WORKING nights can damage your long-term health, pioneering research by leading scientists has found.

A study by Surrey University’s Clinical Research Centre discovered daily rhythms of genes are disrupted when sleep patterns shift.

It revealed more than 97 per cent of rhythmic genes were out of sync if the body’s light-dark cycle was altered.

Disruption of the body clock indicated widespread disruption of the immune system and how the body works.

Previous studies have shown disrupting the body clock can raise the risk of heart attacks and strokes by more than 40 per cent and increase the risk of cancer and diabetes.

Firefighters, nurses, cleaners and security guards are among the thousands of nocturnal labourers tirelessly toiling through the small hours to keep Hampshire’s towns and cities running.

Some opt for these anti-social hours by choice, others out of necessity but they all find themselves at odds with regular day-to-day family and social life and can be prone to fatigue and insomnia.

Crew manager Craig Hawkes at St Mary’s fire station has worked night shifts for 15 years.

He works four-day stretches, with two 9am-6pm and two 6pm-9am shifts.

The 39-year-old, whose responsibilities include tackling fires and instructing colleagues, said: “It can be challenging – it takes it out of you at times.

“After the second night you feel really groggy and normally half of your first day is a bed day.

“When you are tired you are a lot more susceptible to illnesses such as flu.

“But I am used to it, I love the job and I can’t imagine doing anything else.”

Vicky Grace, 21, from Sholing is a bar worker in Café Parfait nightclub in Above Bar Street, Southampton, serving customers from 9pm to 5am four days a week.

The Southampton University graduate initially chose the job to fit in with her studies and now juggles it with working one day a week as a school teaching assistant.

She said: “I’ve never been a going to bed early person and I’ve loved a lie-in since I was young. When you get in from work it’s a bit hard to get back to sleep until about 7am because you are still buzzing. But even on nights I am not working, I normally go out.”

Physiologist Dr Felino Cagampang, a senior medicine lecturer at Southampton University, said altering sleep patterns alters the body’s cycles, making people more susceptible to diseases such as diabetes, obesity and cancer.

He said: “If you disrupt your natural rhythms the whole body is in chaos. It creates stress on the body and it makes you more vulnerable and lowers your immunity.”

He recommended night workers try to return to the normal night-time sleep pattern when they have time off.