It feels like we already knew this, although there was no scientific confirmation – long-term stress leads to obesity. Scientists from UCL discovered that higher levels of cortisol, which regulates the body’s response to stress, over several months is associated with people being more overweight. But it is just because of overeating?
People have been reporting it for quite some time – stress leads to eating more, and usually unhealthy foods. However, although this is true, there is another reason, why stress leads to obesity – cortisol plays a role in determining where fat is stored. 2,527 men and women aged 54 and older were included in this new study, which took four years to complete. Scientists wanted to see long-term effects of high cortisol levels, so not only they analysed weight, body mass index and waist circumference of the participants, but also took 2 cm of hair samples.
Then it was just the matter of connecting the dots. Scientists found that those people who had higher levels of cortisol in their hair usually had larger waist circumference measurements, were heavier, and had a higher body mass index. In fact, obese people had particularly high cortisol levels in their hair samples. This is bad news for people under a lot of stress, since larger waist has been linked to a higher risk factor of heart disease, diabetes, and even premature death.
Interestingly, hair cortisol is a relatively new measurement. Dr Sarah Jackson, leader of the research, said that it “offers a suitable and easily obtainable method for assessing chronically high levels of cortisol concentrations in weight research and may therefore aid in further advancing understanding in this area”. Scientists took samples as close to the scalp as possible, because hair represents an accurate timeline for a person’s health. Cortisol in this 2 cm sample accumulated in around two months.
This is a very important research, but there are some limitations. Scientists are not sure, if high cortisol levels caused obesity or obesity caused higher cortisol levels. Furthermore, only older population was researched and thus further stages are going to be needed.