Allergic diseases have been virtually multiplied by four in the past 30 years and it is estimated that currently 25% of children develop some allergy at some point during their growth, as we have been explained by Àngel Mazón, allergist pediatrician at the unit of pulmonology and infant allergy of the Hospital de la Fe in Valencia. It is known that allergies have a genetic component, but genetics does not change in a single generation. “A sudden change has to be caused by an external factor, by an environmental factor”, he says.
This is exactly what is being investigated in the new phase of the INMA project (Children and the Environment) which has just been launched with the cohort of Valencia. INMA is a research project that examines the role of environmental contaminants during pregnancy and during the first years of life; it takes place on several points of the Spanish state. In Valencia it is composed by around 500 children in 32 municipalities starting during the first medical visit made by the pregnant mother. Today this group of volunteer participants are already 7 years old children (they were also considered when they were 1 year, 4 and 5 and a half years of age), and on this occasion they are looking for triggers causing the respiratory diseases and possible allergies which may develop.
“With the statistics in hand, we know that at least 150 of the 500 members of this cohort study will suffer some kind of allergy and we want to have all the possible data to try to detect the causes. Mainly we focus on the environmental exposure, food and air pollution,” explains Dr. Mazon.
Ferran Ballester, one of the coordinators of the cohort of INMA project in Valencia, explains to us what the visit consists in. It starts with questionnaires to assess the overall state of health of each participant, the environmental exposure (where he/she lives, presence of smokers around, etc. ) and the child’s diet. Tests are also performed anthropometric (height, weight), a test of bioimpedance (to measure the fat and detect childhood obesity), a visual examination of the skin and specific evidence of the respiratory system: Spirometry, oscillometric (a vest captures the movements of the chest during inspiration and expiration) as well as a collection of bronchial condensate (blowing continuously to capture samples of fluid from the inside of the lungs, which provides markers of oxidation and enables to detect possible problems of lung development). The visit is completed with the collection of biological samples and neuropsychological tests by computer to measure the working memory and the attention ability.
With all of this, and thanks to the continuous supervising that is made from the stage of embryo, one can get to know the evolution of the presence of toxic compounds in the body, such as mercury and pesticides, the emergence of other environmental factors and the possible connection with conditions the person can suffer. Detecting any small alteration can be a symptom of asthma or allergy in the future and the supervising that makes the INMA project will allow volunteers to check if they will later develop these affections or not and will attempt to find the cause.
Data are crossed, in addition, with the internal and external environmental factors. Among the internal ones, special attention is paid to the mother’s smoking or other persons of the usual environment, something which is known to cause breathing problems, bronchial affections, asthma, and the persistence and evolution more complicated for the disease. It is also important to know the quality of the domestic air, because the current of air conditioning systems make many houses not to let air run enough and this creates a microenvironment that can accumulate allergens such as dust mites and pets dander.
External pollutants are substances present in the air pollution that are recorded through environmental sensors located in the areas where these children have their home. Likewise, we must bear in mind that there is a relationship between air pollution and pollen, one of the most common causes of allergy. “The trees of the city, being immersed in a polluted air, create a pollen more chemically aggressive than that one coming from the natural environments and, therefore, with a greater capacity to induce allergy,” says Àngel Mazon.
“All of this information,” says Ballester, “will allow us to see which factors increase the risk, the probability of suffering from respiratory diseases or allergies. ”
The INMA project, which is the first study of these features that is carried out from pregnancy, has already begun to offer results. For example, it has been noticed that children whose mothers have high levels of chlorinated pesticides suffer more risk to suffer from respiratory diseases and the times which are most determinants regarding exposure during the child’s development are being studied. “We are already noticing that the intrauterine exposure, prenatal, has a great significance“, according to Ferrán Ballester statement. It has also been proved that breastfeeding protects of pneumologic and respiratory problems. Another outcome of the study says that women who eat more than 200 grams of vegetables per day during pregnancy reduce the risk of having babies with low birth weight than expected by gestational age.
To draw conclusions about the causes of allergy we will still have to wait. This new phase of the INMA project in Valencia has just started and will last almost one year. Later, the project will focus on childhood obesity, because the figures that have been detected so far make it possible to anticipate that it will be an important subject: in the control children had to pass when they were 4 years old, 14% of them had overweight and 6% suffered from obesity. And in addition to the direct challenge that this represents, it is known that obesity is associated with asthma.