Of all the traditions surrounding St. Valentine's Day, the gift of chocolates is, perhaps, among the most honored and long-standing. Besides tradition, the reason for the popularity of chocolate as a Valentine's Day gift may have something to do with its complicated chemistry.

Researchers have known for some time that chocolate contains certain enzymes that enhance and trigger feelings of well-being, sometimes thought to promote or mimic those feelings associated with being in love. Recent studies suggest chocolate contains both chemicals beneficial to one's health, and pharmacologically active substances, similar to marijuana that promote feelings of well-being.

The latter phenomenon has been well known for centuries. When chocolate, a native American food, first arrived in Europe, it was a treat only for the very wealthy. Its popularity immediately spread throughout the upper classes following its introduction in the first decades of the17th century.

One of the earliest first-hand descriptions of the pleasures of chocolate, which was at first enjoyed only as a hot drink, comes from Madame de Sevigne, the writer and denizen of the French court. She is quoted in Waverly Root's authoritative history of food:

"It [chocolate] flatters you for a while, it warms for an instant; then, all of sudden it kindles a mortal fever in you."

Chocolate's reputation as a love potion and the tradition it has engendered is responsible for Valentine's Day holiday sales of $1 billion last year. This year, over 35 million boxes of chocolate candy are expected to be sold in the U.S. alone.

Besides its reputation as a treat for lovers, medical research has shown that chocolate, which is derived from cocoa beans, contains large quantities of flavonoids, a natural antioxidant associated with reduced risk of cardiovascular and other diseases.

Bio-flavonoids are found in the pigments of plants. Besides chocolate, other flavonoid-rich foods, recently touted for their cancer fighting, immune system boosting and heart health-giving properties are red wine, green and black tea and certain fruits such as blueberries.

Exactly how much chocolate one has to consume to reap the suspected benefits of eating chocolate is uncertain. Unsweetened dark chocolate contains the most antioxidants, about 400 mg per 40 gram serving. Semi-sweet and milk chocolate provide less.

The potential of chocolate becoming a popular 'health food' has chocolate manufacturers and candy companies eagerly modifying production methods to maximize the amount of the suspected health-giving compounds.

As if most of us need an excuse to consume more chocolate! 90 percent of Americans admit to having some chocolate every day. On average, Americans eat about twelve pounds of chocolate a year. Worldwide, over 600,000 tons of chocolate are consumed each year.

An ounce of solid chocolate contains about 150 calories, 50 percent of those from fat. Some premium chocolate has as much as 70 percent fat. Chocolate clearly belongs at the very apex of the USDA food pyramid. But enjoyed in occasional small quantities, even people on restricted diets may partake of this special treat.

The very best chocolate, that most prized by serious pastry chefs and confectioners for its richness and flavor, is imported. Valrhona from France, Lindt from Switzerland and Callebaut from Belgium lead the list.