Hair Samples Reveal People Who Suffer Long-Term Stress Could Also Be Prone To Obesity

A research conducted at the University College London has discovered that people who suffer long term stress may have something else to worry about: Obesity.

The findings used hair samples to determined levels of cortisol, a hormone responsible for the regulation of the body’s response to stress.

The result of the study, which is published in the health journal Obesity, shows that continuous exposure to increasing levels of cortisol over several months could result in an individual becoming heavy and persistently gaining excess weight.

Hypotheses have long been developed on the link between chronic stress and obesity, as patients often report resorting to overeating or engage in ‘comfort eating’ of foods with unhealthy amounts of fats, sugar and calories in times of stress. Besides, cortisol plays a vital function in body metabolism and determining where fat is stored.

Earlier researcher trying to establish a relationship between the stress hormone and obesity essentially relied on measuring the cortisol levels in blood, saliva or urine, which could fluctuate depending on the time of day and other environmental factors. The studies failed to accurately record and analyse long-term cortisol levels.

The study was conducted with 2,527 men and women who were 54 years old with a four year test period. The researcher cut a 2cm strand of hair from every participant. The cut section of the hair was as close as possible to the individual’s scalp to represent about 2 months’ hair growth with higher levels of cortisol.

They also take in account the weight of each participant, their body mass index (BMI) and waist size, as well as the link between their hair cortisol and persistence of obesity over time.

The scientists discovered that individuals who have larger waist lines tend to also equally have higher cortisol levels present in their hair. They were also heavier and had higher BMI.

Study participant who were classified as obese if they had 30 or higher BMI, or a waist circumference that was 102cm or higher in men, or 88cm or higher in women particularly showed higher hair cortisol levels.

The study team leader, Dr Sarah Jackson of the Epidemiology and Public Health department of UCL said the results showed consistent proofs that chronic stress is linked with higher levels of obesity.

She added that people with concentrated cortisol levels present in their hair also tended to have bigger waist lines which is important because carrying the weight of excess fat accumulated around the abdomen exposes the individuals to dangerous ailments and situations like diabetes, heart diseases, and even premature death.

The chief researcher stated that using cortisol levels to determine the association between stress and overweight problems is a relatively new method and provides a quick and easy diagnosis in assessing dangerously high levels of cortisol concentration in the study of obesity. She said the study could aid in further understanding this link and the subject area.

However, the study had certain limitations, including the fact that data was generated from an older population which could have a varied cortisol levels compared to younger adults. Also, the sample population was exclusively white.