Overeating? Blame fructose
Fructose is a low-cost sweetener found in many foods and beverages. Some experts are concerned that this trend may be contributing to our growing epidemic of obesity. Such concerns are likely to increase after recent research suggests that the brain may perceive fructose differently, and that this may lead to overeating. In the study, published in the Jan. 2, 2013, Journal of the American Medical Association, volunteers underwent a brain MRI before and after drinking a beverage made of pure glucose or pure fructose. The results were telling: the areas of the brain associated with appetite, reward, and motivation responded differently to glucose than fructose. Fructose seemed less able to signal the brain that sufficient food or drink had been consumed—likely because fructose cannot enter the brain from the bloodstream like glucose can. As a result, fructose may not turn off the desire for sweets, and lead to overeating and weight gain. Because table sugar is 50% fructose, this work offers another reason to cut back on the consumption of sugar-sweetened beverages and foods.