Study reveals what soaps make humans more attractive to mosquitos

12 May 2023 --- What soap brand and scent you choose might make you more or less attractive to mosquitos, according to a study published in the journal iScience.

Consumer safety might be a new aspect for the industry to consider when formulating their products, as some scents, such as coconut or vanilla, are found to be repellent. Knowing what scents to avoid might help users prevent yellow fever, dengue, Zika or chikungunya viruses.

Meanwhile, pineapple and other fruity smells might increase your attractiveness to mosquitoes.

According to the World Health Organization (WHO) estimates, mosquito-borne diseases kill around 725,000 people a year, making it the most deadly animal to humans.

Pineapple and other fruity smells might increase your attractiveness to mosquitoes.Study methodology
Scientists tested four of the most used body washes in the US.

During the study, the participants washed one arm using a specific soap and then covered both arms with nylon sleeves for an hour. The sleeves were then exposed to mosquitoes in a laboratory and the researchers recorded the number of mosquitoes landing on each arm.

No participant was stung by the mosquitos as the nylon sleeves were removed during the analysis with live mosquitos.

Three of the participants were identified as attractive to mosquitos because of their natural body odors. The study revealed that three soaps, namely Dial, Dove and Simple Truth, made the participants even more appealing to mosquitoes when compared to their unwashed odor.

These soaps that were more attractive use compounds such as lilial (a synthetic aromatic aldehyde), α-isomethyl ionone (naturally found in bacterial fermentation and flower headspace volatiles), allyl heptanoate (naturally found in the scent of tropical fruits and used in perfumery to imitate pineapple scent) and 4-tert-butylcyclohexyl acetate (a commonly used fragrance ingredient).

On the other hand, only Native brand soap made the participants less attractive to mosquitoes.

“Coconut fatty acids are active against a broad array of blood-sucking arthropods including biting flies, ticks, bed bugs and mosquitoes,” explained a previous study on mosquitos published in Nature.

The scientist flags that this knowledge will help create both repellents and better personal care products.

“These results provide proof-of-concept that data on host-soap valences can be reverse-engineered to produce chemical blends for artificial baits or mosquito repellents and evince the impact of personal care products on host selection processes,” the scientists explain.

In related research, researchers found that biomaterial cellulose nanocrystal had “excellent potential” for active repellents against Aedes Aegytpi (the same kind of mosquitos), which is also produced safely and sustainably.

Edited by Marc Cervera