What is your perception of a food addict? For most, it would conjure images of an ill disciplined glutton, perhaps even someone irresponsible and obese. What if the truth is that the individual does not have control over their decision to eat; that the compulsion to eat is driven by the biochemistry of their brain? Would that knowledge make us more empathetic in terms of eating disorders? Probably so. As someone who is passionate in learning about nutrition, I see it as my duty to understand the drivers of eating disorders, including compulsive eating and food addiction. Science has provided some answers to what I suspected - that compulsive eating is not simply a behavioral problem but in many cases, is indeed a behavior driven by problematic physiological mechanisms.
I chanced upon the article "Curb Compulsive Eating Naturally", published in a free magazine Life Extension (1), which expounds that the same neurochemical mechanism that pushes people to eat uncontrollably are the same ones which drive people to drug addiction. The article goes further to explore the power of saffron in combatting this problem. But for the sake of brevity, I shall focus on the mechanisms of the neurotransmitters dopamine and serotonin, pertaining specifically to compulsive eating and food addiction.
According to a study done in 2010 by Johnson PM and Kenny PJ (2), the similarity between drug and food addiction lies in the reaction of dopamine receptor D2. Dopamine is released by pleasurable experiences such as food, sex and drugs. Consumption of drugs blocks dopamine retrieval thereby flooding brain with the neurotransmitter, and overstimulating receptors. Over time, the brain adapts by decreasing activity. However, the need for constant stimulation will draw people to consume more drugs, creating a vicious cycle. In the same way, consumption of excessive or junk food drives food addicts into compulsive eating.
Although this is the first time parallels have been drawn between drug and food addiction, the relationship between food and release of dopamine is a well established one. In an earlier study in 2002 by scientists at Brookhaven National Laboratory (3), it has been determined that the mere sight and smell of food spikes levels of dopamine. Even more interesting is the fact that obese subjects had elevated levels of dopamine but decreased levels of dopamine receptors.
While researching for serotonin's role in regulating the psychiatric nature of compulsive eating, I came across a study by Kaye, Walter in 2008 (4) which showed how disruptions to 5 H-T functions upsets emotional and reward pathways which also mediates feeding, hence exposing individuals to the possibility of disturbed eating behaviors, known as emotional eating or worse, compulsive eating. Additionally, in 1992, Blundell, J (5) had proven serotonin's central role in modulating feeding behavior lies in how nutritional information is being transcribed onto 5 H-T systems and also, in the distribution of 5 H-T neurons in the brain at locations known to be crucial for feeding. Based on these findings, the researchers showed how manipulation of serotonin could cause changes in feeding behavior.
This proves that our feeding behaviors can hardly be viewed in isolation from our psychiatric and physiological makeup. It is indeed heartening to learn that by targeting the neurochemistry of compulsive eating, which is the root of the problem, we might be in a better position to help food addicts, or at the very least, have more empathy for their predicament.
Sources:
1. Goepp, Julius. (2010). Curb Compulsive Eating Naturally. Life Ext. Sept-Oct 2010:29-35
2. Johnson PM, Kenny PJ. Scripps Research Institute (2010, March 29). Compulsive eating shares addictive biochemical mechanism with cocaine, heroin abuse, study shows. ScienceDaily. Retrieved September 23, 2010, from http://www.sciencedaily.com /releases/2010/03/100328170243.
3. New Addiction Link Found. U.S. Dept of Energy Research News. (2002, June 3) Retrieved September 23, 2010 from http://www.eurekalert.org/features/doe/2002-06/dnl-nfl061302.php
4. Kaye, W. (2008) Neurobiology of Anorexia and Bulimia Nervosa. Physiol Behav. 94(1): 121–135
5. Blundell, J. (1992) Serotonin and the biology of feeding. The American Journal of Clinical Nutrition. 55 (1 Supp): 156S-157S
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