Night shifts linked to poorer health, with age

Anyone who has ever had to work nights knows it can make you feel out of sorts, and now new US research suggests long-term shift work may interfere with healthy ageing, including chronic disease risk, cognitive and physical function and mental health.

The large cohort study of 46,318 women with a history of long-term rotating night shift work found, at a 24-year follow-up, an associated deterioration in overall health.

The researchers defined healthy ageing as survival to at least 70 years of age with health no major chronic diseases and no impairment in cognitive function, physical function or mental health.

They found 10 years or more of rotating night shift work was associated with 20 per cent decreased odds of healthy ageing.

Adding to the body of evidence

Previous studies have found associations with shift work and premature death and/or individual health conditions, including cardiovascular disease, diabetes, cancer and mental illness.

It’s unclear exactly why shift work is associated with health risks but, the researchers say, interference with circadian rhythms affects metabolic function and may contribute to insulin resistance and poor sleep quality or disorders. Stress, disturbed social patterns and overweight and obesity may also be factors, they say.

“Because an increasing proportion of the working population is involved in rotating night shift work, these findings further highlight the importance of understanding the association of night shift work with human health,” the study published in JAMA Network Open says.

Study limitations

The study was observational, so can’t prove cause and effect. Participants were all women and predominantly white, so further investigation into other genders and ethnicities is warranted.

5 ways to help make shift work healthier

Some of the trickiest aspects of shift work include getting good quality sleep, regular exercise and eating healthily. Here are five ways to help on all counts:

1. Practise sleep hygiene. This can be a bit harder, especially if you’re attempting to sleep in daylight hours, but using blackout blinds or curtains to keep your room dark and avoiding screen use before bed may help you sleep better. Keep your room cool and quiet, avoid vigorous exercise just before bed and limit caffeine and alcohol. Try to sleep in one block after a shift, rather than taking lots of little naps.
2. Before sleeping, try to limit your exposure to daylight. Wear sunglasses if you’re driving home from a shift in the morning. Once you have slept, try to spend some time outside to get a little sunlight.
3. Turn your phone to silent, so you’re not disturbed while sleeping. Get household members on board to try to not disturb your sleep.
4. Eat your substantial ‘main meal’ before your shift starts, and keep the meal you have before sleeping light. In a 24-hour period, try to have one breakfast-style meal, eg, eggs on wholegrain toast or oats/cereal; one light meal, such as a sandwich or vegetable soup; and one main meal, such as fish or chicken with sweet potato and a salad. One or two small snacks, such as fruit and yoghurt or nuts, should help keep you going.
5. Try to get some exercise in. It can be hard if your routine is all over the place but even doing a small home workout, once you’ve woken up, can help energise you and lift your mood. There are a variety of online workouts available.