Craving sugar? New research reveals why our brains seek the next hit

A desire to eat sugary foods is something familiar to many of us but new research conducted by Yale University found that the reason sugar is so hard to resist is because it activates two distinct reward centres in the brain stimulating both a desire to taste something sweet and a desire for calories.  The research, published last week in Nature Neuroscience, found that the latter is more important and when given the choice between pleasant taste and no energy, or unpleasant taste and energy, the brain will choose energy.

This discovery was made when researchers fed mice sugar with an appealing sweet taste but with no calorific content, while they fed others foul-tasting sugar laced with chemicals but which did contain calories.  The team used optogenetics — a new technique allowing neurons to be activated, using light — to compare neural activity involved in each feeding session. They found that both the sweet taste and the energy content of sugar register in the striatum, a region of the brain responsible for reward processing, but that the two signals were processed separately.  However, the mice consistently chose to eat the calorific bad tasting sugar over the zero-calorie sugar, leading the researchers to conclude that the sugar-responsive areas of the brain are hardwired to prioritize quantity of calories over quality of taste.

This work has important implications for the use of artificial sweeteners and could explain why they are less satisfying, compared to sugar.  The researchers also hope their findings will help develop new approaches aimed at curbing excess sugar intake in those who are prone to overconsumption.

Source: Pierce JB, et al. Nature Neuroscience . 2016.

Photo Credit: Uwe Hermann