Some evidence from animal studies suggests that sugar can be addictive. A Princeton University research team has shown that lab rats accustomed to sugar display the cravings and the relapses that signal addiction, as well as brain changes similar to those associated with addiction to narcotics and nicotine. For example, the investigators found that the brain chemical dopamine is released when hungry rats drink sugared water and that a surge of dopamine occurs in the brains of hungry rats that binge on sugar. Over time, these increased dopamine levels resulted in fewer of a certain type of dopamine receptor and more opioid receptors in the animals' brains. The same studies showed that rats deprived of sugar exhibited anxiety characteristic of withdrawal.
Other intriguing findings in this area come from the Monell Chemical Senses Center in Philadelphia. In 2010, a research team from the center published a study showing that children's response to intense sweet taste is related to a family history of alcoholism and a child's own report of depression. The investigators noted that sweet taste and alcohol activate many of the same reward circuits in the brain. They found that among those kids who had both a positive family history of alcoholism and also reported depressive symptoms, liking intense sweetness was more common than among the other children. These kids preferred a level of sweetness equivalent to about 14 teaspoons of sugar in a cup of water - twice the sweetness of a cola.
While we can't say on the basis of these findings that humans can become addicted to sugar as they can to drugs, we know that individuals can experience very strong cravings for certain foods that they describe as "addictions." Cravings affect 97 percent of all women and 68 percent of men. Women tend to crave sweets while men go for meat.
Cravings for chocolate and other comfort foods may be explained in part by the fact that these foods increase levels of serotonin, the brain chemical that may be involved in depression. The female hormones estrogen and progesterone may also play a role, particularly in the cravings of pregnant or premenstrual women.
You can try to control cravings, including sweets, by paying attention to what sets them off and then focusing your attention elsewhere. Hypnotherapy can help, too, and if stress is a factor, you should practice breathing techniques or progressive relaxation and try to get more exercise. In addition, mindfulness meditation has been shown to help reduce the frequency of compulsive binge eating in some individuals.
Andrew Weil, M.D.