GOTHENBURG, Sweden — Men who maintain good fitness are up to 40 percent less likely to develop nine specific types of cancer later in life, a new study finds. The study, which monitored over a million Swedish men for an average of 30 years, found that those with strong cardiorespiratory health as young men were significantly less likely to develop cancers of the head, neck, throat, stomach, lung, liver, kidney, and colon later in life.
Interestingly, those with higher cardio fitness levels exhibited a seven-percent increased risk of prostate cancer and a 31-percent elevated risk of skin cancer.
This research utilized data from the Swedish registry up to 2019. The data pertained to male conscripts who started their military service in Sweden between 1968 and 2005. All participants, between 18 and 25 at the start of the study, underwent tests measuring BMI, blood pressure, muscular strength, and cardiorespiratory fitness upon conscription.
Cardiorespiratory fitness evaluates a person’s aerobic capacity through activities like running, cycling, and swimming. While it’s known that high levels of fitness can reduce certain cancer risks, comprehensive long-term studies like this one remain rare.
Conscripts with lower cardiorespiratory fitness were slightly more prone to obesity, and substance or alcohol abuse, and often had parents with lower educational levels. In total, the study considered data from 1,078,000 male conscripts, monitored for an average of 33 years.
The study revealed that roughly 519,652 conscripts had a moderate level of cardio fitness. The remaining participants were almost equally divided between low (365,874) and high (340,952) fitness levels. Overall, 84,117 conscripts (6.9%) were diagnosed with various cancers.
Compared to those with low fitness, individuals with higher fitness levels had reduced risks for nine specific cancers. Notably, they had a 40-percent reduced risk for liver cancer and a 42-percent lower risk for lung cancer.
However, an unexpected finding was the increased risk associated with higher cardiorespiratory fitness: a seven-percent rise in prostate cancer and a 31-percent surge in skin cancer. The researchers hypothesized that these increases could relate to prostate cancer screening practices and sun exposure.
The study, being observational, didn’t draw definite cause-and-effect conclusions. The researchers acknowledged gaps in data related to influential factors such as diet, alcohol intake, smoking habits, and potential genetic influences.
“This study shows that higher fitness in healthy young men is associated with a lower hazard of developing 9 out of 18 investigated site-specific cancers, with the most clinically relevant hazard rates in the gastrointestinal tract,” says Dr. Aron Onerup of the University of Gothenburg Institute of Clinical Sciences, the study’s lead author, in a media release. “These results could be used in public health policymaking, further strengthening the incentive for promoting interventions aimed at increasing [cardiorespiratory fitness] in youth.”
The study is published in the British Journal of Sports Medicine.
South West News Service writer James Gamble contributed to this report.