One Third of Breast Cancer Cases Avoided with Diet and Exercise
You might not be able to change your genes, but you can change your jeans. The International Agency for Research on Cancer estimates that up to one-third of the breast cancer cases in Western countries could possibly be avoided if women put exercised more and ate less.
Mammogram screening, early diagnosis and better treatments have all contributed to the reduction in breast cancer cases by around 2% a year and the improved survival rate in the US. But still an estimated one in eight American women will suffer from breast cancer during their lifetime. Experts say now the focus needs to shift on improving personal lifestyle habits to prevent the disease even more.
Dr. Sarah Brennan of Queen’s University Belfast in Northern Ireland and colleagues reviewed the results of 18 studies that enrolled a total of more than 400,000. Each study aimed to associate breast cancer risks with diet and alcohol intake. Because individual studies may be too small to uncover modest relationships, the team combined the data to offer a better chance of detecting diet’s true effect on the prevention of breast cancer. Although combining different studies together has limitations, looking at a diet pattern rather than individual nutrients provides a more holistic view of the role that food intake plays on a person’s risk.
The team found an 11% lower risk of breast cancer in those women consuming the more healthful diet, including more whole grains, fruits and vegetables and less fatty, processed foods. They also found that those consuming large amounts of alcohol had a 21% increased risk.
Exercise also plays a role in the reduction of breast cancer risk In one study from the Women’s Health Initiative, as little as 1.25 to 2.5 hours per week of brisk walking reduced a woman’s risk by 18 percent. Walking 10 hours a week reduce the risk more. The American Cancer Society recommends 45 to 60 minutes of physical activity five or more days a week to reduce a woman’s risk of breast cancer.
Diet and exercise can lead to weight reduction, another positive lifestyle change that can influence breast cancer disease risk. A 2006 British study that followed almost 6,000 women concluded that obesity increases a postmenopausal woman’s risk of developing breast cancer by 60%. Many breast cancers are fueled by estrogen, a hormone produced in fat tissue. Experts suspect that more fat tissue equals more estrogen resulting in more cases of breast cancer that could possibly be avoided.
Breast cancer is the most common cancer in women. Last year in the United States more than 190,000 new cases were diagnosed and 40,000 deaths resulted. In Europe, there were about 421,000 new cases and nearly 90,000 deaths in 2008, the latest available figures. A woman’s lifetime chance of getting breast cancer is about one in eight.
Addressing lifestyle habits and weight with women is difficult, but as one researcher put it: "It's hard to lose weight, but it's not impossible. The potential benefit of preventing cancer is worth it."