"Are Beer, Bananas, and B Vitamins Mosquito Repellents?"
An online survey of personal mosquito-repellent strategies
unearthed all sorts of strange stratagems
from cutting a tomato in half and leaving it next to the bed,
to rubbing yourself with cigarette butts soaked in alcohol.
You could also soak yourself in alcohol with a gin and tonic,
cut down on sugar, cut out meat, or bananas.
But what’s funny is some say avoid bananas,
some say eat bananas to stave off mosquitos,
and others say topically rub them on your skin.
(I don’t even want to know about what else you might do with them).
Eat bananas? Avoid bananas?
You don’t know...until you put it to the test.
The impact of the consumption of bananas
on attraction of a malaria mosquito to humans.
Researchers in Wisconsin randomized subjects to eat grapes
or bananas before testing what they then tasted like to mosquitoes and...
the ingestion of bananas was strongly associated with an increase
in the number of mosquito contacts for hours after eating a banana,
translating to about 11 extra contacts
after 1 hour and 7 contacts after 2 hours.
Meanwhile, the ingestion of grapes had no effect.
Interestingly, it didn’t seem to matter
how many bananas you eat at once,
as eating three bananas didn’t appear
to make people any tastier than eating one.
Bottomline, after years of repeat experiments,
they concluded that ingestion of bananas, but not grapes,
resulted in a significantly higher attraction of mosquitoes
for hours after ingestion on average,
though some people did appear to be immune to the banana effect.
What about that gin and tonic?
Some have suggested alcohol will keep the bugs away;
others suggest we might suffer more mosquito bites
after ingesting liquor.
Well, there’s only one way to find out.
Drink some beer and put your arm in a box with some mosquitoes.
The title of the study gives it away.
Alcohol ingestion stimulates mosquito attraction.
About 40 percent of the mosquitoes landed on their arms
before drinking a bottle of beer
compared to about 50 percent afterwards.
And it didn’t appear to have anything to do with changes
in sweat production or skin temperature after the booze.
It might just be something you start exuding after you drink.
And so, it’s also not just because you got bit a bunch of times
because you like blacked out in an alley or something.
The researchers concluded that since the percent of mosquitos
landing on volunteers significantly increased after beer ingestion,
drinking alcohol stimulates mosquito attraction.
But it could just be drinking beer, not necessarily all alcohol.
And they only tested one species of mosquito,
the one that transmits diseases like dengue, zika, and yellow fever.
What about gauging human attractiveness to malaria mosquitoes,
before and after volunteers consumed either beer
(using 25 volunteers and a total of 2500 mosquitoes)
or water as a control,
with 18 volunteers and only about 1800 mosquitoes. And..?
Water consumption had no effect,
but beer consumption increased the attractiveness of the volunteers.
It’s like the mosquitos put on beer goggles.
Beer consumption increases human attractiveness.
To date, bananas and beer are the only dietary components
that have been shown to increase mosquito attraction.
OK, but we want to repel mosquitos, not attract them.
What about testing B vitamins
as a home remedy against mosquitoes?
B vitamins are often recommended in the popular media
as a systemic repellent against mosquitoes, especially on the web.
The first studies date back over a half century.
They gave people doses of vitamins B1 and B6,
yet in a series of subsequent tests the mosquitoes
probed avidly and bit promptly.
They only tested the vitamins on four people,
but the vitamins appeared so useless,
they didn’t think it worth repeating
the experiments in view of the obvious lack
of repellency of these vitamins.
We believe, the researchers wrote, that we have disproved
the notions that vitamins taken orally act as mosquito repellents.
But they only tested vitamins B1 and B6.
What about B-2, B-3, B-5, B-9, B12?
You don’t know...until you put it to the test.
These are the results of a small number of published studies
like the one I showed that suggested that vitamin B complex supplements
are not effective as repellents, but these studies were limited
by the use of very few human subjects,
only 1 species of mosquito, and a limited number of B vitamins.
So, researchers decided to put it to rest once and for all.
B-1, B-2, B-3, B-5, B-6, B-7, also known as biotin, B-9, B12.
They also just tried a mega-dose of thiamine, B1,
which is rumored to be the most effective B and...nothing.
No effect of vitamin B supplementation.
Any of them. I mean it would be nice
to have an effective oral insect repellent.
Unfortunately, vitamin B1 has been proved to be ineffective.
And this includes so-called mosquito repellent patches,
that supposedly deliver B1 through the skin.
No protection provided whatsoever.
Bottomline: Vitamin B1, also known as thiamine,
is not a systemic mosquito repellent in men.
They also tried smearing it on people’s skin.
With failure after failure,
you start feeling bad for the volunteers,
seated in a room with their shirts off.
Then, they just release 100 suckers into the room.
Look at some of those bite rates.
These are bites per minute. Up to 96 bites per minute.
Just think how bad it would have been
if they had had some bananas and beer.