May Have A Shorter Life-Span
A study suggests that women who are left-handed have a higher
risk of dying, particularly from cancer and cerebrovascular disease
- damage to an artery in the brain or an artery that supplies
blood to the brain.
While it could be a chance finding and the evidence is far from
conclusive, numerous reports have associated left-handedness with
various disorders and, in general, a shorter life span, Dutch
researchers note in their report in the journal Epidemiology.
"Left-handers are reported to be underrepresented in the
older age groups, although such findings are still much debated,"
write Dr. Made K. Ramadhani and colleagues from University Medical
Center Utrecht. It is estimated that about 1 in 10 people are
Among 12,178 middle-aged Dutch women the researchers followed
for nearly 13 years, 252 died.
When left-handed women were compared with the other women, and
the data were adjusted for a number of potentially confounding
factors, lefties had a 40 percent higher risk of dying from any
cause, a 70 percent higher risk of dying from cancer, and a 30
percent higher risk of dying from diseases of the circulatory
Left-handed women also had a 2-fold increased risk of dying from
breast cancer, close to a 5-fold increased risk of dying from
colorectal cancer, and more than a 3-fold higher risk of cerebrovascular
The underlying mechanisms remain elusive, although genetics and
environmental factors may be involved, Ramadhani and colleagues
suggest. Much of the research into handedness and mortality has
been fueled by the hypothesis that left-handedness is the result
of an insult suffered during prenatal life, which ultimately leads
to the early death.
The author of a commentary, Dr. Olga Basso, who is left-handed,
is highly skeptical, in general, of research relating disease
and death with handedness. "I am not alone in thinking that
the literature on handedness suffers from a number of ills,"
regardless of the putative illnesses seen in those who are left-handed,
"Having successfully dodged a number of disorders,"
adds Basso, "I doubt that my left hand is prematurely pulling
me toward my grave."
Basso is with National Institute of Environmental Health Sciences,
Research Triangle Park, North Carolina.
SOURCE: Epidemiology March 2007.