The American Institute for Cancer Research (AICR) estimates that approximately 1 in 8 women will eventually develop breast cancer, and approximately 38 percent of all breast cancer cases could be avoided by taking preventive measures. Breast cancer is one of the most widely studied cancers, and the research is convincing that nutrition can make an impact on risk for individuals with and without a breast cancer diagnosis.
What Has Been Studied?
The Vitamins and Lifestyle (VITAL) study was designed to study the health habits of women who have never been diagnosed with breast cancer. Researchers wanted to determine if there was a reduced risk of breast cancer in women who followed the World Cancer Research Fund (WCRF) and AICR cancer prevention recommendations and, if so, to determine which recommendations were associated with the strongest reduction in risk.
The Results Are Convincing
The study found that women who met five to six of the recommendations (listed below) had a 60 percent reduced risk of developing breast cancer. Those women who met two to four of the recommendations had almost a 50 percent reduction in risk. And even following only one of the six recommendations showed a reduction in risk by one-third. There were three recommendations that appear to have the most influence — limiting alcohol, consuming mostly plant foods, and being as lean as possible.
The Importance of Drinking in Moderation
Of all six recommendations, limiting alcohol had the strongest reduction in risk. Consuming no more than one drink per day reduced breast cancer risk by more than one-third. A standard serving of alcohol is considered 12 ounces of beer, five ounces of wine, or one and a half ounces of 80-proof spirits.
Consuming a Mostly Plant Based Diet
The second most important recommendation was the suggestion to consume mostly plant foods. This can be achieved by striving to consume at least five servings of fruits and vegetables and at least one serving of whole grains or legumes per day.
Managing Your Weight
The third most important finding was related to body fatness. Women who had a body mass index (BMI) in the normal range had a 13 percent reduction in risk. The recommendation is to be as lean as possible without becoming underweight. The range for a normal BMI is 18.5 to 25.
Women who met these three recommendations saw a decrease in breast cancer risk that was equally great as the women who met at least 5 of the 6 recommendations, though modest added benefit could also be gained from meeting recommended guidelines for red, processed meat and physical activity.
What About Those With Breast Cancer?
One study looked at the effects of dietary fat intake in women who had been diagnosed with breast cancer. The Women’s Intervention Nutrition Study (WINS) found that reducing dietary fat intake could improve relapse-free survival rates in women with breast cancer. After five years, women in the lower fat diet group had a 24 percent lower risk of relapse than those following their regular diet. The impact of a reduction in dietary fat was even greater in women with hormone receptor-negative breast cancer. Individuals with hormone receptor-negative breast cancer who consumed the lower fat diet had a 42 percent reduced risk of relapse. Based on this study, women with breast cancer may have less risk of recurrence when following a lower fat diet.
What You Can Do Now
The WCRF/AICR recommendations are for cancer prevention and also for cancer survivors. Adherence to the WCRF/AICR cancer prevention guidelines could considerably reduce incidence of postmenopausal breast cancer and are our best guidelines for breast cancer survivors. Women can decrease their risk of breast cancer by limiting alcohol consumption, consuming a mostly plant-based diet, and managing their weight. Increasing physical activity and adopting a more Mediterranean-style diet, may help in maintaining a healthy body weight and meeting the dietary recommendations set forth by the WCRF/AICR. The basis of the Mediterranean-style diet consists of a variety of fruits, vegetables, whole grains, beans and legumes, nuts, lean proteins, including fish. Breast cancer survivors, especially those with hormone receptor-negative breast cancer, appear to benefit from a lower fat diet.
Setting Goals for Success
Below are the WCRF/AICR recommendations for cancer prevention and cancer survivors. Begin to slowly incorporate the recommendations that you are not currently meeting. Making changes in small, positive, and consistent steps will help you to make these recommendations become a part of your everyday lifestyle.
- Be as lean as possible without becoming underweight.
- Be physically active for at least 30 minutes every day.
- Avoid sugary drinks and limit consumption of energy dense foods.
- Eat more of a variety of vegetables, fruits, whole grains, and legumes such as beans.
- Limit consumption of red meats and avoid processed meats.
- If consumed at all, limit alcohol consumption to one drink per day for women and two drinks per day for men.
- Limit consumption of salty foods and avoid foods processed with salt.
- Avoid using supplements to protect against cancer, and instead try to eat nutrient-rich foods.
- It is best for mothers to breastfeed exclusively for up to six months and then add other liquids and foods.
- After treatment, cancer survivors should follow the recommendations for cancer prevention.