# 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
\begin{table}
**Author and Year** & **Level of Evidence (CEBM 2009)** & **Study Population and Design** & **Main Findings** \\ \hline [PERSON] et al., 2024 [4] & Level 5 & \begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} Review on dietary allergenicity and immune modulation in plant-based contexts & \begin{tabular}{p{113.8 pt} p{113.8 pt}} Review on sustainable diets and immune modulation; patches preclinical and human data \\ \end{tabular} & \begin{tabular}{p{113.8 pt} p{113.8 pt}} Higher dietary diversity, especially in unprocessed plant foods, increased SCFA-producing microbial species, improved mucosal barrier markers, and decreased systemic Th2 cytokines. Supports the role of seasonal diversity in dampening allergic inflammation. \(p\)-values not applicable. \\ \hline [PERSON] et al., 2019 [7] & Level 5 & \begin{tabular}{p{113.8 pt} p{113.8 pt}} Review on SCFAs and their immunological effects; immunological effects; \(\sim\)40 studies including murine and cellular models \\ \end{tabular} & \begin{tabular}{p{113.8 pt} p{113.8 pt}} Greater plant diversity led to enhanced fermentation of dietary fiber into butyrate and propionate, which reduced IL-4, IL-5, and eosinophil infiltration. Mice fed seasonally varied diets showed reduced allergen-specific IgE. \(p\) \(<\) 0.01. \\ \hline [PERSON] et al., 2023 [8] & Level 5 & \begin{tabular}{p{113.8 pt} p{113.8 pt}} Narrative review of molecular pathways involved in immune modulation by dietary bioactives \\ \end{tabular} & \begin{tabular}{p{113.8 pt} p{113.8 pt}} Diverse polyphenols from seasonal vegetables and fruits enhanced Treg responses and reduced mast cell degranulation. \\ \end{tabular} \\ \hline [PERSON] et al., 2023 [10] & Level 5 & \
\begin{tabular}{p{113.8 pt} p{113.8 pt}} Review on food bioactives in allergy prevention; includes 60 studies \\ \end{tabular} &
\begin{tabular}{p{113.8 pt} p{113.8 pt}} Varied plant-based diets rich in flavonoids lowered intestinal permeability, suppressed NF-\(\kappa\)B signaling, and improved resistance to allergen-induced gut inflammation. Particularly strong effects seen in early-life models \(p\) \(<\) 0.01. \\ \hline \end{tabular}
\end{table} 
Table 14: Dietary diversity and seasonal foods in symptom modulation. [PERSON] and colleagues [4] emphasized the role of dietary complexity in promoting immune tolerance and decreasing the frequency and severity of allergic symptoms. Their findings, based on multiple preclinical models, suggest that epigenetic modulation and enhanced microbial signaling contribute to a more balanced immune response, particularly in individuals adhering to diets with high plant food variety. [PERSON] and colleagues [7] confirmed that mice receiving seasonally rotated, fiber-diverse diets showed reduced infiltration of eosinophils and lower expression of Th2 cytokines (IL-4 and IL-5), alongside decreased allergen-specific IgE levels. These outcomes support the relevance of microbiota-mediated mechanisms in allergy symptom attenuation. [PERSON] and colleagues and [PERSON] and colleagues [8; 10], further observed that seasonal intake of diverse flavonoid-rich vegetables and fruits contributed to reduced mast cell degranulation and improved mucosal resilience. These benefits were particularly evident in early-life models but also showed translational relevance for adult allergic populations. It is essential to note that these immunological effects are not derived from food diversity per se, but from its role in amplifying the functional potential of plant-based diets--especially when characterized by a reduction in animal-derived products. This dietary shift favors the development of a non-putrefractive, eubiotic microbiota and enhances the intake of nutrient-dense, prebiotic foods rich in antioxidants and anti-inflammatory compounds. Such profiles align with allergy prevention and management principles grounded in mucosal tolerance and epithelial defense.