10/29/2009 - 3:49pm

Sometimes, Sugar Might Be Good For You

We all know by now that sugar is generally not a good thing for our bodies- empty calories, diabetes, bad for your teeth- there is not much to be said for sugar...until now.

Prof. Roy Baumeister, in his psychology lab at Florida State University in Tallahassee, asked subjects to perform a mentally taxing task (watching video while being careful to ignore random words scrolling across the bottom of the screen).

After finishing this task, the subjects were given some lemonade to drink. Some of the subjects drank lemonade made with sugar and others with a sugar substitute. Fifteen minutes elapsed, in order to give the sugar a chance to reach their brains, and then the subjects were asked to perform another cognitively challenging task (choosing an apartment based on descriptions of various options).

The results were a bit surprising.

The subjects who drank the sugar-free lemonade were significantly more likely to choose impulsively and make poor decisions. Dr. Baumeister attributed this to “exhaustion of the prefrontal cortex.” The subjects who drank the sugar, however, were better able to restore function to that area of the brain.

This might explain why we get cranky when we are hungry or tired. Our brains are less able to suppress the negative emotions that little annoyances generate. That hungry bad mood might be caused by a pre-frontal cortex that is too tired to work.

So, a little bit of sugar now and then might actually keep our brains sharper.