Links between cardiorespiratory fitness and cardiovascular events are well-established. More recently, researchers are turning their attention to the connections between fitness and certain cancers.
Maintaining a high fitness level at midlife appears to reduce a man’s risk of lung or colorectal cancer, and staying fit may also reduce the risk of death of cancer occurs, according to a study published today by JAMA Oncology. The publication is issued by the Journal of the American Medical Association.
The benefit, however, does not appear to extend to prostate cancer, according to research led by Susan G. Lakoski, MD, MS, of the University of Vermont, Burlington.
Links between cardiovascular fitness and the presence or absence of heart disease are well-established. Researchers are starting to pay more attention to the role that fitness—or lack thereof—plays in cancer, especially colorectal cancer.
In this study, the authors examined the association between midlife cardio-respiratory fitness and incident cancer and survival following a cancer diagnosis starting at the age 65, the date of eligibility for Medicare. The study included 13,949 men who received a baseline fitness exam that evaluated cardio-respiratory fitness levels with a treadmill test. Fitness levels were assessed between 1971 and 2009, and the diagnosis of lung, prostate, and colorectal cancers were tracked with Medicare data from 1999 to 2009.
Men were tracked for an average of 6.5 years. During that period, 1310 were diagnosed with prostate cancer, 200 with lung cancer, and 181 with colorectal cancer. Researchers found that high cardio-respiratory fitness was associated with a 55% lower risk of lung cancer and a 44% lower risk of colorectal cancer, compared to men with low levels of fitness.
However, this association was not seen with prostate cancer, for reasons the researchers could not determine. They speculate men who are in good physical condition may be more likely to undergo screenings for prostate cancer, and therefore may be more likely to receive a diagnosis. Overdiagnosis and overtreatment of certain low-risk prostate cancers has been a source of controversy in recent years.
Also, high cardio-respiratory fitness at midlife was associated with a 32% lower risk of death from cancer for men who developed any of the cancers studied, compared with men who had low fitness levels. Also, high fitness levels were associated with a 68% reduction in death from cardiovascular disease compared with those with low-level fitness who developed cancer.
Cardiovascular disease and events are known risks to those being treated for cancer.
“To our knowledge, this is the first study to demonstrate that cardio-respiratory fitness is predictive of site-specific cancer incidence, as well as risk of death from cancer or cardiovascular disease following a cancer diagnosis,” the study concludes, adding that the findings support assessment of cardio-respiratory fitness in preventive health settings.
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