How stressed are you? Your earwax may have the answer.

A new method of collecting and analysing earwax to see levels of the stress hormone cortisol may be an easy and inexpensive way for people with depression and anxiety to track their mental health.

Cortisol is an important hormone that spikes when a person is stressed and drops when they relax. In the short term, cortisol is responsible for the “fight or escape” reaction, so it is important for subsistence. But cortisol usually rises in people with depression or anxiety, and persistently high levels of cortisol have a negative impact on the immune system, blood pressure and other body functions.

Other disorders are because of cortisol disorders, including Cushing’s disease (caused by excessive cortisol production) and Addison’s disease (caused by insufficient cortisol production). Cushing's disease has abnormal fat accumulation, a weak immune system and is prone to fractures. People with Addison's have dangerously low blood pressure.

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Tracking cortisol levels

Cortisol can be measured in a variety of ways, from saliva to blood and even hair. But saliva and blood samples show only short-term levels, while cortisol fluctuates significantly throughout the day. Even drawing blood with a needle increases stress, causing cortisol levels to rise. Hair samples can provide a snapshot of cortisol over several months, but they are expensive to analyse -- and not everyone has hair.

Andres Herane-Vives, a lecturer at London University, and his colleagues have turned the researching target to the ears. Earwax is stable and resistant to bacterial infections, so it can be easily sent to a laboratory for analysis. It also keeps records of cortisol levels for weeks.

But the previous method of collecting earwax was to insert a syringe into the ear canal and then flush water out of the earwax, causing the person to experience some pain and stress. So Herane-Vives and his colleagues developed a swab that works like a cotton swab. A ring of protection around the handle prevents it from going too deep into the eardrum, and at the other end is a sponge for collecting earwax.

Collecting earwax

In a small pilot study, the researchers took blood, hair and earwax samples from 37 participants in two separate studies. At each collection, they used a syringe to collect earwax from one ear and a new self-collecting swab from the other ear. The researchers then compared the reliability of cortisol measurements collected by the two methods.

They found that the concentration of cortisol in earwax was higher than in hair, which was easier to analyse. Analysing earwax collected from a swab is also faster and more efficient than using a syringe, which people need to wait for the wax to dry out before analysing it.  In the end, earwax levels were more consistent than in other ways, and were more sensitive to cortisol fluctuations such as those caused by recent drinking. Participants also reported that self-collecting swabs were more comfortable than using syringes.

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The researchers published their findings in the 2nd Nov issue of the journal “Heliyon”. Herane-Vives has also created a company named Trears to market the new approach. He hopes earwax could also be used to monitor the activities of other hormones in the future. The researchers also need to carry out further studies on Asian individuals, who were not included in the preliminary study because many Asians have dry, brittle earwax rather than moist, waxy wax.

He said in a statement, “After this successful pilot study, if our device can stand up to further testing in large trials, we hope to transform the diagnosis and treatment of millions of patients with depression or cortisol-related disorders, and perhaps contribute to many other diseases.”