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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.
Lynne Peeples, a science writer, is the author of “The Inner Clock: Living in Sync With Our Circadian Rhythms.”
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Ideas expressed in the piece
The article argues that long-term night and rotating shift work is a serious, cumulative health exposure rather than a mere scheduling inconvenience, pointing to evidence that such schedules are associated with higher rates of cardiovascular disease, diabetes, gastrointestinal problems, depression, anxiety and sleep disorders among shift workers.[2][4][7][10] It further notes emerging data that mortality is higher among people with existing cardiometabolic disease who continue to work nights, reinforcing the claim that night shifts can be “deadly,” not just uncomfortable.[4][7]
Building on circadian science, the piece contends that the core problem is chronic disruption of the body’s internal clocks: nearly every cell follows a roughly 24‑hour rhythm tied to light and dark, coordinating sleep, metabolism, immune function and hormone release.[1][5][11] When workers are repeatedly awake and working at night and trying to sleep during the day—especially on schedules that flip back and forth—the article emphasizes that this persistent circadian misalignment can drive metabolic syndrome, obesity, insulin resistance and broader cardiometabolic risk.[3][5][7][10]
The article underscores that these harms are not confined to long-term disease but also include immediate safety risks, noting that fatigue and circadian “lows” at night are linked to more medical errors, industrial accidents and traffic crashes after shifts.[5][8][11] In doing so, it frames night work as a threat to public safety, not only to individual workers’ health.
To make the science tangible, the piece recounts the experience of a night-shift nurse who saw colleagues struggle with chronic illness, cancer, stroke and suicide, and who initially suffered severe exhaustion and weight gain while oscillating between day and night schedules. The article uses this story to illustrate research showing that irregular sleep timing and rotating schedules can be especially harmful, while more stable sleep-wake patterns may lessen strain, even if they occur at night.[1][5][15]
The article stresses that the burden of night and rotating shifts falls disproportionately on workers with the least bargaining power, arguing that immigrants and racial minorities are overrepresented in night-shift jobs in hospitals, warehouses, ports and farms. It links this pattern to broader concerns about health inequities and labor rights, suggesting that these workers are effectively subsidizing the 24‑hour economy with their health while having limited ability to refuse unsafe hours or demand safer conditions.[12][16]
Drawing on classifications by international and national health bodies, the piece highlights that night-shift work that disrupts circadian rhythms has been deemed “probably carcinogenic,” and notes that ongoing circadian disruption has been identified as a modifiable cardiometabolic risk factor, yet is still rarely treated as such in workplace policy.[3][7][10] It criticizes the fact that many employers offer only small night differentials—enough to buy coffee, not to compensate for elevated lifetime health risks.[6]
The article advocates for a shift from viewing night work as a neutral scheduling tool to treating it like other regulated workplace hazards such as asbestos or excessive noise, arguing that legal protections should arrive before decades of preventable harm accumulate.[7][10] It proposes concrete measures: routine health screenings for long-term night workers, higher hazard pay, safer scheduling practices (including forward‑rotating shifts that move from days to evenings to nights), and education about sleep and meal timing tailored to circadian biology.[1][5][15][17]
At the same time, the piece acknowledges that many night-shift jobs are essential and will not disappear, so it highlights emerging harm-reduction strategies informed by circadian research, such as strategic light exposure, restricting eating to daytime even when working nights, clustering shifts and maintaining a consistent sleep schedule, and providing practical supports like blackout curtains and healthier food options at work.[5][11][15][17] It points to ongoing trials, including research on time‑restricted eating among night‑shift nurses, as examples of how science can be translated into workplace practices.[5][7]
Finally, the article calls for California to serve as a testing ground for stronger protections, noting the state’s heavy reliance on overnight labor across hospitals, ports, agriculture, warehouses and entertainment, and its existing worker-protection infrastructure.[9][12][13] It argues that if California demonstrates how to integrate circadian science into labor standards—through screenings, scheduling rules and meaningful compensation—other states could follow, leading to healthier workers, fewer costly errors and lower turnover, and forcing a clearer reckoning with who pays for the nation’s 24‑hour convenience.[10][16]
Different views on the topic
In contrast to the article’s characterization of night shifts as inherently “deadly,” many medical and public health sources describe night and rotating shift work as conditions that raise relative risk for certain diseases rather than as uniformly catastrophic exposures, emphasizing that individual susceptibility and coexisting lifestyle factors play significant roles.[4][10][11] These sources often stress that while circadian disruption is associated with obesity, diabetes, cardiovascular disease and mood disorders, the magnitude of risk varies, and preventive measures such as regular exercise, smoking cessation and routine medical screening can meaningfully mitigate overall health impact.[4][10][17]
Whereas the article pushes for treating night work like asbestos or lead, clinical guidance on shift-work sleep disorder and occupational health frequently focuses on practical, individualized coping strategies rather than broad regulatory reclassification. For example, resources from major health systems recommend limiting the number of consecutive night shifts, avoiding frequent rotations, using bright light therapy, melatonin and carefully timed naps, and optimizing sleep environments (dark, quiet rooms, blackout curtains) to help workers adapt, implying that night work can be managed rather than fundamentally redefined as an intolerable hazard.[11][15][17]
Circadian researchers have also highlighted that the degree of misalignment between a worker’s internal clock and external schedule is a key determinant of health and performance outcomes, which complicates blanket claims about night work being universally harmful.[1][18] Studies on night-shift adaptation suggest that workers who achieve greater circadian alignment with their night schedules—often by keeping a stable sleep pattern or because they have naturally late chronotypes—may experience less sleepiness, fewer performance impairments and better mood, indicating that targeted interventions to improve alignment could reduce risk without eliminating night shifts altogether.[1][18]
From a labor-policy standpoint, current federal law reflects a more restrained view of night work than the article advocates: U.S. Department of Labor guidance notes that extra pay for night shifts is left to agreement between employers and employees, and the Fair Labor Standards Act does not require a specific premium for night work or mandate special health monitoring for night-shift workers.[6] This regulatory posture aligns with a perspective that night and rotating schedules are primarily economic arrangements to be negotiated in the market, rather than occupational hazards warranting explicit federal standards or hazard-pay requirements.
Some occupational-health and worker-rights materials emphasize using existing legal frameworks—such as general safety protections, anti-retaliation provisions and rules around rest breaks and reporting-time pay—to address excess fatigue, unsafe staffing and abusive scheduling practices, rather than creating new, shift-specific health regulations.[12][13][16] This approach prioritizes enforcement of current labor standards and incremental improvements in scheduling, arguing that stronger compliance and worker empowerment can reduce harms associated with night work even without formally classifying it as carcinogenic or mandating specialized health screenings.
Additionally, practical guidance for nurses and other night workers often acknowledges that 24‑hour staffing is indispensable in sectors like healthcare, emergency services and transportation, and therefore focuses on helping workers stay as healthy as possible while maintaining these services.[10][17] These materials typically frame night work as a necessary trade‑off, encouraging self-care, mental health support and workplace wellness programs, and suggesting that with thoughtful scheduling, employer support and individual strategies, many workers can sustain night shifts without the extreme outcomes highlighted in the article.[14][17]
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