Formulating a deodorant: Part 1 - the biochemistry of sweat

I've been trying to make a deodorant for some time now. My tween has officially joined the body odor group :( and I have been attempting to make something strong enough to last through PE and dance. My goal was to make something that would control the body odor using ingredients healthy enough to eat or at the very least, non-toxic. In this post series, I share my thought process as I formulate such a deodorant.

But first, we need to talk about the biochemistry of body odor. Yay! Body odor is caused by the breakdown of sweat into foul smelling acids by some of the harmless bacteria our bodies house. Sweat itself is odorless. Propionibacteria live in the ducts of the sebaceous glands of adult and adolescent humans and break down sweat into propionic acid. Staphylococcus epidermidis breaks down sweat into isovaleric acid. To prevent body odor, the cosmetics industry has gone the route of "no sweat, no stink" aka the antiperspirant. Antiperspirants contain an aluminum or aluminum zirconium salts that works to plug the sweat glands and thus prevent sweat from reaching the skin's surfact. The the higher the concentration of the salt, the better it works. Basically the pH of sweat causes the aluminum to precipitate and thus block the sweat gland. There have been associations of aluminum with cancer and Alzheimer's disease. While there might be a connection between the element and these diseases, it is unlikely that they are caused by the use of antiperspirants. This really long paper is an excellent summary of aluminum, toxicity: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2782734/www.ncbi.nlm.nih.gov/pmc/articles/PMC2782734/

A less common and less effective product that has been used for body odor is the deodorant. Deodorants work by killing the bacteria that cause those smelly acids to form. Typically, deodorants contain chemicals like alcohol, propylene glycol, and sodium bicarbonate (baking soda) as key ingredients. The problem with these ingredients is that they are skin irritants. Often times, deodorants and antiperspirants are used interchangeably - many aluminum containing products are labeled as deodorants: 

Now that we have covered the basics, stay tuned for part 2 where I explore formulating a deodorant using ingredients that are naturally found in our bodies or derived from plants. Why do I care? For one, why should we use products blindly without caring about what we put on our bodies? I want to be empowered to use products that I will not regret using. As a mother I feel compelled to make good choices for my kids in all respects. Second, nature always has a solution. However, these are not well publicized. In part 2, I will go through scientific literature (published in peer reviewed scientific journals - I love PubMed! - http://www.ncbi.nlm.nih.gov/pubmed) to formulate a deodorant.