Recently, aluminium salts have been demonised as one of the major cause of breast cancer. Analysis of the cancerous material analysed from breast cancer cells showed a conspicuous amount of aluminium. Hence, the claim that aluminium salts, such as aluminium hydroxide and aluminium chloride are responsible for it. To which extent this is true?
Only two studies have attempted to address directly the issue of underarm cosmetic use and breast cancer. In one study it is reported that there is no difference in the risk of getting breast cancer between those who use antiperspirant/deodorant products and those who don’t. By contrast, McGrath reported within a population of breast cancer patients that those who used more antiperspirant products were diagnosed with breast cancer at an earlier age. The first study is limited by the reliance on self-reported information, by the lack of a nonuser population and by the lack of consideration to historical usage. The second study suggests a dose-response relationship to chemical exposure and sensitivity at a younger age, consistent with patterns of breast cancer development, but does not exclude other risk factors or the issue that cosmetic use is simply higher in younger women.
So, none of these studies is enough to support the claim that aluminium in deodorant and cosmetics is linked to a higher risk of breast cancer.
Paracelsus principle states that everything is toxic depending on the dose. So, let’s talk about numbers.
Can aluminium from deodorants be absorbed by the skin and to which extent? Studies showed aluminium absorption of 1.81 μg/cm2 for intact skin but this was increased to 11.5 μg/cm2 for stripped (a procedure equivalent to shaving) skin. So, providing skin isn’t damaged or broken, aluminium from cosmetics is absorbed in a very low dose and I would say safe to use. Is this a breakthrough news? Really not. Aluminium chlorohydrate is limited to 25%w/v by the Food and Drug Administration (FDA) of the USA and aluminium zirconium chloride hydroxide complexes are limited in cosmetics to 20% w/v by the FDA and in the European Union (EU). Both the USA and EU include statements that these products should not be applied to broken, damaged or irritated skin, but current cultural practices can include shaving before antiperspirant application, thereby negating the specific warning by the FDA and EU.
Another study showed that the use of aluminium in cosmetics raise its concentration in blood plasma to 4 μM. When those products haven’t used the concentration of aluminium salts in the blood plasma is less and 0.5 μM. Safe levels of aluminium in the blood serum should be below 7 μg/L. So, aluminium can be absorbed by the skin but at levels that are below its toxic dose. In my opinion if deodorants are used according to the FDA and EU guidelines and with moderation, they won’t pose a threat to one’s health.
- Underarm antiperspirants/deodorants and breast cancer, Breast Cancer Research2009, 11(Suppl 3):S5
- Aluminium and breast cancer: Sources of exposure, tissue measurements and mechanisms of toxicological actions on breast biology, J Inorg Biochem. 2013; 128, 257.
- The Health Effects of Aluminium Exposure, Dtsch Arztebl Int. 2017; 114, 653.