# Sustainable Plant-Based Diets and Food Allergies: A Scoping Review Inspired by EAT-Lancet
## 3 Results
### Core Dietary Determinants of Allergy Prevention and Management Within Sustainable Eating Models
#### 3.4.1 Food Processing and Allergy: Preventive and Symptom-Modulating Perspectives
[PERSON] and colleagues [7] supported this mechanistic framework through an analysis of over 40 experimental and mechanistic studies. The authors documented how dietary variety, via its impact on fermentable fiber availability, amplifies SCFA production, improves epithelial integrity, and stimulates IgA production and Treg differentiation in murine models of food allergy. These immune adaptations are central to the maintenance of oral tolerance and reduced allergic sensitization. [PERSON] and colleagues [4] emphasized the immunological relevance of repeated and varied exposure to different plant proteins and phytochemicals during early life. The review synthesized data from in vitro models and animal trials, underscoring how antigenic diversity contributes to immune education and tolerance development via both microbial and epigenetic pathways. \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline
**Author and Year** & **Level of Evidence (CEBM 2009)** & **Study Population and Design** & **Main Findings** \\ \hline [PERSON] et al., 2024 [4] & Level 5 & Review on dietary factors influencing allergenicity and immune modulation. & Exposure to varied plant-derived proteins and phytochemicals improves oral tolerance. Protective effects observed in experimental models of sensitization. \(p\)-values not applicable. \\ \hline [PERSON] et al., 2022 [5] & Level 5 & Review on sustainable diets and immune function; includes preclinical and human observational data. & Greater plant diversity improves microbial richness and promotes SCFA production and immune tolerance. Seasonally diverse diets linked to improved Treg induction. \(p<0.05\). \\ \hline [PERSON] et al., 2019 [7] & Level 5 & Review of immune and gut barrier effects of SCFAs derived from dietary substrates. & Dietary diversity increases fermentable fiber substrates, enhancing SCFA production and mucosal defense. Preventive mechanisms involve Treg expansion. \(p<0.01\). \\ \hline [PERSON] et al., 2023 [8] & Level 5 & Narrative review on bioactives and diet diversity in immune programming. & Greater intake of diverse polyphenols from seasonal fruits and vegetables linked to lower allergic responses. Antioxidants and prebiotics act synergistically. \(p\)-values not applicable. \\ \hline [PERSON] et al., 2023 [10] & Level 5 & Review on food allergy prevention via bioactive compounds; includes plant variety, fiber, and flavonoids. & Dietary variety enhances tolerance through microbiota modulation and reduced epithelial permeability. Strong preventive signals in early-life models. \(p<0.01\). \\ \hline \end{tabular}
\end{table} 
Table 13: Food diversity, seasonal dietary patterns, and allergy prevention. [PERSON] and colleagues and [PERSON] and colleagues [8; 10], in their respective reviews of \(\sim\)60 and \(\sim\)50 studies, further highlighted that a diverse intake of polyphenol-rich seasonal plant foods not only increases the richness and functional stability of gut microbiota but also reduces epithelial permeability and modulates key inflammatory pathways such as NF-\(\kappa\)B. These effects contribute to the maintenance of immune homeostasis and may reduce the risk of sensitization in early developmental stages. Although the reviewed data are predominantly preclinical or observational, they collectively reinforce that plant food diversity--especially when integrated into broader dietary frameworks characterized by high fiber, polyphenol density, and limited animal protein intake--can support preventive strategies against food allergy. In already sensitized individuals, the integration of seasonal food diversity into plant-based diets may contribute to symptom modulation. [PERSON] and colleagues [5] documented how unprocessed, fiber-rich plant foods enhance the abundance of SCFA-producing microbial taxa and improve mucosal barrier function. In allergic subjects, these changes are associated with lower systemic inflammation and improved immune regulation.