The Usual Suspect

The Usual Suspect
The link between stress and disease has been oversold. The truth about its effect on health.
Dr. Anthony L. Komaroff
NEWSWEEK
Published Feb 14, 2009 Updated: 2:12 p.m. ET Feb 14, 2009
From the magazine issue dated Feb 23, 2009
Walter Bradford Cannon did not strike people as someone interested in black magic. A world-famous physiologist, Cannon often wore three-piece suits in his laboratory at Harvard Medical School. He spent his life making very precise measurements of bodily functions and drawing cautious conclusions from those measurements. That's why his colleagues were surprised by the paper that Cannon published in the American Anthropologist in 1942. In it he described well-documented examples of healthy young adults in South America, Africa, Australia, New Zealand, various islands of the South Pacific and Haiti who had been hexed by witch doctors. Once the word of their hexing was out, the victims were often abandoned by their tribe and even by their families. Within a few days, they were dead. These "voodoo deaths" just happened, without any discernable violence having been done to the victims. Black magic, it would seem. Cannon had an alternative explanation, however: he believed the victims had been scared to death.
Cannon was the first to describe the "fight or flight" reaction: when the brain perceives a serious threat, it sends chemical and electrical signals that prepare the heart, lungs, blood vessels and immune system for the battle or chase to come. Cannon pointed out that—in a world full of sudden physical threats—this stress reaction helped preserve the lives, and hence the reproductive capacity, of human beings; it thus had been fostered and preserved by evolution. In the case of the voodoo victims, however, Cannon argued that the stress reaction was harmful rather than protective. When the reaction remained activated for several days—sustained by fear and aggravated by a loss of social support—it led to a collapse of the circulation and death.
While there is much evidence linking stress to the heart and blood vessels, the relationship is not nearly as simple as a recounting of Cannon's voodoo paper might suggest. And despite some widely held and popular ideas, the link between stress and other diseases is even less clear. Surely, experiencing stress may worsen the symptoms of almost any condition. But there is little evidence that stress is the exclusive or even the principal cause of any disease.