Health Implications of Working Night Shifts

Urban residents have grown accustomed to the 24/7 functioning of their surroundings. Previously, only pharmacies employed workers during the night shift, but presently, night-time sports clubs, libraries, and cinemas are accessible, resulting in an increase in the number of individuals working at night. This schedule has the potential to cause heart disease, depression, and weight gain, and adapting to the night shift can be challenging for both “larks” and “owls.” In this article, we will explore the reasons behind these health issues and suggest ways to cope with night shift work.

Who works at night?

Lawmakers in different countries have varying interpretations of the term “nighttime.” For instance, in the United States, nighttime refers to the period between 23:00 and 07:00. According to estimates from the International Labor Organization in the late 1980s, 7 to 15% of industrialized countries’ workers were engaged in night shifts. Currently, many countries face a similar situation. In 2018, the British Trade Union Congress calculated that 11.5% of British workers were working in night shifts.

However, this figure only takes into account those officially scheduled to work at night. It does not account for those who occasionally work night shifts. The actual number of individuals working night shifts may be significantly higher.

A recent study by researchers at the Higher School of Economics revealed that approximately 60% of Russian employees work on non-traditional schedules, including evenings, nights, and weekends.

Around half of the participants in the survey reported working in the evening or at night several times per month, while a quarter worked weekly or every night. The survey’s data was collected from 27 mostly European countries, where a significant portion of residents have to work non-standard hours. Croatians and Greeks had the highest proportion of such workers (about 70%), with Russia ranking fourth on the list.

However, it is unclear to what extent these numbers reflect night work. While some respondents may work only in the evenings and sleep at night, the survey only considered their primary place of employment. Furthermore, since many people work part-time after their regular work hours, the actual number of individuals working non-standard hours could be even higher.

For those who have worked night shifts, the experience can be challenging, with constant fatigue, excessive caffeine consumption, and a disconnect from loved ones on a daytime schedule. However, some argue that the night shift offers a more peaceful work environment and higher pay due to Russian labor laws mandating additional pay for working during the night. It is crucial to recognize that individuals’ bodies may respond differently to staying up at night, with some feeling drained and others invigorated.

How safe is working at night?

While not everyone enjoys working at night, it can pose genuine health risks. Research indicates that night shifts increase the likelihood of developing heart and vascular diseases, type 2 diabetes, weight gain, and obesity. Although night work does not inherently cause these conditions, it does act as an additional risk factor.

The primary culprits for health issues among night workers are sleep deprivation and disrupted circadian rhythms. Sleep is vital for the body to recuperate and eliminate waste generated during the day’s metabolic processes. Insufficient sleep can lead to various adverse effects, from irritability and headaches to obesity and hypertension.

Unfortunately, not all night workers can recover during the day. Many suffer from insomnia, and even those who avoid it may not receive adequate rest.

Working a night shift can create challenges for individuals, as many activities can only be completed during regular business hours, such as visiting institutions open from 9 to 6 on weekdays or communicating with loved ones on a five-day schedule during weekends.

Disruptions to the “internal clock” can also lead to problems. Our body systems work harmoniously and accurately thanks to a multitude of processes, and one of them is circadian rhythms. These rhythms cause fluctuations in the intensity of various bodily functions throughout the day due to the shift from day to night. For example, body temperature, arterial pressure, and hormone levels fluctuate underwater. When we wake up, our body has already adjusted all the necessary parameters for an active day, and in the evening, it prepares for sleep carefully and for a long time. These rhythms are regulated by special “clock” genes, which are responsible for producing the necessary proteins. One of these genes, called CLOCK (Circadian Locomotor Output Cycles Kaput), has been named by researchers.

In order to maintain a regular circadian rhythm, our internal clocks rely not only on their own bodily mechanisms, but also on external cues. Various natural phenomena can act as these cues, such as the daily oscillations in reptilian organisms that are sensitive to changes in air temperature. For humans, sunlight serves as the primary cue. Our photoreceptors transmit signals about the level of illumination to the “control center” of the hypothalamus, specifically the suprachiasmatic nucleus. Depending on the brightness of the surrounding environment, the neurons in this region of the hypothalamus send out signals that initiate the necessary processes at that particular time of day.

