A report published Tuesday examines how diet, physical activity and nutrition impact a woman’s likelihood of developing breast cancer. The report analyzed 119 studies, which include data on 12 million women and 260,000 cases of breast cancer.
The research shows that drinking a small glass of wine – about 10 grams of alcohol content – can elevate pre-menopausal breast cancer risk by 5 percent, while post-menopausal women are 9 percent more likely to develop the disease if they consume alcohol at that rate. A standard drink has 14 grams of alcohol.
The authors also highlight the connection between physical activity and lowered risk of developing breast cancer. The report presents strong evidence that intense exercise – such as fast bicycling or running – decreases the risk of pre- and post-menopausal breast cancer. Previous studies have found that moderate exercise decreases post-menopausal cancer risk.
“It can be confusing with single studies when the findings get swept back and forth,” said Anne McTiernan, a lead author of the report and cancer-prevention expert at the Fred Hutchinson Cancer Research Center.
For vigorous exercise, the most active pre-menopausal women had a 17 percent lower risk and post-menopausal women had a 10 percent lower risk of developing breast cancer compared to those who were the least active. Total moderate activity – which includes gardening and walking – was linked to a 13 percent decrease in risk when comparing the most active to the least active women.
“With this comprehensive and up-to-date report the evidence is clear: Having a physically active lifestyle, maintaining a healthy weight throughout life and limiting alcohol – these are all steps women can take to lower their risk,” McTiernan said.
Breast cancer is the most common cancer in women in the United States, with more than 252,000 projected new cases this year. The American Institute for Cancer Research – which funded the study with the World Cancer Research Fund – estimates that one in three breast cancer cases in the U.S. could be prevented if women were physically active, did not drink alcohol, and maintained a healthy weight.
Alice Bender, head of nutrition programs at the American Institute for Cancer Research, said that despite uncontrollable risk factors like age, the report presents steps women can take to lower the likelihood of developing breast cancer risk.
“Wherever you are with physical activity, try to nudge it up a bit, either a little longer or a little harder. Make simple food shifts to boost protection – substitute veggies like carrots, bell peppers or green salad for chips and crackers – and if you drink alcohol, stick to a single drink or less,” Bender said.
“There are no guarantees when it comes to cancer, but it’s empowering to know you can do something to lower your risk.”