The most recent publication on the role of dopamine and dopamine receptors appears in the March 2010 edition of "Neuroscience" - a well known and respected professional journal. In effect, the researchers found a significant difference among laboratory animals who were "over-fed" and exposed to unlimited amounts of sugar laden and high glycemic foods as they developed an "addiction-like reward deficit" in their brain's dopamine receptors. Translation - over time, when over eating highly "palatable" foods (e.g. sugar, high fat foods) they developed deficits in their ability to properly assimilate the neurotransmitter dopamine. Deficits in dopamine are seen with cocaine addicts when they are "crashing" and withdrawing from cocaine - they become depressed and hyperphagic (their appetite becomes almost insatiable). Likewise, the deficit in dopamine for compulsive eaters and bulimics seems to evolve over time with the result being a biological (addiction) to overeating. For the bulimic, the misguided attempt to deal with this is purging, for the compulsive overeater, the attempt is yet another "diet".

Hence, the cocaine user becomes an abuser, then an addict with his brain chemistry (dopamine receptors) disrupted for an extended period of time. The only relief is...more cocaine. The phenomenon of tolerance takes hold and the addict "needs more  and more of the substance to achieve the same effect".

The "food addict" may begin abusing food and developes a similar "tolerance" to refined carbohydrates (sugar, flour) and, likewise, alters the brain's (reward) structure (doipamine receptors) and the physical addiction to overeating takes hold.

As with cocaine addicts, it's likely that over any extended period of time, the mechanisms responsible for manufacturing and making available dopamine at normal levels will re-emerge... provided the "addict" adheres to a prescribed course of treatment (e.g. abstains from the offender - cocaine or, for the food addict, high glycemic (fat and sugar ladden) foods.

The "solution" becomes abstaining" from the offending agents. Those with an eating disorder may need to consider a food plan that does not evoke an addiction like craving- namly staying clear of "binge foods" - which typically are sugar and flour laden or high glycemic foods.

Reference: Laboratory of Behavioral and Molecular Neuroscience, Dept. of Molecular Therapeutics - Published 3/2010 in Nature Neuroscience

Summary: Marty Lerner, Ph.D.