Team deciphers sugar's siren song

January 25, 2016
brain
Credit: public domain

Sugar's sweetness and calorie content combine to give it lethal power to destroy diets, many scientists have assumed. However, new study by Yale University researchers says the brain responds to taste and calorie counts in fundamentally different ways. And only one of these responses explains why most New Years' resolutions have already disappeared under a deluge of Boston Crème Pies.

It's the brain's desire for calories—not sweetness—that dominates our desire for sugars, according to the study appearing Jan. 25, 2016 in the journal Nature Neuroscience.

"It turns out the brain actually has two segregated sets of neurons to process sweetness and energy signals," said Ivan de Araujo of the John B. Pierce Laboratory and senior author of the study. "If the brain is given the choice between pleasant taste and no energy, or unpleasant taste and energy, the brain picks energy."

Both and nutrient value register in the striatum, an ancient region of the brain involved in processing rewards. Humans have a sweet tooth as one way to ensure we eat enough to give our large brains enough calories to operate at peak efficiency. However, the Yale team studying the brains of mice showed that signals for taste and nutrients are processed in two separate areas of the striatum, the ventral and dorsal, respectively. Signals about the value of taste are processed in the while nutritional value was processed in the dorsal striatum. The dorsal striatum remained responsive to energy even when calories fed to mice were paired with a very aversive taste.

The researchers then asked which signal had more control over eating behavior. Mice fed both sugar with sweet taste but no calories or sugar that contained calories but was altered to taste horribly preferred the sugar with . When neurons in dorsal striatum were activated by light a technique called optogenetics, mice also ate copious amounts of bad-tasting sugar.

"The sugar-responsive circuitry in the is therefore hardwired to prioritize calorie seeking over taste quality," de Iraujo said.

The authors hope findings help spur new strategies aiming at curbing excess sugar intake.

Explore further: How weight-loss surgery reduces sugar cravings

More information: Separate circuitries encode the hedonic and nutritional values of sugar, DOI: 10.1038/nn.4224

Related Stories

How weight-loss surgery reduces sugar cravings

November 19, 2015

Weight loss surgery curbs the sweet tooth by acting on the brain's reward system, according to a study published November 19 in Cell Metabolism. The researchers found that gastrointestinal bypass surgery, which is used to ...

Carbonation alters the mind's perception of sweetness

September 17, 2013

Carbonation, an essential component of popular soft drinks, alters the brain's perception of sweetness and makes it difficult for the brain to determine the difference between sugar and artificial sweeteners, according to ...

Children's ability to detect sugar varies widely

December 14, 2015

Everyone knows that children love sweets, but ever wonder why some kids seem to want more sugary food than others? It could be because they need more sugar to get that same sweet taste. According to new research from the ...

Recommended for you

Researchers identify brain network organization changes

May 25, 2017

As children age into adolescence and on into young adulthood, they show dramatic improvements in their ability to control impulses, stay organized, and make decisions. Those executive functions of the brain are key factors ...

Fathers' brains respond differently to daughters than sons

May 25, 2017

Fathers with toddler daughters are more attentive and responsive to those daughters' needs than fathers with toddler sons are to the needs of those sons, according to brain scans and recordings of the parents' daily interactions ...

How fear can develop out of others' traumas

May 25, 2017

What happens in the brain when we see other people experiencing a trauma or being subjected to pain? Well, the same regions that are involved when we feel pain ourselves are also activated when we observe other people who ...

Scientists demonstrate the existence of 'social neurons'

May 25, 2017

The existence of new "social" neurons has just been demonstrated by scientists from the Institut de neurosciences des systèmes (Aix-Marseille University / INSERM), the Laboratoire de psychologie sociale et cognitive (Université ...

Babies' slow brain waves could predict problems

May 25, 2017

The brain waves of healthy newborns – which appear more abnormal than those of severe stroke victims – could be used to accurately predict which babies will have neurodevelopmental disorders.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.