According to the American Institute for Cancer Research, about one third of cancers in high-income countries can be attributed to preventable factors such as nutrition and physical activity. In the United States, breast cancer is the most commonly diagnosed cancer in women, astoundingly impacting one in every eight women in their lifetimes.
At this time, we don’t know exactly why many women develop breast cancer, but the following tips from the Dubin Breast Center’s Clinical Nutrition Coordinator Alexandra Rothwell, RD, can help to reduce your risk for cancer and may help to prevent recurrence among cancer survivors.
1. Participate in 45-60 minutes of moderate to vigorous physical activity every day throughout life.
Evidence supports that getting enough exercise provides some protection from breast cancer for both pre and postmenopausal women, but higher levels of activity in adolescence and after menopause may provide even greater risk reduction. In 73 studies conducted across the world there was a 25 percent average risk reduction in physically active women compared to the least active women, and the greatest risk reductions were seen in exercise durations that took place over a longer period of time.
2. Maintain or become a healthy weight.
Though easier said than done, being as lean as possible within a normal weight range is recommended to reduce the risk for cancer. The body mass index (BMI) indicates appropriate weight for height, and a healthy number for most people is somewhere between 18.5 and 24.9. You can have your BMI checked at your next doctor appointment or by using an online calculator. Maintaining a healthy weight is particularly important for the prevention of breast cancer in postmenopausal women, as many studies have found a connection between body weight and breast cancer in this population. Try not to be discouraged if your weight is not currently at a healthy level. For people who are overweight or obese, losing even a small percentage of weight can have major health benefits.
3. Eat a minimum of 5 servings of fruit and vegetables daily, making many of these servings vegetables and some of these servings raw.
Fruit and vegetables contain a number of beneficial nutrients such as vitamins, minerals, fiber, and phytochemicals that may help to prevent cancer. Evidence shows that high fruit and vegetable intake is associated with reduced risk for estrogen receptor negative tumors, which can be harder to treat. Cruciferous vegetables such as broccoli, cauliflower, and cabbage may be particularly protective, with one study demonstrating reduced incidence of breast cancer among women who ate those foods at least once per week.
4. Limit alcohol and consider not drinking at all.
Alcohol consumption is largely recognized as the dietary behavior that is most consistently associated with an increased risk for breast cancer. The exact mechanism by which alcohol influences the growth of breast cancer cells is unknown. Though, it may be due to effects on sex hormone metabolism or by supplying excess calories to the diet and promoting weight gain. A large study in Europe found that alcohol intake was the cause of about 4 percent of breast tumors in developed countries.
5. Minimize intake of saturated animal fats.
The fats found in dairy products, meat and poultry, called “saturated fats” have been studied for their potential to impact the development of breast cancer. An analysis was conducted on a number of these studies, which found a 19 percent increase in the risk for breast cancer among women with the highest intakes of these fats compared to the lowest. This association was stronger for postmenopausal women, indicating that it is particularly important to cut out harmful fats later in life. If you eat dairy products, always choose the low or nonfat varieties. If eating meat or poultry, choose lean cuts and stay away from the skin. Replace saturated animal fats with those found in fish and plant foods such as oils, nuts, seeds, and avocados.
Alexandra Rothwell, RD, CSO, CDN, is a registered dietitian and specialist in oncology nutrition. She has worked within the Tisch Cancer Institute for the past 3 years, now focusing on breast cancer nutrition for the Dubin Breast Center. Alexandra provides individual counseling in the areas of wellness, weight management and symptom/side effect management, in addition to creating patient education programs in this realm.