Elevated Thalamic Response to High-Sugar Milkshake in Ethnic and Racial Minorities

In the USA, Hispanics and African-Americans show elevated obesity, yet little is known about possible ethnic/racial differences in brain response during intake of palatable foods. To examine potential differences between non-Hispanic white (nHW) and racial/ethnic minority individuals, we used functional magnetic resonance imaging (fMRI) to assess brain response to intake of eucaloric milkshakes that were either high-sugar or high-fat and a calorie-free, tasteless control solution. Our sample included healthy-weight adolescents who identified as African-American and/or Hispanic (minority, n = 27) and non-Hispanic white (nHW, n = 106). Minority participants showed elevated response in the pre-/postcentral gyrus, precuneus, and left thalamus in response to the high-sugar milkshake compared to high-fat milkshake. To confirm these effects were not driven by differences in body mass or a function of unequal cell sizes, we performed the same analyses in minority participants and a randomly selected subsample of nHW participants (n = 27) that were matched on BMI percentile. Similar to the full sample, we observed an elevated ventral posterior thalamic response to high-sugar milkshake in minority participants. This effect held after controlling for self-reported sugar and fat intake. These results suggest that African-American and Hispanic groups may have elevated response to specifically high-sugar foods in regions of the brain associated with sensory processing, providing novel information regarding the possible neural underpinnings of the disproportional risk for obesity seen in African-American and Hispanic populations.