Allergic sensitization to foods in India and other Low-Middle-income countries

Early Origins of Asthma and Allergies: Clues From Studies in China

Asthma and allergies have emerged as some of the most common chronic diseases, particularly in developed countries. Epidemiological studies have consistently demonstrated that children growing up in farming/rural environments are less likely to develop these conditions. Over the past three decades, China has experienced unprecedented economic development and urbanisation, accompanied by a rapid rise in the prevalence of allergic disorders. Despite the substantial number of affected individuals, allergy management in China remains inconsistent and often inadequate, compounded by variations in diagnostic criteria and limited healthcare access in less developed regions. Furthermore, the vast population, regional disparities, and methodological inconsistencies in data collection have hindered the acquisition of comprehensive, large-scale epidemiological data. This review examines the factors contributing to asthma and allergies from their early origins, focusing on modifiable factors from a specific perspective of China. Factors related to traditional lifestyle, such as early-life exposure to agricultural farming and poultry, diverse dietary patterns, and early introduction of allergenic foods, appear to offer protection against allergies. Conversely, exposure to open-fire cooking, incense burning, tobacco smoke, as well as early-life antibiotic use and perinatal factors like Caesarean section delivery and prematurity may represent potential risks. A clear understanding of the role of these factors would pave the way for developing effective interventions to mitigate the substantial health and socioeconomic burdens associated with asthma and allergies.

Food Allergy in Children in China

The prevalence of food allergies in China seems to be increasing, but there are limited studies describing the pattern of food allergies across the country. This review highlights regional variations observed across China, with data indicating a higher prevalence in the more economically developed eastern and southern coastal regions compared to inland areas. Egg and milk are the most common allergies among children under 3 years old; for children above 3 years old, specific food allergens also show regional differences, with shellfish allergies being more common in southern and eastern coastal areas, while wheat and fruit allergies are more prevalent in northern regions. Emerging peanut and tree nut allergies have also been observed in China's megacities, although the prevalence remains relatively low compared to Western countries. These geographic and environmental influences highlight the complexity of the food allergy landscape in China and the need for a more nuanced understanding of the underlying drivers. Despite the growing burden of food allergies, significant gaps exist in effectively managing these conditions in China. Lack of standardised diagnostic tools, limited access to oral food challenges and a shortage of trained allergists pose major challenges. Another critical gap is the limited availability and affordability of epinephrine autoinjectors, essential for managing life-threatening anaphylactic reactions. Addressing these systemic deficiencies in China's food allergy management infrastructure will require concerted efforts from policymakers, healthcare systems and pharmaceutical companies. Investing in the development of standardised diagnostics, expanding the allergy speciality workforce and ensuring equitable access to emergency care and treatment options are crucial steps towards improving health outcomes for the millions of individuals affected by food allergies in China.

Air pollution is associated with persistent peanut allergy in the first 10 years

BACKGROUND

The role of air pollution in eczema and food allergy development remains understudied.

OBJECTIVE

We aimed to assess whether exposure to air pollution is associated with eczema and food allergies in the first 10 years of life.

METHODS

HealthNuts recruited a population-based sample of 1-year-old infants who were followed up at ages 4, 6, and 10 years. Annual average fine particulate matter (particulate matter with diameter of 2.5 μm or less, or PM2.5) and nitrogen dioxide (NO2) exposures were assigned to geocoded residential addresses. Eczema was defined by parent report. Oral food challenges to peanut, egg, and sesame were used to measure food allergy. Multilevel logistic regression models were fitted, and estimates were reported as adjusted odds ratios.

RESULTS

Those exposed to high concentration of NO2 (<10 ppb) at age 1 year had higher peanut allergy prevalence at ages 1 (adjusted odds ratio [95% confidence interval], 2.21 [1.40-3.48]) and 4 (2.29 [1.28-4.11]) years. High exposure to NO2 at 6 years old were associated with higher peanut allergy prevalence at age 6 (1.34 [1.00-1.82] per 2.7 ppb NO2 increase) years. Similarly, increased PM2.5 at age 1 year was associated with peanut allergy at ages 4, 6, and 10 years (respectively, 1.27 [1.01-1.60], 1.27 [1.01-1.56], and 1.46 [1.05-2.04] per 1.2 μg/m PM2.5 increase) years. We found that increased concentrations of NO2 or PM2.5 at age 1 year were associated with persistent peanut allergy at later ages. Little evidence of associations was observed with eczema or with egg allergy.

CONCLUSIONS

Early-life exposure to PM2.5 and NO2 was associated with peanut allergy prevalence and persistence. Policies aiming at reducing air pollution could potentially reduce presence and persistence of peanut allergy.

Dietary Polyphenols, Plant Metabolites, and Allergic Disorders: A Comprehensive Review

Given the ongoing rise in the occurrence of allergic disorders, alterations in dietary patterns have been proposed as a possible factor contributing to the emergence and progression of these conditions. Currently, there is a significant focus on the development of dietary therapies that utilize natural compounds possessing anti-allergy properties. Dietary polyphenols and plant metabolites have been intensively researched due to their well-documented anti-inflammatory, antioxidant, and immunomodulatory characteristics, making them one of the most prominent natural bioactive chemicals. This study seeks to discuss the in-depth mechanisms by which these molecules may exert anti-allergic effects, namely through their capacity to diminish the allergenicity of proteins, modulate immune responses, and modify the composition of the gut microbiota. However, further investigation is required to fully understand these effects. This paper examines the existing evidence from experimental and clinical studies that supports the idea that different polyphenols, such as catechins, resveratrol, curcumin, quercetin, and others, can reduce allergic inflammation, relieve symptoms of food allergy, asthma, atopic dermatitis, and allergic rhinitis, and prevent the progression of the allergic immune response. In summary, dietary polyphenols and plant metabolites possess significant anti-allergic properties and can be utilized for developing both preventative and therapeutic strategies for targeting allergic conditions. The paper also discusses the constraints in investigating and broad usage of polyphenols, as well as potential avenues for future research.

Dietary Polyphenols-Natural Bioactive Compounds with Potential for Preventing and Treating Some Allergic Conditions

In light of the constantly increasing prevalence of allergic diseases, changes in dietary patterns have been suggested as a plausible environmental explanation for the development and progression of these diseases. Nowadays, much attention has been paid to the development of dietary interventions using natural substances with anti-allergy activities. In this respect, dietary polyphenols have been studied extensively as one of the most prominent natural bioactive compounds with well-documented anti-inflammatory, antioxidant, and immunomodulatory properties. This review aims to discuss the mechanisms underlying the potential anti-allergic actions of polyphenols related to their ability to reduce protein allergenicity, regulate immune response, and gut microbiome modification; however, these issues need to be elucidated in detail. This paper reviews the current evidence from experimental and clinical studies confirming that various polyphenols such as quercetin, curcumin, resveratrol, catechins, and many others could attenuate allergic inflammation, alleviate the symptoms of food allergy, asthma, and allergic rhinitis, and prevent the development of allergic immune response. Conclusively, dietary polyphenols are endowed with great anti-allergic potential and therefore could be used either for preventive approaches or therapeutic interventions in relation to allergic diseases. Limitations in studying and widespread use of polyphenols as well as future research directions are also discussed.