A recent study conducted by researchers from the University of the Basque Country in Spain revealed that the hormone cortisol, which the body secretes in response to stressful situations, accumulates in the hair and is considered an indicator of the level of stress in the long term and is reflected in the form of inappropriate behaviors in children.
By knowing the drivers behind chronic stress, policies can be put in place to limit these factors and reduce stress.
Momentary stress and chronic stress
Cortisol is a hormone that the body secretes in response to stressful situations, so measuring cortisol concentration in hair is very useful in analyzing chronic stress.
“Cortisol is normally found in blood, saliva and urine, among other places, and it indicates a temporary level of cortisol that accumulates in the hair, indicating a degree of long-term stress, in other words, chronic stress,” explained Anne Arregi-Ochotorena, a researcher at the University of the Basque Country’s School of Psychology and first author of the study.
To differentiate between momentary stress and chronic stress, Arighi used an example, saying, according to the EurekAlert website: “The stress that occurs when you go to buy bread one day and realize that you don’t have money is not the same as the stress that occurs when you realize every day that you don’t have money to buy bread.”
The researcher at the Basque Research Group for Environmental Health used hair samples from 11-year-old children to assess chronic stress. For the research, she drew on data from the Environment and Childhood Project, which collects all kinds of data on children and families, starting with the mother’s pregnancy, for long-term research purposes.
A model was created to investigate the relationship between environmental, social and individual factors and cortisol concentrations in children’s hair. All factors that may influence stress and have been shown in previous research were taken into account: for example, green and blue spaces, air pollution, environmental noise, family and school relationships, parental stress levels, sleep problems, physical activity, age, gender, etc.
The study, published in the journal Hormones and Behavior on June 8, found that greater behavioral problems were associated with higher levels of cortisol in hair. In addition, Arighi explained, “We observed that maternal stress was associated with behavioral problems in children. This means that maternal stress could also affect children’s cortisol levels through their behavioral problems.”
Environmental, social and individual factors
Chronic stress in children is linked to a range of health problems. Indeed, simultaneous exposure to different environmental, social and individual factors can affect hair cortisol concentrations. “Childhood and adolescence are very critical periods because they are periods of rapid development. It is very important to know how different factors affect the health of children and adolescents at this stage so that they can become healthy adults,” the researcher said.
“We believe that hair cortisol may be a useful tool when assessing how environmental exposures influence chronic stress,” the researcher concluded. “In short, this may help in implementing effective public policies. In fact, knowing what chronic stress can cause people in a particular location may facilitate the implementation of policies to prevent it.”