An obesity-associated risk allele within the FTO gene affects human brain activity for areas important for emotion, impulse control and reward in response to food images

• Published in: The European journal of neuroscience Vol. 43; no. 9; pp. 1173 - 1180
• Main Authors: Wiemerslage, Lyle, Nilsson, Emil K., Solstrand Dahlberg, Linda, Ence-Eriksson, Fia, Castillo, Sandra, Larsen, Anna L., Bylund, Simon B. A., Hogenkamp, Pleunie S., Olivo, Gaia, Bandstein, Marcus, Titova, Olga E., Larsson, Elna-Marie, Benedict, Christian, Brooks, Samantha J., Schiöth, Helgi B.
• Format: Journal Article
• Language: English
• Published: France Blackwell Publishing Ltd 01.05.2016
• Subjects: Adult; Alleles; Alpha-Ketoglutarate-Dependent Dioxygenase FTO - genetics; Brain - physiology; Brain Mapping; Case-Control Studies; Emotions; fMRI; food; FTO; Humans; Imagination; Impulsive Behavior; Magnetic Resonance Imaging; Male; obesity; Obesity - genetics; Polymorphism, Single Nucleotide; Reward; SNP; FTO; fMRI; SNP; food; obesity
• ISSN: 0953-816X; 1460-9568; 1460-9568
• DOI: 10.1111/ejn.13177

Understanding how genetics influences obesity, brain activity and eating behaviour will add important insight for developing strategies for weight‐loss treatment, as obesity may stem from different causes and as individual feeding behaviour may depend on genetic differences. To this end, we examined how an obesity risk allele for the FTO gene affects brain activity in response to food images of different caloric content via functional magnetic resonance imaging (fMRI). Thirty participants homozygous for the rs9939609 single nucleotide polymorphism were shown images of low‐ or high‐calorie food while brain activity was measured via fMRI. In a whole‐brain analysis, we found that people with the FTO risk allele genotype (AA) had increased activity compared with the non‐risk (TT) genotype in the posterior cingulate, cuneus, precuneus and putamen. Moreover, higher body mass index in the AA genotype was associated with reduced activity to food images in areas important for emotion (cingulate cortex), but also in areas important for impulse control (frontal gyri and lentiform nucleus). Lastly, we corroborate our findings with behavioural scales for the behavioural inhibition and activation systems. Our results suggest that the two genotypes are associated with differential neural processing of food images, which may influence weight status through diminished impulse control and reward processing. Participants were shown images of high‐ or low‐calorie food images while scanned via fMRI. Divergent patterns of neural activity were found between homozygous genotypes for an obesity‐associated risk allele within the FTO gene (rs9939609). Areas included those important for emotion (cingulate cortex), impulse control (frontal gyri and lentiform nucleus), and reward (putamen). Thus, obesity may stem from differential functional processing regarding food depending on genetic background.