June 13, 2003 -- Twins are evidence that it's true: A close bond with other people can lengthen your life, probably by boosting your immune system.
A new study examines longevity among many, many male twins -- all veterans of World War II, now in their 70s and 80s -- to see how their relationship affected their health. This picture would indicate effects on the immune system, writes researcher Malcolm D. Zaretsky, PhD, a biologist with the University of California at Berkeley.
His study appears in this month's Journal of Gerontology.
The 26,974 veterans in the study completed health questionnaires in 1967 and 1983. Zaretsky looked at whether they were fraternal twins or identical; how often they communicated, either by phone or mail; the health problems they had; exercise they got; whether they smoked; if they were married; how much alcohol they drank; how much they weighed.
Identical twins -- more than fraternal twins -- lived longer if they had frequent communication, defined as more than once a month, reports Zaretsky.
Other signs of sociability, like active memberships in church or community groups and close relationships with other relatives or friends, didn't have as much affect on their longevity.
But the identical twins apparently had healthier lifestyles -- they smoked less and exercised more than the fraternal twins.
The message for twins and non-twins: Support from others -- especially ties that last over a lifetime -- could reduce susceptibility to disease and improve one's odds of surviving an illness, writes Zaretsky. Other studies have shown similar effects on the immune system, he adds.
SOURCE: Journal of Gerontology, June 2003.