Adolescents who have grown up in rural areas develop fewer allergies than those who have grown up in cities, according to a study published in PNAS . The explanation would lie in that these people are in contact with a greater biodiversity of beneficial microorganisms that protect the body from autoimmune diseases.
The researchers studied a group of more than 100 teenagers living in a 100 x 150 square kilometer region in eastern Finland. Some lived in rural settings and on isolated farms, and others in large cities. In addition, factors that can also stimulate allergies were taken into account, such as the smoking habits of family members or the presence of pets in the home. The scientists collected a sample of microorganisms from the forearms of all the participants, who were also subjected to allergy tests. A census of all the plant species present in the surroundings of their houses was also carried out.
The results indicated that, the greater the biodiversity and the area of forest or farmland in the vicinity of the young people’s homes, the lower the prevalence of allergies . This relationship is explained because in these areas the diversity of microorganisms is also greater, many of them beneficial for us. Specifically, the scientists found that young people in rural areas had more of a group of bacteria called gammaproteobacteria that could be responsible for immunizing the body against allergy-causing factors.
“We think that the contact of people, especially children, with nature, is very important for the development of the immune system”, explained Ilkka Hanski, researcher at the University of Helsinki (Finland), and one of the authors of the job. Although researchers recognize that not everyone can live in the countryside, contact with nature is essential. “Urbanization cannot be stopped, but perhaps we should plan more green spaces in our cities, as they not only improve the quality of life, but also protect our health,” said Hanski.
