In the 18th century, tea rose to prominence as a highly valued resource for the British Empire. However, it could have reduced death rates as an unforeseen consequence for the British population.
Some Bostonians 250 years ago this week saw tea as a symbol of repressive politics; in addition to being a worldwide commodity and a soothing drink, tea has been many things throughout its history. But a life-saving health intervention is one use of tea you may not have thought about.
Economist Francisca Antman of the University of Colorado, Boulder, argues persuasively in a recent Review of Statistics and Economics article that the widespread use of tea in late 17th-century England was a lifesaver. This couldn't have happened due to the antioxidants or any other properties found in the highly praised leaf.
Instead, many people may have lived longer because they simply boiled water for tea, back when it was known that water-borne germs may cause sickness.
Historians have long been perplexed by the English population statistics of this time.
The yearly mortality rate dropped significantly from 28 to 25 per 1,000 persons between 1761 and 1834. However, it seems that salaries have not grown much, and one might argue that standards of life have not improved either. More and more people were squeezing into cities with questionable sanitation as the industrial revolution gained momentum. The argument is far from over, according to Antman.
Because it is necessary to boil water in order to make the right kind of tea, historians have speculated that this may be the missing piece. Diseases causing diarrhea, such as dysentery, which was once known as "flux" or "bloody flux" in medical records, may be killed by boiling water.
"With people coming into cities to work, you would expect, given the level of sanitation they have, that the big killer is water," he adds. The concept, however intriguing in principle, remained imprecise and hard to demonstrate.
Antman devised a method to verify it by analyzing extensive geographical data pertaining to over 400 parishes in England. At its core, her analysis rests on a basic assumption: a location with more water sources would most likely have cleaner water. In the event that a parish's water supply became polluted, its residents can simply switch to another. Also, according to what Antman deduces from the elevation of the parishes, the water was probably safer closer to the rivers' origins than farther downstream.
Already, there were several reasons why tea should be the drink of choice for the general public.
By giving each parish an inferred water quality rating, Antman could compare the death rates in different places to see whether the one with worse water had a greater impact.
When it came out that tea was suddenly inexpensive for most Britons in 1785, that was the pivotal year in terms of verifying this claim. There were already numerous reasons why tea should be the drink of choice for the masses: a small quantity of leaves could be used to make a satisfying brew, the leaves could be reused for several pots, and tea could be less expensive than beer, which was expensive due to its complex process and a tax on malt.
However, tea consumption skyrocketed when the Tea and Windows Act of 1784 reduced the tax on tea from 119% to 12.5%. According to tea historian Alan Macfarlane, even the poorest peasants were enjoying two cups of tea daily by the late 18th century.
In order to determine if this shift was associated with a decline in mortality, Antman analyzed mortality rates before to and after this turning point. She did this by consulting the groundbreaking work of demographers R S Schofield and E A Wrigley, who collected parish data (including death records) from all throughout England from 1541 to 1871 in the middle of the twentieth century.
The mortality rate did fall in both the good and poor water parishes, as anticipated, but the magnitude of the drop was significantly different. Compared to parishes with excellent water, those with poor water had a greater 18% decline in mortality rates.
Additionally, she investigated the possibility that the amount of tea imported was associated with the number of fatalities in London caused by water-borne infections such as "bloody flux" and air-borne pathogens like TB, or "consumption". As a matter of fact, the number of flux fatalities decreased as tea imports increased, whereas tuberculosis deaths stayed about the same.
A person's preexisting habits may have a greater impact on their health than any external intervention could.
She also looked at whether the importation of tea had any effect on the mortality rate in London among children aged two to five, who are not known to be heavy tea drinkers at any age, and she discovered no such trend.
Is it healthier to drink tea or coffee?
Antman notes that there is no way to tell for sure, but it is intriguing that there was a small decrease in infant fatalities. This might be because parents who drank tea had less diarrheal sickness, which could have protected their early children to some extent.
According to Antman, who mostly focuses on poor country concerns, this old English natural experiment shows a basic truth: sometimes people's current habits might improve their health more than any external intervention could.
If these treatments had been widely known and accessible, they may have prolonged people's lives by, for example, increasing the number of privies, improving plumbing and sewage systems, and educating people to strictly segregate their drinking water and wastes.
People seem to have safeguarded themselves with minimal behavioral modification, opting instead to engage in more of what they loved. All of which contribute to the joy of enjoying a plain cup of tea.