It has long been known that there is an association between food and pain, as people with chronic pain often struggle with their weight. Researchers at the Del Monte Institute for Neuroscience may have found an explanation in a new study that suggests brain circuits responsible for motivation and pleasure are affected when a person experiences pain. “These findings may reveal new physiological mechanisms linking chronic pain to a change in a person’s eating behavior,” said Paul Geha, MD, lead author of the study published in PLOS ONE. “And this change can lead to the development of obesity. »
Finding pleasure in food comes from how our brain reacts to what we eat. In this study, researchers looked at the brain’s response to sugar and fat. Using a gelatin dessert and pudding, the researchers altered the sugar, fat and texture of the food. They found that none of the patients experienced a change in eating behavior with the sugar, but they did with the fats. People with acute lower back pain who later recovered were the most likely to lose the pleasure of eating pudding and show disrupted satiety signals – the communication from the digestive system to the brain – while those with acute lower back pain whose pain persisted at one year did not initially have the same change in their eating behavior. But patients with chronic lower back pain reported that foods high in fat and carbohydrates, such as ice cream and cookies, became problematic for them over time and brain scans showed disturbed satiety signals. .
“It is important to note that this change in the taste of the foods did not alter their caloric intake,” said Geha, who first authored a previous study published in PAIN on which recent research builds. “These results suggest that obesity in patients with chronic pain may not be caused by a lack of movement, but may be changing the way they eat. »
Brain scans of study participants revealed that the nucleus accumbens – a small area of the brain best known for its role in decision-making – may offer clues regarding who is at risk of long-term change in eating behavior. The researchers found that the structure of this area of the brain was normal in patients who had initially experienced changes in their eating behavior but whose pain had not become chronic. However, patients whose eating behavior was normal but whose pain became chronic had a smaller nucleus accumbens. Interestingly, the nucleus accumbens predicted pleasure ratings only in patients with chronic back pain and in patients who became chronic following an acute episode of back pain, suggesting that this region becomes critical in the motivated behavior of patients with pain. of chronic pain. Previous research by Geha found that a smaller nucleus accumbens may indicate whether a person is at higher risk for developing chronic pain.
Other authors include Yezhe Lin, Ph.D., and Gelsina Stanley of the University of Rochester, Ivan de Araujo, Ph.D., of the Icahn School of Medicine at Mount Sinai, and Dana Small, Ph.D. , from Yale University. . The research was funded by the National Institute on Drug Abuse.
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Materials provided by University of Rochester Medical Center. Original written by Kelsie Smith Hayduk. Note: Content may be edited for style and length.
