28 Jul A surprising cause of period cramp pain: air pollution
- Key findings: Regularly breathing in outdoor or indoor air pollution can make you up to 33 times more likely to experience painful menstrual cramps, a large-scale study finds.
JULY 28, 2021—Menstrual cramp pain (known as dysmenorrhea) is so common that even before you get your first period, you’ve likely already heard about it from menstrual cramp sufferers as well as in movies, books, podcasts, videos and articles.
The good news is that not everyone who menstruates actually experiences crampy discomfort. For some of us, this may be due to a lucky genetic advantage that naturally makes us less prone to them. Others may be eating lots of cramp-busting foods, such as fatty fish, which is rich in omega-3 fatty acids that tamp down levels of pain-spurring prostaglandins. Still others may have adopted healthy habits that lower the risk of menstrual cramps, for instance, they may ease mental stress with regular yoga sessions, reducing tension-caused inflammation that worsens cramp pain.
The bad news is that certain activities can intensify menstrual cramps or put you at a greater risk of developing them. These include experiencing high stress and not doing anything to counter it (for instance, practicing yoga), eating lots of processed “junk” foods and using nicotine in cigarettes, vaping or other products, which all increase inflammation that leads to more uterine discomfort during your period.
Now a 2021 study from China Medical University Hospital in Taiwan reveals another risk factor for menstrual cramps that’s important for you to be aware of: air pollution.1
Why the period/pollution connection?
The study authors started out by reviewing past research that shows air pollution is linked to a whole host of menstrual cycle issues: a shorter luteal phase (which is the second half of your cycle that spans the day after ovulation through the day before your next period), irregular menstrual cycles (meaning they don’t follow a consistent number of days from cycle to cycle), menstrual disorders and menstrual irregularity (such as heavy bleeding and skipped periods).2
The researchers noted, however, that despite these many studies showing a wide spectrum of cycle-related problems tied to air pollution, no one had yet examined if pollution could impact menstrual cramps. So, they set out to do just that.
Pulling anonymous health data of 296,078 women and girls between 16 and 55 years old from Taiwan’s Longitudinal Health Insurance Database, they examined reports of menstrual cramps from 2000 through 2013 along with air pollution levels where these patients lived. The female subjects they selected did not experience menstrual cramps before 2000. This meant the researchers could spot if a pattern emerged between newly-diagnosed period pain and what the women and girls were regularly breathing in.
Specifically, the authors looked for a long-term association between the risk of dysmenorrhea and the average exposure over the years to nitrogen oxide (NOx), nitric oxide (NO), nitrogen dioxide (NO2), carbon monoxide (CO) and fine particles smaller than 2.5 micrometers in diameter, which they obtained from the Taiwan Air Quality Monitoring Database of the Environmental Protection Agency.
What the study uncovered
After crunching the numbers, the study authors made a startling discovery:
The risk of developing menstrual cramps was 16.7 to 33.1 times higher for women and girls who lived in areas with the highest exposure to air pollutants compared to those living in areas with the lowest exposure. This study shows that polluted air is, indeed, a significant contributor to period pain.
Drilling down, the study pinpointed the biggest cramp-causing culprit floating in the air: Though NOx, NO, NO2, CO and fine particle levels each contributed separately to the increased risk, the greatest individual effect was from long-term exposure to a high amount of fine particles. These include dust, soot, smoke and exhaust, which can come from a wide range of sources, such as heavy traffic, fireplaces, barbecues, indoor cooking, dusting and vacuuming, just to name a few.
How pollution spurs period pain
Chances are, you’ve probably heard that breathing in polluted air is bad for your health. In fact, research shows that regularly inhaling hazardous chemicals and fine particles is linked to the development of heart disease, stroke, lung infections and asthma.3 Scientists suspect one key reason is inflammation throughout the body caused by breathing in all that gunk.
Coincidentally, inflammation is a major trigger of period pain, too. But, in addition to that, the study authors suspect air pollution may also cause cramps by increasing prostaglandins, creating more oxidative stress and leading to a rise in emotional stress. They also point out that irregular menstrual cycles caused by continually breathing in chemicals and microscopic particles is also a likely culprit.
What can you do about pollution?
Now that you know indoor and outdoor air pollution can significantly increase your risk of painful menstrual cramps, you can take steps to minimize your risk. For example, you can…
- Turn on an exhaust fan or open windows when cooking indoors.
- Wear a face mask when dusting, vacuuming, using household cleaners and gardening.
- Avoid standing in a smoke cloud caused by outdoor barbecues and firepits.
- Steer clear of areas where people are smoking or vaping nicotine.
- Place a high efficiency particle air (HEPA) filter in your home and/or where you work.
- Use a damp cloth or damp mop when cleaning to avoid stirring dust into the air.
- Reduce use of candles and incense in your home.
- Ensure chimneys are clear, cleaned annually and working properly.
- Keep windows closed if you live near a high-traffic area or particle-releasing factories or businesses.
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(1) Shih-Yi Lin, et al., “Increased Incidence of Dysmenorrhea in Women Exposed to Higher Concentrations of NO, NO2, NOx, CO, and PM2.5: A Nationwide Population-Based Study”, Frontiers in Public Health, published online June 17, 2021
(2) Shruthi Mahalingaiah, et al., “Adult air pollution exposure and risk of infertility in the Nurses’ Health Study II”, Human Reproduction, 31 (2016):638–647
Julie Carré, et al., “Does air pollution play a role in infertility?: A systematic review”, Environmental Health, 16 (2017): 82
Radim J. Srám, “Impact of air pollution on reproductive health”, Environmental Health Perspectives, 107 (1999): A542–3
Anna Merklinger-Gruchala, Grazyna Jasienska, Maria Kapiszewska, “Effect of Air Pollution on Menstrual Cycle Length-A Prognostic Factor of Women’s Reproductive Health”, International Journal of Environmental Research and Public Health, 14 (2017):816
Shruthi Mahalingaiah, et al., “Perimenarchal air pollution exposure and menstrual disorders”, Human Reproduction, 33 (2018): 512–9