Recently, aluminium salts have been demonised as one of the major cause of breast cancer. This is because analysis on breast cancer cells showed a large 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 scientific studies have attempted to address directly the link between 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 that, among patients affected by breast cancer, those who use such products at an earlier age, were diagnosed with breast cancer more often. Both studies have limistations. The first study is limited by the reliance on self-reported information, by the lack of non-users data and there’s no mention about long-term usage. The second study suggests a dose-response relationship to chemical exposure and sensitivity at a younger age. However, this does not exclude other risk factors or the fact 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 that aluminium absorption is of about 1.81 μg/cm2 for intact skin, meaning skin before shaving. Absorbion increased to 11.5 μg/cm2 for stripped skin, (a procedure equivalent to shaving). So, providing skin wasn’t damaged or broken, aluminium from cosmetics would be absorbed in a very low dose. Is this a breakthrough news? Really not. Aluminium chlorohydrate in deodorant is limited to 25%w/v by the Food and Drug Administration (FDA) in the USA. Additionally, aluminium hydroxide in cosmetics is limited in to 20% w/v by the FDA and 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 neglecting 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 aren’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 when using deodorants 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.