Every time we bite into one of our favorite foods, we experience a sense of pleasure caused by a surge in dopamine. We are hardwired to experience this incentive to eat as a survival mechanism and it is part of a complex system within the brain that controls decision making, reward responses and hormonal changes. A growing area of research is examining whether compounds can affect the brain’s reward circuitry, specifically with regard to reducing cravings and inducing satiety. One exciting, newly published study in the International Journal of Eating Disorders has indicated that supplementation with Cognizin® Citicoline (manufactured by Kyowa Hakko Bio Co., Ltd.) may in fact have the potential to control one’s appetite and increase feelings of fullness.1
Broadening Our Understanding of Cognizin® Citicoline
Background. Cognizin® Citicoline, a water-soluble, natural ingredient, is a well-established part of the cognitive health category. Much research indicates this safe and effective branded compound helps protect neural tissue from free radical damage. It also supports brain performance by enhancing metabolism and healthy activity. Unlike other single-action ingredients for brain health, Cognizin® Citicoline is multi-functional. It has shown to benefit individuals affected by memory loss, mood/behavioral disorders, mild cognitive impairment and certain vision disorders.
The mechanism by which Cognizin® Citicoline may achieve its central nervous system effects is through the mediation of the dopamine system. Researchers have hypothesized that this action may also directly affect one’s motivation to eat, since the response to appetite is regulated in part by dopamine.
New Satiety Data. To study how Cognizin® Citicoline affects appetite and the brain’s responses to food, researchers gave eight men and eight women Cognizin® Citicoline (500 mg/day or 2,000 mg/day) for six weeks. At baseline and after the study period, the group filled out questionnaires on which they were asked to rate their hunger and other factors.
“Overall, there was a significant decrease in their self-rated appetites after supplementation with Cognizin® Citicoline,” stated Deborah A. Yurgelun-Todd, Ph.D., professor of psychiatry at University of Utah School of Medicine, and a researcher in this study. “Appetite was altered in both males and females, which is a very important finding.” In addition, the high-dose group experienced greater appetite suppression than the other participants.
It’s one thing to report a behavior. It’s another to show it from a biological standpoint and link it to central nervous system changes like brain activity. “That makes the research even stronger,” says Yurgelun-Todd.
To measure brain activity, the group made use of functional Magnetic Resonance Imaging (fMRI), specifically looking at areas that exhibit increased activity in response to appetite control and behavioral inhibition (e.g., left amygdala, bilateral insula and right lateral orbitofrontal cortex). During the fMRI scans, researchers showed the study participants pictures of high-calorie items like cake and French fries while noting activity in the aforementioned regions of the brain. The group also was shown some control images (e.g., rocks, trees and flowers). Such scans were conducted at baseline and after supplementation with Cognizin® Citicoline to see whether the brain was just as “excited” by the food as it was before.
“When we did the neural imaging component and compared the activation after the six weeks of supplementation with the first baseline evaluation, we saw changes in brain activation correlated with changes in appetite,” states Yurgelun-Todd, who is also the director of the Cognitive Neuroimaging Laboratory in The Brain Institute at the University of Utah, and director of the Mental Illness Research, Education, and Clinical Center for the VA System in Salt Lake City, UT. In fact, individuals taking the highest dose of Cognizin® Citicoline who had the greatest activation of the brain also had the largest decline in appetite for high-calorie foods. No one was asked to change diet or exercise, but certain individuals reported some weight loss. “To me, it provides face validity that the brain is actually responding to these food cues differently because of supplementation with Cognizin® Citicoline,” Yurgelun-Todd feels.
She hypothesized that the regions affected by Cognizin® Citicoline may help participants to see high-calorie food as less rewarding, so they are not as enticed to eat them. “Our finding shows that there are differences in the amount of activation that the brain is producing in response to high-calorie foods,” Yurgelun-Todd says. “In other words, the activation that the brain is generating is altered after you supplement it with Cognizin® Citicoline. We believe it is related to these changes in dopamine neurotransmission, which we know mediate the reward circuitry.”
The Next Step. Research continues on Cognizin® Citicoline and the effect it has on dopamine and other systems. A study is underway on 60 women to better understand the link to satiety and dosing.
Kyowa Hakko’s Cognizin® Citicoline is sold to manufacturers in North America as a dietary supplement ingredient for cognitive health. It is known to protect against cognitive decline, have neuroprotective effects with stroke and benefit those with certain mood/behavior disorders.
1. W.D.S. Killgore, A.J. Ross, T. Kamiya, Y. Kawada, P.F. Renshaw, D.A. Yurgelun-Todd, “Citicoline Affects Appetite and Cortico-Limbic Responses to Images of High-Calorie Foods,” Int. J. Eat. Disord. 43 (1), 6–13 (2010).
Published in WholeFoods Magazine, Aug. 2010 (epub July 20, 2010)