Why do people love chocolate so much? Is it the smell, the taste, the texture or something more?

Chocolate’s ingredients have a significant impact on brain chemistry, says Bankole A. Johnson, M.D., Ph.D., of The University of Texas Health Science Center at San Antonio. Dr. Johnson, the William and Marguerite S. Wurzbach Distinguished Professor in the departments of psychiatry and pharmacology, is one of the country’s foremost researchers of addictive behavior, particularly in the areas of alcoholism and cocaine abuse. Chocolate is a drug, too, he notes, with specific pharmacological actions.

The sweet stuff contains cannabinoids, the compounds responsible for the high of marijuana. The concentration is too low to cause an effect. More significantly, chocolate contains caffeine and two substances, tyramine and tryptophan, that the brain converts into the feel-good chemicals dopamine and serotonin.

“It stimulates the brain’s pleasure centers,” Dr. Johnson says.

The result: We like chocolate, and we want to enjoy it again and again. Our memories create a powerful conditioned response. “Even opening the wrapper and looking at the contents starts your serotonin fibers firing,” Dr. Johnson says.

Too much chocolate causes a headache, however. “That’s probably due to the rush of serotonin, but no one has really studied it,” Dr. Johnson says. “It’s interesting that while too much serotonin can cause headaches, other medications that interact with serotonin in a different way are used to treat migraine and cluster headaches.”

Dr. Johnson reports that the Southwest Texas Addiction Research and Technology (START) Center is a specialized facility where faculty members develop new interventions in the areas of alcoholism and drug addiction. The START Center approach integrates neuroscience and psychosocial interventions into treatment design.

“We rarely see cases of chocolate addiction, but we have seen many people who wanted to give up caffeine,” Dr. Johnson says. “An overwhelming number of people are able to enjoy chocolate with no problems.”

Dr. Johnson is deputy chairman for research in the department of psychiatry and chief of the department’s alcohol and drug addiction division. His research team receives support from the National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, and various other public and private funding sources.

Dr. Johnson, who received much of his education in England, is fond of both dark and white Belgian chocolates. “I think Brussels is the chocolate capital of the world,” he says. “One of the few undiluted pleasures nowadays is tasting real chocolate.”

The rate of chocolate consumption is astounding. According to a story on ABCNews.com, the U.S. retail chocolate industry brings in $13 billion a year, and the average American eats more than 11 pounds of chocolate per year. That’s a lot of Snickers^® for our sweethearts and us.

Contact: Will Sansom