The Concept of One Health for Allergic Diseases and Asthma

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TL;DR

This narrative review argues that allergic diseases and asthma are quintessential 'One Health' conditions, directly influenced by environmental degradation, climate change, and biodiversity loss. The authors propose that a holistic exposomic approach, integrating human, animal, and ecosystem health, is necessary to mitigate the rising burden of these diseases. The clinical significance lies in urging healthcare professionals to incorporate environmental health counseling and advocacy into practice to address the root environmental drivers of allergy and asthma.

Full summary

3,109 CHARS

**Background:** The paper frames the rising global prevalence of allergic diseases within the context of the Anthropocene, where human activity has profoundly impacted planetary systems. It introduces the Planetary Boundaries concept, noting that four boundaries (climate change, loss of biosphere integrity, land-system change, and altered biogeochemical cycles) have been crossed. Key environmental stressors include greenhouse gas emissions (CO₂ rising from 280 ppm pre-industrially to 400 ppm in 2014), air pollutants (PM, ozone, NO₂), and global plastic pollution (less than 10% recycled). The authors argue that these changes disrupt the 'holobiont'—the collective genome of the human body and its resident microbiomes—leading to impaired immune resilience and chronic inflammation.

**Methods:** This is a narrative review synthesizing evidence from environmental science, immunology, and clinical allergy literature. The authors do not describe a systematic search methodology but draw on a broad range of cited sources (references 1-100) to build a conceptual framework linking environmental degradation to allergic disease pathogenesis.

**Key Results:** The review presents several lines of evidence: (1) Climate change directly impacts allergic disease through extreme weather events (e.g., thunderstorm asthma linked to peaks in respirable sub-pollen particles and fungal spores), prolonged pollen seasons, and increased allergenicity of plants due to elevated CO₂ and ozone. (2) Biodiversity loss, particularly in urban environments where humans spend ~22 hours/day indoors, reduces protective microbial exposure. (3) Dietary shifts from plant-based, fiber-rich foods to processed foods with additives damage epithelial barriers and reduce microbiome diversity. (4) Environmental exposures (e.g., to microbes, green spaces, 'dirty soil') can protect against allergy, while excessive hygiene and detergents favor type 2 immune responses. The authors highlight that the 'metaexposome'—the bidirectional interaction between environment and human biology—shapes allostatic load and epigenetic regulation from early life.

**Clinical Implications:** The authors advocate for a One Health approach integrating human, animal, and environmental health. Specific interventions include: promoting sustainable, plant-rich diets (per EAT-Lancet Commission recommendations targeting 5 billion tons CO₂ equivalent from food systems by 2050); implementing regenerative agriculture to improve soil health and nutrient density; designing urban green spaces with non-allergenic native plant species; and incorporating climate change mitigation into allergy practice (citing the Finnish Allergy Program 2008-2018 and Lahti's 'Natural Step to Health' program as examples). Healthcare professionals are urged to provide One Health counseling and advocate for policies addressing climate change and biodiversity loss. Open questions remain regarding the precise mechanisms by which multiple environmental stressors shape allostatic load and the optimal balance between population-level and personalized interventions.