Maternal diet rich in omega-6 polyunsaturated fatty acids during gestation and lactation produces autistic-like sociability deficits in adult offspring

Multiple studies have reported prenatal stress as a potential risk factor for the development of autism spectrum disorder (ASD). In rodents, a significant reduction in sociability is seen in prenatally stressed offspring of genetically stress-susceptible dams. Certain dietary factors that contribute to stress reactivity may, therefore, exacerbate prenatal stress-mediated behavioral changes in adult offspring. Adults with a diet rich in omega-6 polyunsaturated fatty acids (PUFAs) display increased stress reactivity. In the current study, the effects of prenatal diet and prenatal stress on social behavior in adult offspring mice were examined. Pregnant C57BL/6 J dams received either chronic variable stress or no stress, and were also placed on a control diet or a diet rich in omega-6 PUFAs, in a 2 × 2 design. We subsequently tested the adult offspring for sociability, anxiety, and locomotor behaviors using a 3-chambered social approach task, an elevated-plus maze, an open field task and a rotarod task. Results indicated that a maternal diet rich in omega-6 PUFAs during gestation and lactation produce changes in sociability consistent with those observed in ASD. Additionally, offspring exposed to a diet rich in omega-6 PUFAs during gestation and lactation had increased levels of anxiety in the elevated-plus maze. Prenatal stress had no effect on offspring behavior. These findings provide evidence for a possible environmental risk factor that contributes to the production of autistic-like behavior in mice.

► Mice exposed to a diet rich in omega-6 PUFAs during gestation display decreased sociability.
► Omega-6 exposed offspring additionally had an increase in anxiety-like behavior.
► Prenatal diet rich in omega-6 PUFAs appears to result in at least 1 of the classic features of autism.