How Stress Affects Our Health

We all know that stress isn't good for us, but a new study shows exactly why -- and it turns out that inflammation may be the culprit.

Researchers from Carnegie Mellon University found that feeling stressed is linked with a decreased inflammatory response regulation. Their research was published in the journal Proceedings of the National Academy of Sciences.

"The immune system's ability to regulate inflammation predicts who will develop a cold, but more importantly it provides an explanation of how stress can promote disease," study researcher Sheldon Cohen, of Carnegie Mellon, said in a statement. "When under stress, cells of the immune system are unable to respond to hormonal control, and consequently, produce levels of inflammation that promote disease. Because inflammation plays a role in many diseases such as cardiovascular, asthma and autoimmune disorders, this model suggests why stress impacts them as well."

HealthDay reported some potential causes for this relationship. One is that stressed-out people may engage in more unhealthy activities, which can then put them at an increased risk of getting sick. Another possibility is that hormones in the body may react a certain way to stress.

The study was comprised of two parts, one of which included 276 healthy adults who were exposed to the common cold virus and then were quarantined for the next five days. The researchers kept note of their symptoms. (They noted that when someone is infected with the common cold, their symptoms aren't actually caused by the cold, but rather are a byproduct of the body fighting off the cold.)

The researchers found that if a person was undergoing long-term stress, he or she was more likely to not be able to properly regulate inflammation. In turn, the inability to regulate inflammation was linked with having an increased risk of actually getting a cold after being exposed to the virus.

Recently, a study in the journal Neuron showed that stress may have other effects, too -- on memory.

That research, which was done in mice, showed that repeat exposure to stress could lead to impairments in a part of the brain called the prefrontal cortex (which is known as the "CEO of the brain" and is in charge of abstract thoughts and cognitive analysis).