Abstracts

Background

Anxiety and psychological stress are increasingly prevalent, with dietary factors emerging as potential modifiable risk factors. Protein intake may have an impact on mental health by modulating neurochemical pathways. Despite growing interest, there has been no systematic investigation of the role of dietary protein in anxiety and stress symptoms and disorders.

Objective

This scoping review aimed to identify and map the existing evidence on the relationship between dietary protein quantity or quality and anxiety or psychological stress symptoms or disorders in human and animal studies.

Methods

Data was sourced from Medline (PubMed), EMBASE, Web of Science, and CINAHL. A comprehensive search strategy included keywords and subject headings related to anxiety, stress, and dietary protein, with no restrictions on language or publication date. Screening was completed independently and in duplicate. Data was extracted and synthesized qualitatively to identify key trends and gaps in the literature.

Results

The search yielded 20,270 results after deduplication. 282 were eligible after full text screening. Inadequate dietary protein quantity was associated with worse anxiety and psychological stress outcomes. Protein adequacy, rather than maximization may be relevant to anxiety and stress outcomes. Dairy-derived protein hydrolysates showed the most consistent anxiolytic effects across studies. Specific amino acid bioavailability and the metabolic or inflammatory context of the individual may influence the impact of dietary protein on anxiety and stress symptoms.

Conclusions

Dietary protein is associated with anxiety and stress outcomes. Clinical trials modifying dietary protein quantity or quality are warranted.

DOI link: doi.org/10.1016/j.nupsyc.2026.100045