When disgust helps avoid infection

Does the idea of eating something like balut (foetal duck in the egg) gross you out? Listen to your gut, it might be saving you from an infection. — Filepic

Eww, gross! There’s no need to feel there’s something wrong with you if you recoil when foodie friends talk about the interesting and exotic delicacies they’ve tried, such as still-beating cobra hearts, soft-boiled foetal duck, or even the more banal chocolate-covered crickets.

And you don’t need to change – in fact, these reactions could keep you healthy.

Disgust, it turns out, is good for you, according to a new study published on Feb 20 (2021) in the journal Proceedings of the National Academy of Sciences that suggests revulsion could be the body’s way of avoiding infection.

The idea is not new: Charles Darwin hypothesised that humans evolved a sense of disgust to help avoid tainted food.

But this is the first study to have directly tested whether greater pathogen disgust sensitivity is associated with fewer current infections, according to a Washington State University (WSU) write-up on the study.

Aaron D. Blackwell, an associate professor of anthropology at WSU in the United States and co-author of the study, said participants from three indigenous Ecuadorian Shuar communities were asked to rate their level of disgust on things like touching a dead animal, stepping in animal droppings or drinking a fermented corn drink called chicha – made in this instance by someone with rotten teeth chewing the corn and spitting it into water to let it ferment.

“The higher the level of disgust, the lower the level of their inflammatory biomarkers indicative of infections,” he said.

“While the study shows that disgust functions to protect against infection, it also showed it varies across different environments, based on how easily people can avoid certain things.”

Assoc Prof Blackwell, along with a research team led by Tara Cepon-Robins from the University of Colorado, Colorado Springs, also found that levels of disgust went up when people had access to fresh water and purchased food, and could afford to avoid disgusting things.

But in communities that relied more heavily on subsistence activities like hunting and small-scale agriculture, there were lower levels of disgust.

Assoc Prof Blackwell pointed out in an interview that the findings do not have bearing on every pathogen or pandemic, including the SARS-CoV-2 virus, which causes illness before symptoms appear.

“Disgust doesn’t protect us very well against pandemics like Covid-19, in part because there isn’t something you can see to avoid.”

Nevertheless, avoiding things that disgust you seems like a good overall bet. – By Christine Clarridge/The Seattle Times/Tribune News Service