Wearing the same pair of socks day after day could put you at risk of developing nasty infections… and not only in your feet.
A leading microbiologist has warned that not changing your socks daily could trigger respiratory and gut infections, and it’s because of the thousands of potentially harmful pathogens which fester on your feet.
Dr Primrose Freestone, from the University of Leicester, wrote in The Conversation: ‘If you knew what really lived in your socks after even one day of wearing, you might think twice about doing it.
‘Our feet are home to a microscopic rainforest of bacteria and fungi – typically containing up to 1,000 different bacterial and fungal species.
‘The foot also has a more diverse range of fungi living on it than any other region of the human body.
‘Most foot bacteria and fungi prefer to live in warm, moist areas between your toes where they dine on nutrients within your sweat and dead skin cells.
‘The waste products produced by these microbes are the reason why feet, socks and shoes can become smelly.’
Adding to the cesspit of naturally present nasties, dirty socks can harbour unhealthy bacteria that they can pick up from the floor at home, the gym or even from the ground outside.
A microbiologist has explained why you should only wear socks once before washing them
She highlighted research which found socks had between eight to nine million bacteria per sample, while t-shirts only had 83,000.
Another study she referred to found that socks harbour both harmless bacteria and also dangerous pathogens including Aspergillus, Candida and Cryptococcus.
An Aspergillus infection typically comes from breathing in the pathogen—for example from mould—and affects vulnerable patients with a compromised immune system.
Meanwhile, there are several types of Candida, some live harmlessly on the skin while invasive types can trigger life-threatening infections.
This happens when Candida enters the bloodstream and spreads to internal organs, with people in hospitals with weakened immune systems most at risk.
Lastly, Cryptococcus, another type of fungi, can cause an infection in the brain or lungs, and can prove fatal if left untreated.
The dirty habit can also increase your risk of spreading the Athlete’s foot, added Dr Freestone
Allowing your feet to become a breeding ground for potentially dangerous entities doesn’t just put your own health at risk but can also cause infections to spread to others, said Dr Freestone.
‘The microbes living in your socks can also transfer to any surface they come in contact with – including your shoes, bed, couch or floor.
‘This means dirty socks could spread the fungus which causes Athlete’s foot, a contagious infection that affects the skin on and around the toes.’
The contagious fungal infection, which causes itchy, red and flaky skin, typically between the toes, can lead to blisters if left untreated.
Wearing socks for multiple days can also cause feet to smell, as bacteria feeds off sweat added Dr Freestone—and a whiff can reveal what is festering on your feet.
‘The bacteria Staphylococcal hominis produces alcohol from the sweat it consumes that makes a rotten onion smell,’ she explained.
‘Staphylococcus epidermis on the other hand, produces a compound that has a cheese smell.
‘Corynebacterium another member of the foot microbiome, creates an acid which is described as having a goat-like smell.’
This graphic shows the different things your feet can tell you about your health
The bacteria are part of a healthy foot microbiome, a diverse set of bacteria, viruses and microscopic mites living on the feet.
But she explained they are fed by sweat, and the more we sweat the stronger the odour will be.
‘As socks can trap sweat in, this creates an even more optimal environment for odour-producing bacteria,’ she said.
‘And these bacteria can survive on fabric for months. For instance, bacteria can survive on cotton for up to 90 days.
‘So, if you re-wear unwashed socks, you’re only allowing more bacteria to grow and thrive.’
There are also other things people should do to prevent bad smelling feet and harmful microbes festering, says Dr Freestone.
‘It’s a good idea to avoid wearing socks or shoes that make the feet sweat,’ she explained.
‘Washing your feet twice daily may help reduce foot odour by inhibiting bacterial growth.
‘Foot antiperspirants can also help, as these stop the sweat – thereby inhibiting bacterial growth.’
It’s also possible to buy antimicrobial socks, which contain heavy metals such as silver or zinc which can kill the bacteria that causes foot odour, she added.
‘Bamboo socks allow more air flow, which means sweat more readily evaporates – making the environment less hospitable for odour-producing bacteria.
‘But for those who wear socks that are made out of cotton, wool or synthetic fibres, it’s best to only wear them once to prevent smelly feet and avoid foot infections.’
There are also important things to do when you wash them.
‘If your feet aren’t unusually smelly, it’s fine to wash them in warm water that’s between 30C and 40C with a mild detergent,’ said Dr Freestone.
‘However, not all bacteria and fungi will be killed using this method.
‘So, to thoroughly sanitise socks, use an enzyme-containing detergent and wash at a temperature of 60C.
‘The enzymes help to detach microbes from the socks while the high temperature kills them.
‘Drying the socks outdoors is also a good idea as the is antimicrobial to most sock bacteria and fungi.
‘While socks might be a commonly re-worn clothing item, as a microbiologist I’d say it’s best you change your socks daily to keep feet fresh and clean.’
