Not all sugar is the same … at least as far as your body is concerned. A recent study found that consuming the sugar found in corn syrup and fruit, fructose, seems to make the brain more likely to respond to images of food.
The study was published recently in the Proceedings of the National Academies of Science. Researchers from the Keck School of Medicine at the University of Southern California tested the reactions of 24 people to fructose and glucose. In addition to sparking a response to pictures of food, eating fructose was more likely to make the study participants choose a high-calorie food instead of a monetary reward.
To test reactions to the two sugars, volunteers drank a 10-ounce drink that was one-fourth sugar. Researchers took blood samples from the participants to measure their blood chemistry and sugar levels. They also performed brain scans of the volunteers while showing them food and non-food images and quizzing them about their hunger.
Fructose did more prompting of the brain’s frontal cortex, which plays a role in reward processing. The fructose also produced greater activity in the visual cortex when food images were shown, suggesting that fructose can affect cravings. All of that made the volunteers more likely to choose a food reward over a monetary reward.
Researchers also noted that fructose did not cause insulin levels to spike. Without insulin, the brain does not get a message from the body to stop eating. The scientists say that missing signal could be what drives food cravings after consuming fructose.
So is it a good idea to give up fruit because it contains fructose? Not necessarily. Fruit contains fiber, which slows down food absorption and can make you feel full.
But you may want to reconsider the strawberry jelly-filled doughnuts.