Aside from being up to the task of drying our dishes, we don’t usually give the humble tea towel much thought. But this week it’s being blamed for causing food poisoning:
But there’s no cause for concern.
Yes, bacteria can accumulate on tea towels, especially when they’re infrequently washed and don’t dry out between use. But most of the bacteria the researchers found on tea towels are not responsible for food poisoning or other gastrointestinal symptoms.
While the media reports focused on the food poisoning risk, the research didn’t actually look at the participants’ gastrointestinal health.
How was the research conducted?
The story came about from a June 9 poster presentation to the American Society of Microbiology’s 2018 meeting in Atlanta, based on research carried out at the University of Mauritius.
The Mauritian researchers purchased 100 tea towels to give to the study participants; 36 were a mixture of cotton and nylon, 33 were pure nylon, and 31 were pure cotton.
After one month of use, the towels were collected to “culture” any bacteria present on them. This means taking bacterial samples and letting them grow in a petri dish to determine the type of organism.
The participants also completed a questionnaire about their tea towel use, diet and family size.
The research did not look at whether the participants had food poisoning or other gastrointestinal illnesses.
What were the results?
Bacterial growth was found in 49% of the kitchen towels. Cotton towels had higher levels of bacteria than nylon towels or a mixture of the two.
Bacterial growth increased significantly with increased family size and the presence of children.
Tea towels which were considered “multipurpose” – such as for cleaning table and bench tops in addition to the kitchen – had higher levels of bacteria than towels that were “single purpose”, such as drying hands and dishes in the kitchen.
The researchers found “humid” (or moist) towels had significantly greater concentrations of certain types of bacteria, such as coliforms. Coliforms are a broad class of bacteria found in the digestive tract of animals including humans, and are found in their faeces. Although most coliforms are harmless, some rare strains can cause serious illness.