Physical inactivity costs the UK an estimated £7.4 billion each year - but more importantly, it costs lives. In today's increasingly sedentary world, sitting too much is raising the risk of many serious diseases, including cancer. But could something as simple as walking offer real protection?
Author
- Mhairi Morris
Senior Lecturer in Biochemistry, Loughborough University
It turns out the answer may be yes.
A growing body of research shows that regular physical activity can lower the risk of cancer. Now, recent findings from the University of Oxford add more weight to that idea. According to a large study involving over 85,000 people in the UK, the more steps you take each day, the lower your chances of developing up to 13 different types of cancer.
In the study, participants wore activity trackers that measured both the amount and intensity of their daily movement. On average, researchers followed up with participants six years later. They found a clear pattern: more steps meant lower cancer risk, regardless of how fast those steps were taken.
Get your news from actual experts, straight to your inbox. Sign up to our daily newsletter to receive all The Conversation UK's latest coverage of news and research, from politics and business to the arts and sciences.
The benefits began to appear at around 5,000 steps a day - anything below that didn't seem to offer much protection.
At 7,000 steps, the risk of developing cancer dropped by 11%. At 9,000 steps, it dropped by 16%. Beyond 9,000 steps, the benefits levelled off. The difference in risk reduction became marginal, and varied slightly between men and women.
These findings support the popular recommendation of aiming for 10,000 steps a day - not just for general health, but potentially for cancer prevention too. These associations also held up when results were adjusted for demographic, BMI and other lifestyle factors, such as smoking, suggesting that the observed changes in cancer risk were indeed down to the average number of daily steps a participant took.
Step intensity was also analysed - essentially, how fast participants were walking. Researchers found that faster walking was linked with lower cancer risk. However, when total physical activity was taken into account, the speed of walking no longer made a statistically significant difference. In other words: it's the total amount of walking that counts, not how brisk it is.
Likewise, replacing sitting time with either light or moderate activity lowered cancer risk - but swapping light activity for moderate activity didn't offer additional benefits. So just moving more, at any pace, appears to be what matters most.
The researchers looked at 13 specific cancers, including oesophageal, liver, lung, kidney, gastric, endometrial, myeloid leukaemia, myeloma, colon, head and neck, rectal, bladder and breast.
Over the six year follow-up period, around 3% of participants developed one of these cancers. The most common were colon, rectal, and lung cancers in men, and breast, colon, endometrial, and lung cancers in women.
Higher physical activity levels were most strongly linked to reduced risk of six cancers: gastric, bladder, liver, endometrial, lung and head and neck.
Break it up
Previous studies have relied on self-reported activity logs, which can be unreliable - people often forget or misjudge their activity levels. This study used wearable devices, providing a more accurate picture of how much and how intensely people were moving.
The study also stands out because it didn't focus solely on vigorous exercise. Many past studies have shown that intense workouts can reduce cancer risk - but not everyone is able (or willing) to hit the gym hard. This new research shows that even light activity like walking can make a difference, making cancer prevention more accessible to more people.
Walking just two miles a day - roughly 4,000 steps, or about 40 minutes of light walking - could make a significant impact on your long-term health. You don't have to do it all at once either. Break it up throughout the day by: taking the stairs instead of the lift; having a stroll at lunchtime; walking during phone calls; parking a bit further away from your destination.
Getting more steps into your routine, especially during middle age, could be one of the simplest ways to lower your risk of developing certain cancers.
Of course, the link between physical activity and cancer is complex. More long-term research is needed, especially focused on individual cancer types, to better understand why walking helps - and how we can make movement a regular part of cancer prevention strategies.
But for now, the message is clear: sit less, move more - and you could walk your way toward better health.
Mhairi Morris does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
