New research shows chocolate has been a diet mainstay for even longer than researchers previously believed. It seems humankind's love affair with chocolate dates back to about 600 B.C. That's 1,000 years earlier than researchers previously believed chocolate began to cast its culinary spell.

This news flash comes from W. Jeffrey Hurst, a research scientist at Hershey Foods Corp. He painstakingly analyzed residue extracted from ceramic vessels believed to have been used 2,600 years ago by the Mayans in what is now northern Belize.

The Mayans, it seems, may have been the original chocoholics. Hurst's analysis, which appears in today's issue of Nature, proves that cocoa was used by the earliest Mayan civilization.

"What came to me [in the lab] was residue from the vessels," Hurst says. "We extracted it and analyzed it, using a technique called high-performance liquid chromatography (HPLC). We found the existence of a compound in quantities unique to cocoa. That compound is theobromine. The compound occurs in other plants but not in the same amount as in cocoa."

Hurst's analysis is thought to be the first time the new HPLC technique has been used to analyze dry residues from the interior of prehistoric pottery.

It's also proof the Mayans did indeed have a chocolate habit.

The vessels unearthed are spouted somewhat like earthenware teapots. Archaeological experts think the pots were used to pour a cocoa mixture from one vessel to another to generate a voluptuous froth -- the preferred Mayan form of the drink.

"It's a neat archaeological find," says Hurst, who has worked at Hershey's for 26 years and eats chocolate daily. Before this analysis, he says, "the earliest we were able to prove cocoa was in use was 400 A.D. With this new information, we know it could be as early as 600 B.C."

In recent years, chocolate has been proven by researchers to have some healthful qualities, partly because it's been found to contain antioxidants, which can undo the cell damage wrought by "free radical" molecules. No one is suggesting chocolate is a health food, but it can fit into a healthy diet, in moderation.

The good news for modern-day chocolate lovers?

Our chocolate sounds a lot more palatable than the Mayan form. For an idea of what the typical Mayan cocoa tasted like, Hurst suggests grinding cocoa beans, roasting them, mixing them in a blender with water and spices, and then indulging.

Should his discovery be cause for celebration for chocolate lovers?

"I don't even want to go there," Hurst says. "I am a research scientist."

However, dietitian Marlene Clark, from Cedars-Sinai Medical Center in Los Angeles, says the discovery makes perfect sense, helping to explain why so many of her clients love the dark, sweet stuff.

"Everyone loves chocolate," she says. "There must be a long history. There must be some reason people feel this innate love of chocolate."

So does chocolate belong in a healthy diet?

"It would depend on the individual," Clark says. In most cases, though, she would say there's a place for all foods in moderation for everyone.

If you eat a nutritious, healthy diet and have some calories to spare, "finishing off a nutritious meal with a little chocolate is usually fine," she says. "It's a comfort food."

In fact, some diet experts say eating chocolate at the end of a meal, when you're already full, is the best time because it won't set off more cravings, as it might if you eat chocolate between meals when you're ravenous.

What To Do

For information on the history of chocolate, check out National Confectioners Association and the Chocolate Manufacturers Association. For another view on chocolate and some of its myths, visit the Center for Science in the Public Interest.