As much as it pains me to write this (I have a very strong sweet tooth), a recent article in Neurology has demonstrated that sugar has a negative impact on learning and other cognitive functions.  The study found a strong link between high glucose levels and poor performance on memory tasks.

The authors note that even in the absence of diabetes, “chronically higher blood glucose levels exert a negative influence on cognition.”  They add that “strategies aimed at lowering glucose levels even in the normal range may beneficially influence cognition in the older population.”

Despite this, I’ve been snacking on M&Ms while writing this.