It’s official, tea IS a life-saver: Experts say rise of the traditional cuppa in the 1700s killed off bugs in dirty water and reduced dysentery deaths

A nice cup of tea is known to work wonders after a busy day, but new research suggests the drink may have saved lives in the 18th century.

Experts found that the rise in popularity of tea was linked to a decline in deaths across England during the Industrial Revolution, when sanitation was poor.

They believe this is because boiling water to make a cup of tea killed bacteria and parasites that caused fatal diseases such as dysentery.

Professor Francisca Antman of the University of Colorado Boulder said: ‘The nice thing about this situation is that it happened before we realized the importance of clean water.

‘The evidence suggests that tea became affordable to almost everyone in England in the late 1980s, during the Industrial Revolution.

Samuel Johnson was one of the early proponents of the English cuppa and called himself ‘a hardened and shameless tea drinker’

‘Population density increased, cities really grew, people became more and more densely packed together. That should actually be a period in which we see much increasing mortality. But ultimately we see this surprising decline in mortality, which can be explained by the introduction of tea and, more specifically, by boiling water.”

The famous English writer Samuel Johnson was one of the first proponents of drinking tea.

Economics professor Francisca Antman studied data from more than 400 English parishes and looked at death rates before and after tea became popular

In 1757 he described himself as ‘a hardy and shameless tea-drinker… whose kettle has scarcely time to cool; who with tea amuses the evening, with tea comforts the midnight, and with tea welcomes the morning.”

Dysentery, a serious gastrointestinal disease, caused many deaths in the 18th century, when it was known as ‘bloody flux’. In some parts of Europe, 90 percent of all deaths were due to dysentery during the worst outbreaks.

Professor Antman looked at data from more than 400 parishes across England and looked at death rates before and after tea became popular and affordable.

The analysis compared areas based on water quality, which had to be inferred based on geographic characteristics such as the number of flowing water sources or elevation.

She said: ‘In areas where you expect the water quality should have been inherently worse, you see a bigger drop in mortality when tea comes.

‘It is not that the water itself is pure or meets the standards for drinking water that we have today. But what you see is that the areas that should have benefited more are also benefiting more now that they are starting to boil water for tea consumption.”

The researcher added that the vast amount of historical data available in Britain made her research possible.

“There are very few places in the world that have this kind of data,” she said. ‘This would not have been possible without the enormous efforts of demographers and historians who have gone through the parish registers in England and in fact put together these data sets that I have then been able to analyze.’

In many developing countries, access to clean water is still a struggle.

Professor Antman said the English tea obsession is an example of how a simple behavioral change – boiling water before drinking it – can have profound positive effects.

“People changed their behavior not because of outside influences or suggestions about healthy habits or clean water, but simply because they wanted to drink tea,” she said.

‘It’s a great example of how a population adopted healthy behavior without anyone from outside trying to change culture or habits, but because they wanted to adopt the practice from within.

‘It’s something we can look at and potentially try to emulate when considering future interventions aimed at improving health in general, including in relation to water.’