Aluminum toxicity
Aluminum is present most often in antiperspirants in form of aluminum chlorohydrate.[25] In addition, aluminum chlorohydrate[26] is not the same as the compound aluminum chloride, which has been established as a neurotoxin.[27][28][29][30] At high doses, aluminum itself adversely affects the blood–brain barrier, is capable of causing DNA damage, and has adverse epigenetic effects.[27][31] High doses of aluminum have detrimental effects to a number of species such as non-human primates,[32] mice,[33] rabbits,[27] and dogs.[34]A preliminary study (2001) showed that the use of aluminum chlorohydrate, the active ingredient in many antiperspirants, does not lead to a significant (vs. ingestion via diet) increase in aluminum levels in the body with one-time use.[35] The Food and Drug Administration "acknowledges that small amounts of aluminium can be absorbed from the gastrointestinal tract and through the skin."[36]
Breast cancer
A 2002 study stated "the rumor that antiperspirant use causes breast cancer continues to circulate the Internet. Although unfounded, there have been no published epidemiologic studies to support or refute this claim."[37] The American Cancer Society (ACS) and the National Cancer Institute (NCI) were very much concerned about the e-mails rumors directly linking antiperspirants to cancer that both put out information on the Internet stating there was no evidence linking the cosmetic products with cancer.[38] According to the ACS "studies have not shown any direct link between parabens and any health problems, including breast cancer. What has been found is that there are many other compounds in the environment that also mimic naturally produced estrogen."[39] According to researchers at the NCI, they "are not aware of any conclusive evidence linking the use of underarm antiperspirants or deodorants and the subsequent development of breast cancer."[40] "Absence of evidence is not evidence of absence of a harmful effect" and "these chemicals are being directly applied daily, by very large numbers of people, and the long-term health effects of exposure are essentially unknown," toxicologist Philip W. Harvey tells WebMD in an interview.[41] But ACS epidemiologist Michael Thun argued that "even if the parabens do promote estrogen-dependent tumor growth, the risk from cosmetic use is "minuscule" compared with other known tumor promoters."[41] The cosmetics industry insists the paraben chemicals used as preservatives in underarm deodorants and other cosmetics, which are regulatory approved, are safe.[42]A 2003 study found a correlation between earlier diagnosis of breast cancer and antiperspirant/deodorant use.[43] A 2003 study indicated "underarm shaving with antiperspirant/deodorant use may play a role in breast cancer."[43] A 2004 study reviewing the evidence for and against the possible link between breast cancer and underarm cosmetics wrote "Although animal and laboratory studies suggest a possible link between certain chemicals used in underarm cosmetics and breast cancer development, there is no reliable evidence that underarm cosmetics use increases breast cancer risk in humans."[44]
2004 and 2005 studies led by researcher Philippa Darbre, hypothesizes that particular substances in deodorants, such as preservatives called parabens, or bolts such as aluminum 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.[45][46] A 2007 study found that personal care products are a potential contributor to the body burden of aluminum and newer evidence has linked breast cancer with aluminum-based antiperspirants.[7] A 2008 study stated that no scientific evidence supports the hypothesis that deodorants and/or antiperspirants increase the incidence of breast cancer.[8] A study published in 2009 by the journal The Breast Cancer Research proposed a link between breast cancer and the application of cosmetic chemicals including phthalates and aluminum salts in the underarm region, because of their oestrogenic and/or genotoxic properties, which provides an evidence-based hypothesis capable of further research.[47]
