East Asians (Chinese, Koreans, and Japanese) have fewer apocrine sweat glands compared to people of other descent, and the lack of these glands make East Asians less prone to body odor.[16][17] The reduction in body odor and sweating may be due to adaptation to colder climates by their ancient Northeast Asian ancestors.[18] The ABCC11 gene is known to determine axillary body odor, but also the type of earwax.[4][18][19][20] Most of the world's population secrete the wet-type earwax, however, East Asians are genetically predisposed for the allele that codes the dry-type earwax, associated with a reduction in axillary body odor.[4][18][20] The loss of a functional ABCC11 gene is caused by a 538G>A single-nucleotide polymorphism, resulting in a loss of body odor in people who are specifically homozygous for it.[20][21] The non-functional ABCC11 allele is predominant amongst East Asians (8095%), but very low in other ancestral groups (03%).[4] It affects apocrine sweat glands by reducing secretion of odorous molecules and its precursors.[4] It is also associated with a strongly reduced/atrophic size of apocrine sweat glands and a decreased protein (such as ASOB2) concentration in axillary sweat.[4]
