One in five workers runs on a disrupted body clock. The rest of us rarely think about what that costs

💡 The Long View is EnterpriseAM Weekend’s monthly space for the essay — a take on something worth sitting with. Not news, not a how-to. Just a question the week left behind, examined. This week: the night shift.

The night-time economy has long operated behind the scenes in busy capitals and cities, keeping businesses running 24/7 and the infrastructure of everyday life supplied, staffed, and supported. But it comes at a cost: completely flipping the way our bodies naturally function. Whether driven by the nature of their jobs, higher pay, or the freedom to have their days to themselves, night-shift workers are effectively working against their body’s natural rhythm — and inevitably bearing the health costs of doing so.

If you’re reading this on a Friday morning, you are, in all likelihood, among the direct beneficiaries of that arrangement — and rarely have to think about what it costs.

Worldwide, one in five workers, or some 20%, work night shifts. Industries providing essential services — including transportation, healthcare, manufacturing, and social services — often require round-the-clock operations. In Egypt alone, tens of thousands of BPO and call center workers run through the night to serve European and American clients — a number growing at 15-17% a year as more multinationals route their 24/7 operations here.

While the economy may run around the clock, the human body unfortunately can’t.

Fighting against nature

The most obvious concern with night-shift work is sleep — one of the biggest pillars of good health. While working nights doesn’t necessarily mean getting less sleep, it can mean sleeping at the wrong time and getting poor-quality rest. Sleep is governed by our body’s inherent circadian rhythm, which is closely tied to the rising and setting of the sun and regulates our bodily processes according to the natural light-dark cycle. Once you flip your waking and sleeping hours, your sleep system can become severely disrupted — interfering with critical restorative biological processes that take place during sleep.

The brain, above all, needs sleep. During sleep, it processes the day’s memories and emotions, solves problems that troubled it during waking hours, and supports the body’s immune defenses and muscle repair. In short, sleep helps the brain clean itself out through a process of plumbing in the glymphatic system that washes away waste it has accumulated while awake.

So, what happens when this drainage system is impaired? Over time, disrupted sleep may increase the risk of dementia. A Swedish study by the Karolinska Institute, which followed more than 13k shift workers for up to 41 years, found that working shifts in midlife was associated with a 36% higher risk of dementia — though the researchers noted this represents a statistical association rather than a proven causal link.

The risk increased among workers who remained in shift-based jobs for more years. If carried on for years, sleep-disrupted night shifts can also contribute to raised levels of amyloid, a protein in the brain associated with Alzheimer’s disease. For some workers, this can develop into what is known as shift-work sleep disorder (SWSD) — a circadian rhythm sleep disorder that affects people who work non-traditional sleep hours. People with SWSD may struggle to fall asleep (insomnia) or experience excessive sleepiness while awake (hypersomnia). Other symptoms can include difficulty concentrating, lack of energy, headaches, and irritability.

The cost of too little sleep

The effects go deeper than that. The World Health Organization’s International Agency for Research on Cancer (IARC) classifies night shift work as “probably carcinogenic to humans.” Night shift workers are more likely to be overweight and have higher BMIs and waist circumferences, according to Worldwide Cancer Research. Night shift workers, particularly those with a genetic predisposition, may also face higher risks of diabetes, cardiovascular disease, metabolic syndrome, and cancer. Cortisol levels, in particular, are strongly influenced by the circadian rhythm, with levels typically peaking in the morning. A disrupted cortisol rhythm, in turn, can contribute to metabolic problems and increase the risk of obesity and type 2 diabetes.

It can’t take a toll on the body without affecting the mind, too. Psychologically, night shift work is associated with a 28% higher risk of depression and anxiety disorders, according to research in the Journal of Affective Disorders. Working during the hours when most of the population is asleep inevitably leads to social asynchronicity, making it harder to participate in social occasions and maintain relationships when your sleep and work schedules are out of sync.

Working with the body, not against it

There are ways to mitigate some of these effects, though none fully reverse them. Night-shift workers may find some relief in biphasic sleep — a pattern that predates the industrial age and was reportedly common in the West until the mid-19th century. Researchers at Norway’s National Institute of Occupational Health found that shift workers living in the Arctic Circle, where the sun barely sets, often split their sleep into two distinct blocks — one a few hours before noon and another before their shift begins. Evidence on how much this improves health and performance is still emerging, but the pattern offers a useful reframing: the idea of one long, unbroken sleep is itself a relatively recent invention, one the industrial economy imposed on human biology without asking whether it fits.

Other studies suggest that napping during or after a shift reduces sleepiness and improves alertness. Working fewer consecutive night shifts may also reduce some of the associated health risks. Controlling light exposure, sticking to a consistent sleep schedule — even on days off — and limiting caffeine to the early part of a shift are all practical levers. But the deeper point is structural: the 24/7 economy was built around what the market needed, not what the body can sustain. The people running it through the night are paying a price that rarely appears on any balance sheet.