Good cardiovascular fitness reduces cancer risk in middle-aged men
Men in their 50s with high levels of cardiovascular fitness are less likely to develop and die from certain types of cancer later in life, according to the results of a large prospective US study.
In the study, which involved 17,049 participants over a 20-year period, cardiorespiratory fitness was found to be an independent predictor of cancer risk and prognosis in men.
“These findings provide support for the utility of fitness testing in the preventive health care settings to determine cancer risk and prognosis after cancer,” said lead researcher Dr. Susan Lakoski, of the Vermont Cancer Center’s Division of Hematology/Oncology in Burlington, Vermont, US.
The men were given a fitness test during a routine health check-up which involved walking on a treadmill at varying speed and elevation when they were of a mean age of 50.
The men were divided into five groups based on their performance. Those in the least fit category remained on the treadmill for less than 13.5 minutes if they were 40-49 years old, less than 11 minutes if they were 50-50 years old, and less than 7.5 minutes if they were 60 or older.
Researchers used health insurance claims over a 20-25 year period of follow up to determine that 2,332 men were diagnosed with prostate cancer, 276 were diagnosed with colorectal cancer and 277 were diagnosed with lung cancer. These cancers were targeted because they are known to be the most common among American men.
Over the same follow-up period, 347 men died of cancer and 159 died of cardiovascular disease. The data were adjusted for smoking, body mass index, age and other lifestyle factors.
Men who were most fit during their assessment had a 68 percent reduced risk of lung or colorectal cancer diagnosis compared with a 38 percent reduced risk among men who were the least fit (p<0.001). Among men who were least fit, body weight was not a significant factor in their risk of developing cancer.
Men who were most fit and developed cancer had a 14 percent reduced risk of dying from any type of cancer or from cardiovascular disease. Small improvements in fitness level improved the risk of dying from cancer or cardiovascular disease to 23 percent.
Dr. Sandra Swain, president of the American Society of Clinical Oncologists, noted that the findings suggest everyone can benefit from improving their fitness.
“While more research is needed to determine if similar trends are valid in relation to other cancers and among women, these results indicate that people can reduce their risk of cancer with relatively small lifestyle changes,” she said.