High fructose corn syrup is in practically everything we eat these days, and doctors and health nuts have been waxing poetic about its dangers for years. Now, a new study from Yale University School of Medicine may finally prove them the right: fructose is making us fat.
In the study, 20 healthy adult volunteers drank a cherry-flavored beverage that had been sweetened with either fructose or glucose. Scientists then used fMRIs to monitor any changes in the brain's reward and motivation processing as well as the hypothalamus, which plays a role in regulating appetite.
While glucose was found to lower hypothalamic activity, fructose actually lead to a spike, albeit a small one. The two simple sugars may appear molecularly similar, but the body metabolizes fructose in way that triggers less insulin production than glucose. Therein lies the rub: it's insulin that tells our body when to put the fork down.
This is still a relatively small study, though, and certainly doesn't provide definitive proof that fructose causes obesity. It does, however, suggest a strong link. Dr. Jonathan Purnell, an endocrinologist at Oregon Health & Science University, cites a common counterargument that basically boils down to "just don't eat as much." But with our society's growing dependence on high-fructose corn syrup, this seems easier said than done—and science agrees. [Business Insider]