Would you volunteer to participate in a study where viruses are injected in order to measure the risk that you catch a cold? 276 volunteers actually participated in an American study of this kind*). After the injection of the virus, the participants stayed in quarantine for five days. Then measures were taken of congested noses, and the snot was weighed.
The results indicated that stressed persons more easily catch a cold, which may not come as a big surprise, and those who experience chronic stress are most likely to catch a cold. The researchers wanted to assess the participants’ level of stress. After the necessary interviews, the conclusion left no doubt: those who had been most stressed were also the hardest hit by the cold.
Professor of immunology at NTNU, Vibeke Videm, reports several studies with similar results: stress weakens the body’s immune system. Those who have been stressed over a long time catch a cold more easily, and their infections are stronger. Medical students who got a vaccine just before their exam had a poorer effect of it than those students who got it before or after periods of such stress.
Cannot kill the virus
According to professor Videm, different mechanisms can contribute to bodily damages if one is stressed, e.g. due to psychic stressors. Changes of hormones and neurotransmitters occur during periods of stress, making the body less able to kill the cold viruses. Usually, the body produces protection cells that kill cells infected with viruses, but after long term stress the body produces fewer such cells. The viruses intrude the body more easily.
Even though research supports that stress makes you more easily infected, there are some simple actions we can take to improve the body’s immune system, e.g. good stress reduction with a suitable method – there are several such techniques available. Videm emphasizes that e.g. meditation is a widely used method. General advices for good health may also help, like a healthy diet and regular physical activity also contribute to strengthening of the immune system.
*) doi: 10.1073/pnas.1118355109