In the first two articles of this series, I talked about chemicals you might want to avoid in your soap, shampoo, lotion, and makeup. In this article, I’ll focus on deodorants and antiperspirants. These products are cocktails of many different chemicals, including several I’ve already covered, such as parabens, phthalates, and triclosan. But the most concerning (and most researched) ingredient in deodorant is aluminum, which is what I’ll focus on here.
Aluminum is the active ingredient in most antiperspirants, and it functions by forming a precipitate that physically blocks sweat glands. (1)
Can Aluminum in Deodorant Be Absorbed?
Before we consider the health effects of aluminum in deodorant, we need to know whether it can even be absorbed through the skin. There isn’t consensus on this point, but most evidence indicates that it can be. One 2001 study found that aluminum from a single application of antiperspirant was absorbed, but only to a small extent, especially relative to the amount of aluminum absorbed in the gut from food. (3)
However, a case study of a woman who had used an aluminum-containing antiperspirant for 4 years had toxic blood levels of aluminum, which resolved 8 months after discontinuing use of the antiperspirant. (4) Her symptoms of severe bone pain and fatigue also ceased.
Is there aluminum in your deodorant? Here’s why you should check:
A more recent study using an in vitro model shows that aluminum can be absorbed through human skin, and that stripped skin (such as freshly-shaved underarm skin) is significantly more permeable to aluminum than intact skin. (5) Aluminum is also regularly detected in both normal and cancerous breast tissue. (6) This suggests that aluminum indeed can be absorbed by the skin as well as into the breast tissue.
Can Aluminum Contribute to Breast Cancer?
What about the link with breast cancer? We know that estrogen plays a key role in the development of breast cancer, and one study demonstrated that aluminum can interact with estrogen receptors on human breast cancer cells. (7) Additional preliminary research indicates that aluminum might promote breast cancer growth in other ways as well, though more research is needed before any conclusions can be drawn. (8,9)
Human mammary epithelial cells grown in media with aluminum concentrations around 100-300µm (which is around 100,000 times lower than aluminum concentrations in antiperspirants, and comparable to aluminum concentrations found in breast tissue), resulted in DNA double strand breaks and loss of contact inhibition, two occurrences that often precede cancer. (10) Aluminum might also contribute to oxidative damage in breast tissue and increase breast cancer cells’ invasive and migratory tendencies. (11)
There is also speculation that the blockage of sweat glands caused by aluminum-based antiperspirants could lead to the dermal absorption of abnormal levels of sex hormones and pheromones, which could contribute to cancer development. (12)
Aluminum and Alzheimer’s Disease
We can’t discuss the potential health dangers of aluminum without mentioning Alzheimer’s disease. Like breast cancer, the link between aluminum and Alzheimer’s has been a popular topic in the media. But does this link have merit?
A review conducted in 2011 says “yes.” (13) The author points to evidence that aluminum tends to accumulate in brain tissue and is capable of producing Alzheimer’s-like symptoms, and that only small amounts of aluminum are necessary to have a neurotoxic effect. If aluminum from deodorant does indeed make it into systemic circulation, this evidence indicates that it could accumulate in brain tissue over time and possibly contribute to Alzheimer’s disease.
Nontoxic Alternatives to Deodorant
Conventional deodorant isn’t always the easiest thing to replace, but at the very least, try to find a brand that doesn’t contain aluminum. This means avoiding anything that is an “antiperspirant.” For completely non-toxic deodorants that don’t contain aluminum, parabens, or any other questionable chemicals, you can try Primal Pit Paste or Primal Life Organics.
If you’re feeling a little more adventurous (or want to save some money), you can try one of the many recipes online for homemade deodorant. The most popular formulation is based on baking soda, like this recipe from Mommypotamus. Other recipes use diatomaceous earth, bentonite clay, or magnesium oil as the active ingredient, and some people find that simply applying magnesium oil as deodorant eliminates odor. (Plus, you get an extra dose of magnesium – something you actually want your skin to absorb!) Wellness Mama also suggests that using bentonite clay to “detox” your armpits can reduce odor and make deodorant less necessary.
“Crystal” deodorants are another popular choice, although I have mixed feelings about them. These deodorant stones are made of alum, which is a compound made up of aluminum sulfate bonded to either potassium or ammonium (plus a bunch of water molecules). On the one hand, this compound is larger than the aluminum compounds found in conventional deodorant, and is therefore unlikely to be absorbed through the skin, but I haven’t been able to find any actual data on dermal absorption of alum. So while crystal deodorants are a better choice than conventional deodorants, you might be better off forgoing aluminum altogether and trying a baking soda or clay-based deodorant.