Earth, not as a processed food," says Dr. Robert Steinberg, who practices family medicine in San Francisco. He compares the nutritional value of cocoa beans to other plant-based foods, such as nuts.
      In its pure state, chocolate comes from cocoa beans, the seeds of a fruit grown on Theobroma cacao trees found predominantly in South America. Chocolate in its most processed form -- the kind of bar you'll find in a typical vending machine -- is loaded with extra oils and sugars. What's in between the two extremes, scientists say, is the good stuff: It still carries the healthy components and the sweet taste, but isn't diluted with too much fat.
      Chemists have found chocolate, especially dark varieties, contains high levels of antioxidants known as polyphenols -- the same antioxidants found in red wine and black tea. The more fat in the chocolate, says Joe Vinson, a chemistry professor at the University of Scranton in Pennsylvania, the weaker the polyphenols. Dark chocolate is a power source for polyphenols because much of the original cocoa bean remains intact after processing, Vinson explains. The same is true for cocoa baking powder. But how many people rip into the baking chocolate to satisfy a craving?
      Milk chocolate, an American favorite used in candy bars such as Snickers and Milky Way, contains some level of polyphenols, but they are not as strong as those found in dark chocolate. A bar of dark chocolate weighing about 40 grams (about 1.5 ounces) contains approximately 950 milligrams of antioxidants, according to Vinson. A similar bar of milk chocolate contains about 400 milligrams of the good stuff. And milk chocolate contains higher levels of fat, in the form of cocoa butter.
      White chocolate, a confection of fat and sugar some chocolate purists won't even consider, contains no antioxidants at all, Vinson says.
      Still need the scientific references? Last spring, researchers from the University of California at Davis and from Mars Inc., the manufacturer of M&Ms and Snickers, found the antioxidants in chocolate reduced plaque buildup in arteries. Cindy Moore, a registered dietitian at the Cleveland Clinic Foundation and a spokeswoman for the American Dietetic Association, points out that even the type of fat found in chocolate, called stearic acid, does not seem to raise cholesterol levels.
      And a study last summer from the Netherlands, where chocolate is as much a part of the landscape as windmills, concluded the high antioxidant concentrations in chocolate might make eating a chocolate cookie "not only enjoyable, but healthy as well."
      But Debra Zellner, a professor of psychology at Shippensburg University in Pennsylvania, questions all the recent hype surrounding chocolate. She says some chocoholics may use the information to bolster the argument that they're powerless against cravings, since their bodies "need" the food. While the candy may contain antioxidants, Zellner argues, so do grapes. "How many women do you know," she asks, "who crave grapes?"
      Even the chocolate industry is wary of overselling its product's health benefits. "A standard chocolate bar has as much antioxidant polyphenols as a glass of red wine," says Frances Seligson, associate director of nutrition at Hershey Food Corp., maker of the Hershey's chocolate. Still, Seligson quickly cautions, "we don't want to go so far as to say a chocolate bar a day keeps the doctor away."
      Chocolate won't keep the dietitians away either. Chocolate can fit into a sensible diet, but as with everything else you eat, it's important to consider the concepts of moderation and variety. "You can't live on chocolate alone," says Liz Applegate, a professor of nutrition at the University of California at Davis, a columnist for OnHealth and a self-described fan of dark chocolate. "Everything has to be put in perspective with the total diet and exercise and lifestyle."
      Perhaps chocolate lovers should follow the practices set by the ancient societies of Mexico. The Aztecs and Mayans considered chocolate, in the form of a beverage, to be a food of the gods, and so reserved it for special occasions. The Cleveland Clinic's Moore says the Mayans and Aztecs also considered chocolate an aphrodisiac. Even today, she adds, there's some scientific evidence to suggest the chemicals in chocolate can give people a nice pick-me-up. "Chocolate actually helps elevate mood and can help reduce depression," she says.
      But don't expect that box of chocolates from your Valentine to be a cure-all. "It's not going to make you immune to heart disease and other chronic diseases," Applegate says. "You have to look at the big picture."