There is an emerging public health nexus between climate change and food allergies, with the scientific research being currently expanded in this area globally. While the precise mechanisms remain under investigation, accumulating evidence points to a complex interplay between environmental perturbations and human immunology.
Australia’s latest statistics on asthma and allergies
According to a recently released biannual report by the Australian Institute of Health and Welfare (2 July 2024), 45% of Australian children (0-14) or 2 in 5 had one or more chronic health conditions. The most common condition was hay fever and allergic rhinitis (13%) followed by asthma (8.2%). Food allergies were not accounted for in this report.
Australia is getting hotter, with longer fire seasons and heavier rainfalls
Australia’s premier national science agency (known as CSIRO) highlights that climate research is important for all Australians as “Australia has warmed, on average, by 1.47 ± 0.24 °C since national records began in 1910.” The biannual publication by CSIRO, the State of the Climate Report, predicts that national and global temperature rise and sea level rise will continue, heavy rainfall will become more intense, and Australia will experience more heat waves with fewer cool days. With Australia being infamously known as “the food allergy capital of the world”, we should invest more public health resources into studying how climate change may be affecting allergies and asthma among Australians. It is being expected that Australian hay fever sufferers will grow by at least 70 per cent over the next 30 years.
Climate-Induced Modifications in Allergenic Potential
- Elevated Pollen Production: Empirical studies demonstrate that warmer temperatures and increased atmospheric CO2 concentrations enhance pollen production in allergenic plant species. This amplified pollen load not only exacerbates pollinosis but potentially triggers or worsens food allergies via cross-reactivity.
- Altered Plant Proteomes: Elevated CO2 concentrations can modify plant protein expression, potentially increasing allergenicity. For example, controlled experiments have shown that peanuts cultivated under high CO2 conditions exhibit elevated allergen levels.
- Shifting Agricultural Practices: Climate change necessitates agricultural adaptations, such as increased pesticide application and cultivation of genetically modified crops. These interventions may inadvertently influence food allergenicity.
- Environmental Pollution Exacerbation: Climate change intensifies air pollution, a known contributor to allergen sensitization and heightened immune reactivity.
- Nutritional Insufficiency: Extreme weather events linked to climate change disrupt food systems, leading to nutritional deficiencies associated with elevated allergy risk.
Converging Scientific Evidence
Recent research provides compelling evidence linking climate change to food allergies:
- A longitudinal study published in Public Health Research & Practice revealed a doubling of peanut allergy prevalence in the US within a five-year period.
- Controlled experiments demonstrated that elevated CO2 levels enhance peanut allergenicity.
- Ongoing research is investigating the relationship between climate change and the rise of other food allergies,including shellfish and tree nut allergies.
Mitigation Strategies
While the implications are concerning, several interventions can mitigate the impact of climate change on food allergies:
- Greenhouse Gas Emission Reduction: Transitioning to renewable energy and adopting sustainable practices can mitigate climate change and its associated effects on food allergies.
- Sustainable Agriculture Promotion: Prioritising organic produce and supporting farmers employing sustainable practices can minimise environmental impact.
- Research Prioritisation and Public Awareness: Investment in research to elucidate the complex climate-allergy relationship is crucial. Raising public awareness can catalyse preventive actions.
Further reading:
Akdis C.A. The epithelial barrier hypothesis proposes a comprehensive understanding of the origins of allergic and other chronic noncommunicable diseases. J Allergy Clin Immunol. 2022; 149: 41-44.
Singh AB, Kumar P. Climate change and allergic diseases: An overview. Front Allergy. 2022 Oct 13;3:964987. doi: 10.3389/falgy.2022.964987. PMID: 36310569; PMCID: PMC9606573.
Rothenberg M.E. The climate change hypothesis for the allergy epidemic. J Allergy Clin Immunol. 2022; 149: 1522-1524.
Rocque R.J., Beaudoin C. et al. Health effects of climate change: an overview of systematic reviews. BMJ Open. 2021; 11e046333.
Ray C, Ming X. Climate Change and Human Health: A Review of Allergies, Autoimmunity and the Microbiome. Int J Environ Res Public Health. 2020 Jul 4;17(13):4814. doi: 10.3390/ijerph17134814. PMID: 32635435; PMCID: PMC7369820.
Celebi Sözener Z. et al. Environmental factors in epithelial barrier dysfunction. J Allergy Clin Immunol. 2020; 145: 1517-1528.
Bggs P.J., Walczyk N.E. Impacts of climate change on plant food allergens: a previously unrecognized threat to human health. Air Qual Atmosphere Health. 2008; 1: 119-123.
