Drugs and Food

Although the war on drugs has been fought since the 1980s, drug use, abuse, and dependence is still a part of our society. The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Revised, outlines eleven classes of drugs with which people experience significant problems. Although many drugs are illegal, legal substances continue to have a significant public health impact. Tobacco use in the United States is still the number one cause of preventable death in the United States. Alcohol is one of the most commonly used mind-altering drugs in American culture, with up to 90 percent of people consuming it at some point in their lifetime. The lifetime risk of alcohol dependence is at approximately 15 percent, with an overall rate of current alcohol dependence on an annual basis of approximately 5 percent. The prolific use of alcohol, tobacco, and other substances in American society has illuminated the indelible link between drug and food consumption, which spans the emotional, social, and biological realms.

Perhaps the most apparent connection between food and drugs is emotional and social. As alcohol is the one of the most commonly used and socially acceptable addictive drug in American culture it provides the clearest examples. Socially, many get-togethers are centered on a good meal, a strong drink, or a combination of the two, as evidenced by the prolific variety of bars and restaurants available. Additionally, both food and alcohol are woven into the culture of celebration and commiseration.

Birthday parties begin with cake as the main event, but in later years, 21st birthday shots take center stage. Similarly, cultural representations of consoling oneself with a pint of ice cream are as well known as crying into one's beer. The special ability of food and alcohol to regulate emotion has been associated with problematic use. People who are motivated to consume alcohol or food to alter or cope with negative emotions are more likely to experience out of control eating and problem drinking.

Advances in scientific methodology have also begun to shed light on the neurobiological links between food and drugs. Imaging studies of the brain have found a similar pattern of brain activation when participants have been presented with either a palatable food or a drug of abuse.

More specifically, food and alcohol both produce part of their behavioral reinforcement by releasing endogenous opioids and dopamine in the limbic system. Depending on how rewarding the food is to the participant, the dopamine system reacts in a similar manner as it does with drugs of abuse, by releasing dopamine in the nucleus accumbens. Additionally, other brain imaging studies in humans have suggested that areas of the brain involved with drug consumption are also involved in food consumption and the neurobiological processes that drive emotional eating.

Further, positron emission tomographic imaging studies have shown that obese individuals and individuals who are substance dependent both have significantly lower dopamine D2 receptor levels in the brain, with the lowest D2 receptors in the participants with the highest BMIs. Lower dopamine D2 receptors in obese individuals would make them less sensitive to rewarding experiences, thus they may be vulnerable to excessive food intake as a mechanism to temporarily compensate for this deficiency.

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