The Oregon Research Institute recently published a study in Science magazine that seems to provide a link between obesity and what the researchers term a “blunted striatal response” to food intake. In other words, people who overeat do so because of a “compromised signaling” within their brains’ pleasure and reward centers that causes them to derive less enjoyment and fulfillment from calorically-dense foods (which in this study involved chocolate milkshakes).
The scientists go on to explain that the subjects most at risk for obesity in the study possessed a genetic variation known as the Taq1A1 allele, which is becoming more prominent in addiction studies as the presence of this genetic factor appears to lead to “higher reward dependency” due to a lower number of dopamine D2 receptors.
It’s an interesting result, but what I don’t particularly like are the researchers’ conclusions and recommendations:
These results suggest that individuals with hypofunctioning reward circuitry are at increased risk for unhealthy weight gain,” said Stice. “Thus, it is possible that behavioral or pharmacological interventions that correct this reward deficit may help prevent and treat obesity – an avenue we are currently pursuing in our research.
It’s the “pharmacological interventions” part that disturbs me…
The bottom line is that, while this study indicates a potential link between a “compromised reward circuitry” in the brain and an individual’s propensity towards obesity, it doesn’t really explain how this reward circuitry became compromised in the first place. Instead, the conclusions appear to indicate that this is a genetic factor that can be addressed with some sort of “magic pill” such as a lower intensity dopamine agonist (hey, while we’re at it, let’s just prescribe Requip “off label” right now…).
The key is, your “reward circuitry” evolved to its current state as a result of ages of exposure to an environment where calorically-dense food sources were quite scarce. The only real pure sugar source available to our paleolithic ancestors was honey, and these sources were typically defended by hordes of savage bees. Contrast that with our modern society where high-fat, high-sugar foods are readily available in abundant quantities (just check out the snack section of any grocer or convenience store).
So it doesn’t take a “brain scientist” to figure out that constant unnatural bombardment and hyperstimulation of these neural pathways is bound to “short circuit” something sooner or later.