Air Pollution: How to Protect Your Heart & Blood Vessels

By Adin Smith, MS | Posted September 7, 2021

Hands in shape of a heart

More than 90% of the world’s population is exposed to unhealthy levels of air pollution.[1]Allen RW, Barn P. Individual- and Household-Level Interventions to Reduce Air Pollution Exposures and Health Risks: a Review of the Recent Literature. Curr Environ Health Rep. 2020;7(4):424-440.

What is air pollution?

Air pollution comes in a mixture of gasses and particulate matter. Examples of gas pollutants include ozone, carbon monoxide, and nitrogen oxides. In contrast, particulate pollutants include dust, dirt, soot, and smoke. Particles of less than 2.5 micrometers in diameter—known as fine particulate matter—represent the most significant threat to our well-being. Examples of fine particle sources include wildfires, power plants, waste incinerators, wood stoves, and road traffic exhaust. 

What are the harmful effects of fine particulate matter?

Long-term exposure to fine particulate matter is associated with reduced life expectancy and increased risk for several conditions, including depression, lung cancer, high blood pressure, type 2 diabetes, and cardiovascular disease.[2]Lao XQ, Guo C, et al. Long-term exposure to ambient fine particulate matter (PM2.5) and incident type 2 diabetes: a longitudinal cohort study. Diabetologia. 2019 May;62(5):759-769.,[3]Hayes RB, Lim C, Zhang Y, et al. PM2.5 air pollution and cause-specific cardiovascular disease mortality. Int J Epidemiol. 2020;49(1):25-35.

Studies show that even 60-minutes of exposure to heavily polluted air can lead to irregular heart rhythms, heart attacks, and stroke for people with existing heart disease.[4]Peters A, von Klot S, et al. Exposure to traffic and the onset of myocardial infarction. N Engl J Med. 2004 Oct 21;351(17):1721-30. Because cardiovascular disease is the leading cause of death worldwide, it’s imperative to identify the strategies that help protect the heart and blood vessels from the toxic effects of air pollution.

1.) Face Masks

Several studies show that people living in heavily polluted areas may benefit from wearing face masks.[5]Morishita M, Wang L, et al. Acute Blood Pressure and Cardiovascular Effects of Near-Roadway Exposures With and Without N95 Respirators. Am J Hypertens. 2019;32(11):1054-1065.,[6]Langrish JP, Mills NL, et al. Beneficial cardiovascular effects of reducing exposure to particulate air pollution with a simple facemask. Part Fibre Toxicol. 2009 Mar 13;6:8. For example, one study analyzed the cardiovascular effects of wearing an N95 mask for 48 hours among college students in Shanghai, China—where air pollution levels are commonly unhealthy. Students were randomly assigned to wear a face mask or go without masking for 48 hours.[7]Shi J, Lin Z, et al. Cardiovascular Benefits of Wearing Particulate-Filtering Respirators: A Randomized Crossover Trial. Environ Health Perspect. 2017;125(2):175-180. Researchers measured blood pressure and heart rate variability (a marker of heart function) throughout the testing period. At trial completion, results showed that compared to the non-masking group, wearing face masks led to lower blood pressure levels and positive changes in heart rate variability.

These preliminary findings show that wearing a well-fitted face mask in polluted areas may aid in heart health.

2.) Air purifiers

High blood pressure is involved in the onset of heart failure, stroke, vascular dementia, and kidney disease.[8]Fuchs FD, Whelton PK. High Blood Pressure and Cardiovascular Disease. Hypertension. 2020 Feb;75(2):285-292. Because poor air quality may increase blood pressure, many studies have investigated the effects of air purifiers on blood pressure. A recent analysis of several studies concluded that home air purifiers do appear to help reduce blood pressure.[9]Walzer D, Gordon T, et al. Effects of Home Particulate Air Filtration on Blood Pressure: A Systematic Review. Hypertension. 2020 Jul;76(1):44-50.

Air purifiers may reduce other vital markers such as inflammation and blood clotting—two factors involved in stroke risk. For example, one study showed that in addition to lowering blood pressure, air purifier usage among college students resulted in a significant reduction of inflammation and blood clotting markers.[10]Chen R, Zhao A, et al. Cardiopulmonary benefits of reducing indoor particles of outdoor origin: a randomized, double-blind crossover trial of air purifiers. J Am Coll Cardiol. 2015;65(21):2279-2287.

The type of air purification system is important. New research shows that negative ion air purifiers may negatively impact health.[11]Liu W, Huang J, et al. Negative ions offset cardiorespiratory benefits of PM2.5 reduction from residential use of negative ion air purifiers. Indoor Air. 2021 Jan;31(1):220-228. Based on this new data, it’s critical to use HEPA air filtration systems without ionizers.

