Stress measurement: a reactive “cotton swab” to easily assess the level of cortisol

Earwax in our ears can tell us more about our state of stress. Researchers from King’s College and University College London (UK) have invented a method of sampling earwax that measures the level of cortisol, a hormone made by the adrenal glands that plays an essential role in the balance blood glucose and the release of sugar from body stores in response to increased energy demand. The cortisol that our body produces naturally fulfills many functions, whether for the regulation of blood sugar or its anti-inflammatory effect for example. But when it is secreted in excess, this hormone becomes above all the stress hormone! The results of their research were published on 1^er November 2020 in the academic journal Heliyon.

A special cotton swab

What the London researchers have managed to put in place is a self-sampling device for earwax. Their tool, which looks like a cotton swab, is covered at the end with an organic sponge soaked in a solution that people have to stick in the ear to recover earwax. The samples can then be sent to the laboratory without any problem. The advantage of this device is that it can be carried out at home without any medical supervision, which facilitates remote examinations, particularly requested because of the Covid-19 pandemic. Ultimately, the researchers assure that this process will also make it possible to measure the glucose or the Covid-19 antibodies which accumulate in the earwax.

Normally, the most common technique for measuring the level of cortisol in the body is to take a hair sample. Unfortunately, this technique does not shine for its reliability and effectiveness in people who do not have enough scalp. In addition, it lasts longer and costs more than the earwax technique.

“Sampling cortisol is notoriously difficult because levels of the hormone can fluctuate, so a sample may not be an accurate reflection of a person’s chronic cortisol levels. Moreover, the sampling methods themselves can induce stress and influence the results.says Andres Herane-Vives, researcher at the Institute of Cognitive Neuroscience at University College London. Earwax cortisol levels appear to be more stable, and with our new device, it is easy to collect a sample and have it tested quickly, cheaply and efficiently.”

A cheaper, more reliable and less stressful technique for patients

For this method, Andres Herane-Vives was inspired by beeswax, which is known for its good preservation and its resistance to bacteria. In order to realize the effectiveness of the technique, the research team called on 37 participants to perform cortisol readings on them. First, they took blood and hair from the contributors, and then they took a sample with their new cotton swab. The participants were also able to take a sample from their ear themselves using the cotton swab.

They found that the earwax samples gave more cortisol than the hair samples, and that it did not cause the same level of anxiety in the participants as the blood or hair sample.

“After this successful pilot study, if our device stands up to further scrutiny in larger trials, we hope to transform diagnostics and care for millions of people with depression or cortisol-related illnesses, such as Addison’s syndrome and Cushing’s syndrome, and potentially many other conditions”, rejoices Andres Herane-Vives.