The World Cancer Research Fund with the American institute for Cancer Research have recently published the most comprehensive review on breast cancer and it’s relation to diet, nutrition and physical activity. Click on the following link to read this compelling review in order to find out how certain lifestyle choices may increase or decrease risk of breast cancer.
This review is an epitome of research; it compiles conclusions that have been independently determined by an international panel of experts. WCRF have estimated that around 38% of cancer is due to lifestyle choices, which corresponds to estimates of around 30% reported by Howell et al in 2014.
The decrease in cancer risk that can potentially be achieved by lifestyle change is difficult to ignore. The review focuses on various environmental determinants of the disease and discusses the corresponding risk of premenopausal and postmenopausal breast cancer in women. In order to help highlight some of the conclusions of this overarching report we thought you might like to test your knowledge on some key topics. We asked how much you knew about alcohol and breast cancer in June, now let’s see how much you know about the rest, starting with physical activity. For a tabular overview of some causes of increased and decreased risk of breast cancer you can visit pages 8 and 9 of the WCRF report.
Micha, Digital Communications Assistant at the SCPN
Here are some key facts that we think it is important to know –
· Vigorous physical activity serves to protect against premenopausal and postmenopausal breast cancer
· Occupational and recreational physical activity significantly protect against postmenopausal breast cancer
· A 13% decrease in risk of postmenopausal breast cancer was observed in women who did the highest levels of activity compared with that of the lowest
Mechanisms by which physical activity influences breast cancer
· Physical activity decreases overall body fat and the fat of specific organs, altering their susceptibility to cancer
· Physical activity may decrease circulating oestrogen levels
· Physical activity improves our immune systems which have the ability to monitor and eliminate cancer cells
But note….Always take precautions when venturing outdoors for exercise, as sunlight exposure increases your risk of skin cancer
· Increased weight gain in adulthood has been shown to significantly increase risk of postmenopausal breast cancer
· Increased weight gain in adulthood appears to have a linear relationship with increased risk of postmenopausal breast cancer
Mechanisms by which weight gain influences breast cancer
· In postmenopausal cases there is a significant association between weight gain and hormone receptor cancers Obesity Menopausal status
· In premenopausal women, greater body fatness may protect against premenopausal breast cancer
· Increased body fatness during adulthood is convincingly associated with postmenopausal breast cancer
· The WCRF have stated that, in regards to obesity, “the decreased risk of premenopausal breast cancer would be outweighed by an increased risk of postmenopausal breast cancer” It is beneficial to always maintain a healthy weight throughout life Mechanisms by which obesity influences breast cancer
· Obesity results in excess adipose (or fat) tissue and after the menopause adipose tissue are a main source of oestrogens
· Obesity has been identified with an increase in the hormone insulin, which may promote the growth of cancer cells
· Obesity may also be linked to insulin resistance which causes the body to over-produce insulin (promoting cancer)
· Obesity is associated with higher levels of circulatory pro-inflammatory cytokines that act as part of the immune system. These may become susceptible to cancer