Deodorant

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Deodorants are cosmetic substances applied to the body, most frequently the armpits, to reduce the body odor caused by the bacterial breakdown of perspiration. A subgroup of deodorants are "'antiperspirants'", which prevents odor and reduces sweat produced by parts of the body. Antiperspirants are typically applied to the underarms, while deodorants can also be used on feet and other areas in the form of body sprays.

Human sweat itself is largely odorless. The principal cause of body odor are bacteria thriving in hot, humid environments such as the human underarm, which has a high density of sweat glands and is relatively occluded. The armpits are among the consistently warmest areas on the surface of the human body, and sweat glands provide moisture. Armpit hair adds to the odor because of the increased surface area.

The odor is seen as negative in some cultures (see below), hence many people's desire to eliminate or suppress it. One obvious way to reduce odor is to remove some (or all) of the underarm hair. There are a variety of cultural preferences around this practice.

Contents 1 Adolescence 2 Deodorant Types 2.1 Aluminium Neurotoxicity 3 Culture 4 See also 5 References

[edit] Adolescence

Adolescence is usually when the axillary (armpit) sweat glands are activated and bring about body odor. Girls and boys usually receive, through some method, their first deodorant or anti-perspirant during early to mid-puberty. Some teens see this as a "coming of age" event, while others just see it as a necessary application.

[edit] Deodorant Types

Deodorants – classified and regulated as over-the-counter (OTC) cosmetics by the U.S. Food and Drug Administration (FDA) – work to inhibit the growth of bacteria which cause odors. The first commercial deodorant, Mum, was introduced in the late nineteenth century. Deodorants are usually alcohol-based, which kills bacteria effectively. Deodorants can be formulated with other, more persistent antimicrobials such as triclosan, or with metal chelant compounds that slow bacterial growth. Deodorants also often contain perfume fragrances intended to mask the odor of perspiration.

Deodorants may be combined with antiperspirants – classified as drugs by the FDA – which attempt to stop or significantly reduce perspiration. Aluminum chloride, aluminum chlorohydrate, and aluminum-zirconium compounds are the most widely used antiperspirants. Aluminum-based complexes react with the electrolytes in the sweat to form a gel plug in the duct of the sweat gland. The plugs prevent the gland from excreting liquid and are removed over time by the natural sloughing of the skin. The blockage of a large number of sweat glands reduces the amount of sweat produced in the underarms, though this may vary from person to person.

A popular alternative to modern commercial deodorants is Ammonium alum, which is a common type of Alum sold in crystal form. It has been used as a deodorant throughout history in Thailand, the Far East, Mexico and other countries.

Deodorants and antiperspirants come in many forms. What is commonly used varies in different countries. In Europe, aerosol sprays are popular, as are cream and roll-on forms which are prevalent in less affluent parts of the world. In the United States, solid or gel forms are dominant.

==Health Effects==

Email rumors^{[1] [2]} surfaced on the internet in the early 1990s that antiperspirants have a link in causing breast cancer; these are now widely considered to be an urban myth. According to the National Cancer Institute (NCI) and the American Cancer Society (ACS), these rumors are largely unsubstantiated by scientific research.^[3][4]

The rumors suggested that antiperspirants keep a person from sweating out toxins and that this would help the spread of cancer-causing toxins via the lymph nodes.^[5] While lymph nodes do help to clear toxins, they are not connected to the sweat glands. Furthermore, sweat is not a significant route for eliminating toxins from the body. ^[6]

NCI discusses two studies that address the breast cancer rumor: A 2002 study of over 800 patients at Fred Hutchinson Cancer Research Institute that found no link between breast cancer and the use of antiperspirant/deodorant^[7]; and a study of 437 cancer patients, published in 2003 by the European Journal of Cancer Prevention, which found a correlation between earlier diagnosis of breast cancer and antiperspirant/deodorant use^[8]. The NCI's analysis of the second study said that it "does not demonstrate a conclusive link between these underarm hygiene habits and breast cancer. Additional research is needed to investigate this relationship and other factors that may be involved." ^[9]

One school of thought, advanced by the studies of researcher Phillipa Darbre, PhD, hypothesizes that particular substances in deodorants, such as preservatives called parabens, or aluminium salts such as alumnimum chloride used in antiperspirants, get into the bloodstream or accumulate in breast tissue, where they enhance or emulate the effects of estrogen, which stimulates the growth of cancerous breast cells. ^{[10] [11]} The ACS and other scientists consider these studies to be early and inconclusive, but merit further research; Darbre also stated that her findings did not show causality. The main reservations have to do with the source and significance of the parabens or other toxic substances. ^[12] Michael Thun, MD, of the ACS argued that even if some of the substances in antiperspirants do promote tumor growth, the risk from cosmetic use appears minuscule compared with other known tumor promoters -- from 500 to 10,000 times less potent than taking oral estrogen or being obese.^[13]

[edit] Aluminium Neurotoxicity

Aluminium has been established as a neurotoxin.^[14] Aluminium chloride, an aluminum salt that is commonly used in antiperspirants, is also commonly used in studies on aluminium-induced neurotoxicity^{[15][16][17][18][19]}. Aluminium itself adversely affects the blood-brain barrier, is capable of causing DNA damage, and has adverse epigenetic effects.^[20][21] Research has shown that the aluminium salts used in antiperspirants have detrimental effects to a number of species such as non-human primates^[22], mice^[23], dogs^[24] and others. An increased amount of Aluminium is also present in the brains of many Alzheimer's patients, although it is not yet known if this link is causal.^[25][26]

An experiment with mice found that applying an aqueous solution of aluminum chloride to the skin resulted in "a significant increase in urine, serum, and whole brain aluminium."^[27] Other experiments on pregnant mice showed transplacental passage of aluminium chloride.^[23]

[edit] Culture

Cultures and individuals differ in their beliefs about the need for deodorant, and on whether bodily odors are offensive. Various foods such as garlic may also affect body odor.

Commercially-manufactured deodorants may also target areas of the body other than the armpits, such as the genitals, and particularly the female genitals. Such products are sometimes the target of sexually graphic humor.

Tom Robbins' novel Even Cowgirls Get the Blues involves a humorous plot line that takes a position in favor of natural body odors, and presents the positions of those on both sides of the issue.

An episode of Foster's Home For Imaginary Friends features the lead character, Bloo, as the mascot for an ineffective deodorant called "Deo".

"Ode To Deodorant" was the first song recorded by British band Coldplay as an ensemble.

[edit] See also

• Air freshener
• Perfume

[edit] References