Not All Foods Are Neutral: Which Products Are Linked to Autism Risk

In a study published in Frontiers in Nutrition, scientists examined whether certain dietary habits are associated with the risk of developing autism spectrum disorder (ASD) and whether such associations might have biological, including immune-related, explanations. Interest in this topic remains high, as the number of children diagnosed with autism is increasing worldwide, and diet is often viewed by families as one of the few modifiable factors.

The authors used Mendelian randomization, analyzing genetic data that reflect an individual’s long-term dietary preferences. This approach helps reduce the influence of confounding factors and reverse causality. The analysis included nearly 200 dietary factors, as well as indicators of food allergy and metabolism. Immune and inflammatory markers were also examined, and the clinical component involved observations of 78 children diagnosed with ASD, some of whom followed a gluten-free and casein-free diet.

The results showed that not all foods are equally associated with autism risk. A genetic predisposition to more frequent consumption of whole-grain pasta containing gluten and processed cheese rich in casein was associated with a higher risk of the disorder. At the same time, the researchers emphasize that the findings relate not to individual meals, but to long-term, stable dietary habits. The estimates were imprecise, so the conclusions are considered probable associations rather than proven causality.

In contrast, a tendency toward more frequent banana consumption was linked to a lower risk of autism, although the authors note that this effect may reflect overall diet quality rather than the impact of a specific food.

The clinical part of the study showed that a gluten-free and casein-free diet did not lead to significant improvements in behavioral symptoms compared with a regular diet. However, such diets markedly reduced levels of immune antibodies to milk and wheat, indicating an effect on the immune system.

Overall, the authors conclude that some foods rich in gluten and casein may be linked to autism through immune mechanisms. At the same time, diet should be viewed as an auxiliary factor rather than a means of preventing or treating autism, and the need for larger-scale studies is emphasized.