[youtube //www.youtube.com/watch?v=lEXBxijQREo]

Post by Eliza Barclay, The Salt at NPR Food (1/16/14)

Last week, I reported that scientists are working their way toward a consensus that sugar is addictive. While some researchers are still hesitant to liken sweet stuff to drugs or alcohol, the evidence is accumulating to explain why some of us really struggle to resist or moderate our sugar intake. (I count myself among them.)

I mentioned a new book called Why Diets Fail by Nicole Avena, a neuroscientist and research psychologist at Columbia University who has done a lot of work in this area. She's particularly interested in the neurotransmitters and brain receptors involved in eating. In lab experiments with rats, she's shown how overeating tasty foods (like sugar) can produce changes in the brain and behavior that resemble addiction.

Avena has also just put out a clever TED-Ed video with colorful visuals to help explain the details of just why sugar makes our brains go bonkers.

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As the video shows, the key player in the reward system of our brain — where we get that feeling of pleasure — is dopamine. Dopamine receptors are all over our brain. And doing a drug like heroin brings on a deluge of dopamine.

Guess what happens when we eat sugar? Yes, those dopamine levels also surge — though not nearly as much as they do with heroin.

How sugar affects the brain - Nicole Avena, animation by STK Films.

Still, too much sugar too can steer the brain into overdrive, the video says. And that kickstarts a series of "unfortunate events" — loss of control, cravings and increased tolerance to sugar. All of those effects can be physically and psychologically taxing over time, leading to weight gain and dependence.

The takeaway is pretty clear: If you're sensitive to sugar and inclined to indulge in a super sugary treat, do it rarely and cautiously. Otherwise, there's a pretty good chance that your brain is going to start demanding sugar loudly and often. And we're probably better off without that extra voice in our head.

Copyright 2014 NPR.

Nicole AvenaNicole Avena

Why Sugar Makes Us Feel So Good