The relationship of autistic traits to taste and olfactory processing in anorexia nervosa

Background There is a heightened prevalence of autism in anorexia nervosa (AN) compared to the general population. Autistic people with AN experience a longer illness duration and poorer treatment outcomes. Whether sensory differences in autism could contribute to altered taste and smell as a potential maintaining factor in AN is under-explored. The aim of this study was to explore whether autistic traits are associated with taste and olfaction differences in AN. Methods The study recruited n = 40 people with AN, and n = 40 healthy controls (HC). Smell sensitivity was measured using the Sniffin' Sticks test. Taste sensitivity was measured using taste strips. Participants self-rated their autistic traits using the Autism Spectrum Quotient. Results There were no significant differences on taste and olfactory outcomes between people with AN and HC. These findings did not change after controlling for the heightened levels of autistic traits in the AN group. No relationship between taste and smell outcomes and autistic traits were identified within the AN group. Limitations The current study is not able to draw conclusions about taste and smell processing in co-occurring autism and AN as it only measured levels of autistic traits, rather than comparing people with and without an autism diagnosis. Conclusions No significant associations between autistic traits and taste and smell processing in AN were identified. Future research should consider further exploring this area, including by comparing autistic women to women with AN.