Exercise has long been known to have numerous health benefits, including reducing the risk of cancer and improving survival rates for those with the disease. However, the specific mechanisms behind these benefits have been somewhat unclear. Recent research conducted by Rachel Perry and her team at Yale School of Medicine sheds light on how exercise may help slow tumour growth in mice, and potentially in humans as well.
In a study involving mice injected with breast cancer cells, Perry and her colleagues found that exercise could significantly reduce tumour size. Mice that had access to an exercise wheel and chose to run showed tumours that were 60% smaller than those in sedentary mice. This effect was even more pronounced in obese mice, where exercise led to a decrease in glucose uptake by tumours and an increase in uptake by muscle cells.
The researchers identified 417 genes in key metabolic pathways that were affected by exercise, leading to a shift in how glucose is metabolized in the body. In particular, the down-regulation of the protein mTOR in cancer cells may be responsible for restricting tumour growth. These metabolic changes were similar to those seen in humans with cancer who engage in regular exercise.
This study highlights the importance of aerobic fitness in reshaping the metabolic competition between muscle and tumours. Perry emphasizes that the exercise intervention in the study was voluntary, indicating that even moderate levels of physical activity can have a significant impact on cancer growth. The findings suggest that exercise creates a more cancer-suppressive environment by altering metabolic pathways in the body.
Rob Newton, a researcher at Edith Cowan University, believes that exercise should be seen as a form of cancer medicine, to be used in conjunction with other treatments. He suggests that targeting muscle mass through resistance training may be particularly beneficial for patients with low muscle mass, as muscle cells play a key role in glucose metabolism and tumour growth.
Overall, this research underscores the importance of regular exercise in cancer prevention and treatment. By understanding how exercise influences metabolic pathways and gene activity, we can develop more targeted strategies for combating cancer. Further clinical trials in humans are needed to confirm these findings and explore the full potential of exercise as a therapeutic tool in the fight against cancer.

