Children living in cities have a significantly higher incidence of allergies than those who grow up in the countryside, where they are often in close contact with animals.

A recent study conducted in South Africa found that children living in cities have a significantly higher incidence of allergies than those raised in rural areas, where they are often in close contact with animals. The study analysed and compared the prevalence of allergic diseases and food sensitisation among children aged 12 to 36 months living in urban and rural areas.

The study examined infant feeding practices and the nutritional status of children, highlighting the profound influence of environment and lifestyle on the development of allergies. Specifically, the researchers evaluated the relationship between breastfeeding, weaning methods, nutritional status, and the onset of atopic diseases, including asthma, allergic rhinitis, atopic dermatitis, food allergies, and sensitisation to food and inhaled allergens.

Differences between urban and rural areas in immune health and allergy risk

The study involved 1,185 children from urban areas and 398 from rural areas, providing insight into differences in immune health and allergy risk between the two environments. Surprisingly, the study revealed that allergies are significantly more prevalent in children living in cities than in those raised in rural areas.

Specifically, food allergies affected 2.5% of urban children, compared to just 0.5% of rural children. This significant disparity may be partly attributed to the less natural eating habits that are typical of urban settings, as well as to lower environmental exposure to microbes and animals. The most common food allergies in urban children were to raw eggs (1.9%), followed by cooked eggs (0.8%) and peanuts (0.8%). In rural children, however, all detected food allergies were exclusively related to eggs.

The importance of the environmental context in the early stages of life

These data confirm the importance of environmental factors in early life and the potential protective effects of a simpler, more natural lifestyle. The study also found respiratory and skin allergies, such as asthma, eczema and allergic rhinitis, to be significantly more common in children living in urban settings. Specifically, asthma was found in 9% of urban children compared to 1% of rural children. Eczema affected 25.6% of children in urban areas, compared to 2% in rural areas, while allergic rhinitis was present in 25.3% of urban cases, compared to 3.3% of rural cases.

Among the analysed children, 13.1% of those living in cities were found to be sensitised to aeroallergens, i.e. substances present in the air such as pollen, mites, or mould, compared to 3.8% of children living in rural areas. The difference was also clear about food allergies: 9% of urban children were sensitised to at least one food, compared to just 0.5% of rural children.

Why do city children have more allergies?

The authors propose several hypotheses to explain why allergies are more prevalent among children living in urban areas. One of the main explanations is lower exposure to animals during pregnancy and in the first months of life. Mothers living in urban environments are less likely to come into contact with pets or farm animals, which reduces the transmission of beneficial microbes to their children. Furthermore, children raised in rural areas tend to have more diverse gut microbiota, which could strengthen the immune system and offer natural protection against allergic diseases.

Rural children also experienced a longer period of exclusive breastfeeding, and the introduction of potentially allergenic foods occurred later compared to urban children. Although obesity rates were similar in both groups, signs of growth failure, known as stunting, were more prevalent in rural South African children, often due to nutritional deficiencies or challenging living conditions. Among urban children, excess weight was associated with a higher incidence of asthma, while children with allergies tended to be lighter than their peers without allergies.

The importance of growing up in rural settings

The results of this study strongly emphasise the importance of growing up in rural areas, where greater exposure to nature, animals, and a microbe-rich environment appears to protect children against developing allergies. Farming plays a crucial role not only in providing wholesome, nutritious food but also in creating an environment that fosters the healthy development of the immune system in both children and adults. This evidence highlights the importance of enhancing and preserving rural areas, which serve as both a food source and a public health asset.

The growing depopulation of rural areas in favour of urban ones is a cause for concern, as abandoning these areas leads not only to the loss of agricultural biodiversity and traditional cultures but also could negatively impact the well-being and health of future generations. In an era of constantly increasing immunological and allergic diseases, rediscovering and protecting the connection between humans, land, and animals is more urgent than ever.