Neuroscientifically Challenged had a great post awhile back, Every Sweet Hath Its Sour, reporting on research that basically equates modern, processed food with drugs.

Why? As the Duke Health news release tells us, “Researchers at Duke University Medical Center have discovered that the brain can respond to the calorie content of food, even in the absence of taste.” An even better title summarizing this research is “Tasteless Food Reward.”

This March 2008 Neuron paper “Food Reward in the Absence of Taste Receptor Signaling” by Ivan de Araujo, Albino Oliveira-Maia and colleagues shows that high-calorie food can directly reinforce the mesolimbic dopamine system. This result overturns that common assumption that what we eat relies on conditioned preference, pairing taste with the ingestion of a particular substance, say, cops and their donuts. This assumption has been used to great effect in evolutionary medicine research—we evolved in a fat-, sugar- and salt-limited environment, and today our evolved tastes drive our excessive consumptions of fast food in the modern world.

Now the modern situation appears even more dire, for calories alone can also reinforce food consumption, at least in mice “which lack the cellular machinery required for sweet taste transduction.” The Tasteless Food Reward editorial by Zane Andrews and Tamas Horvath tells us that “de Araujo et al. show that mice lacking functional ‘sweet’ taste receptors (trpm5−/−) develop a preference for sucrose by activating the mesolimbic dopamine-accumbal pathway, solely based on calorie load.”

Continue reading “The Sugar Made Me Do It”