A while back, I switched from using a deodorant to an antiperspirant. I was enchanted by a new smell that I needed to have wafting out of my armpits. And for a week, I happily swiped it on and floated through the day in a floral cloud... until I wasn’t anymore. Until the smell coming out of my armpits was unlike anything I had ever experienced before. What was going on?
It’s all Natural
Armpits aren't the only place you can sweat from. The average person produces around a litre of sweat a day, from (roughly) 3 million sweat glands. These sweat glands come in two styles: eccrine glands and aprocine glands. Eccrine glands are smaller and cover most of your body. They produce a watery, odourless sweat that helps control you temperature. The larger apocrine glands are mostly found in your armpits. They start producing sweat when you hit puberty, and secrete a thicker, more plasma-like sweat, filled with proteins and fatty acids. This is why the the underarm stains on your t-shirts can sometimes appear yellowish. (Tip: if you want to get rid of those yellow stains, rub in some non-seasoned meat tenderizer before you throw your shirts in the wash! The tenderizer contains enzymes that will break down the sweat and help it wash out.)
Deodorants vs Antiperspirants
While often lumped in with deodorants, antiperspirants actually work quite differently. Deodorants work by masking smells after being swiped across your armpit. Antiperspirants prevent sweat through the use of an aluminum-based compound. If you swipe your antiperspirant on before bed, the antiperspirant will dissolve throughout the night and create a gel-like plug that blocks and contricts your sweat glands. This temporarily prevents sweat from coming out.
It was about a week after I started using the antiperspirant that I noticed my sweat’s odour changing. There had always been a smell in my armits, but suddenly it was worse. Way worse!
It turns out, there was a lot of action going on in my armpits and by introducing an external force into the equation, I had messed up my armpit ecosystem.
There are quite a few different types of bateria that like to live in your armpits. They feed on the fatty sweat you produce there. Some of them produce more noticable odours than others. Research has found that the salts in antiperspirants can cause an imbalance of bacteria. The aluminum compounds kill off the less smelly bacteria, giving the smellier bacteria more opportunity to thrive, causing more body odour. Reading this brought my relationship with my antiperspirant to an abrupt end, and after a brief detox period, I made the switch back to deodorants (and my smell returned to normal, thankfully!)
But antiperspirant isn't the only thing that can mess with your armpit's natural odour. Eating strong smelling foods like garlic can cause a temporary change in body odour as their chemical compounds make their way out of your body.