St. Louis, Sept. 23, 1998 -- Investigators at the Veterans Affairs Medical Center and Washington University School of Medicine in St. Louis have found that the psychological trauma of combat had little effect on the physical health of Vietnam Veterans 20 years after their experience in Southeast Asia.
Studying more than 4,700 pairs of identical and fraternal twin brothers who served during the Vietnam War, the researchers found that combat played only a minor role in health problems, such as hypertension, respiratory difficulty and gastrointestinal disorders. The findings, reported in the Sept. 23, 1998 issue of the journal Psychosomatic Medicine, show that inherited factors and environmental experiences not related to combat explain more than 90 percent of reported health problems.
Past studies that have suggested an association between combat and physical health lacked adequate control groups, according to principal investigator Seth A. Eisen, M.D. He points out that while it is relatively easy to find subjects exposed to substantial psychological stress from combat, it is difficult to find an appropriate control group, individuals who are very similar yet lack combat exposure.
"Everything about the characteristics of people is explained by some
combination of inherited factors and environmental experiences," explained
Eisen, associate professor of medicine at Washington University School of
Medicine and staff physician for the Department of Veterans' Affairs. "Twins
provide a wonderful way to better understand this because if we find differences
between twin siblings, those differences must be due to influences from outside
of the family."
Because the twins in this study were raised in the same households, they
are as similar to each other as possible prior to entering military service.
Identical twins have exactly the same genes, and fraternal twins share about
half of their genes, so this sample also allowe
Contact: Jim Dryden
Washington University School of Medicine