Just half an hour of walking a day could slash younger women’s breast cancer risk, new research suggests.
The findings come from a study examining how aerobic exercise affects proteins in the blood known to have cancer-fighting properties.
While breast cancer is more common after the menopause, it can be more aggressive and harder to treat in younger women – prompting scientists to look for ways to prevent the disease in this group.
Experts from Rīga Stradiņš University in Latvia studied 18 healthy pre-menopausal women aged around 41, tracking how levels of six anti-cancer biomarkers changed after exercise.
These included myokines – proteins released by muscles during physical activity that are thought to play a role in suppressing tumour growth.
They found that even walking on a treadmill at low intensity for just 30 minutes triggered changes in the blood that slowed the proliferation of cancer cells.
Higher intensity exercise produced stronger effects.
When participants walked for between 30 and 45 minutes at a moderate-to-high intensity, around half of the biomarkers showed enhanced anti-cancer activity.
Just half an hour of walking a day could slash younger women’s breast cancer risk, new research suggests
To test this, researchers used blood samples taken immediately after exercise and exposed them to HER2-positive breast cancer cells – an aggressive form of the disease that grows rapidly and is more likely to spread.
They found that the myokine-rich fluid significantly reduced the rate at which these cancer cells divided.
Around 15 to 20 per cent of breast cancer patients have HER2-positive disease.
HER2 is a protein found on the surface of all breast cells that helps regulate growth and repair. But when the gene controlling it malfunctions, it can drive uncontrolled cell division and tumour formation.
While the exact biological mechanism is not yet fully understood, researchers say the findings add to growing evidence that physical activity may help to prevent – and potentially slow the progression of – breast cancer.
The study, presented at the 15th European Breast Cancer Conference in Barcelona, looked at the immediate biological response to a single bout of exercise.
However, the authors say the results align with broader public health advice.
Lead author Linda Laizāne, a PhD researcher in medical biochemistry, said: ‘We can certainly draw a bridge between these findings and global health recommendations.
‘If 30 minutes of high-intensity exercise is enough to ‘prime’ the blood with cancer-inhibiting factors, then consistency is key to maintaining that protective environment.’
She added: ‘We wanted to provide women with protocols that are actually doable.
‘Some people may not enjoy or have the time to go to the gym, but walking is something we do every day – so maybe we can just increase the speed a little to help support these natural cancer-fighting mechanisms.’
According to the NHS, adults should aim for at least 150 minutes of moderate-intensity exercise a week or 75 minutes of vigorous activity.
Prof Laizāne added: ‘A practical way to achieve this, and one that aligns with our findings, would be 30 minutes of moderate-to-vigorous exercise five times a week.
‘This frequency ensures a regular ‘pulse’ of beneficial myokines and hormones in the bloodstream that could help protect against cancer.
‘That said, these implications remain speculative at this stage, and further research is required to validate the long-term effects.’
Breast cancer is the most common cancer in women in the UK, with more than 56,000 new cases each year.
Globally, cases are predicted to rise by a third to more than 3.5 million a year by 2050, according to the Global Burden of Disease Study Breast Cancer Collaborators.
