Like how humans keep track of time, the body also has a way of tracking time. A human being’s body works on an internal clock, also known as the circadian clock, which follows the circadian rhythm (CR), the sleep-wake pattern that repeats every 24 hours. Night shifts can throw off the rhythm of the body’s internal clock. According to a study published in the BMJ Open in 2021, around 71 per cent of night shift workers have poor sleep quality compared to 50 per cent of day shift workers.
“Sleep is part of the triad of wellness (along with exercise and nutrition). Working the night shift takes a big toll because being up at night and sleeping during the day is contrary to human biology. It disrupts the body’s circadian rhythms or 24-hour internal clock that controls sleep-wake cycles,” says Dr Sheetal Chaurasia, consultant, pulmonary medicine, Manipal hospitals, Bengaluru.
How does working at night change the sleep cycle?
The body’s internal clock (circadian clock) uses circadian rhythm to signal when it is time to wake up or sleep. The more consistent and conventional it is, the better sleep one gets.
There are external factors that determine the circadian rhythm. Stimuli, for instance, light in the environment, can significantly impact the circadian clock. The circadian rhythms must be appropriately aligned, and the circadian clock must not be disturbed to promote restorative and consistent sleep.
Those who stay up during the night must fight their body’s natural clock to be awake.
Effects of working night shift on the body
According to a research paper, ‘New Insights into the Circadian Rhythm and Its Related Diseases,’ shift workers and people with jet lag face a disruption of the circadian rhythm. It can lead to cognitive impairment, metabolic syndrome and psychiatric illness. It can also cause sleep problems like insomnia.
Speaking to Happiest Health, Dr Shivani Swami, consultant, pulmonology and sleep Medicine, Narayana Multi-speciality hospital, Jaipur, says, “night shifts are harmful to the body because it disturbs the hormonal balance when we don’t sleep at night and sleep during the day. Also, the quality of sleep is not the same during the night.”
According to Dr Chaurasia, some of the health effects faced by night shift workers are increased stress responsivity, somatic pain, reduced quality of life, emotional distress, mood disorders, and cognitive, memory and performance deficits. “Long-term consequences of sleep disruption in otherwise healthy individuals include hypertension, dyslipidaemia, cardiovascular disease, weight-related issues, metabolic syndrome, diabetes and colorectal cancer. All-cause mortality also increases in men with sleep disturbances,” she points out.
Following sleep hygiene
Experts say there are ways to deal with a disrupted circadian rhythm.
Take a nap
It is good to nap before reporting for a night shift. Well-timed naps can help increase the general alertness of the mind and body. “Keep the room dark, quiet and at a comfortable temperature when sleeping,” says Dr Swami.
Experts suggest sticking to a balanced, low-fat diet with plenty of fruits, vegetables and cereals. They also advise staying away from fast food and sugary food.
It is also important to eat meals at the right time. “Many shift workers eat poorly and at odd times. Try to eat three regular meals spaced evenly throughout the day. Regular mealtimes are important for your body,” says Dr Chaurasia.
“Do not eat your largest meal of the day within three hours of bedtime. You should also avoid drinking alcohol within three hours of bedtime,” she adds.
Have a routine
“Night shift workers should try to have a sleep schedule. This means that you do not change your sleep time,” says Dr Chaurasia. This will align the body clock and the sleep pattern.
Though people rely on coffee to stay awake during night shifts, experts advise against it. “Having tea, coffee, alcohol and exercising late evenings interfere with your sleep quality,” says Dr Swami.
Follow good sleep hygiene
Artificial bright light can affect the body clock the same way sunlight does. Use eye masks and opaque curtains to ensure light is not affecting your daytime sleep.
Dr Swami says to get restorative sleep, one must stay away from using electronic devices before going to bed.