Left-handed women may have shorter lifespan

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," writes Dr. Made K. Ramadhani and colleagues from University Medical Center Utrecht. It is estimated that about one in 10 people are lefties.

Left-handed women also had a two-fold increased risk of dying from breast cancer, close to a five-fold increased risk of dying from colorectal cancer, and more than a three-fold higher risk of cerebrovascular mortality.

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.