Glucose and fructose are both simple sugars, but scientists have long suspected there are differences in the way your body processes them.
In a new study, researchers scanned the brains of nine subjects after they got an infusion of equal volumes of glucose, fructose or saline. The brain scans were looking at activity in the hypothalamus, a part of the brain which plays a key role in setting appetite levels and controlling production of metabolic hormones.
According to the Chicago Tribune:
“The researchers ... found that ‘cortical control areas’ -- broad swaths of gray matter that surrounded the hypothalamus -- responded quite differently to the infusion of fructose than they did to glucose. Across the limited regions of the brain they scanned ... glucose significantly raised the level of neural activity for about 20 minutes following the infusion. Fructose had the opposite effect, causing activity in the same areas to drop and stay low for 20 minutes after the infusion.”