Men’s fitness protects against common cancers – and mortality

Results from one of the first studies looking at fitness has concluded that a high level of cardiovascular fitness in middle-age men reduces their risk of developing and dying from lung and colorectal cancer. In addition, while it doesn't reduce their risk of developing prostate cancer, it does reduce their risk of dying from the disease. Lead author Susan Lakoski, MD, assistant professor of medicine at the University of Vermont, partnered with the Cooper Institute in Dallas where she followed more than 17,000 men who underwent a single cardiovascular fitness assessment at the institute as part of a specialized preventive health checkup at a mean age of 50 years. The test entailed walking on a treadmill while the speed and elevation were increased. Each man's performance was recorded in one of five groups (quintiles) of established units of fitness called metabolic equivalents (METs) depending on their level of fitness. "When you ask someone about their physical activity, you get information that may or may not be correct," Lakoski points out. "Fitness is a formal measurement that is known to prevent cardiovascular disease. Now it is also known that it helps in terms of survival risk. What hasn't been known is if it prevents cancer and affects mortality after cancer diagnosis and that is what is elucidated in the current study."Over a median follow up of 20 to 25 years, researchers analyzed the Medicare claims data of the men who took part to identify who had developed lung, colorectal or prostate cancer. They found 2,332 were diagnosed with prostate cancer, 276 with colorectal cancer and 277 were diagnosed with lung cancer. There were 347 deaths attributable to cancer and 159 deaths due to cardiovascular disease. Analysis of the numbers indicated that the risk of being diagnosed with lung or colorectal cancer was reduced by 68 and 38 percent, respectively, in men who were the most fit, relative to those who were the least fit. Prostate risk was not significantly impacted. Factors such as body mass index, age and smoking were taken into consideration. Indeed, an interesting finding was that men with low fitness score had an increased risk of cardiovascular disease and cancer even if they were not obese. For the men who developed cancer, those who were more fit at middle age, their chances of dying were lower. Lakoski calls the research into fitness and its connection to cancer "early and promising." "There are several benefits in measuring fitness," she says. "It's an accurate and stable marker to exercise exposure and it can be measured over time. It also provides a benchmark for patients to determine how they stack up against other individuals of similar age and sex and it allows clinicians to personalize prescriptions for their patients."These findings, she says, make clear that patients should be advised that they need to achieve a certain fitness level and not just be told they need to exercise.