A Newcastle research team have shown exactly why exercise helps prevent – and treat – bowel cancer. And it’s not simply about someone’s weight.
Newcastle University scientists have proven a connection between exercise and the production of a specific protein in the bloodstream – and this protein, called IL6, helps repair the DNA of damaged cells. That helps prevent the development of bowel cancer and can even help limit a tumour’s growth if cancer does occur.
Dr Sam Orange – a former Rugby League star turned lecturer in exercise physiology – specialises in the connections between physical exercise and cancer prevention. He’s played a key role in a team which has just published a study in the International Journal of Cancer which highlights the precise way that being active fights cancer.
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Dr Orange told ChronicleLive : “Evidence shows that physical activity is associated with reduced risk of certain cancers – one being bowel cancer – but we don’t really know why. The prevailing thought has been around how exercise helps you maintain a healthy weight.
“But it’s become more and more clear that physical activity reduces risk of cancer independently of weight – and we were really interested in why that might be. Every time you exercise there are a catalogue of changes in hormone levels and the levels of proteins in your blood – we wanted to see how these things alter the growth of cancer cells themselves.”
The study involved taking 16 men aged between 50 and 80 – each of whom had “lifestyle risk factors” for bowel cancer such as being overweight or physically inactive – and testing their blood both before and after a 30-minute session on an exercise bike. Blood samples from after the exercise showed high levels of IL6, and these samples were then added to bowel cancer cells in a lab.
The scientists found that the samples with high amounts of the protein slowed the growth of the cancer cells. Similarly, they reduced the extent of DNA damage to the cells – which suggests that physical activity can repair cells to create a genetically stable cell type.
“It’s important to note that exercise has such a widespread effect on our bodies so It’s very likely there are more things involved,” Dr Orange added. “But we’ve been able to establish the link between IL6 and cancer prevention.
“Understanding the process here can help develop new practical ways of preventing cancer. It helps us better understand how lifestyle like exercise reduce the risk of cancer. We can drill down into what the best kinds of exercise for this might be, but also potentially develop new drugs which might mimic the effects of exercise.
“There’s also a really positive public health message: weight is a problem for a pretty large proportion of the population – and it’s not something that’s always in our control. But what this study shows is that each time you exercise you are changing the chemical make-up in your bloodstream. So each time you exercise [regardless of your weight] you are contributing to a reduction in your risk of cancer. “
Dr Adam Odell, a senior biosciences lecturer at York St John University also worked on the study. Others involved included Dr Alastair Jordan and Dr Owen Kavanagh. Dr Odell added: “Importantly, it is not just bowel cancer risk that can be reduced by leading a more active lifestyle. Clear links exist between higher exercise levels and a lower risk of developing other cancers, such as cancers of the breast and endometrium.
“By working out a mechanism through which regular physical activity is able to produce anti-cancer effects, our study provides further support for current national and global efforts to increase exercise participation.”