Fructose or “fruit sugar” is the culprit that keeps you hooked onto unhealthy snacks and fuels your cravings to high-calorie foods, suggests researchers.
Trying to establish the effects of consuming different types of sugars on a person’s hunger levels, researchers at the University of Southern California in the U.S gave 24 healthy volunteers a cup of cherry-flavored liquid sweetened with glucose on one day. Thereafter the same group, some days later, was given a fructose-sweetened drink.
After each drink, each of the volunteers was hooked to a functional Magnetic Resonance Imaging (fMRI) machine and asked to rate their desire to eat something. Their reactions were mapped while being shown images of high-calorie foods like burgers and pizza as well as “neutral” or non-food items like baskets and bridges. Additionally, while drinking each of the liquids, volunteers were asked to choose between immediate food rewards and a monetary bonus in a month’s time.
As expected, the fructose-infused drinks appeared to steer the volunteers towards immediate food rewards. Moreover, their neural activity jumped in the orbital frontal cortex, which is associated with feelings of reward and attention when images of high-calorie foods were presented. Unsurprisingly, almost all tested reported that their desire to eat was stronger after drinking fructose.
As an added bonus to the research, it was observed that the plasma insulin response dropped drastically, which might be a good indicator on how fructose has a direct effect on our food choices, commented Kathleen A. Page, a member of the research team,
“Insulin is released when we consume glucose. The pancreas secretes insulin, and insulin drives glucose into cells so that it can be used for energy. But it also sends a signal to the brain that says ‘you’ve eaten.’ Fructose doesn’t stimulate insulin secretion, and if there’s no insulin, you don’t get the information that you’re full.”
In simpler terms, Fructose doesn’t allow the body to feel “full,” and the person is likely eat more than what is needed to fulfill a craving. However, Priya Tew from the British Dietetic Association suggests it might not be a good idea to cut fructose outright. She points out,
“Fructose in fruit is tied up within the cellular structure of that fruit and the fiber content slows down the release of the fructose into the bloodstream. Fruit also has high water content and takes a while for us to chew and digest so the fructose is not instantly released.”
Interestingly, she was referring primarily to fruits and not high-calorie, low-in-fiber fast food that is causing myriad health problems. The study seems to be linked to fructose which is a key ingredient in the common and controversial food additive, High-Fructose Corn Syrup (HFCS).
[Image Credit | Green America]