A new study has found that men who engage in running, swimming, and cycling may reduce their risk of developing nine types of cancer. Researchers discovered that men with good cardiovascular and respiratory fitness are less likely to develop cancers of the head and neck, stomach, pancreas, liver, intestines, rectum, kidneys, lungs, and esophagus. Cardiovascular fitness refers to an individual's ability to perform aerobic exercises for extended periods, such as running, cycling, swimming, or even climbing stairs.
The Swedish researchers, in this new study published in the British Journal of Sports Medicine, tracked just over a million men for an average of 33 years. The study participants were recruited for military service in Sweden between 1968 and 2005. Upon enlistment, the men underwent a series of tests to assess various factors including height, weight, blood pressure, muscle strength, and cardiovascular fitness.
During the follow-up period, approximately 84,000 participants were diagnosed with cancer. The researchers found that compared to those with low cardiovascular fitness, men with higher levels of cardiovascular fitness were:
- 19% less likely to develop head and neck cancer.
- 39% less likely to develop esophageal cancer (food tube).
- 21% less likely to develop gastric cancer.
- 40% less likely to develop liver cancer.
- 18% less likely to develop intestinal cancer.
- 5% less likely to develop rectal cancer.
- 20% less likely to develop kidney cancer.
- 42% less likely to develop lung cancer.
- 12% less likely to develop pancreatic cancer.
The researchers noted in the paper that "these results can be used to inform public health policy, increasing the motivation to promote interventions aimed at enhancing cardiovascular fitness among youth." They also found that higher cardiovascular fitness was associated with a slight (7%) increase in the risk of prostate cancer and a 31% increase in the risk of skin cancer. A previous study examining the same dataset indicated that the slight increase in prostate cancer risk was not linked to a higher rate of aggressive prostate cancer or prostate cancer mortality and could be attributed to increased screening.
The team hypothesized that the higher rate of skin cancer could be explained by "high exposure to ultraviolet rays" during exercise.
