Myth: There is nothing you can do to reduce your risk.
While it’s important that we all exercise caution around exposure to toxins and known carcinogens in our environment, it’s also important that we keep complicated information/issues from being misinterpreted and spread as frightening rumours. There’s nothing anyone can do to become “immune” to breast cancer. However, there are many things you can do to reduce your risk for developing the disease. 1/3 of cancers can be linked to lifestyle factors including diet and exercise so creating healthy habits while you are young, like exercise, will help to reduce your risk and ensure that you are putting your health front and center for the rest of your life.
Physical Activity: Research shows that any quantity of regular exercise is beneficial, with the frequency, intensity and consistency directly related to the benefits in reducing risk. According to a 2017 study by the World Cancer Research Fund, premenopausal women who exercise vigorously have a 17% lower risk of breast cancer and postmenopausal women who do the same have a 10% lower risk compared to women who rarely exercise. Additionally, women who exercise moderately (ie/ walking or gardening), have a 13% lower risk of breast cancer compared to sedentary women.
Additionally, recent research from the University of Toronto has shown that regardless of how much exercise a person gets, sitting too much has negative health impacts. Sedentary behaviour has been independently associated with chronic disease-related risk factors such as central adiposity, insulin resistance and inflammation. These factors are hypothesized to be operative in the development and progression of breast cancer.
Healthy Body Weight: Rethink encourages young women to have their doctor check their Body Mass Index (BMI) to help indicate a healthy body weight. Numerous studies have demonstrated the association between being overweight (defined as BMI of 25 to 29.9) or obese (BMI of 30 or greater) and breast cancer incidence. A study by the International Agency for Research on Cancer (IARC) in 2016, found a correlation between body fat and cancer risk, where those with an absence of excess fat had reduced risk for most cancers.
The effect of weight on breast cancer risk is due to differences in the levels of the female sex hormones estrogen and progesterone. Although these natural hormones are important in the body, they can encourage some breast cancers to grow. The more fat tissue you have, the higher your levels of estrogen are likely to be and this, in turn, increases your risk of breast cancer. Fat also contributes to the body’s ability to fight cancer by decreasing the immune response and increasing inflammation through increased glucose and insulin in the body responses, both of which are involved in cancer (Source). Regular exercise and a balanced diet are key to maintaining a healthy body weight.