Aluminium and Good and Bad Bacteria

Fact Check: Aluminium-free Deodorants and Good and Bad Bacteria

We heard of deodorant brands that claim that their products keep 'bad bacteria' in check and promote 'the good ones'. Truth or fairytale?

 

What are good and bad bacteria?

First of all the classification into good and bad bacteria is highly subjective and translates to bacteria that don’t give us body odour (BO) vs bacteria that make us smelly, respectively. From a medical perspective we would perceive bacteria that make us sick as bad and the ones that don’t or have beneficial effects on our wellbeing as good. Keep in mind that even good bacteria can become bad if they end up in the wrong place: E. Coli inhabits our lower GI tract and has crucial functions helping us to digest food. If it ends up in our upper GI tract, it can get us severely ill. What if a bacteria gives us strong body odour but prevents our skin from becoming infected with a fungi, is it a bad or a good bacteria? As you can see good and bad isn’t that simple in regards to bacteria and depends on what we perceive as important in a certain context.

 

Can deodorants promote the good and repel the bad?

The most advanced antibiotics in the therapeutics market are unable to target a single species of bacteria and always work against several bacterial species at once. When we kill a nasty bacterial infection with an antibiotic we always have casualties within species of bacteria that are not harmful to us or are even beneficial for our wellbeing. No deodorant on the market can differentiate between good and bad bacteria. There is evidence that aluminium-free deodorants promote a microbiome in our armpits that has reduced amounts of bacteria that are associated with BO when compared with aluminium-based deodorants. The latter have been shown to promote the accumulation of BO producing bacteria. This is rather an effect of the presence or absence of sweat (aluminium containing deodorants are antiperspirants) than the deodorant promoting good bacteria.

 

Do natural deodorants kill bacteria?

Most deodorants don’t. There are formulations of nanoparticles made from magnesium hydroxide that possess the physical properties to disrupt bacterial cell walls and thereby effectively killing them. No magnesium hydroxide deodorant on the marked can do this, including our deodorants, simply because they are not formulated with the nanoparticle-sized ingredient. No aluminium, bicarb soda or magnesium hydroxide deodorant kills any bacteria when used in amounts that are usually applied to our armpits. However, they can be effective without killing bacteria, read the next paragraph to understand why.

 

Can natural deodorants prevent bacterial growth?

Yes! Bacteria produce energy with a system very similar to the one that is used by mitochondria (little power plants) in our own cells. This machinery is dependent on a flow of charged compounds across their cell wall. Certain ingredients in deodorants (e.g. magnesium hydroxide, which we use) can create an environment which inhibits this process. While it doesn’t kill the bacteria in the short term, it effectively slows down cellular processes including bacterial growth. Less bacteria which are less busy eating sweat release less bad smelling metabolic products. This is the key principle of how our deodorants work. They keep the amount and activity of bacteria (good and bad) in check.

 

How do Magnesium Hydroxide and Sodium Bicarbonate (Baking Soda) compare?

Both ingredients are often used in all-natural or aluminium-free deodorants and are considered safe for skin care applications. They have the same mode of action: they create an environment (high pH) that makes it difficult for bacteria to thrive in. Magnesium Hydroxide is widely known as the more skin friendly option of the two, causing less irritation and being suitable for most people with sensitive skin. One important difference between the two is how well they dissolve in water (or sweat). 1 L of water can dissolve almost 100 g of Sodium Bicarbonate. To dissolve the same amount of Magnesium Hydroxide it needs more than 15 000 L of water - it is practically insoluble in water. This means that not all of its active form is available at once when applied to your armpit, minimising the risk of skin irritation.

 

Are aluminium-free deodorants always formulated without aluminium?

No, that's not always the case. Some brands market their deodorants as aluminium-free, but they may only mean that they are free from aluminium salts. Certain aluminium-free deodorants still contain hidden aluminium compounds like bentonite and kaolin, which technically do not qualify them as completely aluminium-free. While bentonite and kaolin are considered safe for use, it's essential to provide customers with accurate information about product ingredients. A product labeled as 'aluminium-free' should ideally be formulated without any added aluminium compounds. You will not find any hidden aluminium in our deodorants!

We hope this overview helps you to better understand marketing claims around aluminium-free deodorants and making an informed decision when buying your next aluminium-free deodorant.

 

Browse our range of truly aluminium-free deodorants here.