Exercise’s Role in Slowing Cancer Growth

Regular exercise is often touted as essential for preventing obesity, aging, and various chronic conditions. A growing body of research supports the notion that even modest workouts can significantly reduce the risk of death from cancer.

A new study has pinpointed a particular exercise routine that could help slow the growth of cancer cells, with effects noticeable after just a single session. Researchers from Australia recruited women who had survived breast cancer to participate in the study, involving either resistance training (like weightlifting) or high-intensity interval training (HIIT), which consists of intense bursts of exercise followed by short breaks.

The findings revealed that participants exhibited up to a 47% increase in myokines—proteins released by muscles—after just one 45-minute session of either type of exercise. Myokines play a crucial role in the body’s communication, helping regulate metabolism and combat inflammation, a significant factor in cancer cell formation.

Estimations from the research team suggest that the elevated levels of myokines could slow cancer growth by about 20 to 30%.

Francesco Bettariga, the lead researcher and PhD student at Edith Cowan University, explained that the study’s results might clarify how exercise can reduce cancer progression, recurrence, and mortality. However, he also notes some limitations, emphasizing that further in vivo research is necessary to deepen our understanding of these effects.

This study was published in the journal Breast Cancer Research and Treatment and involved 32 patients treated for breast cancer, at least four months prior. Most participants were in stage two of the disease, with an average age of 59 and a body mass index (BMI) categorized as overweight.

Those in the resistance training group performed five sets of eight repetitions targeting major muscle groups, with exercises including chest presses and lunges. The HIIT group, on the other hand, completed seven 30-second bursts of intense exercise on machines like the treadmill and stationary bike, resting for three minutes between bouts.

Bettariga mentioned that these two forms of exercise were chosen for their distinct physiological benefits—resistance training enhances strength, while aerobic exercises improve cardio-respiratory fitness. The goal was to see which method might yield greater cancer-suppressing effects, particularly through the intensity of the workout.

Blood tests taken before, immediately after, and 30 minutes post-exercise showed increased levels of myokines in participants from both groups. The HIIT group recorded a 47% surge in the myokine IL-6, which plays a vital role in immunity, while the resistance training group saw a 23% increase in decorin, a myokine that regulates tissue development, alongside a 9% boost in IL-6.

It was noted that myokine levels dipped gradually after exercise, but they remained higher than baseline levels. The researchers believe that the myokine increase from exercise could potentially reduce cancer cell growth significantly.

Myokines can inhibit inflammatory proteins known as cytokines, which, when elevated, can lead to excessive inflammation, damaging DNA and heightening cancer risk.

Bettariga observed notable similarities between the two training modalities, suggesting that exercise intensity may be a more crucial factor in inducing anti-cancer changes than the specific type of exercise performed. 

Breast cancer affects 311,000 women in the U.S. annually, resulting in approximately 42,000 deaths, as per the American Cancer Society. Although the overall survival rate is around 92%, it can drop to 33% if cancer spreads.

Interestingly, the prevalence of breast cancer among younger women has been increasing, with rising rates noted from 2000 to 2019. Factors contributing to this rise may include hormone-disrupting chemicals and early menstruation, which increases hormone exposure that can promote the disease.

Despite the promising findings for breast cancer, it remains uncertain whether these results will apply to other cancer types. Bettariga stressed the relevance of the study, noting the lack of similar research in this demographic.

Yet, there were limitations, such as a small sample size and a focus on just one cancer type. The research team plans to explore these exercise effects in different cancer types and populations moving forward.

Bettariga concluded that further investigation into the impact of consistent, long-term exercise on anti-cancer responses is necessary, alongside examining the immune system’s role in managing cancer cell growth.