Why do sweaty feet smell like cheese?
By Meera
Have you ever kicked off your shoes at the end of a long day just to have the whiff of stinky feet waft up to your nose? Let’s talk about why this smell happens, and which food item it most closely resembles.
Why do our feet sweat?
There are millions of sweat glands in your skin all over your body. These secrete sweat normally, but especially when you are exercising, laying out in the sun, or when you have a ‘flight or fight’ experience, for example when you realise you haven’t done the homework that your teacher is starting to collect.
During a day of being trapped in close-toed shoes, your feet will sweat. Did you know your feet can sweat up to a litre on a warm day? Germs like bacteria love this wet, warm environment, and before long start to grow on your feet.
What are these germs growing on your feet? Well, your skin is covered by thousands of bacteria all the time. Most of these are ‘good’ bacteria, that help you by getting rid of dead skin, or even fighting intruders that might otherwise make you very ill.
When your skin is warm and wet however, which happens with sweaty feet, these bacteria can multiply to levels they do not normally reach. One particular bacterium (bacterium is the singular form of bacteria), called Brevibacterium linens, love these conditions. This bacterium is used in real life to ripen cheese, especially Limburger and Brick. Don’t worry – it’s perfectly safe to eat!
The Brevibacterium chomps away at the sweat that your feet are producing, especially enjoying the salt content. As part of their feast, they produce waste gases, which is what you smell as stinky feet.
What can you do about the smell?
Everyone’s feet sweat. Some people are more likely to have sweatier feet, especially teenagers and pregnant women, because of hormonal changes.
There are a few things you can do to reduce the cheese smell, however: wash your feet every day especially between your toes, make sure to fully dry your feet and toes, and change your socks every day.
How can we use this cheese smell to our advantage?
If you’ve ever been bitten by a mosquito, you’ll know that an itchy bite is the best outcome. Some mosquitoes carry around malaria, a deadly disease which kills over a million people every year.
Since mosquitoes are attracted to sweaty feet, and sweaty feet smell similar to cheese, scientists have been experimenting with mosquito traps which use cheese-based bait to lure the mosquitoes away from humans and stop the spread of malaria.
So…the next time you take your socks off after playing sport at school, think about how this lovely smelly process is saving hundreds of lives from diseases as deadly as malaria (don’t use this as an excuse not to wash though!).
