Students at New York’s Trinity High School conducted a study, which claimed that the commercial herbal tea bags were full of extra and unlisted ingredients. The Nature journal Scientific Reports made the study public.

To investigate the composition of the herbal tea products, the teenage scientist used DNA bar-coding process. They concluded that every species has a distinct portion of their DNA that can be sorted out amidst a mish-mash of genes and genetic material.

For conducting the study, the team purchased various 33 company herbal tea bags. They bought almost 70 bags and took some tea sample for the DNA test.

The test results concluded that more than 30% of herbal teas, including bluegrass, goosefoot and four herbal tea mixes contained some parts of parsley and seven included unlisted chamomile elements.

Catherine Gamble, one of the high school student participants of the study, added, “After water, tea and its many herbal variations represent the world's most popular beverage -- by far. Literally billions of cups are consumed every day, more than all the coffee, pop and every other drink combined and what are in those little bags of tea and herbal tea products are a matter of interest to billions of people”.