Comment on "Impact of AOC1 and HNMT Variants on the Therapeutic Outcomes of a Histamine Reducing Diet in Autism Spectrum Disorder".

This article critiques a study about special diets for autistic children. The original study looked at removing high-histamine foods, but also removed gluten, dairy, and sugar at the same time. The critics say this makes it impossible to know which dietary changes actually helped. They also point out the study had very small numbers of children and didn't clearly explain the results. The authors suggest better research is needed.

This is a commentary critiquing a recent study on histamine-reducing diets for children with autism spectrum disorder. The authors identify several methodological concerns with the original research, including the use of a broad elimination diet that removed multiple food components beyond histamine, making it impossible to isolate histamine's specific effects. Other limitations highlighted include unexplained participant selection criteria, very small sample sizes for genetic analyses (sometimes single participants), lack of post-intervention histamine measurements, and unclear clinical significance of outcomes. The commentary calls for more rigorous research with controlled diets, standardized methods, larger samples, and clinically meaningful outcomes.

Current evidence for histamine-reducing diets in autism is insufficient due to methodological limitations. Clinicians should be cautious about recommending such restrictive diets without stronger evidence. Future research should use controlled methodologies, larger samples, and measure clinically relevant outcomes to establish whether histamine reduction specifically benefits autistic individuals.

This is a commentary, not original research. The limitations discussed pertain to the critiqued study rather than new data. The commentary does not provide alternative evidence or conduct independent analysis of histamine-reducing diets in autism.

Kadiyska et al. recently investigated the impact of a histamine-reducing diet in children with autism spectrum disorder (ASD), with attention to potential modifying effects of AOC1 and HNMT gene variants. Although the study poses an important question, several design limitations may affect the certainty of its conclusions. The dietary intervention removed not only foods high in histamine but also gluten, dairy, sugar, and other items. Such broad restrictions can influence health and behavior on their own.

This makes it difficult to determine whether the reported improvements were specifically the result of reduced histamine. The histamine cut-off chosen for participant selection was not explained or tied to clinical standards, which makes reproducibility less clear. In addition, some of the genetic results rested on very small numbers, at times a single child, reducing confidence in their reliability. Finally, histamine levels were not re-measured after the intervention, and the developmental outcomes were not fully explained in terms of clinical significance.

Stronger evidence will require controlled diets, standardized thresholds, larger cohorts, and outcomes relevant to daily life.