My over-sensitive nasal passages are already constricting as I think about all the sweaty, au naturel armpits I’ll have to stand next to on the subway if people take note of the latest research regarding antiperspirants — and if further research corroborates the adverse effects of the product’s use.

The concern with antiperspirants stems from aluminum salts, which are the active ingredients in these products.  Aluminum in antiperspirants prevents perspiration by blocking sweat secretion from the sweat glands. Unfortunately, the aluminum salts that provide antiperspirant activity are highly toxic, and an overload can cause anemia, bone disease, and dementia. Worse, a recent study found these same aluminum-containing antiperspirants may be linked to breast cancer.

An article published in 2003 in the European Journal of Cancer Prevention found an earlier age of breast cancer diagnosis (by 3 years) in American women who used antiperspirant, but not deodorant – a product that serves only to reduce body odor by masking it with fragrance – on shaved underarmsi.  The authors of the study posit that the “unique valveless and bi-directional lymphatic flow [that] exists between the breast and axillae [(underarm)]”ii creates an ideal environment that “could easily provide direct and chronic exposure of breast tissue to [aluminum].”iii Studies reveal that aluminum can adversely affect cell replication by increasing DNA replication errors.  All this provides circumstantial evidence that aluminum has [cancer-causing] potential.”iv Although a small retrospective study such as this cannot conclusively link a woman’s underarm habits to breast cancer, it certainly has utility as an initial investigation, and raises suspicion and awareness regarding the underarm hygiene habits practiced by American women. Further well-designed investigations are necessary to evaluate this association.

A separate study reported a case of a woman with dangerously high aluminum levels in her blood resulting from the use of aluminum-containing antiperspirant.  This particular woman, 43 years of age, applied about 1 g of an aluminum chlorohydrate-containing cream on each underarm every morning for four years. Her underarms, which were shaved regularly, did not show signs of rash or skin irritation. Yet after experiencing bone pain and extreme fatigue without other obvious explanation, she was evaluated in detail.v

Use of the antiperspirant was discontinued in her case, and one to three months later aluminum levels in her blood plasma and urine had decreased markedly.  By eight months after discontinuation of the antiperspirant, the aluminum overload disappeared completely and her symptoms resolved concurrently.vi Circumstantial evidence from this case indicates that severe hyperaluminemia resulted from repeated applications of an aluminum-containing antiperspirant during a considerable period of time (four years being “considerable”).  The disappearance of bone pain in the woman a few months after antiperspirant use was stopped, as well as the pronounced decrease in plasma and urine aluminum concentrations to normal levels, strongly suggest that the toxicity observed was due to aluminum chlorohydrate — the active ingredient in the antiperspirant.  The authors of this study suggest that, “although individual variations in aluminum absorption are likely, the risk of increased aluminum uptake suggests that caution should be exercised when using aluminum-containing antiperspirants frequently”vii, i.e. every day.

Take home message: As mentioned above, more investigation is needed to determine whether there is a true link between breast cancer and aluminum-containing antiperspirant.  Further, the one case of a 43 year-old woman with high blood aluminum levels is just that … one case. We cannot apply the findings in her situation to the general population.  However, erring on the side of caution is always a good idea.

The prudent approach then would be as follows: bathe, with soap, regularly.  Most of us don’t sweat that much in our day-to-day activities, therefore antiperspirant use is unnecessary on a daily basis.  If you anticipate you will be sweating (for example, if you are going to the gym), consider rolling on a bit of aluminum-free, fresh-smelling deodorant.  Remember, though, that sweating is natural.  The potential stench of the sweat is also natural, but obviously less pleasant. Deodorant is a better option than antiperspirant because it will mask the sweaty smell without blocking your sweat glands — and of course without introducing toxic metals into your bloodstream. Future research may confirm this lifestyle change to be quite beneficial to your health and longevity.