Pollution-Induced Allergy Skews Metabolism Toward Obesity—A Conceptual Review

Rapid urbanization and significant lifestyle changes have become the risk drivers for the epidemiology of diseases. With urban transitions, substantial persistence of pollutants in the environment has been observed. Epidemiological studies indicate a strong relationship between air pollution and exacerbation of asthma and other allergic diseases due to particulate matter (PM). PMs in bioaerosols and aeroallergens induce the immune response, eliciting systemic inflammation. Continuous exposure to PM_2.5 along with gases like nitrogen oxide aggravate oxidative stress and inflammatory responses. Other pollutants elevate blood glucose, inducing poor sleep patterns which in turn induce low-grade chronic inflammation. This in turn acts as a trigger for adipocyte dysfunction and reduced energy expenditure. Taken together, air pollution, allergy, and obesity constitute a jigsaw with missing pieces. Transient Receptor Protein (TRP) channels have important roles in allergic rhinitis, systemic inflammation, adipogenesis, and obesity development, underscoring a potential role as a common mechanistic link. The goal of this review is to summarize and comprehend the intricate network connecting these "modern-day hyperendemic diseases" and the plausible role played by TRP in shaping their epidemiology. Bioactive compounds in dietary spices also modulate TRP channels. Thus, spices position themselves as potential regulators at the interface of environmental sensing, inflammation, and metabolism, indicating spice-based interventions may represent an adjunct strategy to alleviate the pollution-induced allergy and obesity risk.