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Fructose may trigger brain changes that cause you to overeat


It's long been known that sugar is a direct culprit when it comes to weight gain.

But now a new study suggests the reason for that may be different than we thought. Yes, eating sugar causes changes in blood sugar that can trigger weight fluctuations--not to mention that it's loaded with calories--but it may also trick the brain into signaling that you're still hungry, even when you're not.

Sugars aren't created equal

It appears that fructose is the real culprit, which is different than glucose (table sugar is about half fructose and half glucose). In the study, published in the Journal of the American Medical Association, researchers used MRI scans to monitor the blood flow in the brains of 20 young people of normal weight after they had consumed drinks with either fructose or glucose. The sessions testing the effects of glucose were conducted weeks apart from those testing fructose.


It appears that, after consuming glucose, the areas of the brain associated with reward and desire for food were suppressed or shut off. With fructose, however, those changes weren't witnessed.

"As a result, the desire to eat continues -- it isn't turned off," said Dr. Robert Sherwin, chief of endocrinology at Yale University School of Medicine in New Haven, Conn.

Researchers note that the study was small and does not necessarily prove that fructose causes weight gain, but they think it's an important piece of evidence to study further--especially with the obese population.

The best way to avoid consuming too much fructose, the authors say, is to cook at home and minimize processed foods.

"Try to avoid the sugar-sweetened beverages," said Dr. Jonathan Purnell, an endocrinologist at Oregon Health & Science University. "It doesn't mean you can't ever have them," but make sure to watch portion sizes and frequency of consumption, he noted.

Source: CBS News