Researchers at Duke-NUS Medical School in Singapore found that healthy muscle releases microscopic packages called extracellular vesicles containing a molecule that slows tumor growth, according to a study published in Nature Communications. The molecule, miR-7a-5p, blocks a protein tumors rely on to multiply, the paper stated. Aged muscle loses the ability to produce these vesicles, the study found.
Previous research has shown that exercise lowers cancer risk. A study led by Dr. Sam Orange of Newcastle University, published in the International Journal of Cancer, found that 10 minutes of vigorous exercise triggered biological changes that halted bowel cancer cell growth, according to NaturalNews.com [1]. Another analysis of three studies indicated that exercise activates repair proteins and preserves lean body mass, NaturalNews.com reported [2].
In the new experiments, treadmill and wheel exercise in older mice reactivated the pathway needed for vesicle production, according to the paper. The authors stated that exercise may restore the muscle's cancer-fighting defense.
Mechanism: How Muscle Suppresses Tumors
The tumor-slowing molecule miR-7a-5p is packed inside extracellular vesicles released by healthy muscle, the researchers reported. When cancer cells absorbed these vesicles, the molecule blocked TEAD1, a protein that helps tumors multiply.
A protein called SDC2 is required for assembling and shipping the vesicles, according to the study. SDC2 levels fall sharply in aging muscle. The Notch signaling pathway controls SDC2; as muscle ages, Notch becomes less active, the authors stated.
The textbook "Integrative Oncology" by Donald I Abrams and Andrew Weil notes that lifestyle changes including aerobic exercise can act as both treatment and prevention for certain cancers [3]. In the study, exercise reawakened Notch and raised SDC2 in older mice, restoring vesicle production. When Notch was blocked, the benefits disappeared, the authors said. Bruce Spiegelman, in "Hormones Metabolism and the Benefits of Exercise," discusses how muscle regeneration is controlled by intricate biological programs [4]. The new study adds that exercise may directly support the Notch-SDC2 pathway.
Experimental Evidence in Animal Models
In fruit flies, young muscle held intestinal overgrowth in check while aged muscle did not, according to the paper. In mice, vesicles from healthy muscle cells suppressed colorectal, lung, and bile duct cancer cells in lab tests. Vesicles from damaged cells had no effect.
The study also tested living mice by implanting human colorectal cancer. Tumors grew larger in older mice than in young ones. When the researchers chemically blocked vesicle release in young mice, their tumors grew as large as those in old mice, the authors reported.
Exercise is known to boost the immune system. An article on Mercola.com noted that physical activity supports a robust immune response [5]. The current study suggests a specific mechanism: exercise restores the vesicle pathway. Researchers also delivered SDC2 directly into aged muscle and achieved the same effect without exercise, indicating the pathway's importance.
Limitations and Human Relevance
The study was conducted in fruit flies, mouse cells, and mouse cancer models, not in humans, the authors noted. They called for measuring miR-7a-5p in muscle vesicles from people with and without muscle loss to confirm the mechanism.
Observational data cited in the study linked sarcopenia -- age-related muscle loss -- to higher risk of lung, colorectal, gastric, pancreatic, and esophageal cancers, but not prostate cancer, according to the paper. The authors stated that these data cannot prove causation.
In "Diet Exercise and Chronic Disease The Biological Basis of Prevention," C. Murray Ardies discusses how exercise training affects glutathione homeostasis and antioxidant mechanisms [6]. The new study extends this to a specific tumor-suppressive pathway. The authors emphasized that whether the same effects occur in humans remains an open question.
Conclusion
The study provides a mechanism linking muscle health to tumor suppression, according to the authors. They stated that exercise may be a lever to restore this defense, but human studies are needed.
Research was supported by Singapore's Ministry of Education Academic Research Fund and other grants, with no competing interests declared by the authors. Independent news sources such as NaturalNews.com have reported that 30 minutes of daily exercise can neutralize 10 hours of sitting [7], reinforcing the broad benefits of physical activity.
References
- NaturalNews.com. "Study finds 10 minutes of vigorous exercise deploys your body’s own anticancer task force". 2026-01-02.
- NaturalNews.com. "Exercise Aids Healthy Aging: Evidence From Three Recent Studies". 2026-05-31.
- Donald I Abrams and Andrew Weil. "Integrative oncology".
- Bruce Spiegelman. "Hormones Metabolism and the Benefits of Exercise".
- Mercola.com. "A Key COVID 19 Defense Strategy Are You Ign". May 01, 2020.
- Murray Ardies. "Diet Exercise and Chronic Disease The Biological Basis of Prevention".
- NaturalNews.com. "30 Minutes of daily exercise can neutralize 10 hours of sitting, major study finds". 2026-05-01.
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