A new study reveals women working night shifts face a higher risk of asthma compared to those working daytime hours.
Study Highlights Health Concerns for Women
A recent study from the University of Manchester, published on June 16, 2025, in ERJ Open Research, shows that women who work night shifts are more likely to develop moderate or severe asthma. The research, led by Dr. Robert Maidstone, found no similar risk for men. This discovery raises concerns about the health impacts of night shift work, particularly for women.
Understanding the Research
The study analyzed data from the UK Biobank, including 274,541 working adults. Of these, 5.3% had asthma, with 1.9% experiencing moderate or severe cases, requiring treatments like inhalers or oral steroids. Researchers grouped participants based on their work schedules: daytime only, night shifts only, or mixed shifts.
Key findings include:
- Women working night shifts are 50% more likely to have moderate or severe asthma compared to daytime workers.
- The risk was even higher for postmenopausal women not using hormone replacement therapy (HRT), nearly doubling their asthma risk.
- Men showed no increased asthma risk, regardless of their work schedule.
Dr. Maidstone explained, “Women already face a higher risk of severe asthma and hospitalization compared to men. Our study shows night shift work could make this worse for women, but we don’t see the same effect in men.”
Why Does This Happen?
The study does not pinpoint why night shifts affect women’s asthma risk, but researchers have some theories:
- Body Clock Disruption: Night shifts can disrupt the body’s natural rhythms, affecting hormone levels. Lower testosterone in women might increase asthma risk, as higher testosterone has been linked to asthma protection.
- Job Differences: Men and women may work different types of night shift jobs, which could influence health outcomes.
- Hormonal Factors: The study suggests HRT might lower asthma risk in night shift workers, but more research is needed.
Dr. Maidstone noted, “We can’t say for sure why this link exists, but it could be related to how shift work affects hormones or the types of jobs women do at night.”
Expert Insights
Professor Florence Schleich, an asthma expert from the University of Liège, Belgium, who was not involved in the study, emphasized its importance. “Asthma affects millions globally, and women are more likely to have severe cases. This study suggests night shifts could be a risk factor for women, but not men. We need more research to confirm this and find ways to protect women working these schedules.”
She added, “Most workers can’t easily change their shifts, so understanding this link could help us develop solutions to reduce health risks.”
What’s Next?
The research team plans to explore whether sex hormones play a role in the asthma-night shift connection. They will use data from the UK Biobank and Our Future Health, a new UK health research program. Future studies may also test if HRT can protect against asthma in night shift workers.
Dr. Maidstone said, “We’re looking at whether hormones explain this link. If confirmed, it could lead to new ways to support women’s health in shift work.”
Why It Matters
This study highlights the need to address workplace health risks, especially for women. With asthma affecting millions worldwide, understanding how work schedules impact health is critical. The findings could lead to better workplace policies, such as:
- Health screenings for night shift workers.
- Support for women in high-risk roles.
- Research into protective measures, like hormone therapy or adjusted schedules.
As President Donald Trump begins his second term in 2025, workplace health policies may gain attention, especially for industries like healthcare and manufacturing, where night shifts are common.
Conclusion
The University of Manchester’s study is a step toward understanding how night shifts affect women’s health. While the findings are concerning, they open the door to further research and potential solutions. For now, women working night shifts should be aware of their asthma risk and consult healthcare providers for guidance. As research continues, experts hope to find ways to make night shift work safer for everyone.