Sweat
glands produce sweat which, combined with bacteria, results in under-arm odour.
This is due to the existence of an active ABCC11 gene. Most people have at
least one “G” allele in that gene, giving a smelliness propensity (and
also wet/sticky earwax), while others have the non-smelly, dry earwax AA genetic
allele which means that though they sweat they don't get body odour.
East Asians tend more often to have the non-smelly AA allele, while
European and African populations are more likely to have the G allele, which
leads to body odor. In the UK around 2% of the population have the non-smelly gene.
So if you are someone with the non-smelly AA allele, you don't need deodorant. However, people who don't need to are still using deodorant. This unneccesary use of deodorant by those who don’t need it varies around the world (e.g. around 75% of non-odour producers in the UK, but very
few in north-east Asia), and is probably due to socio-cultural beliefs and, in the
West, pressure of marketing.
Univ. Bristol report 2013 (sample of 6,495
women who are part of the wider Children of the 90s study).
