Physical activity even during exposure to air pollution can reduce the risk of heart attack

July 18, 2018

Even in areas where road pollution is moderate to high, regular physical activity reduces the risk of initial and recurrent heart attack, according to a new study published in Journal of the American Heart Association the Open Access Journal of the American Heart Association / American Stroke Association

"While exercise is known to reduce the risk of cardiovascular disease, pollution may increase the risk of cardiovascular diseases, including heart attacks, chronic asthma and lung disease, "said Nadine Kubesch, Ph.D., senior author and researcher at the University of Copenhagen in Denmark. "Currently, there is little evidence that poor air quality negates the protective benefits of physical activity to prevent heart attacks."

Danish, German, and Spanish researchers badessed levels of Outdoor physical activity (sports, cycling, walking and gardening). Nitrogen dioxide (NO ₂ pollutant generated by traffic) exposure in 51,868 adults, aged 50 to 65 years, comparing self-reported activities and lifestyle factors against heart attacks. Over a period of 17.7 years, there were 2,936 first heart attacks and 324 recurrent heart attacks

To estimate the average exposure to NO ₂ researchers used national data road pollution monitoring for each address of the participants.

• Higher levels were badociated with more heart attacks, however, the risk was lower in physically active people.
• Moderate cycling for four hours or more per week reduces the risk of recurrent heart attack by 31%; There was a 58% reduction when the four types of physical activity (totaling four hours a week or more) were combined, regardless of air quality.
• Those who practiced sport had a 15% lower rate of initial heart attacks. A 9% risk reduction was badociated with cycling, regardless of air quality
• Compared to participants with low NO residential exposure, people in high-risk areas had an increased risk of 17% during the first heart attack. and 39 percent for recurrent heart attacks.

Among participants who developed a heart attack (first or recurrent), the average NO exposure level ₂ was 18.9 micrograms per cubic meter of air (μg / m3). overall average of 18.7 μg / m3, which is below the EU's current exposure limit (50 μg / m3 over 24 hours) ₂ "Our study shows that physical activity even during exposure to air pollution, in cities with the virus similar to those in Copenhagen, can reduce the risk of heart attack, "Kubesch said. "Our research supports existing evidence that even moderate levels of regular physical activity, such as active commuting, are intense enough to achieve these health benefits."