We spoke with medical experts and the Breast Cancer UK charity who have been exploring how exercise can reduce your risk of developing the disease.
While we regularly tout the benefits of exercise for long-term health, for Breast Cancer Awarness Week Breast Cancer UK have shared stats showing that exercise can reduce the risk of the disease by around 20%. Being active can also reduce the risk of recurrence and improve your chances of survival following diagnosis by around 40%, according to the charity.
These are the kinds of figures that are too important to ignore. With breast cancer being the most common cancer in women in the UK, we turned to the experts to hear more about how physical activity can reduce your risk of the disease.
“One reason exercise reduces the risk of breast cancer is because it results in lower levels of circulating sex hormones, in particular oestrogen,” says Dr Margaret Wexler, head of science for Breast Cancer UK. This month the charity is running 25 Saves Lives, a new campaign for Breast Cancer Awareness month. Dr Wexler explains to Stylist that high lifetime exposure to oestrogen slightly increases your breast cancer risk – this could be as a result of starting periods earlier, reaching the menopause later, not having children or due to excess fat tissue in women following the menopause.
“Exercise helps reduce levels of insulin and increase insulin sensitivity and glucose metabolism, which helps protect you against breast cancer and other cancers,” Dr Wexler adds.
But it’s important to note that, while exercise helps to reduce the risk of developing breast cancer, it does not eliminate it. Joanna Franks, consultant breast and oncoplastic surgeon at The Wellington Hospital, HCA Healthcare UK, tells Stylist: “I see some women who have always exercised very regularly who unfortunately develop breast cancer because it’s a multifactorial disease.
“Women sometimes feel that they should blame themselves, telling me it’s because their weight went up a bit or they were a bit stressed or didn’t do as much exercise as they wanted to. I don’t think it’s that simple – no one has made a single life decision that has caused this to happen.”
Over the years there’s been hundreds of research papers published about the link between exercise and the risk of developing breast cancer. A review of 22 studies, published in the Canadian Medical Association Journal in 2017, found that physical activity can reduce the risk of deaths caused by breast cancer by around 40%. And in a different study published in 2010 in the Journal of Clinical Oncology, previously sedentary postmenopausal women who took part in a moderate- to vigorous-intensity exercise program had hormonal changes that lowered their risk of breast cancer.
The overall conclusion shows that exercise frequently plays a positive role in reducing the risk of developing breast cancer. And that includes those who are most vulnerable to the disease, for example those who have the BRCA mutation, a hereditary gene that increases risk considerably. Post-menopausal women, who are more at risk of breast cancer due to their age and greater lifetime exposure to oestrogen, also benefit from exercising.
“It’s very important that women who have already been treated for breast cancer continue exercise after remission,” says Joanna. “Helping women feel positive about activity is very key in improving prognosis after treatment for breast cancer.”
The 25 Challenge has been worked into the 25 Saves Lives campaign with the aim of helping us enjoy the process of exercising. Breast Cancer UK is encouraging everyone to set goals and competitions in return for sponsorship from friends and family throughout the month of October, whether in the form of completing 25 press-ups every day for 25 days, running 250 km in the month of October, swimming 25 lengths, or any other fitness challenge related to the number 25.
However, it’s important to understand that to reap the benefits, exercise should be sustainable and something that is maintained throughout life. “One of the most important messages is that any additional amount of activity is helpful. While the government recommends at least 150 minutes of moderate exercise per week, you can still get benefits from adding in just a 20 minute walk every day, especially if you are starting from nothing. And, the more you do, the less risk you have,” says Dr Wexler. “We don’t want to be authoritarian about how much you should do, we just want to encourage everyone to move more and sit less.”
Sir Muir Gray, a senior physician for the NHS, adds: “The evidence is getting stronger and stronger; if you don’t smoke the single best thing you can do to reduce your risk of a number of common diseases is to take more exercise. Try an extra 3,000 steps a day.”
Chloe Gray is the senior writer for stylist.co.uk's fitness brand Strong Women. When she's not writing or lifting weights, she's most likely found practicing handstands, sipping a gin and tonic or eating peanut butter straight out of the jar (not all at the same time).