Why Some People Are Mosquito Magnets

It may seem like it’s impossible to hide from mosquitos, but the fact is that some people truly are “mosquito magnets” and get bitten more often than others. Being a woman, having a certain blood type or blood sugar level, consuming bananas or garlic, and being a child are all common theories for why mosquitoes are attracted to some people. Yet, most of these theories lack credible data. 

Fatty acids may be irresistible to mosquitoes

That is why Maria Elena De Obaldia and Vosshall set out to explore and explain why some people are more appealing to mosquitoes. Through a study, the team demonstrated that fatty acids emanating from the skin are likely to create a heady perfume that mosquitoes cannot resist. The results of the study were published in the journal Cell. 

During the three-year study, eight participants were made to wear nylon stockings over their forearms for a total of six hours. This process was repeated several times. The researchers tested the stockings against each other via a round-robin style tournament. They made use of a two-choice olfactory assay, which consisted of a plexiglass chamber that was split into two tubes — each contained a box that held a particular stocking. The researchers then observed which nylon the mosquitoes were more likely to fly toward. 

Since the samples used for the study were de-identified, the researchers didn’t know who the nylons belonged to. Still, they noticed that the nylons worn by Subject 33 were popular among the insects. De Obaldia said, “It would be obvious within a few seconds of starting the assay. It’s the type of thing that gets me really excited as a scientist. This is something real. This is not splitting hairs. This is a huge effect.”

This study helped the researchers discover that mosquito magnets tend to produce higher levels of carboxylic acids than less-attractive volunteers. This substance is present in the sebum and helps the skin produce its own unique odor. 

Once a magnet, always a magnet

In an effort to confirm the findings, the team enrolled more people for a validation study. Again, Subject 33’s samples remained the most alluring. De Obalia said, “Some subjects were in the study for several years, and we saw that if they were a mosquito magnet, they remained a mosquito magnet. Many things could have changed about the subject or their behaviors over that time, but this was a very stable property of the person.”