Left-handed women under the age of 50 are more than twice as likely to develop breast cancer than those who are right-hand dominant. What?
Yep, that's what a new study reveals.
This left-handed conclusion, published in the journal Epidemiology, comes from the study of 12,000 women in the Netherlands whose medical histories were followed for 13 years. Discounting all other factors -- lifestyle, environment, and other disease -- left-handers came up with a risk of breast cancer 1.39 times that of right-handers. For pre-menopausal women, the figure climbed to 2.41.
When considering all sorts of illness, left-handed women had a 70 percent higher chance of contracting any cancer and a 30 percent higher chance of a fatal disease of the circulatory system. It's not just breast cancer -- it's any number of health conditions that may be linked to regular use of the left hand.
Scientific reactions on this topic are mixed.
One doctor says there are generally few left-handers in the older population sector, explaining the higher incidence among younger women.
Another doctor, scientist Olga Basso, herself a left-hander, has this to say: "I am not alone in thinking that the literature on handedness suffers from a number of ills. Having successfully dodged a number of disorders, I doubt that my left hand is prematurely pulling me toward my grave."
1. Infants who are born left-handed may well have been exposed to higher levels of sex hormones in the womb that can also cause changes in breast tissue. Pre-natal hormones have a profound effect on us. For example, homosexual women tend to be more left-handed as well. We already know that prenatal neuroendocrine levels are a factor in the development of human sexual orientation and there has been evidence that pre-natal hormones affect functional brain asymmetries. So hormones in utero have a profound effect on sexuality, brain characteristics, and could therefore affect cancer risk.
Posted at 3:59PM on Jun 8th 2007 by hchcec