Body odor

# What is body odor? Body odor is a complex phenomenon that is influenced by a combination of environmental factors, biological factors and genetic predisposition. The primary source of body odor is the sweat glands, particularly the apocrine glands located in the armpits and genital area. These glands produce a fatty fluid which, when broken down by bacteria on the surface of the skin, produces unpleasant odors. Sweat itself is largely odorless, but the activity of skin microbes produces the typical odors. In addition to the bacterial decomposition processes, body odor can be influenced by various external factors such as diet, hygiene and state of health. Certain foods, especially those with strong-smelling ingredients such as garlic or cruciferous vegetables, can increase body odor. Hormonal changes, such as those that occur during puberty, menstruation or pregnancy, can also influence and intensify body odor. The perception of body odor is also culturally and individually influenced. What is perceived as unpleasant in one culture may be considered normal in another. Personal preferences and social norms therefore play an important role in the perception and evaluation of body odor. > ## Good to know > Our body odor is not only genetically determined, but can also be strongly influenced by our diet. Foods such as garlic and cruciferous vegetables can significantly change our odor and even influence our attraction to other people. # Influence of hormones on body odor Hormones have a major influence on body odor as they control the activity of the sweat glands and the composition of sweat. In certain phases of life or under certain conditions, hormone fluctuations can occur that significantly change body odor. - Puberty: During puberty, the level of sex hormones, especially testosterone and oestrogen, increases, which leads to increased activity of the apocrine sweat glands. These glands produce a fatty fluid which, when decomposed by bacteria, leads to a more intense body odor. This explains why adolescents often develop stronger body odor. - Menstruation: In women, body odor can change during the menstrual cycle. Hormonal changes, especially the increase in progesterone and estrogen, affect sweat production and therefore odor. Some women report that their body odor is stronger or perceived differently during menstruation. - Pregnancy: During pregnancy, there are strong hormonal changes that can also affect body odor. The increase in hormones such as progesterone and oestrogen can lead to increased sweat production, which can intensify body odor. Changes in metabolism and the skin's microbiota can also influence odor. - Menopause: During the menopause, oestrogen levels drop, which can lead to a change in sweat gland activity. Menopausal women often report a changed or more intense body odor, which can be accompanied by hot flushes and increased sweating. - Hormonal changes can therefore influence body odor in both the short and long term. These fluctuations are a natural part of the biological processes that make body odor variable on an individual and lifelong basis. # What does genetics have to do with it? Genetics plays a major role in determining body odor, particularly through genes that influence the composition of sweat. One prominent example is the ABCC11 gene, which contributes significantly to variation in body odor. The ABCC11 gene codes for an ATP-binding cassette transporter that is responsible for the transport of lipophilic molecules into the apocrine sweat glands. These glands are located in the armpits and in the genital area and produce a lipid-rich fluid. Bacteria on the surface of the skin break down this fluid, resulting in odors. The transporter, which is influenced by the ABCC11 gene, controls the type and quantity of lipophilic molecules that enter the sweat. A specific single base polymorphism (SNP) known as rs17822931 plays a crucial role in the variation of body odor. This SNP has two major alleles: C and T. The genetic variation at this position determines how effectively the ABCC11 transporter works and thus the composition of sweat. Carriers of the C allele tend to produce more lipophilic compounds in sweat, which leads to a more intense body odor, as these compounds are more easily broken down by bacteria. Carriers of the T allele, on the other hand, produce fewer lipophilic compounds, which leads to a less pronounced body odor, as fewer substances are present that can be broken down by bacteria. This genetic variation explains why some people have a more pronounced body odor than others, even if they have similar lifestyles and eating habits. The different alleles of the SNP rs17822931 lead to different sweat compositions, which correlate directly with the intensity of body odor.