Universite de Montreal study reveals physical exercise can reduce that risk
A recent study published in the Journal of Cancer Epidemiology has reinforced the correlation between being overweight, smoking and breast cancer. What makes this study unique is how test subjects were not diagnosed for BRCA1 and BRCA2 gene mutations, which predispose women to breast cancer.
Instead, women with such gene mutations were excluded to allow researchers to concentrate on lifestyle factors such as smoking, exercise, nutrition and weight. All women analyzed in the study were direct ancestors of the first French colonists.
"To our knowledge, this is the first study conducted on a sample of women without BRCA1 and BRCA2 gene mutations, which are often found in French-Canadian women," says lead researcher Vishnee Bissonauth, a graduate of the Universit- de Montr-al's Department of Nutrition and a researcher at the Sainte-Justine University Hospital Research Center.
The study found that weight gains after the age of 20 increases the risk of breast cancer. If the weight gain is more than 15.5 kilos, the risk increases by an average of 68 percent. Risk increases depending on how late in life the weight gain occurs. A woman who gains more than 10 kilos after age 30 or more than 5.5 kilos after age 40 is almost twice as likely to suffer from breast cancer as a woman whose weight is stable. The risk triples if the body mass index is at its maximum after age 50.