What are aluminium salts?
Aluminium salts are the active ingredients used in antiperspirants, but they are also found in other cosmetics including lipsticks and toothpastes. The salts used include aluminium chloride, aluminium chlorohydrate and aluminium zirconium chlorohydrate complexes (1).
The aluminium compounds act by blocking the sweat ducts under the arm to prevent sweat from escaping onto the skin surface (2). This reduces the moist environment in which bacteria, that generate the smell, thrive.
Aluminium is also found in our diet (3), through use of antacids (4) and through use of aluminium-based adjuvants in vaccinations (5).
Why should we be concerned?
Whilst evidence is not conclusive, there are some studies which link aluminium to some health problems, including neurological diseases. Aluminium has been shown to be absorbed through intact skin from application of antiperspirant under the arm (6). Laboratory studies have shown that six-fold more aluminium is absorbed through human skin when the skin is damaged in a procedure similar to shaving (7).
How are aluminium salts linked with breast cancer?
No studies can show a direct causal link between breast cancer and aluminium. However, some recent opinions have questioned or challenged their ascribed safety for use in underarm cosmetics (8,9,10).
Usually antiperspirants are applied to the underarm and upper chest area and are left on the skin which allows for continuous exposure to the aluminium salts. This is the region of the breast where the majority of breast cancers start In the UK, for example, over 50% start in the upper outer quadrant of the breast near the underarm (11).
Recently, aluminium has been measured in several human breast structures including breast tissue (12,13). Other laboratory studies show that human breast epithelial cells can be turned into a cancerous phenotype by exposure to aluminium chloride (14).
Lifetime exposure to oestrogen is an established risk factor for breast cancer and aluminium has been shown to act as a metalloestrogen, capable of interfering in oestrogen action (15).
For more information and a full list of references download our Background briefing on Aluminium Salts.
- Laden K, Felger CB. (1988) Antiperspirants and deodorants: cosmetic science and technology series vol 7, Marcel Dekker, New York.
- Exley C. (2009) In: Molecular and Supramolecular Bioinorganic Chemistry: Applications in Medical Sciences. (Ed. A.L.R. Merce, J. Felcman, M.A.L. Recio), Nova Science Publishers Inc. New York, p 45-68.
- Lee, S. and Nguyen, M. T. (2015). Recent Advances of Vaccine Adjuvants for Infectious Diseases. Immune Network 15(2): 51–57
- Flarend R, Bin T, Elmore D, Hem SL. (2001) A preliminary study of the dermal absorption of aluminium from antiperspirants using aluminium-26. Food Chem. Toxicol. 39: 163-168.
- Pineau A, Guillard O, Fauconneau B, Favreau F, Marty MH, Gaudin A, Vincent CM, Marrauld A, Marty JP. (2012). In vitro study of percutaneous absorption of aluminium from antiperspirants through human skin in the Franz diffusion cell. J. Inorg. Biochem. 110: 21-26.
- Norwegian Scientific Committee for Food Safety. (2013). Risk assessment of the exposure to aluminium through food and the use of cosmetic products in the Norwegian population
- Bundesinstitut fur Risikobewertung. (2014). Aluminiumhaltige Antitranspirantien tragen zur Aufnahme von Aluminium bei. (report in German)
- European Commission Scientific Committee on Consumer Safety (SCCS). (2014). Opinion on the safety of aluminium in cosmetic products SCCS/1525/14.
- Darbre PD. (2010). Environmental oestrogens and breast cancer: evidence for combined involvement of dietary, household and cosmetic xenoestrogens. Anticancer Research 30: 815-828.
- Exley C, Charles LM, Barr L, Martin C, Polwart A, Darbre PD.(2007). Aluminium in human breast tissue. J. Inorg. Biochem. 101: 1344-1346.
- House E, Polwart A, Darbre P, Barr L, Metaxas G, Exley C. (2013). The aluminium content of breast tissue taken from women with breast cancer. J. Trace Elem. Med. Biol. 27: 257-266.
- Sappino AP, Buser R, Lesne L, Gimelli S, Bena F, Belin D, Mandriota SJ. (2012). Aluminium chloride promotes anchorage-independent growth in human mammary epithelial cells. J. Appl. Toxicol. 32: 233-243.
- Darbre PD. (2006). Metalloestrogens: an emerging class of inorganic xenoestrogens with potential to add to the oestrogenic burden of the human breast. J. Appl. Toxicol. 26: 191-197.
We would like to thank Dr Philippa Darbre, Associate Professor at the School of Biological Sciences, University of Reading, for her input and assistance in putting together this information.