3.) Vitamin C and E

Studies show that exposure to particulate matter (PM) causes increases in oxidative stress.[12]Li Z, Liu Q, et al. Association between short-term exposure to ambient particulate air pollution and biomarkers of oxidative stress: A meta-analysis. Environ Res. 2020 Dec;191:110105. Increases in oxidative stress may damage the body’s cells over time. Because this type of cell stress is an important factor involved in the cause of cardiovascular disease, researchers continually study how antioxidant compounds may benefit cardiovascular health.[13]Kelly FJ, Fussell JC. Role of oxidative stress in cardiovascular disease outcomes following exposure to ambient air pollution. Free Radic Biol Med. 2017 Sep;110:345-367.

One six-month study analyzed the effects of vitamin C and E on oxidative stress levels among individuals living or working in proximity to a coal-fired electric power plant.[14]Possamai FP, Júnior SÁ, et al. Antioxidant intervention compensates oxidative stress in blood of subjects. Environ Toxicol Pharmacol. 2010 Sep;30(2):175-80. Researchers also included a control group for comparing pollution-exposed individuals vs. healthy individuals not exposed to air pollution or vitamin supplements. At the end of the trial, individuals taking vitamin C and E supplements reduced their oxidative stress levels—matching the levels seen in those not exposed to air pollution.

In other words, vitamin C and E supplements normalized oxidative stress markers in the blood brought on by air pollution.

4.) Fish Oil

Research shows that particulate matter exposure increases blood clotting, oxidative stress, inflammation, and cortisol levels—all factors linked to cardiovascular disease.[15]Liu C, Cai J, et al. The Acute Effects of Fine Particulate Matter Constituents on Blood Inflammation and Coagulation. Environ Sci Technol. 2017 Jul 18;51(14):8128-8137.,[16]Lodovici M, Bigagli E. Oxidative stress and air pollution exposure. J Toxicol. 2011;2011:487074.

A recent year-long study reported that healthy college students assigned to 2.5 grams per day of fish oil had lower cortisol levels, blood inflammation, blood clotting, and oxidative stress than the placebo group.[17]Lin Z, Chen R, et al. Cardiovascular Benefits of Fish-Oil Supplementation Against Fine Particulate Air Pollution in China. J Am Coll Cardiol. 2019 Apr 30;73(16):2076-2085. Additionally, there were favorable changes in blood vessel function seen in students taking fish oil, as compared to the placebo group.

In another study, participants received 3 grams per day of fish oil or olive oil for four weeks to determine if either treatment helped reduce the effects of air pollution.[18]Tong H, Rappold AG, et al. Omega-3 fatty acid supplementation appears to attenuate particulate air pollution-induced cardiac effects and lipid changes. Environ Health Perspect. 2012;120(7):952-957.

Participants were exposed to controlled levels of air pollution in a lab setting to help ensure consistency and accuracy of results. Upon completion, markers of heart rate variability (a measure of heart function) improved in the fish oil treatment group but not in the olive oil group. Additionally, those consuming olive oil experienced increases in triglyceride and VLDL levels (two heart disease risk factors). In contrast, those taking fish oil maintained their lipids.

These studies suggest that omega-3 fish oil may buffer the effects of air pollution and help keep the body in balance. Based on these results, it also appears that olive oil may not possess the chemical properties that address the adverse effects of air pollution on heart health.

5.) Broccoli Sprout Extract

Several studies show that concentrated broccoli sprout extracts may help the body eliminate benzene and acrolein— two common air pollutants linked to high blood pressure and cardiovascular disease.[19]Abplanalp W, DeJarnett N, Riggs DW, et al. Benzene exposure is associated with cardiovascular disease risk. PLoS One. 2017;12(9):e0183602. Published 2017 Sep 8.,[20]Wiwanitkit V. Benzene exposure and hypertension: an observation. Cardiovasc J Afr. 2007 Jul-Aug;18(4):264-5. One study evaluated the effects of a broccoli sprout extract on the detoxification of benzene, acrolein, and a third common air pollutant called crotonaldehyde.[21]Egner PA, Chen JG, Zarth AT, et al. Rapid and sustainable detoxication of airborne pollutants by broccoli sprout beverage. Cancer Prev Res (Phila). 2014;7(8):813-823. Participants were randomized to consume broccoli sprout extract or the broccoli placebo drink over 12 weeks—evaluating how effectively each of these air pollutants was eliminated in the urine. Compared to the placebo group, individuals drinking the broccoli sprout beverage more effectively eliminated benzine and acrolein from their system. 

These findings suggest that when air pollutants enter the body, broccoli sprout extracts may help eliminate certain airborne toxins that accumulate in the body, therefore limiting exposures to the heart and blood vessels.

