Medieval monks had a relatively peaceful life, at least compared to other folks of their time. They lived within friaries or other monastic complexes, studied religion, and tended to their garden and picturesque lifestyle. But at least in one regard, they were way worse off than the general population: parasites. According to a new study, medieval monks were riddled with parasites and it’s not exactly clear why.

Hygiene luxury

Modern-day archaeology is less about finding ruins and more about understanding people’s lifestyles. To understand people’s lifestyles, researchers often look for clues in graves and burial centers. But the problem is, only the rich and powerful were buried separately — in medieval times, regular folks were buried in a communal parish cemetery, naked and only wrapped in a shroud, giving very few clues to work with. Without any tomb, any clothes, and any indication of what life they lived, this leaves archaeologists little to go on.

But monks are different. Monks and nuns were typically buried in separate cemeteries, which allows archaeologists to carry out a comparative study and see what differences they can find between monks and the general population. The new study focused on 44 people (19 monks from the friary grounds and 25 locals) from medieval Cambridge, UK.

The Augustinian friary was an international study house — or a studium generale as it was known, where clergy not only from Britain but also from Europe could come to read manuscripts (although most would obviously be British). The friary was founded in the late 1200s and lasted until 1538 — like most English monasteries, it was closed when Henry VIII broke with the Catholic church.

There was an extra bonus challenge in the study: some rich people from the nearby community paid extra money to be buried alongside the monks (presumably because they saw it as a better chance to get into heaven), so in order to truly have a good comparison, the researchers had to separate these wealthy outsiders buried alongside the monks. The important clue here came from their belts. Many of the friary burials had belt buckles in front of their pelvis; the friars had been buried with their habits and belts, while the general population was buried nude.

“The friars were buried wearing the belts they wore as standard clothing of the order, and we could see the metal buckles at excavation,” said co-author Craig Cessford of the Cambridge Archaeological Unit.

Now that the archaeologists knew who the friars were, they could compare them to the general population.

A poop problem

It’s not the first study of this type. Previous research has shown that monks had a longer average lifespan and a better diet than the general population (although the monks’ diet was also far from ideal). But when researchers looked at parasites, they found that 58% of Augustinian friars were infected with roundworm or whipworm, compared to only 32% from the parish cemetery. So what gives?

Friars enjoyed a higher general standard of life than the general population. They had purpose-built latrines and hand-washing facilities, which was a rare luxury at the time.

“It is striking that the friars had nearly double the infection rate of parasites spread by poor hygiene,” the researchers comment in the study.

Researchers aren’t exactly sure why this disparity exists. An explanation could be fertilizers — monks took good care of their gardens, but at the time, taking good care included some practices that seem rather questionable now. For instance, they would fertilize their gardens with feces, but this also includes human poop that would presumably be taken from the latrines. This would create a cycle where if they had parasites, they would be passed on through poop, and then reach the garden and reinfect the friars.

So even though they had a good idea with the latrines and the washing of hands, they didn’t go all the way with dealing with their human waste. In fact, although people were aware of these parasites, their understanding of the link between poop and parasites at the time wasn’t exactly spot on.

“Medical texts available in medieval Cambridge show that doctors of the time were aware of intestinal worms of different shapes and sizes, and knew of medicines that they felt were helpful in treatment,” the researchers note in the study.

John Stockton, a medical practitioner from Cambridge, wrote a manuscript aptly called De Lumbricis (‘on worms’) in which he names ‘phlegm’ as the cause of worms:

“Long roundworms form from an excess of salt phlegm, short round worms from sour phlegm, while short and broad worms came from natural or sweet phlegm,” Stockton wrote.

However, Stockton prescribes “bitter medicinal plants” such as aloe and wormwood, which isn’t really a bad idea as wormwood has been shown to be effective against some parasites. Another text (Tabula medicine), which became popular with leading Cambridge doctors of the 15^th century, suggests remedies recommended by Franciscan monks, including a powder made from moles into a curative drink.

The study was published in the International Journal of Paleopathology.