Scientists have shown, using imaging tests, that fructose can trigger brain changes that lead to overeating. They found that after drinking a fructose beverage, the brain doesn’t register the fullness feeling as it does when simple glucose is consumed.
Scientists think that even though this is a small study and that it doesn’t prove that fructose or high-fructose corn syrup causes obesity, it adds evidence that to the fact that they may play a role. These sugars are often added to processed foods and beverages, whose consumption has risen dramatically since the 1970s along with obesity.
A third of US children and teens, as well as more than two-thirds of adults are obese or overweight. Even though different types of sugars contain the same amount of calories, they are metabolized differently in the body. Sucrose is half fructose, half glucose. High-fructose corn syrup is 55% fructose, 45% glucose. Nutrition experts think that these sweeteners pose special health risks, but not all of them are convinced of this, especially in the food industry. Doctors claim people eat too much sugar in all forms.
The scientists used fMRI scans to track blood flow in the brain of 20 normal-weight people before and after they had drinks containing glucose or fructose in two sessions, weeks apart. Drinking glucose turns off or suppresses the activity of areas of the brain that are critical for reward and the desire for food¹, states Robert Sherwin, an endocrinologist at Yale University.
The imaging results mirrored how hungry the people felt, as well as what earlier studies found in animals. Fructose is detrimental to food intake and weight gain, when compared to glucose². The researchers are now testing how obese people react the same way to fructose and glucose as normal-weight people.
In order to limit the damage, people should cook more at home and eat less processed foods containing fructose and high-fructose corn syrup. The size of sugar-sweetened beverages and how often they are consumed should be limited as well.
“Effects of Fructose vs Glucose on Regional Cerebral Blood Flow in Brain Regions Involved With Appetite and Reward Pathways” by Kathleen A. Page, MD; Owen Chan, PhD; Jagriti Arora, MS; Renata Belfort-DeAguiar, MD, PhD; James Dzuira, PhD; Brian Roehmholdt, MD, PhD; Gary W. Cline, PhD; Sarita Naik, MD; Rajita Sinha, PhD; R. Todd Constable, PhD and Robert S. Sherwin, MD, 2 January 2013, JAMA.
“Fructose Ingestion and Cerebral, Metabolic, and Satiety Responses” by Jonathan Q. Purnell, MD and Damien A. Fair, PA-C, PhD, 2 January 2013, JAMA.