Cardiorespiratory fitness reduces lung cancer mortality risk – even among current smokers

A recent study published in Medicine and Science in Sports and Exercise, the journal of record for the American College of Sports Medicine, revealed that men with at least a moderate level of physical fitness had 57% lower risk of lung cancer mortality and a 52% lower risk of developing lung cancer in the first place. (Xuemei S, et al. Influence of Cardiorespiratory Fitness on Lung Cancer Mortality. Medicine & Science in Sports & Exercise. May 2010: Vol. 42(5); 872-878)

The study examined the medical records of 38,000 adult men who completed preventative medical examinations including fitness testing at the Cooper Clinic in the Dallas, TX area between 1974 and 2002. The men agreed to provide follow up data from the date of their initial examination until their date of death or December 31, 2003 if still living. The research team reviewed the baseline cardiorespiratory fitness tests, follow up reports and mortality data to reach their conclusions.

In addition to looking at the overall connection between fitness level and lung cancer risk among men, the researchers also looked at whether there were differences between current smokers, former smokers and never smokers and lung cancer risk/mortality based on their respective fitness levels (low, moderate, high).

Interestingly, the study results showed that current smokers who had a moderate level of physical fitness had approximately 48% lower risk of lung cancer mortality than smokers who had low cardiorespiratory fitness while current smokers with high cardiorespiratory fitness had 58% lower lung cancer mortality risk.

Still, even current smokers with high cardiorespiratory fitness were 2.5 times more likely to die of lung cancer than those who never smoked and had low cardiorespiratory fitness, and 1.5 times more likely to die from lung cancer than moderately fit former smokers.

So, while exercise does provide substantial protective health benefits for current smokers, those benefits could be dramatically improved by quitting smoking. But the overarching theme of the study results is clear – higher levels of cardiovascular fitness (even for current smokers) dramatically lowers risk of developing and dying from lung cancer.

As the researchers conclude, “In summary, our data provide evidence that low levels of fitness may play a causal role in lung cancer mortality…If fitness does decrease the risk of lung cancer mortality as shown in our data, then there is something more than avoiding tobacco that can be done to lower risk of the leading cause of cancer death in the United States.”