Too much time online 'damages immune system and makes users more likely to catch flu'. People with greater levels of internet addiction are also more likely to suffer stress.

Too much time online could damage your immune system and make you more likely to catch flu, research suggests.

People with greater levels of internet addiction are more susceptible to coughs and colds than those who spend less time online, according to the study.

The research was carried out by Swansea University 's College of Human and Health Science.

They surveyed 500 people, aged between 18 and 101, and discovered that those who go on the web too much have 30% more cold and flu symptoms than those who do not.

It also suggested that internet addicts may suffer stress when they are disconnected from the net and the cycle of "stress and relief" may lead to altered levels of cortisol - a hormone that impacts immune function.

Previous studies have shown that people who spend more time on the internet experience greater sleep deprivation, have worse eating habits and less healthy diets, engage in less exercise, and also tend to smoke and drink alcohol more.

The latest research was conducted by Professor Phil Reed and Rebecca Vile from Swansea University, Dr Lisa A Osborne from Abertawe Bro Morgannwg University Health Board, and Dr Michela Romano and Professor Roberto Truzoli from the University of Milan.

Prof Reed said: "We found that the impact of the internet on people's health was independent of a range of other factors, like depression, sleep deprivation and loneliness, which are associated with high levels of internet use and also with poor health.

"It may also be that those who spend a long time alone on the internet experience reduced immune function as a result of simply not having enough contact with others and their germs."

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