Aluminium, deodorants

Aluminium is a useful light metal. Without aluminium, modern lightweight construction in aircraft construction and the car industry would not be possible. Aluminium plays a role as a food additive (E173) and in medicine. In recent years, a connection has been discussed between increased aluminium intake, neurodegenerative diseases such as Alzheimer's disease and breast cancer.

The most important source of aluminium is food. Aluminium is one of the most common elements on earth and is therefore present in small quantities in almost all foods. Aluminium is mainly found in dried herbs and spices (about 45 micrograms of aluminium/g of substance) and in chocolate (about 33 micrograms/g of chocolate). Of the amount absorbed via the gastrointestinal tract, up to about 1% is absorbed systemically, depending on the dosage form.

Water-soluble aluminium compounds such as aluminium chloride or aluminium chlorohydroxide are frequently found in antiperspirants. These substances act mechanically by precipitating proteins and thus temporarily closing the excretory duct of the sweat glands. In this indication, the aluminium salts act purely externally. Part of the applied aluminium is absorbed through the skin.

It is estimated that the systemic absorption via aluminium-containing antiperspirants (with a 20% aluminium chloride content) corresponds approximately to the proportion (10mg/day) that occurs with purely oral absorption. The Federal Institute for Risk Assessment (BfR) advises not to apply antiperspirants containing aluminium after shaving the armpit hair immediately before (increased absorption via micro-injuries).

Medicines containing aluminium compounds (mostly aluminium hydroxide) are e.g. antacids. In this way, up to 2.0 g of aluminium salts are absorbed.

Long-term effects: There are currently no long-term studies on the risks of long-term health effects. In particular, data on the actual amounts of aluminium absorbed through the skin during prolonged use of antiperspirants are lacking. A connection between the intake of aluminium salts and neurodegenerative diseases (amyotrophic lateral sclerosis, Alzheimer's disease, Parkinson's disease) or breast cancer has not yet been scientifically proven, although some experimental data indicate it.

In order to avoid this problem, the use of "aluminium-free" antiperspirants is recommended, which are now increasingly available on the market.

1. Bundesinstitut für Risikobewertung: Opinion on aluminium
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