Short bursts of energetic activity can trigger rapid molecular changes in the bloodstream, shutting down bowel cancer growth and speeding up DNA damage repair, a new study has shown.

Researchers at Newcastle University have found that exercise increases the concentration of several small molecules in the blood - many linked to reducing inflammation, improving blood vessel function, and metabolism.

When these exercise-induced molecules were applied to bowel cancer cells in the lab, the activity of more than 1,300 genes was altered, including those involved in DNA repair, energy production, and cancer cell growth.

The findings, published in the International Journal of Cancer, help explain one way exercise can protect against bowel cancer: by sending molecular signals in the bloodstream that influence the activity of genes that govern tumour growth and genome instability.

The study is another step forwards in the fight against bowel cancer and further strengthens the importance of staying active.

‘Opens door to new treatments’

Dr Sam Orange, Senior Lecturer in Clinical Exercise Physiology at Newcastle University, who led the study, said: “What’s remarkable is that exercise doesn’t just benefit healthy tissues, it sends powerful signals through the bloodstream that can directly influence thousands of genes in cancer cells.

“It’s an exciting insight because it opens the door to find ways that mimic or augment the biological effects of exercise, potentially improving cancer treatment and, crucially, patient outcomes.

“In the future, these insights could lead to new therapies that imitate the beneficial effects of exercise on how cells repair damaged DNA and use fuel for energy.”

The Newcastle researchers found that exercise boosted the activity of genes that support mitochondrial energy metabolism, enabling cells to use oxygen more efficiently.

At the same time, genes linked to rapid cell growth were switched off, which could reduce the aggressiveness of cancer cells, and exercise-conditioned blood promoted DNA repair, activating a key repair gene called PNKP.

The study involved 30 volunteers, male and female aged 50–78, all overweight or obese (a risk factor of cancer) but otherwise healthy.

After completing a short, intense cycling test lasting approximately 10 minutes, researchers collected blood samples and analysed 249 proteins. As many as 13 proteins increased after exercise, including interleukin-6 (IL-6), which helps repair the DNA of damaged cells.

Dr Orange, a Clinical Exercise Physiologist at The Newcastle upon Tyne Hospitals NHS Foundation Trust, said: “These results suggest that exercise doesn’t just benefit healthy tissues, it may also create a more hostile environment for cancer cells to grow.

“Even a single workout can make a difference. One bout of exercise, lasting just 10 minutes, sends powerful signals to the body.

“It’s a reminder that every step, every session, counts when it comes to doing your best to protect your health.”

Bowel cancer rates

Bowel cancer is the 4th most common cancer in the UK, after breast, prostate and lung.

Every 12 minutes in the UK someone is diagnosed with bowel cancer. That's nearly 44,000 people each year. Every 30 minutes someone dies from the disease in the UK.

It is estimated that physical activity reduces the risk by approximately 20%. It can be done by going to the gym, playing sports or through active travel such as walking or biking to work, but also as part of household tasks or work like gardening or cleaning.

In the future, researchers plan to test whether repeated exercise sessions produce lasting changes and explore how these effects interact with standard cancer treatments like chemotherapy and radiotherapy.

Reference: Exercise serum promotes DNA damage repair and remodels gene expression in colon cancer cells. International Journal of Cancer. Samuel T Orange et al. DOI: 10.1002/ijc.70271