Some Indian researchers did an experiment taking five unique odors and asked the participants to identify them. It includes the smell of peppermint, garlic, coconut oil, fennel, and cardamom.
It is found that participants who could not smell the coconut oil and peppermint are more likely to contract COVID-19 than others. Amongst the participants, almost 25% of them could not identify the smell of peppermint. While 21% of the participants could not identify the smell of coconut oil.