In a report prepared for the Health And Safety Executive, a UK government body looking after the health and safety interests of the employees, researchers had found out that working in shifts can be damaging to one's health.
When people work during nights, the levels of melatonin, or the sleep hormone, which is secreted during nights, do not coincide with the new sleep routines. As a result, people do not get the sleep they require during the day. Such workers remain fatigued and less attentive during the night shift. This may increase safety hazards and many more health consequences. Moreover, at such routines, body secretes more fatty acids in the blood after the meals. This may increase the rate of incidence of a heart attack. The risk of diabetes also is more under such circumstances.
The researchers suggest that one way to get some healthy benefit out of the situation is to avoid frequent change of shifts to allow the body clock to settle down. However the scientists also feel that there may not be a blanket solution for all, and the results will vary with the state of health of the workers concerned.
Reference: New Scientist, issue 23 April 2005