Cancer Prevention
New research from Finland shows that exercise significantly boosts anti-tumor immunity. The evidence suggests that regular physical activity may be one of the most effective natural defenses against cancer.
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We often read about "miraculous cures" through major lifestyle changes in the context of cancer. Severely ill cancer patients become Ironman triathletes – meaning: lots of training – and the tumor disappears.
Of course, we should remain somewhat critical here: First, we can't verify whether tumor-free status was actually "caused" by the sport or whether it was simply a temporal coincidence with other interventions.
Second, we know nothing about long-term effects. The cancer could flare up again tomorrow; we would simply never hear about it.
Let's try to paint as realistic a picture as possible. For this, studies are our best resource. A new one was just published (University of Turku, Finland).1
Twenty breast cancer patients participated in the study, each having just received their diagnosis and not yet having begun cancer treatment. The women were asked to cycle on an ergometer for 30 minutes (approximately 70% of max heart rate, i.e., moderate intensity).
Objective of the study: What happens to immune cells critical for tumor defense during exercise?
And behold: anti-tumor immune cells increased markedly, including leukocytes (+22%), neutrophils (+17%), lymphocytes (+36%). The especially effective T killer cells ("cytotoxic T cells") acutely increased by 36%.
After exercise, the increases disappeared. The researchers suspect, based on prior data, that immune cells specifically migrate into the tumor microenvironment.
This is not new. For years, studies have consistently shown that exercise and movement have a positive effect on immune function and thereby slow tumor growth, sometimes dramatically.
In 2021, for example, a review appeared in the journal Sports (Basel) examining "exercise-induced changes in tumor growth via tumor immunity."2
The review cited ten animal studies, all of which showed that exercise significantly slowed tumor growth. This is why the topic is currently a focus of immunotherapy research.
Because, of course, immunotherapy against cancer is ultimately only as good as the cancer patient's immune system. Therefore, various measures are currently being discussed for naturally stimulating the immune system – through exercise, for example.
Promising human trials are currently underway, with results expected in the coming years. Meanwhile, major reviews summarize the findings:
In agreement with results from tumor mouse models, it has been shown that exercise shifts the composition of immune cells in the tumor from pro- to anti-tumor cells and improves overall patient survival (…). Moreover, preliminary results from intervention studies suggest that exercise has a positive effect on the efficacy of immune checkpoint inhibitor therapy.3
Now, we know from many conversations with edubily that waiting until day X to get started is not the way to go. We're always working in the realm of prevention. Here's what we can conclude:
Exercise is very likely your best cancer prevention.
Large-scale studies present impressive numbers and data: exercise appears to protect against nearly all tumor types. Depending on intensity (the more intense, the better), context, and tumor type, tumor-associated mortality can drop by 30–70%.4
But be careful: pushing yourself to your limits in soccer practice 3–4 times a week is quite different from training 20 hours a week for an Ironman. Here too, there is enough data showing that the immune system can become weaker.5
Our tip: Get out into nature! Do it now ☺ Whether with a dog or running shoes – or both.
