Exercise changes how the body uses energy, leaving less fuel for cancer cells to grow, new research reveals

It’s already well established that regular exercise leads to a decreased risk of 13 types of cancer, particularly breast cancer and bowel cancer. Being active can help to improve mood, reduce stress, assist with maintaining a healthy weight, and reduce the risks of dementia, depression, heart disease, osteoarthritis, and both common and hard-to-treat cancers. However, new research has revealed a greater understanding of how exercise can slow down tumour growth.

Researchers at the Yale School of Medicine have discovered that exercise can slow tumour growth in mice by shifting the body’s metabolism so that muscle cells, instead of cancer cells, take glucose and grow. Researchers believe that a similar process might occur in people. 

A number of different influences of exercise on the growth of cancer within our bodies have previously been uncovered; however, we do not yet have a full understanding of why exercise helps slow cancer. More and more studies are looking to uncover how exercise helps. One study published in July highlighted that exercise impacts the microbes in our guts, boosting the potency of CD8 T cells in our immune systems, which help to fight cancer. 

In this latest study, researchers studied the impact of exercise on mice with breast cancer. Out of 18 test subjects, 12 were made obese (which is known to worsen many cancer types), while half of all mice were freely allowed to use an exercise wheel. After four weeks, the obese mice who exercised had tumours 60% smaller than obese mice that didn’t exercise. Their tumours were also slightly smaller than those of inactive mice, already of a healthy weight. Just 30 minutes of exercise increased how much oxygen and glucose their muscles used, meaning tumours took up less glucose – the fuel they needed to grow. 

Researchers analysed gene activity within the mice and identified 417 genes in key metabolic pathways that were changed as a result of exercise. Because these metabolic pathways are very similar across mammals, researchers indicated that they would expect these findings to extend to people.

Researcher Rachel Perry from Yale School of Medicine said, “It’s possible that metabolic alterations could be the missing link between exercise, the microbiome and the immune system, and tumour growth. But I would be shocked if the beneficial effects of exercise weren’t due to multiple mechanisms.” 

So exercising could offer even more health benefits than we realise. UK guidelines recommend at least 150 minutes of moderate intensity exercise like cycling, swimming, or brisk walking, or 75 minutes of vigorous intensity aerobic exercise like running or sprinting, per week. But what else can we do to help improve our health and wellbeing, and help protect our bodies? 

Gut microbiome and health

The impact your gut microbiome can have on your overall health is something that we have had a growing awareness of over recent years. Research into our understanding of how much it affects us has revealed that healthy gut microbiomes not only help with digestion and nutrition, but also positively impact our immune system, influence our metabolism, and even communicate with our brains via the gut-brain axis, affecting mood, anxiety, and behaviour. An unhealthy gut microbiome can lead to digestive issues, metabolic disease, and immune and inflammatory conditions, among other concerns. 

What we eat, medicines we take, our environment, and our lifestyle (exercise, sleep, and stress) all influence our gut microbiome. But how can we shape a healthier gut microbiome to support our health and wellbeing? Well, according to research, there are a number of different foods and factors we can focus on to help have a healthy gut microbiome.

Eating high-fibre foods (whole grains, fruit and veg, legumes) helps feed beneficial gut bacteria, while fermented foods like yoghurt, kimchi, miso, and kefir increase our microbiome diversity. Nuts, berries, dark chocolate and tea are all polyphenol-rich foods which support microbial balance. Prebiotics (the fibres that feed good bacteria) and probiotics (the live ‘friendly’ bacteria found in fermented foods and supplements) can also help support a healthy, balanced gut.

Exercise and diet work hand in hand to support stronger immune function, which is a key part of the body’s defence against cancer. Regular physical activity has been shown to increase the diversity of the gut microbiome, while a fibre-rich, plant-forward diet provides the fuel these beneficial microbes need to thrive. Together, they help regulate inflammation, strengthen immune cells, and create a healthier internal environment that can make it harder for cancer cells to grow.

While researchers continue to uncover the many ways in which exercise, diet, and our gut microbiome all shape our health, the same message remains clear: small daily habits really make a difference. Moving a little more and looking after your gut health can help support a healthier you, inside and out. We might not be able to control everything, but through nurturing our bodies in gentle, consistent ways, we can make our health and wellbeing a priority – and that’s a pretty great place to start.