Scientists and physicians have been blaming sugar on the worldwide epidemic of obesity, and now a new study out of Yale University suggests that fructose in particular might affect the brain in a way that actually triggers overeating.
The study by the Yale University School of Medicine and published in the Journal of the American Medical Association (JAMA), shows that the brain processes the two forms of simple sugar—fructose and glucose—differently, which has an impact on appetite, feelings of fullness and potential overeating. Glucose suppresses the activity on the regions of the brain that promote the desire to eat, while eating fructose, (as well as high-fructose corn syrup) doesn’t cause the brain to register the feeling of being full, which can lead to weight gain.
Glucose and fructose are found in many fruits and vegetables, and simple table sugar is sucrose, comprise of half fructose and half glucose. Consumption of high-fructose corn syrup, found in most soft drinks and processed foods, has been linked to higher rates of obesity in recent years. According to the Associated Press (AP), one-third of U.S. children and teens and more than two-thirds of adults are obese or overweight.
Researchers at Yale, lead by corresponding author, Dr. Robert Sherwin, professor and section chief of endocrinology at Yale School of Medicine, conducted magnetic resonance imaging (MRI) studies of young, healthy, non-obese adults’ brains to assess changes in cerebral blood flow in the brain after they ingested glucose or fructose.
This small study doesn’t prove that either fructose or high-fructose corn syrup definitely cause obesity, but it adds evidence that they might play a role in overeating. Dr. Jonathan Purnell, an endocrinologist at Oregon Health & Science University, wrote an editorial that appears alongside the study results in the JAMA article, that the findings replicate those found in previous animal studies, but “this does not prove that fructose is the cause of the obesity epidemic, only that it is a possible contributor along with many other environmental and genetic factors.”