Scientists may now be able to assess the amount of stress you are truly experiencing by examining your hair. Researchers found that they can accurately detect levels of cortisol—the body's primary stress hormone—in your hair. Until now, scientists have only been able to measure the stress hormone in blood, urine, or saliva. The team stated that the findings suggest that measuring the hormone in hair could be a good way to identify chronic stress. This condition can lead to anxiety, insomnia, high blood pressure, and even weakened immune function over time.
The study, published in PLOS Global Public Health, analyzed hair samples from 881 women in Mexico and 398 women in Iceland. Researchers collected hair from the root and analyzed a 3 cm segment closest to the scalp. Hair grows approximately 1 cm per month, so this segment represented the previous three months. The same women were then given a 10-item questionnaire asking how stressed they felt. They responded on a five-point scale, and researchers divided respondents into five groups based on their total scores, indicating their level of stress.
The results showed that women who scored in the top fifth for stress levels had cortisol levels 24.3% higher than those in the lowest fifth. Dr. Rebecca Lynch, the study's lead author from Reykjavik University, stated that the study indicates that measuring cortisol in hair could be promising for diagnosing chronic stress. The researchers wrote, "An association was found between perceived stress and cortisol concentrations in hair in a sample of women from diverse geographical and cultural backgrounds. This supports the hypothesis that cortisol concentration in hair is a viable biomarker in studies of chronic psychological stress."
Cortisol acts as an alarm system inherently. While stress is not the only reason for its production, it has been dubbed the "stress hormone" because it is released when the body is in a "fight or flight" mode. Typically, the body produces higher levels in the morning and lower levels at night.
