A good cup of tea is known to work miracles after a busy day, but new research suggests the drink may have saved lives in the 18th century.
Experts found that the rise in tea’s popularity was linked to a drop 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 the bacteria and parasites that caused deadly diseases such as dysentery.
Professor Francisca Antman, of the University of Colorado Boulder, said: “The nice thing about this environment is that it happened before we knew the importance of clean water.
“Evidence suggests that tea became affordable to almost everyone in England in the late 1780s, during the Industrial Revolution.
Tea is highly prized in Britain, where more than 100 million cups are consumed every day.
Samuel Johnson was an early proponent of the English cup and called himself “an inveterate and shameless tea drinker.”
‘Population density was increasing, cities were really growing, people were getting more and more crowded together. In reality, that should be a period where we see a large increase in mortality. But we ended up seeing this surprising decrease in mortality that can be explained by the introduction of tea and, more specifically, by boiling water.’
Renowned English writer Samuel Johnson was an early proponent of tea drinking.
Economics professor Francisca Antman studied data from more than 400 English parishes and analyzed mortality rates before and after tea became popular.
In 1757 he described himself as ‘an inveterate and shameless tea drinker…whose teapot barely has time to cool; who with tea entertains the afternoon, with tea consoles 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 analyzed data from more than 400 parishes in 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 running water sources or elevation.
She said: “In areas where it is expected that water quality should have been inherently worse, you see a greater decrease in mortality when the tea arrives.
‘It’s not that the water itself is pure or up to the drinking water standards we have today. “But what you see is that those areas that should have benefited the most benefit the most when they start boiling water for tea consumption.”
The researcher added that the large amount of historical data available in Great Britain allowed her study.
“Very few places in the world have data like this,” he said. “It wouldn’t have been possible without the monumental efforts of demographers and historians who went through parish records in England and basically built up these data sets that I was then able to analyze.”
In many developing countries, access to clean water remains a struggle.
Professor Antman said England’s obsession with tea is an example of how a simple behavioral change – boiling water before drinking it – can have profoundly positive effects.
“People changed their behavior, not because of outside influences or suggestions about healthy habits or drinking water, but simply because they wanted to drink tea,” he said.
‘It is a great example of how a population adopted healthy behavior without someone trying to change the culture or customs from the outside, but because they wanted to adopt the practice from within.
“It’s something we can consider and possibly try to emulate when considering future interventions aimed at improving overall health, including with respect to water.”