Exercise Shows Cardiovascular Benefits Even in Polluted Areas

Even in polluted areas, regular exercise can help prevent high blood pressure, according to new research published in Circulation.

More than 91% of the worldwide population lives in areas where air quality does not meet World Health Organization guidelines, according to the press release. This means evaluating the risk-benefit relationship between air pollution and physical activity is an especially important public health concern.

The study followed 140,000 non-hypertensive adults in Taiwan for 5 years. Researchers classified participants’ weekly physical activity levels as inactive, moderately active, or highly active. Additionally, researchers also classified level of exposure to fine particulate matter (PM2.5) as low, moderate, and high. PM2.5 is the most commonly used indicator of air pollution, according to the press release.

The study found that people who are highly active and exposed to low levels of pollution had a lower risk of developing high blood pressure. Participants who were inactive and were exposed to highly polluted air had a higher risk of high blood pressure; however, researchers found there are benefits to regular activity regardless of pollution level. Compared with those who didn’t exercise, participants who exercised moderately had a 4% lower risk of high blood pressure. Among individuals who exercised at a high level, it was 13% lower.

There was a similar affect with hypertension. With each increase in PM2.5, there was a 38% increase in risk of incident hypertension; however, with each increase in physical activity there was a 6% decrease in risk of hypertension. According to the press release, this means that reducing air pollution is more effective in preventing high blood pressure.

"While we found that high physical activity combined with lower air pollution exposure was linked to lower risk of high blood pressure, physical activity continued to have a protective effect even when people were exposed to high pollution levels. The message is that physical activity, even in polluted air, is an important high blood pressure prevention strategy," study author and associate professor at the Jockey Club School of Public Health and Primary Care at The Chinese University of Hong Kong in Shatin, Hong Kong Xiang Qian Lao, PhD, said in the press release.

The study’s limitations included that it cannot be generalized to other populations with higher exposure to air pollution as it only included people living in Taiwan. Taiwan’s ambient air is only moderately polluted, according to the press release. Additionally, researchers did not distinguish between outdoor and indoor exercise.

Reference:

Regular exercise helps prevent high blood pressure, even in areas of high air pollution (News Release), Taiwan, July 20, 2020, EurekAlert!, accessed July 20, 2020