However, this delicate system can be disrupted when the normal light-dark cycle is disturbed. If this is the only issue, such as when traveling to a different hemisphere of the earth, a person may experience the unpleasant effects of jet lag, but fatigue and headaches will eventually subside as the body adjusts. However, when one is constantly shifting between day and night, adaptation becomes more challenging.

“Fight or flight”: Why disrupting circadian rhythms is harmful

According to sleep expert Russell Foster from Oxford, the main challenge of a nighttime schedule is not the long hours of work in the dark but the morning light that nocturnal workers see when preparing to rest. As per Foster, when a person is getting ready to sleep, their photoreceptors transmit signals to the suprachiasmatic nucleus to “wake up”. If this deception of the circadian rhythm continues for an extended period, stress levels may rise, leading to a “fight or flight” response that typically aids in escaping a potential danger. In this condition, the body prepares for increased activity by quickly releasing glucose into the bloodstream to provide energy to the muscles for attack or escape, elevating blood pressure, and increasing heart rate.

Remaining in a constant state of heightened alertness through the “fight or flight” response can be beneficial in times of real danger, but it is unsustainable for prolonged periods as it takes a toll on the body. When a person is sleep-deprived, their body’s ability to recover and recharge is further reduced.

Living in a state of prolonged disruption to one’s circadian rhythm, along with the associated high levels of stress, increases the risk of developing various diseases. Other factors that contribute to this risk include age, overeating, sedentary lifestyle, and harmful habits. These factors further increase the risk of cardiovascular diseases, which are already exacerbated by working night shifts. Lack of sleep also disrupts the balance of the hunger and satiety hormones leptin and ghrelin, which can lead to weight gain, another risk factor for many diseases.

Professor Foster believes that the rotating shift schedule and sleep deprivation are the primary concerns, not night work itself. He argues that working at night is not harmful if it is consistent and the individual avoids exposure to bright light in the morning.

How does night activity affect mental health?

Night work and sleep deprivation can have a negative impact on mental health. Various studies have found a link between night shifts and an increased risk of depression. For instance, a survey conducted by Korean researchers in 2017 on over 14,000 employees of an electronics manufacturing company revealed that night workers were more prone to experiencing symptoms of depression and suicidal thoughts. The risk of depression was notably higher in those who suffered from insomnia.

Similarly, researchers in Taiwan reached similar conclusions after analyzing survey data from over 16,000 local workers. The study found that individuals who worked at night slept less than those with a regular daytime schedule, and they reported insomnia more frequently. Additionally, these night workers displayed symptoms of emotional exhaustion and psychiatric disorders such as moderately severe depression and anxiety.

According to the study’s authors, sleep deprivation is considered as the primary reason for the mental health problems that emerge from working at night.

It is intriguing to note that certain psychiatrists utilize sleep deprivation, wherein they intentionally deprive patients of sleep for a day or more, to alleviate the symptoms of depression and bipolar disorder, and the outcomes appear to be promising. This suggests that disturbances in the circadian rhythms are closely linked to the processes that contribute to the development of these disorders. Nevertheless, this technique is still experimental, and doctors researching it stress that it should never be attempted independently since little is known about how it operates.

But what about “night owls”?

Night work may not be suitable for everyone, but what about those who actually enjoy it? This often pertains to “night owls” – individuals who struggle to wake up early but are more active in the evening and at night. “Night owls” are not lazy; studies show that they find it more difficult to wake up early than “larks” and “pigeons,” who represent the morning and intermediate chronotypes. The biological clocks of “night owls” are delayed compared to other “birds,” as certain hormones in their body reach daily peaks several hours later.

Most researchers agree that attempting to retrain “night owls” is futile.

By trying to conform to societal norms and waking up early, individuals with an evening chronotype risk experiencing “social jetlag” – a disruption of the balance between their internal clock and the standard schedule.

