Does looking at the world through rose-colored glasses improve your health? A growing body of evidence supports a correlation between outlook and the strength of the immune system. For example, studies suggest that people with a more positive attitude tend to have greater resistance to colds than those with a negative attitude. Studies also show that emotional stress influences susceptibility to upper-respiratory-tract infections. A recent review of studies even shows associations between a positive attitude and better health, greater longevity, fewer symptoms and less pain.
Researchers from Carnegie Mellon University and elsewhere enrolled 334 healthy volunteers aged 18–54 years and evaluated their tendencies to experience positive emotions (such as happiness, pleasure and relaxation) and negative emotions (such as anxiety, hostility and depression). Participants were then given nasal drops that contained a virus and were monitored to determine whether or not they developed a cold.
Subjects with a positive emotional style had a lower risk of developing a cold than those with a negative outlook. In addition, subjects with a negative attitude tended to report more unfounded symptoms of illness. Investigators concluded that the tendency to experience positive emotions is associated with greater resistance to objectively verifiable colds. The study was published in Psychosomatic Medicine (2003; , 652–57).