The Science of Sweat

Our bodies have two types of sweat glands, known as eccrine and apocrine glands. 

The eccrine sweat glands are found across most of the body, with a high concentration in our hands and feet. When our body temperature rises, the eccrine glands release a clear, odourless fluid to the surface of the skin. The fluid then evaporates, helping us to keep cool.

Apocrine glands are only found in areas where we have hair e.g the armpits and groin. They release a milky fluid when we are stressed. Although the apocrine gland does play a part in regulating body temperature, it works slightly differently to the eccrine gland. 

Interestingly, neither of these glands produce any odour. The sweat our body releases is actually entirely odourless until it reacts with a bacterium that thrives in warm, moist areas of the skin.

The reason our underarms tend to smell more than the rest of our body is due to the different types of sweat glands present. The sweat released by the eccrine glands has a high salt content, making it harder for bacteria to break down. However, the fluid produced by our Apocrine glands contains fats and proteins, such as lipids, that react with the bacteria to create that familiar and unpleasant smell.

How do Antiperspirants Work?

Mainstream antiperspirants work to control unpleasant odours by stopping the sweat altogether. The aim is to stop perspiration and, in the process, avoid the damp, moist environment that odour-causing bacteria thrives in. (This is different to deodorants, which are designed to control odour rather than block sweat.)

So, here’s the science-y bit: Antiperspirants contain aluminium salts which are soluble in acidic formulations. In other words, when the salts come into contact with our sweat, a reaction starts that increases the PH balance of the underarm. This forces the aluminium to precipitate out of the formula and form a plug over the sweat glands. Sweat is still produced by the body, but it is now unable to escape to the surface of the skin.

Regular use of antiperspirants causes blockages that can damage the sweat ducts. This makes it harder for the apocrine glands in our armpits to expel toxins. We personally think there must be a better and more natural way to control our body odour.

Is Antiperspirant Toxic? 

Antiperspirants rely on harmful ingredients to control odour and perspiration. So, not only do antiperspirants inhibit our bodies natural detoxifying process, but they also introduce new toxins into our bodies.

Dr Heather Patisaul, an associate professor of biology at North Carolina State University, has found that many of the ingredients found in deodorant products could be disrupting our reproductive and developmental hormones. 

In an interview with Time Magazine, she said “When you eat something, it’s broken down by your liver and digestive system, but when you put something on your skin, there are times when it can enter your bloodstream without being metabolized.”

Although not everything you apply topically will seep into the skin*, blood tests have shown that many of the toxic ingredients in deodorant pass through the dermis and into our blood. After being absorbed into the body, some of the toxins then end up being stored in the fat cells of the underarm.

*See Magnesium Oxide, a natural mineral we use in our Natural Deodorant Balm, which doesn’t pass through the epidermis.

Toxic Ingredients Commonly Found in Deodorants

Aluminium

Aluminium is known to cause ‘gene instability’ in breast tissue. Philippa Darbre, an oncologist at the University of Reading, has found that this instability can promote the growth of cancer cells. In another study, it was also found that aluminium can cause physical changes to the oestrogen receptors in breast cells, potentially leading to cancer and other illnesses. 

Due to how complicated and slow the development of cancer is, there is no intrinsic proof at this point that aluminium can cause or increase the chances of someone getting cancer. However, over 50% of breast cancers start in the upper quadrant of the breast tissue nearest the underarm region, leading many scientists to believe that there is a strong correlation.

If you are looking for a visual representation of how aluminium can mess with our bodies - the yellow stains that appear on the underarm of your clothes are actually the result of a chemical reaction taking place between the aluminium salts and the proteins in your sweat.

Phthalates

Phthalates are added to cosmetics in order to make the product stick to your skin. With regular use, they can affect the way our bodies produce and use testosterone.  This is because Phthalates disrupt androgen function, potentially leading to reproductive issues for men and women.

Parabens

Parabens are a widely used preservative added to cosmetic and pharmaceutical products in order to stabilise them. However, there is research to suggest that parabens interfere with the way our body produces and regulates oestrogen hormones (a problem for both men and women).

Due to the close proximity of the underarm to the oestrogen-sensitive tissue found in the breast, studies have shown that regular use of certain deodorants can cause an imbalance in the body's hormonal systems.

TEA & DEA

Triethanolamine (TEA) and diethanolamine (DEA) are actually banned in Europe due to their carcinogenic qualities, but they are still used in many US-based deodorant products.

The two compounds are used in cosmetics as emulsifiers to mix oil and water. When used alongside certain preservatives, they can break down into carcinogenic nitrosamines that can be absorbed through the skin.