Losing weight reduces breast cancer risk

Losing weight in young adult life can reduce the risk of early-onset breast cancers associated with BRCA1/2 mutations. Researchers from the University of Toronto, Ontario, Canada found that breast cancer prevention starts early in life. Probably this is a critical period for the hormones involved to be interacting with the breast tissue. The researchers investigated whether changes in body weight were associated with the risk of breast cancer in 1,073 women who carried BRCA1 or BRCA2 mutations. Weight loss of at least 10 pounds between age of 18 and 30 years was associated with a 33 percent reduction in the risk of breast cancer thereafter, whereas weight gain was not associated with a change in risk. This reduction in risk was mainly seen for cancers occurring between the ages of 30 and 40 years. The risk reduction appeared to be greater among women with a BRCA1 mutation (65-percent risk reduction) than among women with a BRCA2 mutation (12-percent risk reduction). A weight gain greater than 10 pounds among women who had at least two full-term pregnancies was associated with a 44 percent increased risk of breast cancer. The findings suggest that weight loss in early adult life (and not weight per se) decreases the risk of BRCA-associated breast cancer diagnosed at an early age. The period between the age of 18 to 30 years appears to be a critical when weight gain should be avoided in mutation carriers.Yet more studies and a careful observation of new cases of breast cancer are needed to confirm and extend these findings.