It’s believed that as many as one-third of Americans are living with extreme stress. But a new study suggests that our modern society isn’t all to blame.

Researchers in Canada have proven that stress has plagued humans for hundreds, if not thousands of years.

The research team took hair samples from 10 individuals at different archaeological sites in Peru, and analyzed them in segments to determine levels of the stress hormone cortisol, since stress releases cortisol into nearly every part of the body, including blood, saliva, urine and hair.

They found that ancient Peruvians living between 550 and 1532 A.D. did show signs of stress, especially right before their deaths.

The study’s lead author, Emily Webb, says the findings may help better understand stress and how it affects modern people.

Stress is known to contribute to many health problems, including hypertension, stroke, heart attack, diabetes, ulcers and neck or low back pain.

According to the Mayo Clinic, natural stress relief techniques include eating a healthy diet, exercising regularly and practicing techniques like yoga, meditation and tai chi.