Women who are left-handed have a higher risk of dying, particularly vascular disease of the blood vessels of the head. Earlier reports have associated left-handedness with various disorders and, in general, a shorter life span. Left-handers are supposedly lesser in the older age groups, although such findings are still controversial. It is estimated that about 1 in 10 people are left-handed. Danish researchers from the University Medical Center Utrecht, studied 12,178 middle-aged women and followed them for nearly 13 years. Of these women, 252 died during the study period. 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 system. 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 death from cerebrovascular accident. The underlying mechanisms remain elusive, although genetics and environmental factors may be involved. 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.
Epidemiology,
April 2007