STANFORD, Calif., Sept. 23 (UPI) -- At least in laboratory mice, bouts of relatively short-term stress can boost the immune system and protect against skin cancer, U.S. researchers say.
Firdaus Dhabhar, associate professor of psychiatry and behavioral sciences at Stanford University's School of Medicine, says the finding is surprising because chronic stress has the opposite effect -- taxing the immune system and increasing susceptibility to disease.
"This is the first evidence that this type of short-lived stress -- public speaking or a job interview -- may enhance anti-tumor activity," Dhabhar said in a statement.
The researchers investigated the effect of short-term, or acute, stress on 30 laboratory mice exposed for 10 weeks to thrice-weekly doses of cancer-causing ultraviolet light.
The light was non-blistering and non-burning and the mice experienced only a slight reddening of the skin after each exposure. But the light was composed mainly of the most dangerous wavelength -- called UV-B. Starting at week 11, many of the mice went on to develop precancerous and cancerous growths similar to those in humans.
The mice were then stressed by restricting their movements.
The study found fewer of the mice that had been acutely stressed developed skin cancer during weeks 11-21.
The findings are scheduled to be published in the journal Brain, Behavior and Immunity.