Shift work causes heart disease and cancer
Following this week’s news that a Scandinavian woman has been paid financial compensation after developing breast cancer following years of working night shifts, and with 20% of United Kingdom employees involved in shift work, we’re looking into the whole subject of shift rostering, staff rotas and their long-standing related link to increased risk of developing cardiovascular disease, high blood pressure and cancer.
Denmark is the first country to formally recognise the health risks of prolonged sleep deprivation due to shift work schedules, disturbed sleeping patterns, fatigue, and the eating problems caused by workers in many diverse industries having to work regular or interrupted shift work patterns. There have been approximately 40 successful claims related to work rosters to date.
Who is doing the research?
The research was carried out in 2007 and led by Dr Vincent Cogliano of the International Agency for Research on Cancer (IARC) – a French based United Nations organisation affiliated to the World Health Organisation. This organisation specialises in the study of cancer risks. The conclusions from their work that focussed on women such as nurses and air hostesses, showed that they face an elevated risk of breast cancer if they are involved in long term shift work and anti-social hours working arrangements.
The evidence was reinforced by animal studies showing that exposure to nocturnal light, or simulated jet lag substantially boosted the development of carcinogenic tumours.
Why does shift work cause health problems?
There is plenty of evidence going back many years that working during the night can cause a variety of health problems. There have been epidemiological studies – the study of factors affecting the health and illness of populations – conducted on people who suffer disruption of the normal body clock (or circadian rhythm) due to their working patterns.
The main factors influencing the development of these health issues are :-
- Sleep deprivation and sleep debt due to shift schedule
- Sleeping pattern disruption as a result of shiftwork
- Loss of synchronisation with natural light levels and light level transitions
- Eating and nutritional disorders associated with night work
- Exhaustion and fatigue, work related
- Number of years involved with shift pattern working
- Greater accident risk due to shift rota
The risk of night time working to human health has now been compared only marginally less than some well known carcinogens such as asbestos or chemical pollutants. A report published in the Journal of the National Cancer Institute, showed a 36% greater risk of breast cancer for women who had worked night shifts for more than 30 years, compared with women who had never worked nights.
The role of Melatonin in suppressing illness
Melatonin is a human hormone that is used to regulate the body’s internal clock. It has been shown to have beneficial effects in preventing the development of some types of cancer. It is believed that major alterations in sleep patterns in shift workers can suppress the production of melatonin in the body.
What you can do to reduce your risk
you don’t have to fall victim to this increasing occupational health risk. There are a number of short and longer term actions that you can pursue to reduce your risk of developing a dread disease such as heart disease or cancer, related to your current working pattern :-
- Talk to your employer about your health concerns – they may offer you an alternative working arrangement or shift pattern
- Ask your doctor’s advice about how to cope with the effects of shift working
- Have regular health checks especially if you have been working at night for many years
- Try to reduce the length of the night shift if possible – your employer may be able to offer more flexible rostering. 12 hour shift work is more problematic than an 8 hour shift
- Do not work nights for many years or decades as this increases the risk even further
- Consider planning to re-train, learn new skills, or applying for a different position within the company
What about shift work and Heart Disease?
Professor Andrew Watterson, an occupational health specialist based at Stirling University in Scotland, has recently been interviewed on the subject, and quoted “we [in the UK] are far behind Scandinavia in recognising the dangers [of shift working]. “I think we can say there is a big public health problem here,” he said. “The evidence has been good over a long period of time about cardiovascular disease and night work, gastro-intestinal problems and nights. “Work indicates there may be risks in terms of low birth-weight babies and longer pregnancies for women. “We don’t tend to identify the damage being done where shift working is prevalent and I think that’s an error. The damage is there but we don’t see it and we don’t count it.”