Men who are more healthy and fit during the middle-age are less likely to be diagnosed with lung or colorectal cancer in their years to come, states a new long-term study.
Furthermore, these fit men are also less likely to die from cancer if they are diagnosed from it later in their life compared to less fit men.
“Among the men who developed cancer, those who were more fit at middle age had a lower risk of dying from all the three cancers studied, as well as cardiovascular disease,” said lead author Dr. Susan G. Lakoski of the University of Vermont in Colchester.
“Even a small improvement in fitness (by 1 MET) made a significant difference in survival – reducing the risks of dying from cancer and cardiovascular disease by 10 and 25 percent, respectively,” she told Reuters Health by email.
One MET, or Metabolic Equivalent of Task, would translate, for example, to running an 11.5-minute mile compared to a 12-minute mile, she explained.
Long-term study data was used by the scientists consisting of more than 13000 men who were an average of 49 years old when they gave a comprehensive physical exam, a cardiovascular risk factor assessment and a treadmill test of fitness test between the years 1971 and 2009.
Then men were made to start out by walking out on the treadmill at a moderate speed as a part of the fitness test. Next, the incline was increased slowly and after that, the speed. Records were being made about individuals who could continue until they were tired.
The results classified the participants into three fitness categories: the first 20% who ran for the least amount of time, the middle 40% and the top 40%.
Once the participants reached the age of 65 years, researchers started looking at Medicare records for diagnosis of prostate, lung and colorectal cancer, and made use of the National Death Index to find information about the deaths from cardiovascular disease or cancer.
Those in the high-fitness group were found to be less than half as likely to be diagnosed with lung cancer compared to those in the lower-fitness group, the difference being same for colorectal cancer but no link existing for prostate cancer.
When the study ended, 20% of the men in their lowest-fitness tier had died, in comparison to 4% in moderate and 3% in the high fitness group.
Lakoski said that fitness is hugely determined on the limit of someone has been physically active and the duration as well, which may be a significant clinical marker of cancer risk.
“These findings provide support for the utility of (cardiorespiratory fitness) assessment, via maximal exercise treadmill testing, in preventive health care settings and possibly following a diagnosis of cancer,” she said.
“Fitness has a huge impact with breast cancer and lung cancer as well, it’s a dramatic relationship but we really don’t know the dose specifics of how many minutes per day,” Archer told Reuters Health.
“If you are meeting the guidelines, that’s a huge step,” he said.
Prostate cancer grows very slowly over time and seems to have no link with the environmental risk factors, so being fit may not be effective against prostate cancer.
Archer added that the new research only associated fitness and cancer risk over time, leaving out the other factors that might affect and also not specifically testing whether becoming more fir would cause the cancer risk to decrease.
“Working out at a moderate or vigorous intensity will improve fitness,” Lakoski said. “Our next steps in our research are to determine the absolute change in fitness to lower risk of all major cancers in men and women.”
“If that is determined, then exercise training regimens can be built to close the fitness gap,” she said.