Obesity has become the primary
health concern across the world, which is evidenced by heart disease’s position
as the number one leading cause of death. Fructose, the sweetener commonly found
in sugary drinks, may be partially responsible for the massive uptick in obesity.
In a study published in the Proceedings of the National Academy of Sciences,
researchers found that consuming fructose may increase high-calorie cravings. This
research attempts to build off of previous findings indicating that fructose is
worse at suppressing appetite compared to glucose. Following consumption of a
drink containing either fructose or glucose, participants viewed images of high-calorie
foods during fMRI sessions. The neuroimaging results showed that the fructose group
had greater activation of the orbital frontal cortex, a brain region involved
in attention and reward processing, indicating their hunger was not as satiated
as the glucose group. They also rated their hunger levels at various time intervals
and got to choose between an immediate food reward or a delayed monetary bonus.
The fructose group reported higher levels of hunger and was also more likely to
choose the immediate food reward as opposed to the delayed monetary reward.
Although there were no differences in leptin and ghrelin levels between the
groups, the fructose group did display increases in insulin levels. Upon
consumption of glucose, insulin is released and signals to the brain that food
has been consumed. Fructose doesn’t stimulate insulin release as well, and
therefore your brain isn’t alerted that you’ve been consuming food.
During Dr. Jennifer Beshel’s talk,
she highlighted the importance that our current food landscape has on the
prevalence of obesity. The rise of fast-food has ensured that we are always surrounded
by high-calorie food options, and the few healthy options that do exist tend to
be more expensive. You can get a burger from McDonald’s off the dollar menu,
but a salad will cost you 5 bucks. In many countries, soft drinks have become
cheaper than bottled water. In Dr. Beshel’s study, she examined the effects
that an obesogenic environment has on manipulated flies. Beshel and colleagues
demonstrated moderate differences in weight gain between normal flies and flies
with their upd1 (the leptin analog) manipulated on a standard diet. When only
provided a high-fat diet, the upd1-manipulated flies showed a much more
significant difference in weight gain compared to the normal flies.
Both of these studies demonstrate
the importance and danger of living in an obesogenic environment. For the flies,
being genetically predisposed to weight gain only became a serious issue when
living off a high-fat diet. For the participants in the fructose/glucose study,
consuming an unhealthy sugary drink (like the ones that are widely available)
further supported and advanced intake of more high-calorie foods.
Works Cited
Bakalar, Nicholas. “Fructose May Increase Cravings for High-Calorie Foods.” The New York Times, The New York Times, 4 May 2015, https://well.blogs.nytimes.com/2015/05/04/fructose-may-increase-cravings-for-high-calorie-foods/?searchResultPosition=6.
Beshel, Jennifer, et al. “A Leptin Analog Locally Produced in the Brain Acts via a Conserved Neural Circuit to Modulate Obesity-Linked Behaviors in Drosophila.” Cell Metabolism, vol. 25, no. 1, 10 Jan. 2017, pp. 208–217., doi:10.1016/j.cmet.2016.12.013.
Luo, Shan, et al. “Differential Effects of Fructose versus Glucose on Brain and Appetitive Responses to Food Cues and Decisions for Food Rewards.” PNAS, National Academy of Sciences, 19 May 2015, https://www.pnas.org/content/112/20/6509.
Links
No comments:
Post a Comment