Think of your passion for chocolate as a way to digest history.

Chocolate dates back more than 2,000 years to Central America, where the Mayan Indians held cocoa beans in high regard, according to the National Confectioners Association. In its infancy, the beans were turned into a drink.

Christopher Columbus took the beans to Europe in 1502, but it was the Spanish explorer Hernando Cortes who popularized the bean when he combined it with sugar.

The Spanish began mixing cocoa beans with spices, such as cinnamon and vanilla. Remarkably, the Spanish were able to keep their ventures in cocoa cultivation and their creation of early cocoa drinks a secret from the rest of Europe for nearly 100 years.

Mass production of cocoa became possible with the introduction of the steam engine, which mechanized the cocoa-grinding process.

In 1847, advances were made in the production of solid chocolate. In 1876 in Switzerland, milk was added, creating, of course, milk chocolate.

The first chocolate factory opened in America in 1765 in pre-revolutionary New England. The rest, as they say, is history.

Uncommon allergen

According to the National Institutes of Health, about 7 million Americans (5 percent to 8 percent of children and 1 percent to 2 percent of adults) have a true food allergy.

Eight major food allergens account for 90 percent of all allergic reactions: milk, eggs, peanuts, tree nuts (such as walnuts or almonds), soy, wheat, fish and shellfish.

Chocolate itself is an uncommon food allergen, although chocolate candies may contain other ingredients that can elicit allergic reactions.

The candy industry is on the forefront of ensuring that its products are properly labeled, said Susan Smith, a spokeswoman with the National Confectioners Association, based in Vienna, Va.

Finding chocolate for those with nut allergies can be challenging. Since a person can have a severe reaction if exposed to even trace amounts of nuts, chocolate made in a factory that uses nuts anywhere should be avoided.

"If a label says the product 'may' contain nuts, then a person with a nut allergy should stay away from that product," Ms. Smith said.

Tasty statistics

The popularity of dark chocolate, which now accounts for about 35 percent of the chocolate market, is on the rise, Ms. Smith said.

Premium chocolate, whether it's milk or dark, also is in demand. Sales of premium chocolates has increased 30 percent each year for the past three years.

Flavor combinations, such as combining salty with sweet, also are becoming more prevalent, Ms. Smith said.

Sixty percent of candy sold in the country is chocolate, making it the No. 1 choice among sweets.

Chocolate sales are highest at Halloween, Ms. Smith said. Easter wins second place, and Christmas is third.

But for shops that sell custom or specialty chocolate, December may be the busiest time of year.

Chocolate is included in gift baskets, placed in stockings and sent by corporations to their best customers. "Chocolate is everywhere at Christmastime," Ms. Smith said.

For more on chocolate, including its history, food allergies and a summary of how chocolate is made, visit www.candyusa.org.