According to research, “social jetlag” is a common issue experienced by individuals with an evening chronotype. This can lead to significant differences between their weekday and weekend schedules, causing stress to the body. Sleep researcher Russell Foster has warned about the harmful consequences of such swings.

Despite this, for some “night owls,” working during the evening or at night may be a more suitable option than a standard schedule. To minimize the negative impact of this lifestyle, it is recommended to prioritize sufficient sleep, establish a consistent routine, and avoid exposure to sunlight in the morning to facilitate proper rest.

Surviving in the world of “night owls”: instructions for “morning larks”

Congratulations to those who have found a job with a convenient schedule that suits their night owl tendencies. However, what about those who are forced to work at night despite their dislike for it? In such cases, experts recommend taking several important steps.

Quality sleep

Ensure that nothing disrupts your sleep after working at night. It’s best to establish a consistent sleep schedule and go to bed around the same time each morning. Plan for a full, uninterrupted sleep session, preferably lasting 7-9 hours. Avoid postponing sleep, as it can lead to insomnia and ruin your much-needed rest. It’s best to sleep in a dark and quiet environment, and you can use earplugs, sleep masks, and blackout curtains to achieve this. Before going to bed, eat something to avoid feeling hungry, but avoid consuming alcohol. Although alcohol can help you relax, it interferes with your natural sleep cycle, preventing your body from fully recovering.

As for power naps, which are brief naps lasting about 30 minutes, there’s uncertainty about whether they can boost alertness during the night. Some studies have suggested that napping can increase alertness, but many of these studies were conducted during the day, and there isn’t a clear consensus among scientists.

Balance of light and darkness

Bright light is known to help people wake up, which is why waking up early in the summer is often easier than in the winter. The same principle can be applied to working at night. It is important to assess the amount of light in your work environment and add additional sources of light, such as a desk lamp, if necessary.

When it’s time to finish work, it is essential to do the opposite. Avoid excessive exposure to light, especially before going to bed. If you work from home, it’s best to avoid staring at bright screens before sleeping and instead go straight to bed. If your commute home involves walking on sunny streets, wearing dark glasses can help. Researchers in Korea conducted an experiment with nurses working night shifts and found that wearing dark glasses on the way home helped improve their sleep quality during the day and maintain their alertness during night shifts. Conversely, when the same women returned from their night shift without dark glasses, their sleep was less restful and shorter.

Healthy eating

The guidelines for healthy eating at night are similar to those for daytime. It is important to have a diverse range of food items, including sources of lean dietary proteins such as fish, poultry, legumes, and nuts, as well as a good amount of fruits and vegetables. It is advisable to limit the intake of red meat, fried and fast foods. Ideally, one should consume small and frequent meals if the work schedule permits. Overeating due to hunger pangs can lead to sluggishness and lethargy.

Coffee – but with caution

Night work is often associated with drinking strong coffee to stay awake. However, it’s important not to overdo it, as excessive caffeine intake can lead to side effects such as increased heart rate, headaches, anxiety, and tremors. According to a study conducted by Harvard scientists, the same “little but often” rule that applies to food intake also applies to coffee. Small doses of caffeine were found to help participants stay alert and perform memory and reaction speed tasks efficiently. It’s best to consume coffee or tea during the first half of the night to avoid disrupting sleep after work due to their stimulating effects.

Self-care

When working at night, it’s crucial to regularly assess your comfort level with the schedule. Take note of how it impacts your mood and well-being, and monitor any changes over time. For instance, evaluate how you feel after starting night work and compare it to your condition after a few months.

It’s equally important to consider your overall lifestyle, including your diet and exercise habits. Regular medical check-ups can also be beneficial. If you find that night work is negatively affecting you and things are only getting worse, it may be time to consider a different schedule.

Encouraging a “morning person” to work diligently at night is as challenging as persuading a committed “night owl” to work standard hours.

What measures can an employer take to support their staff? According to Russell Foster, employers should prioritize offering night workers the option to receive periodic medical check-ups and access to medical attention if required. This will help detect any alarming changes in their health earlier. Providing nutritious, healthy food or ensuring comfortable snacking conditions are also beneficial solutions for supporting night workers.