Walnuts Can Help Fill You Up
Research from Boston’s Beth Israel Deaconess Medical Center reveals that consuming walnuts affects a brain area that regulates hunger and cravings. This finding emerged from a study of 10 obese volunteers who spent two 5-day sessions in the hospital’s Clinical Research Center. During one of these sessions, the participants drank daily smoothies containing 48 grams of walnuts. During their other stay, the smoothies tasted the same and were nutritionally identical but contained no walnuts. At the end of each session, the researchers used functional magnetic resonance imaging (fMRI) to monitor the volunteers’ brain activity while they viewed images of hamburgers, desserts and other desirable foods as well as neutral items such as flowers, rocks and foods considered less desirable. After drinking walnut smoothies, the images of desirable foods triggered increased activity in a brain area called the right insula, which helps regulate appetite. This activity was much less pronounced in the fMRI monitoring that followed consuming smoothies that were walnut-free. Neither participants nor researchers knew during which session the walnut smoothies were served. The volunteers also reported that they felt less hungry during the session they received the walnut-rich smoothies.
Christos S. Mantzoros et al, “Walnut consumption increases activation of the insula to highly desirable food dues: A randomized, double-blind, placebo-controlled, cross-over fMRI study.” Diabetes, Obesity and Metabolism, August 17, 2017, DOI: 10.1111/dom.13060
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