Regular Exercise May Lower Death Risk From Natural Causes: Study

The study, published in the journal CMAJ (Canadian Medical Association Journal), indicates that a higher level of regular exercise compared with inactivity was beneficial, even in polluted areas, although less exposure to pollution was better.

Regular exercise, even performed in areas with air pollution, can reduce the risk of death from natural causes, a new study published in the journal CMAJ (Canadian Medical Association Journal) suggests.

"Habitual exercise reduces the risk of death regardless of exposure to air pollution, and air pollution generally increases the risk of death regardless of habitual exercise," said researcher Xiang Qian Lao from the Chinese University of Hong Kong.

"Thus, habitual exercise should be promoted as a health improvement strategy, even for people residing in relatively polluted areas," Lao added.

For the study, the team conducted a large study, over 15 years from 2001 to 2016, with 384,130 adults in Taiwan, seeking to understand the effects of regular exercise and long-term exposure to fine particulate matter on the risk of death from natural causes.

"We found that a high level of habitual exercise and a low level of exposure to air pollution was associated with lower risk of death from natural causes, whereas a low level of habitual exercise and a high level of exposure was associated with a higher risk of death," the researcher said.

This study adds to several other smaller studies conducted in the US, Denmark, and Hong Kong that found that regular exercise, even in polluted areas, is beneficial.

“As people exercise, their ventilation rate increases, which increases the volume of air pollutants they inhale. This may exacerbate the adverse health effects of air pollutants. Thus, the risk-benefit relation between air pollution and exercise needs to be assessed to understand whether it is safe to exercise regularly in polluted regions. Indeed, some studies have shown that acute exposure to air pollution when exercising may override the benefits of exercise. It is possible that the effects of long-term exposure to air pollution may be irreversible and cause a much larger disease burden than short-term exposure. Limited information exists on the combined effects of long-term exposure to air pollution and habitual exercise on human health, and findings have been inconsistent depending on health outcome”, states the study.

The authors said that "further studies in areas with more severe air pollution are required to examine the applicability of our findings". "Our study reinforces the importance of air pollution mitigation, such as to reduce the harmful effects of air pollution and maximize the beneficial effects of regular exercise," the team said.