Stearic Acid Side Effects

What is Stearic Acid Made From?
Stearic acid is a saturated fatty acid which goes by the formal IUPAC name octadecanoic acid. It is a waxy, solid acid whose name comes from the Greek word 'stéar', which means 'tallow'. The salts and esters of stearic acid are known as stearates. As far as stearic acid structure goes, it is made up of carbon, hydrogen and oxygen atoms. Its chemical formula is C₁₈H₃₆O₂, or CH₃(CH2)₁₆COOH. Although stearic acid is found in both animal and vegetable oil, it is more commonly found in animal fat compared to vegetable fat. Stearic acid is made by treating animal fat with water at a high temperature and pressure. This causes hydrolysis of triglycerides. Stearic acid can also be obtained from the hydrogenation of some unsaturated vegetable oils.

Stearic Acid Uses
There are many uses of stearic acid. When stearic acid is combined with magnesium, it forms magnesium stearate. This acid is naturally found in many of the foods that are widely consumed such as poultry, fish, meat, eggs, butter, milk products, grains, cocoa, coconut and many other such food stuff. One of the most common uses of stearic acid and its variants is as an ingredient in making candles, plastics, dietary supplements, oil pastels and cosmetics, and for softening rubber. It is also used to harden soaps, especially those that are made with vegetable oil.

Side Effects of Stearic Acid
Stearic Acid is generally considered to be a low to moderate hazard ingredient. There have been claims, in studies that were done, that in slight amounts, stearic acid may lead to some types of cancer. There have also been lesser concerns regarding neurotoxicity, organ toxicity and irritation of skin as possible stearic acid side effects. Another study that was done on animals showed that there was some amount of effect on the brain and nervous system effects, respiratory system, along with some amount of skin irritation at very low doses. In fact, in vitro tests on mammalian cells were positive for mutation results. This is where the concern for its possible carcinogenic effect stems from.

Despite all these claims, stearic acid is generally considered a safe and mild ingredient when it is in concentrations that are below limits that have been shown to cause irritation to the skin, especially in cases of very sensitive skin. The reason why stearic acid has managed to create such a furor is because animal lovers claim that it is derived from slaughterhouses. They claim that unless it is specified that the stearic acid is derived from coconut oil, it is almost always assumed that it is in fact an animal derivative. They claim that the meat is separated from the animals and then, the fat cells are taken and concentrated to turn it into stearic acid. Some even claim that the stearic acid side effects that are seen are in part due to this procedure.

Furthermore, magnesium stearate is most commonly found as a combined product of stearic acid and some claim that it is made by the hydrogenation of cottonseed or palm oil. Cottonseed oil has the highest amount of pesticide residues compared to any other commercial oil and this is what coats the nutrients that are found in supplements. Therefore, this will tend to delay the absorption of these nutrients in the intestines. In large doses, magnesium stearate can cause damage to the skin and can even cause liver toxicity.

In the end, whether the side effects of stearic acid are due to its topical effect in the skin, or due to its concentration which eventually leads to neurotoxicity and nephrotoxicity is yet to be seen. However, it is widely advocated to always try and settle for using natural soaps and products that contain minimal preservatives and animal derivatives.