6.) Air quality monitoring

Checking the Air Quality Index (AQI) in your area is a great way to make informed decisions about participating in outdoor activities. For example, suppose the AQI indicates an unhealthy air quality level. In that case, you may want to avoid exercising outside and go to an indoor gym instead. Additionally, checking AQI may help certain people decide if N95 mask-wearing is prudent—especially for sensitive individuals (i.e., allergies or asthma). 

For quality AQI levels and forecasts, visit the AirNow webpage.

Conclusion

Today, nearly everyone gets exposed to polluted air. Vitamin C and E, omega-3 fish oil, and broccoli sprout extract represent dietary strategies that may help protect the heart and blood vessels against air pollution. Studies also suggest that air purifiers and wearing N95 masks provide cardioprotection against particulate pollutants.

References

References
1Allen RW, Barn P. Individual- and Household-Level Interventions to Reduce Air Pollution Exposures and Health Risks: a Review of the Recent Literature. Curr Environ Health Rep. 2020;7(4):424-440.
2Lao XQ, Guo C, et al. Long-term exposure to ambient fine particulate matter (PM2.5) and incident type 2 diabetes: a longitudinal cohort study. Diabetologia. 2019 May;62(5):759-769.
3Hayes RB, Lim C, Zhang Y, et al. PM2.5 air pollution and cause-specific cardiovascular disease mortality. Int J Epidemiol. 2020;49(1):25-35.
4Peters A, von Klot S, et al. Exposure to traffic and the onset of myocardial infarction. N Engl J Med. 2004 Oct 21;351(17):1721-30.
5Morishita M, Wang L, et al. Acute Blood Pressure and Cardiovascular Effects of Near-Roadway Exposures With and Without N95 Respirators. Am J Hypertens. 2019;32(11):1054-1065.
6Langrish JP, Mills NL, et al. Beneficial cardiovascular effects of reducing exposure to particulate air pollution with a simple facemask. Part Fibre Toxicol. 2009 Mar 13;6:8.
7Shi J, Lin Z, et al. Cardiovascular Benefits of Wearing Particulate-Filtering Respirators: A Randomized Crossover Trial. Environ Health Perspect. 2017;125(2):175-180.
8Fuchs FD, Whelton PK. High Blood Pressure and Cardiovascular Disease. Hypertension. 2020 Feb;75(2):285-292.
9Walzer D, Gordon T, et al. Effects of Home Particulate Air Filtration on Blood Pressure: A Systematic Review. Hypertension. 2020 Jul;76(1):44-50.
10Chen R, Zhao A, et al. Cardiopulmonary benefits of reducing indoor particles of outdoor origin: a randomized, double-blind crossover trial of air purifiers. J Am Coll Cardiol. 2015;65(21):2279-2287.
11Liu W, Huang J, et al. Negative ions offset cardiorespiratory benefits of PM2.5 reduction from residential use of negative ion air purifiers. Indoor Air. 2021 Jan;31(1):220-228.
12Li Z, Liu Q, et al. Association between short-term exposure to ambient particulate air pollution and biomarkers of oxidative stress: A meta-analysis. Environ Res. 2020 Dec;191:110105.
13Kelly FJ, Fussell JC. Role of oxidative stress in cardiovascular disease outcomes following exposure to ambient air pollution. Free Radic Biol Med. 2017 Sep;110:345-367.
14Possamai FP, Júnior SÁ, et al. Antioxidant intervention compensates oxidative stress in blood of subjects. Environ Toxicol Pharmacol. 2010 Sep;30(2):175-80.
15Liu C, Cai J, et al. The Acute Effects of Fine Particulate Matter Constituents on Blood Inflammation and Coagulation. Environ Sci Technol. 2017 Jul 18;51(14):8128-8137.
16Lodovici M, Bigagli E. Oxidative stress and air pollution exposure. J Toxicol. 2011;2011:487074.
17Lin Z, Chen R, et al. Cardiovascular Benefits of Fish-Oil Supplementation Against Fine Particulate Air Pollution in China. J Am Coll Cardiol. 2019 Apr 30;73(16):2076-2085.
18Tong H, Rappold AG, et al. Omega-3 fatty acid supplementation appears to attenuate particulate air pollution-induced cardiac effects and lipid changes. Environ Health Perspect. 2012;120(7):952-957.
19Abplanalp W, DeJarnett N, Riggs DW, et al. Benzene exposure is associated with cardiovascular disease risk. PLoS One. 2017;12(9):e0183602. Published 2017 Sep 8.
20Wiwanitkit V. Benzene exposure and hypertension: an observation. Cardiovasc J Afr. 2007 Jul-Aug;18(4):264-5.
21Egner PA, Chen JG, Zarth AT, et al. Rapid and sustainable detoxication of airborne pollutants by broccoli sprout beverage. Cancer Prev Res (Phila). 2014;7(8):813-823.

    Image author credit: NejroN © 123RF.com