Body odor
Body odor is influenced by many factor and can influence other people in different ways.
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[edit] Causes
Not only sweat glands but also sebaceous glands and apocrine sweat glands produce substances contributing to body odor. Sebaceous and apocrine become active at puberty. This as well as many apocrine glands being close to the sex organs points to a role related to mating. In humans the armpit regions seem more important than the genital region for body odor which may be related to human bipedalism. The genital and armpit regions also contain springy hairs which help diffuse body odors.[1]
Factors such as food, drink, and diseases can affect body odor.[1] An individual's body odor is also influenced by lifestyle, gender, genetics, and medication.
Body odor is influenced by the actions of the skin flora, including members of Corynebacterium, which manufacture enzymes called lipases that break down the lipids in sweat to create smaller molecules like butyric acid. These smaller molecules smell, and give body odor its characteristic aroma.[2] Propionic acid (propanoic acid) is present in many sweat samples. This acid is a breakdown product of some amino acids by propionibacteria, which thrive in the ducts of adolescent and adult sebaceous glands. Because propionic acid is chemically similar to acetic acid with similar characteristics including odor, body odors may be identified as having a vinegar-like smell by certain people.[citation needed] Isovaleric acid (3-methyl butanoic acid) is the other source of body odor as a result of actions of the bacteria Staphylococcus epidermidis,[3] which is also present in several strong cheese types.
[edit] Specificity
Body odor can smell pleasant and specific to the individual and can be used to identify people, though this is more often done by dogs and other animals than by humans.
Babies can recognize their mothers by smell and mothers and other relatives can identify a baby by smell.[1]
[edit] Genetics
Body odor is largely influenced by major histocompatibility complex (MHC) molecules. These are genetically determined and play an important role in immunity of the organism. The vomeronasal organ contains cells sensitive to MHC molecules in a genotype-specific way.
Experiments on animals and volunteers have shown that potential sexual partners tend to be perceived more attractive if their MHC composition is substantially different. Married couples are more different regarding MHC genes than would be expected by chance. This behavior pattern promotes variability of the immune system of individuals in the population, thus making the population more robust against new diseases. Another reason may be to prevent inbreeding.[1]
One study suggests that body odor is genetically determined by a gene that also codes the type of earwax one has.[4][5] East Asians (those of Chinese, Japanese, Korean, and Vietnamese descent) have the type of sweat glands that even after hitting puberty still don't produce the chemicals found in the perspiration of other ancestral groups. East Asians evidently have a greater chance of having the 'dry' earwax type and reduced axial sweating and odor. This may be due to adaptation to colder climates.
[edit] Alterations
Body odor may be reduced or prevented or even aggravated by using deodorants, antiperspirants, disinfectants , underarm liners, triclosan), special soaps or foams with antiseptic plant extracts such as ribwort and liquorice, chlorophyllin ointments and sprays topically, and chlorophyllin supplements internally.[6] Although body odor is commonly associated with hygiene practices, its presentation can be affected by changes in diet as well as the other factors discussed above.[7]
[edit] Bad smell
| Body odor | |
|---|---|
| Classification and external resources | |
| ICD-10 | L75.0 |
| ICD-9 | 705.89 |
| DiseasesDB | 28886 |
| eMedicine | derm/597 |
The condition can be known medically as bromhidrosis, apocrine bromhidrosis, bromidrosis, osmidrosis, ozochrotia, fetid sweat, body smell or malodorous sweating.[8]:779[9]:707
[edit] See also
[edit] References
- Notes
- ^ a b c d The Oxford Handbook of Evolutionary Psychology, Edited by Robin Dunbar and Louise Barret, Oxford University Press, 2007, Chapter 22 Body odours and body odour preferences in humans by Claus Wedekind
- ^ Buckman, Dr. Robert (2003). Human Wildlife: The Life That Lives On Us. Baltimore: The Johns Hopkins University Press. pp. 93-4
- ^ Ara K, Hama M, Akiba S et al (2006). "Foot odor due to microbial metabolism and its control". Can. J. Microbiol. 52 (4): 357–64. doi:10.1139/w05-130. PMID 16699586.
- ^ Wade, Nicholas (2006-01-29). "Japanese Scientists Identify Ear Wax Gene". New York Times. http://www.nytimes.com/2006/01/29/science/29cnd-ear.html?ex=1296190800&en=7f6c667589328421&ei=5088&partner=rssnyt&emc=rss. Retrieved 2007-07-05.
- ^ Yoshiura K, Kinoshita A, Ishida T et al (2006). "A SNP in the ABCC11 gene is the determinant of human earwax type". Nat. Genet. 38 (3): 324–30. doi:10.1038/ng1733. PMID 16444273. http://www.nature.com/ng/journal/v38/n3/abs/ng1733.html.
- ^ "Chlorophyll and Chlorophyllin". http://lpi.oregonstate.edu/infocenter/phytochemicals/chlorophylls/. Retrieved 2010-01-29.
- ^ "Learn How to Fight Body Odor". http://www.mdhealthnetwork.org/BodyOder.html. Retrieved 2007-07-05.
- ^ James, William; Berger, Timothy; Elston, Dirk (2005). Andrews' Diseases of the Skin: Clinical Dermatology. (10th ed.). Saunders. ISBN 0721629210.
- ^ Freedberg, et al. (2003). Fitzpatrick's Dermatology in General Medicine. (6th ed.). McGraw-Hill. ISBN 0071380760.
[edit] External links
- Flores G (2004). "Immunity, smell linked". The Scientist 5 (1). http://www.the-scientist.com/news/20041105/02.
- Male sweat boosts women's hormone levels -- from UC Berkeley, February 2007
- "Odors and metabolic disease" from Miami Children's Brain Institute
- Causes of body odor
- What is body odour? - Medical article, December 2009.
