PEOPLE are living longer in the modern era because of healthcare and diet rather than the success in tackling childhood diseases such as whopping cough, smallpox and measles, scientists claim.

A new biological study by the Stirling University has found that exposure to infections in early life does not have long-lasting consequences for later-life survival and reproduction.

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Working with colleagues from the University of Turku in Finland, the Scots scientists said their findings debunked previous research which suggested diseases once common in childhood caused long-lasting inflammation, increasing the risk of cardiovascular disease in adulthood and early death.

It comes as a further new study of over a million people found at least one hour of physical activity per day, such as brisk walking or cycling for pleasure, may eliminate the increased risk of death associated with sitting daily for eight hours.

The authors of the report, published in the Lancet, warned there had been too little progress in tackling the global pandemic of physical inactivity since the 2012 Olympics, with a quarter of adults worldwide still failing to meet current recommendations on physical activity.

According to the Stirling research, there is nothing to support the idea that exposure to infections in early life can result in higher mortality risk during adulthood.

It said that experts had previously thought that since the introduction of vaccines and eradication of these diseases, children rarely get these illnesses anymore and do not experience long-lasting inflammation, and as a result, are living longer.

In the UK 150 years ago, a 20-year-old could be expected to live to age 60. Now days, a 20-year-old is expected to live to over 80.

However, there was no link between infections in childhood to early death from heart disease, stroke and cancer.

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Lead researcher, Adam Hayward, Impact Research Fellow at Stirling University, said: “Our analyses are significant because they show that early-life disease exposure was not linked to increased risk of death in later life. It was also not linked to risk of death specifically from heart disease, stroke and cancer and was not related to age at first birth, number of children born, or child survival rate in either men or women.

“Overall, we found no support for the idea that exposure to infections in early life can have long-lasting consequences for later-life survival and reproduction. Instead, it appears more likely that improved conditions during adulthood, such as healthcare and diet, are responsible for recent increases in adult lifespan.”

Meanwhile, the report in The Lancet claims physical inactivity costs the global economy over US$67.5 billion per year in health care costs and lost productivity

The four-paper Series, launched in London ahead of the Summer Olympic Games, warns a quarter of adults worldwide still failing to meet current recommendations on physical activity.

The research team wanted to see how many hours of daily physical activity would be required to eliminate the association between prolonged sitting time and increased risk of death.

They found that people who sat for eight hours a day but were physically active had a much lower risk of death compared with those who sat for fewer hours but were not physically active.

The greatest risk of death was for people who sat for long periods of time and were inactive.

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Lead author Professor Ulf Ekelund, of the Norwegian School of Sports Sciences, said: “For many people who commute to work and have office-based jobs, there is no way to escape sitting for prolonged periods of time. For these people in particular, we cannot stress enough the importance of getting exercise, whether it’s getting out for a walk at lunchtime, going for a run in the morning or cycling to work. An hour of physical activity per day is the ideal, but if this is unmanageable, then at least doing some exercise each day can help reduce the risk.”