New research found that men with high cardiorespiratory fitness levels had a lower chance of getting colon cancer and a reduced risk of dying from prostate and lung cancers.
Recent statistics estimate that nearly 2 million new cancer diagnoses and around 600,000 cancer deaths will occur in 2023. Though many factors play a role in cancer development, some are modifiable — meaning a person can change their lifestyle or behaviors to lessen the risk.
Engaging in regular exercise is one behavior that can reduce the risk of several types of cancer. Still, little is known about whether cardiorespiratory fitness (CRF) — or the cardiovascular and respiratory system’s ability to supply oxygen during continual physical activity — contributes to a lower risk of cancer.
Now, a new study — published on June 29 in JAMA Network Open — found that men with higher cardiorespiratory fitness may have a reduced risk of developing colon cancer and a lower risk of dying from prostate and lung cancer.
To conduct the research, scientists examined health profile assessment data from 177,709 Swedish males aged 18 and 75 between 1982 and 2019. They also assessed the participants’ CRF using a submaximal cycle ergometer test.
Then, the team followed the participants for an average of 9.6 years and tracked cancer incidences and mortality.
After adjusting for other cancer risk factors, such as lifestyle habits, the researchers found that moderate and high CRF levels were associated with a significantly lower risk of developing colon cancer. In addition, low, moderate, and high CRF levels were associated with a lower risk of death from prostate cancer.
However, only high CRF among the older participants was associated with less risk of death due to lung cancer.
In addition, after the scientists performed a theoretical calculation of preventable cancer cases, they found that avoiding very low CRF levels could have potentially prevented 4% to 8% of all colon cancer cases, 4% of all deaths from lung cancer, and 4% to 19% of deaths from prostate cancer.
The scientists suggest that a higher CRF may reduce systemic inflammation, abdominal obesity, cholesterol imbalances, and impaired insulin sensitivity, which may play a role in the lower cancer incidence and mortality found in the study.
Still, the study authors note that these mechanisms are not fully understood, and more research is needed. In addition, the study examined data from male participants only, so it’s unknown if the results would be similar for women.
"CRF appears to have a potentially important role in reducing the risk of developing and dying from certain common cancers in men," the authors wrote. "If evidence for causality is established, interventions to improve CRF in individuals with low CRF should be prioritized."