Hundreds of teams from practically all over the world have been searching for the solution for years, but not even the most specialized scientists have yet managed to find the effective method to prevent mosquitoes from biting us.
Among the most recent advances in this field, a study published in February 2022 stands out, indicating that, in addition to capturing carbon dioxide from our breath, female mosquitoes (those that bite) fly towards us attracted by specific colors, in especially red, orange, black and cyan.
In October last year, another scientific study claimed that, in addition to the heat and carbon dioxide we exhale, the key to mosquito attraction lies in the carboxylic acids that are also released naturally from our bodies. The list of studies of this type is very long...
The most recent contribution, published this week in the journal iScience, is a study led by experts from Virginia Tech (Virginia State University and Technological Institute, USA) that indicates that the aroma of the soap we serve is one of the factors that make us more or less attractive to mosquitoes.
In this investigation, the possible attractive or repellent action of soaps from the brands Dial, Dove, Native and Simple Truth were put to the test in a group of volunteers.
The researchers compared each volunteer's attractiveness to female Aedes aegypti species mosquitoes before washing with these soaps and one hour after using these products.
The experiment revealed that soap washing influenced mosquito preferences, but in different ways for different types of soap and volunteers. Washing with Dove and Simple Truth raised the attractiveness of some (but not all) volunteers, and washing with Native soap tended to repel mosquitoes.
"What really matters to the mosquito is not the most abundant chemical, but the specific associations and combinations of chemicals, not just from soap, but also from our personal body odors," Vinauger says.
In fact, although all four soaps contained limonene - a known natural repellent - three of them increased the attraction of mosquitoes. And it is that "the proportions of the chemical substances are extremely important to determine if the mosquitoes are attracted or not", adds Chloé Lahondère, co-author of the study.
The next step was to analyze the chemical compositions of the different soaps according to their impact on the mosquitoes' preference. Thus, they identified four chemical substances associated with the attraction of mosquitoes and three associated with repulsion (pinene, linalool and limonene).
In this case, too, there is no single, miraculous solution, but when asked about it, Clément Vinauger, leader of the team responsible for this new research, commented: "If I wanted to reduce the attraction of mosquitoes, I would choose a coconut-scented soap."
To identify the specific ingredients that attract and repel mosquitoes, the researchers analyzed the chemical compositions of the different soaps and compared them to their impact on mosquito preference. They were able to identify four chemicals associated with attracting mosquitoes and three chemicals associated with repelling them, including a coconut-scented chemical that's a key component in American bourbon (whiskey) and a floral compound used to treat scabies. and head lice, according to Virginia Tech in a fact sheet.
The team combined these chemicals to create and test mixtures of attractive and repellent odors, which had a strong impact on mosquito preference. The conclusion of the study, as has been indicated, does not provide a unique and specific solution, but it does leave the clue of the coconut aroma open. It would not be surprising if soaps with this detail indicated on the label proliferated in the coming months.
Whether or not it has immediate commercial and healthcare applications, the study authors say they intend to expand their research and try to find some patterns or rules of thumb by testing more varieties of soap and many more people.
They also plan to explore how soap affects mosquito preference over a longer period of time. "We are very curious to observe the time course of this effect; for example, if you take a shower in the morning, do mosquitoes still care at night?" Clément Vinauger asks.
El estudio indica que los productos (jabones) puestos a prueba son 1) Dial® Body Wash, Marula Oil, 21 fl oz (Henkel North American Consumer Goods, The Dial Corporation, Scottsdale, AZ, USA); 2) Dove® Deep Moisture Nourishing Body Wash, 24 fl oz (Unilever, London, England); 3) Simple Truth® Organic Honey Blossom Baby Shampoo