Dear Doctors: I've been offered a new job that would start this summer. It comes with a sizable pay raise, so I am considering it. What worries me is that it's an overnight shift, which I've read is hard on your health. I would like to know more about that, and if I can avoid the negative health impacts.
Dear Reader: You are weighing the pros and cons of joining the estimated 15 million employees in the United States who work an overnight shift. That's a schedule that begins at 10 or 11 p.m. and lasts until the next morning. As the world around them turns off the lights and slips into bed, night shift workers are just clocking in.
In some professions, such as health care, public safety and law enforcement, an overnight shift is essential. In others, it's a strategy to maximize efficiency and profits. Regardless of the nature of their jobs, all night shift workers all have one thing in common -- a disruption of their body's circadian cycle.
Often referred to as the biological clock, the circadian cycle coincides with the daily shift of light and dark. It influences sleep, metabolism, appetite, body temperature, hormones and numerous other body functions. Repeated or long-term disruption of the circadian cycle, such as with night shift work, puts people at risk of a wide range of physical, mental and emotional health challenges.
Research shows that night shift workers have a higher incidence of serious health conditions such as Type 2 diabetes, heart attack, stroke, obesity, heart disease, pregnancy complications and certain cancers, including colorectal cancer. Insomnia and other sleep disorders are also common. Many struggle to get adequate sleep, which puts them at higher risk of accidents and injury. The toll on mental health is also potentially steep. Studies have found a strong correlation between overnight work and depression and anxiety.
If you decide to move forward with the new job, there are steps you can take to ease the impact of the new hours. When it comes to diabetes risk, changing your eating schedule can help. Newer research shows that meals eaten at night take a high toll on blood sugar control. Limiting eating to daylight hours has been found to counteract this negative effect on the metabolism.
Going eight or 10 hours without eating is a big ask. With that in mind, it is suggested that overnight workers plan high-protein snacks that also include high-quality carbs, such as fruit or vegetables, to ease hunger and boost energy.
Research also makes it clear that prioritizing sleep is important. Use blackout curtains and earplugs to block light and sound. Turn off all devices, have an early bedtime and stay in the ballpark of the new schedule on days off.
There is also evidence that modulating exposure to light may help. In one intriguing experiment, overnight workers mimicked evening light at the end of their shifts. They wore very dark sunglasses or blue-block glasses, dimmed artificial lights, avoided screens and went to sleep as early as possible. These steps helped them to reset their circadian clocks and more closely align them to their work hours.
(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)
