Fructose may boost cravings for high-calorie foods
Eating right is complicated. According to new research at the University of Southern California, fructose, the sugar found in fruits, honey and corn syrup, increases activity in the brain's reward center and may actually ramp up our cravings for high-calorie foods.
The researchers had participants drink a 10-ounce glass of cherry-flavored liquid that contained two and a half ounces of fructose or glucose. However, before consuming the drink, study participants rated their desire to eat on a one-to-10 scale from “not at all” to “very much.” Then they drank the liquids and had MRI brain scans while looking at images of both food and neutral objects, such as buildings or baskets. As they did so, they rated their hunger using the scale. The volunteers were then presented with images of high-calorie foods and asked whether they would like to have the food now, or receive a monetary award a month later instead.
The results showed that compared with glucose, fructose seemed to produce greater responses to food cues in the orbital frontal cortex of the brain, which is a region that plays an important role in reward processing. The fructose drink also produced greater activity in the visual cortex when volunteers looked at images of food, which suggests increased cravings compared with glucose.
The researchers did emphasize that the results shouldn't encourage people to cut fruit from their diets, pointing out that fruit actually has a low amount of sugar compared with processed foods and soda, and the amount of fiber in fruit is more important to the body than the few grams of sugar. Much better to stop drinking so much soda or fruit drinks.