New Study: Cardiorespiratory Training Reduces Cancer Threat
A new study shows that exercising early in life reduces cancer risk in later life. Data from more than 1 million men aged 16 to 25 over five decades show that cardiorespiratory training can reduce cancer risk by up to 42%.
According to a large, long-term study, keeping fit early in life is associated with a reduced risk, in some cases up to 42%, of developing nine different types of cancer later in life.
While exercise has previously been associated with more low risk of developing certain types of cancer, long-term and large cohort studies on multiple cancer sites are rare, writes The Guardian.
The new study, published in the British Journal of Sports Medicine, was based on more than 1 million Swedish male conscripts aged 16 to 25 who were followed for an average of 33 years from 1968 to 2005 year. The results showed that good cardiorespiratory training – a person's ability to engage in long-term aerobic exercise such as running, cycling and swimming – was associated with a 42% reduction in the risk of lung cancer, 40% liver cancer, and 39% esophageal cancer.
It has also been associated with a lower risk of developing head and neck, stomach, pancreatic, intestinal and kidney cancers, The Guardian continues.
Better cardiorespiratory fitness appears to have been associated with increased cancer risk prostate by 7% and skin cancer by 31% — although it is possible that more frequent screening for prostate cancer and exposure to sunlight could explain these results.
Lead researcher, Dr. Aron Oneerup of the University of Gothenburg in Sweden, notes that he was surprised by some of these broad associations across multiple organ systems and «strong associations between cardiorespiratory fitness and gastrointestinal cancer».
Speaking of the unexpected increase in the risk of prostate and skin cancer, Dr. Onerup said that subsequent studies have shown that men with higher fitness levels are more likely to be diagnosed with non-fatal prostate cancer.
However, this study «does not fully account for the effects of diet, alcohol and smoking, which are more likely to affect cancer risk,» emphasizes Dr. Claire Knight, senior medical information manager at Cancer Research UK.
Overall, the results are compelling and increase the incentive to promote activities aimed at improving the cardiorespiratory fitness of young people throughout their school and university years, said Dr. Mark Hamer, professor of sports medicine and exercise at University College London.
B while other researchers have warned against drawing causal inferences from these kinds of observational studies, Dr. Hamer added: “This long follow-up largely rules out problems of reverse causation (an existing disease leading to poor fitness and early death) that many previous studies have tried to cope with”.
“While cardiorespiratory fitness was associated with half of the cancers included, this was less true for muscle strength. So, although we did not look at activities in our study, this may indicate that aerobic activities such as running, cycling, playing sports, and swimming are more likely to be associated with cancer risk than strength training.” — says Aron Onerup.
Reducing the risk of cancer is not the only reason to exercise, The Guardian emphasizes. There are complex benefits associated with emotional health and cardiovascular disease prevention. Onerup notes that «some physical activity is better than no physical activity, that more physical activity is better for optimal health outcomes» and stressed that it's never too late to get in shape to reap the health benefits.
In terms of the amount of exercise, Claire Knight recommends 150 minutes per week, but advises: “You can build up activity over time, and there are many ways to be more active. You don't have to run a marathon or hit the gym – everything that warms you, slightly knocks your breath and speeds up your heartbeat is important. Whether you're going for a brisk walk, cycling with a friend, or even doing housework, it can all count as a way to be active”.