The Smell of Sickness: Applying the Senses

A recent study shows how our sense of smell may show signs of problems in the immune system within just a few hours of toxin exposure.

According to lead study author Mats Olsson of the Karolinska Instiutet in Sweden, she conducted a study that shows both anecdotal and scientific evidence for diseases and particular smells. For instance, previous findings have shown that those with diabetes may sometimes report to have breath that smells like rotten apples or acetone.

"There may be early, possibly generic, biomarkers for illness in the form of volatile substances coming from the body," she explains, via a press release.

For the study, researchers had eight healthy individuals visit a laboratory to be injected with either lipopolysaccharide (LPS)--a toxin known to ramp up an immune response--or a saline solution. Those injected with LPS produced a noticeable immune response that elevated their body temperatures and increased levels of immune system molecules known as cytokines.

A separate group involved was also asked to smell the sweat samples. These participants rated t-shirts with LPS sweat as more intense or containing an unpleasant odor than the other t-shirts.

Researchers note that the association between immune activation and smell was accounted for due to the level of cytokines present in the LPS-exposed blood.

However, they added that no difference was found between the LPS and the control group.

More information regarding the study can be found via Psychological Science, a journal of the Association for Psychological Science.