Chocoholics Beware: Addiction could be worse than you think…
A recent study by the Scripps Research Institute Committee on the Neurobiology of Addictive Disorders reveals an interesting fact about food addiction. While it has been known that sugary or fatty foods can cause an addiction much like that of heroin or alcohol, Pietro Cottone and his team proves that the “sugar high” isn’t the only reason for the addiction. In fact, in his studies with rats, he found that there is also a negative reinforcement system, much like that found in drug addicts, which can cause feelings of anxiety during a withdrawal of the sugary or fatty foods. This increases the probability for continued addiction. Hypophagia, or under-eating of regular (non-preferred) foods, is common when rats and people are influenced by food addiction. Cottone’s hypothesis involved a non-nutritional explanation for this phenomenon, which is commonly credited to an “energy compensation” theory. The nutritional explanation of hypophagia is that it stems from a “corrective energy homeostasis mechanism which opposes weight gain.”
The study to test this hypothesis was conducted with male Wistar rats that were fed a chow diet (A/I) which was preferred to their regular Chow, and were also offered the choice of a chocolate-flavored chow. The rats were given the regular Chow for 5 days, and then were given the highly preferred sugary chow for 2 days. While they ate roughly the same amount of regular food each day, the rats over-ate the sugary chow, and then under-ate the less-preferable but equally acceptable chow (hypophagia). The group used A/I as well as the sugary chow, which had the same initial levels of energy intake and weight gain, to prove that the rats’ addiction was more than just nutritional. Given their similar caloric value, the rats still preferred and overate the chocolate diet more than the preferred A/I chow.
Ultimately, the group discovered that the rats going through chocolate withdrawal spent more time in corners of a maze, rather than the open parts, illustrating the previously mentioned anxiety effect. They found the anxiety to be attributed to corticotropin-releasing factor (CRF), which is involved in stress-response in the brain (commonly found in drug and alcohol withdrawal cases). This research marks the first time this factor was indicated in a type of food, or chocolate addiction. Could a CRF blocker be the answer to every chocoholic’s addiction? Cottone says yes.
What I found most remarkable about this study was the severity of chocolate or food addiction, and how it could be equated biologically to alcohol or drug addiction. This study suggests that on-and-off dieting could increase addiction and anxiety in withdrawal of that addiction.
PNAS, 2009. DOI: 10.1073/pnas.0908789106