Left-handed people don't necessarily die any younger than
right-handers, according to new research that disputes the findings suggested by
some studies.
In a nine-year study, Dr. Simon Ellis and his colleagues at Keele University
in England examined the link between left-handedness and the risk of dying
earlier using 6,049 people ranging in age from 15 to 70.
"Handedness did not make a significant contribution to the outcome of death,"
concluded the study, published Friday in this week's issue of The Lancet, a
British medical journal.
The question of whether lefties die younger is controversial. Several studies
have suggested a connection, but others have shown no link.
One theory suggests that older age groups contain fewer left-handers not
because they die earlier, but because many in the older generation were forced
as children to become right-handed, whereas children today are less likely to be
pressured into switching.
Researchers found in 1991 that the proportion of left-handers decreases with
age, dropping from 13 percent in 20-year-olds to less than 1 percent in
80-year-olds.
That led scientists to suggest that left-handedness may be associated with a
shorter lifespan, perhaps because southpaws are less adapted to survival and
thus more prone to immune disease or accidents.
One study suggested that right-handed people live about nine years longer
than left-handers.
But some researchers, such as Richard Peto, professor of medical statistics
and epidemiology at Oxford University, dispute those conclusions.
"I haven't seen any competent studies showing a link," said Peto, who was not
involved in the Keele University study. "You've got to adjust for age."
In the study, the left-handed group was younger than the right-handed group,
but the analysis accounted for the effect of age.
The investigators initially received 6,097 correctly completed questionnaires
to their initial mailing to people between 15 and 70 years old. Nine years
later, they attempted to trace the respondents: Forty-eight could not be traced,
387 had died and the remaining 5,662 were known to be alive.
Emma Ross
Associated Press Writer
May 28, 1998
