During his 26 years as a night-shift nurse, Ed Collum watched colleagues nod off mid-conversation, battle chronic illnesses and, too often, die young from cancer, stroke or suicide.

Collum puts it bluntly: “The night shift is not good for you.”

The science backs him up. Shift work, especially overnight and rotating schedules, is a major biological stressor. Yet workplace policy still treats it mostly as a scheduling inconvenience, compensated — if at all — with a small hourly premium, rather than as a chronic exposure that accumulates.

Every night, millions go to work while most of the nation sleeps. Hospitals hum. Highways fill with trucks. Evidence now links long-term night and rotating shift work to reduced brain volume and to increased risks of gastrointestinal disorders, heart disease and diabetes. Recent UCLA-led research also found higher mortality among shift workers already living with cardiometabolic disease. The World Health Organization’s cancer agency has even classified night-shift work that disrupts circadian rhythms as probably carcinogenic to humans.

The burden is not evenly shared. Immigrants and racial minorities disproportionately shoulder shift schedules, concentrating the consequences among workers with the least power to refuse unsafe hours or negotiate better ones. The risks also extend beyond workers themselves. Medical errors increase at night, as do industrial accidents and traffic fatalities.

To understand the problem, we must go deep inside the body. Nearly every cell runs on a circadian clock tuned to the light-dark cycle, coordinating sleep, metabolism, immunity and more. When chronically misaligned, the effects ripple through the body. And unlike an international traveler, a shift worker struggles to adjust. Many swing between day and night schedules in the same week. It’s like living in a permanent state of jet lag without the vacation.

Collum felt the strain early in his career at Harborview Medical Center in Seattle. Years of sleeping by day after shifts and reverting to sleeping by night on days off left him, in his words, “as miserable as you could be.”

Then, one year, he picked up 13 of 14 consecutive night shifts to help pay for home renovations and noticed something surprising: He felt better. So he stopped flip-flopping. He kept nights as his “days” seven days a week. Within a year, he had lost 100 pounds, stopped getting sick and felt sharper and happier.

“I know I was an oddity at work,” he says. “But I was by far healthier than others.”

Newly retired, Collum urges nurses to take day shifts. For those who can’t, he recommends going fully nocturnal. Recent studies show that irregular sleep timing can be more harmful than not getting enough hours of sleep.

Of course, the permanent night owl solution isn’t realistic for many workers. But it is just one of several harm-reducing strategies emerging from circadian science. Others include forward-rotating schedules (progressing from days to evenings to nights, because the body generally prefers to stay up later rather than sleep earlier), strategic light exposure and restricting eating to the daytime even when working at night.

The Salk Institute and UCSD are currently testing whether such circadian-informed meal timing can lessen the health burden on night-shift nurses. Meanwhile, the airline industry has begun using artificial intelligence to predict fatigue-related risk, and at least one airline has advertised its consideration of circadian rhythms in organizing a.m. and p.m. flight patterns. “Whether you’re an early bird or a night owl,” reads their pilot recruitment page, “we have something to suit you!”

Still, many employers have little incentive to acknowledge the full liability. Shift differentials typically amount to only a few dollars an hour. That’s enough to buy a coffee to stay awake, not enough to offset elevated lifetime health risks.

Higher hazard pay should be paired with safer scheduling, education on sleep and meal timing, and practical supports such as blackout curtains and healthier alternatives to vending machines. The U.S. Occupational Safety and Health Administration already enforces strict standards for some workplace hazards such as asbestos, lead and excessive noise. But those legal protections came only after decades of mounting evidence and preventable harm. Chronic shift work deserves the same seriousness without repeating history and forcing another generation of workers to wait for the law to catch up with the science. A good first step would be requiring health screenings for workers logging years of overnight shifts.

California could become a proving ground. Its hospitals, ports, farms, warehouses and film sets all depend on overnight labor, and the state already has the worker-protection infrastructure to turn this principle into practice. If California shows how to do this, the rest of the country can follow.

The investments would pay off in healthier workers, fewer costly errors and lower turnover. They would also force an honest accounting of who bears the cost of our 24-hour economy. Americans have grown to expect pre-dawn deliveries. Casinos never close. Much of this exists because we’ve decided convenience and entertainment are worth the costs — costs that workers, not consumers, are paying with their health.

“It was definitely not worth the $4.50,” says Collum.

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Lynne Peeples, a science writer, is the author of “The Inner Clock: Living in Sync With Our Circadian Rhythms.”

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