The Unexpected Ingredient That Might Be In Your Tea

In addition to being aromatic, relaxing, and great-tasting, tea can offer a number of valuable health benefits. Made either from the leaves of the Camellia sinensis plant or dried blends of spices, herbs, flowers, or other plant roots or leaves, tea "is the most popular beverage in the world after water," according to the Harvard School of Public Health, and you are likely to enjoy its health benefits no matter which type of tea you enjoy. Green tea has long been lauded for its high antioxidant content and significant health benefits. Studies have shown that regularly drinking green tea can help boost heart and brain health, reduce the risk of certain cancers, aid in weight loss, and even help you live longer, according to Healthline.

But green tea isn't the only star of the show. Herbal teas like chamomile and ginger have been shown to help reduce stress, improve sleep, aid in digestion, and help with pain management, while white tea can help fight cancer and even strengthen teeth, according to Penn Medicine. Even highly caffeinated teas like black tea and Earl Grey contain flavonoids that reduce inflammation and help boost the immune system. However, it turns out there is one other big thing that different kinds of tea all have in common, and it is not quite as appealing as the myriad health benefits.

A 2022 study, published by researchers from Trier University in Germany and the Max Planck Institute for Evolutionary Biology in Biology Letters, has shown that traces of bug DNA has been found in samples of store-bought tea — and it's not limited to just one type or brand of tea. As unpleasant as it may sound, bug traces are accepted as an inevitable fact in many foods. It is so common that the FDA even has a standard for allowable quantities of insect parts in certain foods, such as 10 whole insects per 8-ounce box of raisins or 40 insect fragments (and maybe a little rodent hair) in a single teaspoon of black pepper — quantities which they deem to cause no ill health effects in humans, according to CNN Health.

Goods that are more processed, such as coffee, tend to only have small amounts of bug DNA traces in the final product. But this study showed that teas, which are natural and significantly less processed than other items, retain substantial traces of bug DNA by the time you pick up a box of your favorite flavor at the store. The study revealed a shocking 1,200 different species of bug traces across 40 different samples of tea, Food and Wine reported.

The researchers set originally out to study the hidden interactions between plants and animals. In particular, they wanted to examine how arthropods leave behind tiny remnants of DNA in dried plant material through a process called environmental DNA, or eDNA, analysis. To do so, they analyzed different versions and brands of four different dried herbs and plants — chamomile, mint, tea, and parsley — across four different continents. "I basically just went to a couple of different grocery stores and bought a whole bunch of different types of tea they had," Henrik Krehenwinkel, an ecological geneticist at Trier University and lead researcher in the study, explained to Smithsonian Magazine.

The study found specifically that the DNA of arthropods (otherwise known as creepy-crawly invertebrates with hard exoskeletons like spiders, mites, and centipedes) shows up in tea leaves. The researchers reported that "dried plant material is a highly promising source for arthropod community eDNA," per Biology Letters; because dried herbs and tea are not heavily chemically processed, traces of the arthropod DNA remain in greater quantities and allow scientists to study certain ecological relationships more deeply.

However, the presence of this DNA may not be as gross as you might think at first. "Probably 99.999 ... percent of the DNA we extract is plant DNA, and only a tiny fraction, which is left, is the insect DNA," Krehenwinkel explained. Krehenwinkel added that the presence of the bug DNA might actually be a good thing, since it indicates a lack of pesticides in your morning cuppa — so maybe it's a tradeoff we can live with.