After several beers, you tend to think you’re a bit better looking than you are. Now researchers have scientific proof, you really are more attractive to females when you drink beer. The bad news is you’re more attractive to female mosquitoes.

How mosquitoes find dinner

Mosquitoes use olfactory cues to find their victims. Every person smells a bit different due to different hygiene, diets, or general health conditions. The more attractive the smell, the more likely you’ll be mosquito bait. Some studies have shown pregnant women attract mosquitoes, but I’m not sure what pregnant women and beer drunks have in common. Finding out why some people are more attractive to mosquitoes than others is important, because mosquitoes are vectors for diseases like malaria or West Nile virus. Determining what attracts mosquitoes and neutralizing the attracting scent can play an important role in preventing the spread of diseases. In a study titled Beer Consumption Increases Human Attractiveness to Malaria Mosquitoes by Thierry Lefèvre et al, researchers found people who drink beer smell better to mosquitoes. I guess the mosquitoes know a party when they smell one.

Beer makes you attractive to mosquitoes

25 of the human subjects were asked to drink a liter of beer, while 18 unlucky (or possibly lucky) subjects were given a liter of water. The researchers placed 50 adult female mosquitoes (Anopheles gambiae Giles sensu stricto) who had never eaten blood (read “very hungry”) in a cup downwind from both a subject and an open air vent. At a point in their flight, the mosquitoes have to choose between open air or human stink. The mosquitoes showed a preference for the subjects who drank beer.

The mosquitoes were counted by the number motivated enough to fly upwind, and those smart enough to pick the path which led to a stinky human. Beer consuming subjects significantly motivated more mosquitoes to fly upwind. 47% of the total number of mosquitoes flew upwind for beer drinkers, compared to 38% flying upwind for water drinkers. Of the mosquitoes who flew upwind, 65% picked the correct path to the beery victim compared to 47% picking the path to the water drinking subject. For beer drinkers (and the mosquitoes), that sucks.

All of the subjects were tested before and after drinking their beverage, so it wasn’t just luck that the beer group smelled better. The increase didn’t happen until after they pounded the beer. Their CO2 production (breathing) and body temperature had no effect on attracting mosquitoes. The big question is “why beer”?

Why beer might make you more attractive

The study really doesn’t say why the mosquitoes prefer beer drinkers. It would be interesting to see if the results are the same after consuming a shot of vodka. Since they mention pregnant women are more attractive to mosquitoes than other human snack bars, I wonder if the attraction is hormonal. There are hormones in hops, so that could be a link. A test with vodka could rule out this possibility. It is also possible multiple factors make some humans tastier than others, and hormones are just one attractant.

Lesson learned: when your at your next beer picnic, bring the DEET (N,N-Diethyl-meta-toluamid).