When it comes to the sugars that we eat, would you believe that our bodies may respond more positively to some rather than others? It's a pretty simple assumption that our bodies may respond differently to each sugar we ingest, but it turns out that the physiological responses and mental associations made are far more complex than even researchers in neurobiology could have ever assumed. In a new study published this week in the journal PNAS, researchers with the University of Southern California investigated appetite responses and food choices with regards to ingestion of fructose versus glucose. And what the researchers found was that fructose was far more likely to be dangerous to your diet.
Looking to determine just how different the sugars' effects were on the brain, hormone and appetitive responses of their test subjects, researchers led by Kathleen A. Page of USC's Department of Internal Medicine worked with 24 healthy volunteers who underwent two sessions of functional magnetic resonance imaging (fMRI) to reveal just how differently the brain acted after being fed different sources of sugar. While the biochemistry for how the sugars are digested is similar, the researchers found that the body's response to the two are far from the same. In fact, fructose may reward poorer dietary choices and even prompt you to eat far more than your diet says you should.
"Obesity is a major public health problem, and increases in the consumption of fructose as a sweetener may be an important contributor to the current obesity epidemic" Page says. "Fructose compared with glucose may be a weaker suppressor of appetite. These findings suggest that ingestion of fructose relative to glucose activates brain regions involved in attention and reward processing, and may promote feeding behavior."
Using sugary-sweet drinks as their model for fructose and glucose ingestion, the researchers followed the biological tests of hormone and blood glucose levels, with food-approach behavioral tests to see just how hungry you could be after ingesting the two sweeteners. Though the fMRI results revealed higher brain activity in the region that deals with rewards, indicating a higher-ranking of this sugar amongst others that the body may encounter, the researchers also came to find that subjects were left dissatisfied and hungry shortly after fructose consumption.
What does this mean for you?
Well, while physicians and researchers have been asking you to steer clear of high-fructose corn syrup for quite some time now because of the high number of calories associated with the sweetener, it turns out that there's a reason why we interpret this treat to be sweeter than most. But in spite of its great taste, that constant nagging hunger will undoubtedly get the best of you on a fructose diet, so why not opt for a more filling sugar instead. Because even though you'll think that you're happier with fructose instead, it may be prompting you to eat far more than your fair share.
"We observed that ingestion of fructose compared with glucose resulted in a greater appetite and desire for food and greater willingness to give up long-term monetary rewards to obtain immediate high-calorie food rewards" Page says. "These disparate brain and behavioral responses to fructose relative to glucose may promote appetitive behavior."
