Q. Would you please comment on the safety of alum as a deodorant? I think it is the ingredient in many “Crystal” antiperspirant products.
A. We have heard from lots of readers that they gave up aluminum-based antiperspirants because of a fear of either Alzheimer’s disease or cancer. Here are just a couple of examples:
“The women in our family have been using Crystal roll-on for some time, as we’ve been avoiding aluminum and paraben for years and we find that it works well.”
“For more than 10 years I’ve used deodorant-only products, because someone warned of a cancer risk. It’s a bit hard to find, but I found a crystal roll-on product that is fragrance, paraben and aluminum chlorohydrate free. Seems to work well. If I hadn’t just bought a new bottle, I’d try the Graedons’ Milk of Magnesia roll-on deodorant.”
“Have started using Crystal roll on deodorant which is paraben free and is a natural product. It is made from mineral salts and is also hypoallergenic and safe for the environment.”
Crystal deodorant sounds like the ideal solution for avoiding aluminum in an antiperspirant. There is one problem, however. Many of the manufacturers of such products are very cagey about the ingredients in their “natural” crystal deodorant products. There is no doubt that such products are natural, since aluminum is a mineral found in nature. You will sometimes see the word “alum” or potassium alum as the main ingredient.
The online Merriam-Webster dictionary defines alum as:
“a potassium aluminum sulfate KAl(SO4)2·12H2O or an ammonium aluminum sulfate NH4Al(SO4)2·12H2O used especially as an emetic [causes vomiting] and as an astringent and styptic [to prevent bleeding].”
Alum has been used for a very long time in reservoirs to clarify water. That is, it helps suspended particles settle to the bottom so they can be removed. It has also been used as a remedy for canker sores and in a styptic pencil to stop bleeding after shaving. That said, there is no doubt that alum contains aluminum, often hydrated potassium aluminum sulfate (potassium alum). Anyone who thinks that using a natural crystal deodorant eliminates aluminum is kidding herself.
Is the aluminum in natural crystal deodorants dangerous? That is a question that remains unanswered. How much aluminum is absorbed from delicate underarm tissue? No one has a good answer. If this aluminum is absorbed, does it pose any health risk?
An article in the Journal of the National Cancer Institute (Oct 16, 2002) concluded that there was no connection between use of antiperspirants and the risk of breast cancer. More recently, though, a study suggests that aluminum compounds can change the way breast cells divide, even at low concentrations (Journal of Applied Toxicology, online, Jan. 6, 2012). The authors of this research conclude: “Our observations do not formally identify aluminium [British spelling for aluminum] as a breast carcinogen, but challenge the safety ascribed to its widespread use in underarm cosmetics.” There is also research to suggest that aluminum concentrates in breast tissue, possibly from exposure to aluminum-containing antiperspirants (Journal of Applied Toxicology, April, 2011).
A study in the Journal of Inorganic Biochemistry (Nov. 2011) points out that: “The human breast is exposed to aluminium from many sources including diet and personal care products, but dermal [skin] application of aluminium-based antiperspirant salts provides a local long-term source of exposure.” These researchers note that nipple aspirate fluids have been shown to contain aluminum at higher levels in breast cancer patients than from healthy control subjects “providing evidence of raised aluminium levels in the breast microenvironment when cancer is present.”
A thoughtful review of this entire topic was published in Best Practice & Research. Clinical Endocrinology and Metabolism by a British oncology professor. Some of the comments include:
“Several components of cosmetics have genotoxic properties, including the aluminium salts..”
“Dermal absorption of topically applied antiperspirant aluminium salts has been demonstrated through intact mouse skin and and the skin of the human underarm. Aluminium in the form of aluminium chloride or aluminium chlorhydrate has been shown capable of interfering with the function of oestrogen receptors of human breast cancer cells both in terms of ligand binding and oestrogen-regulated gene expression.”
That is, these compounds may act as hormone disruptors.
It will probably take many more years to resolve the controversy about any relationship between aluminum and breast cancer. In the meantime, people who seek to avoid aluminum in their armpits will probably want to look beyond crystal-type natural deodorants. Many people find that milk of magnesia applied to the underarm helps against odor, so that may be an attractive alternative. There is more information about this here.