Reasons for using lecithin in cosmetics and its risks

Ingredients to be aware of other than beauty ingredients

Many people are researching popular beauty ingredients such as vitamin C, retinol , and CICA .

However, there are actually many beauty ingredients that aren't talked about.

Lecithin, which will be discussed in this article, is one such substance. It is used in foods with the expectation of various effects and functions, but most people probably don't pay much attention to it.

Please read this article to find out more.

Lecithin in eggs

Lecithin is a type of lipid called phospholipid. It is the main component of the membrane that surrounds cells and is present in all animal and plant cells. Of course, it is also present in tissues of the human body, and is particularly abundant in the brain, nervous tissue, and liver.

Lecithin is found in large amounts in plants, such as egg yolks and legumes like soybeans. Many people may know that most of the fat in egg yolks is lecithin.

Lecithin helps water and oil mix

Water and oil do not mix by themselves. However, if you use lecithin, they will mix. This is because lecithin has the property of mixing water and oil. The reason why the vinegar and oil in mayonnaise do not separate is because of the lecithin in the egg yolks used in mayonnaise.

Its ability to keep water and oil mixed together is also used in cosmetics.

This is because cosmetics are basically made of water-based ingredients (water) and oil-based ingredients (oil). By adding lecithin, which can blend with both water and oil, as an emulsifier, the ingredients can be kept mixed together evenly.

Natural and functional

As mentioned above, lecithin is a component found in plants and animals. Because it is a naturally derived component, it is often used in natural and organic cosmetics .

Lecithin's role as a cosmetic ingredient is not limited to emulsification. It is also expected to have a variety of other effects, such as the following:

Emollient effect

An emollient is something that increases the moisture level on the skin's surface, and lecithin is sometimes used as an emollient to soften the skin, as it attracts moisture and keeps the skin hydrated.
Lecithin, which is rich in lipids, creates an oily layer on the surface of the skin, which traps moisture on the surface of the skin and prevents it from drying out.

Related article: What is the emollient effect on dry skin?

Penetration promotion

Lecithin is said to promote the penetration of other ingredients . By delivering effective ingredients deeper into the skin, it is believed to have a greater moisturizing and beauty effect.

Antioxidant

Lecithin is known to have antioxidant properties , which may help prevent damage to the skin caused by ultraviolet rays and external stimuli.
Combined with Vitamin E, such as tocopherol , it may provide additional skin repair benefits.

Improve the texture

Lecithin can also be used to thicken creams and lotions, making them creamy, easy to spread, and giving them a smooth texture.

Hydrogenated Lecithin

Generally, lecithin itself is an ingredient that easily oxidizes. It also becomes unstable when exposed to heat, so most cosmetics contain hydrogenated lecithin.

Hydrogenated lecithin is lecithin with hydrogen added. By adding hydrogen, its original function and stability are improved. It seems that EWG considers it safe to use in cosmetics .

Who should avoid lecithin?

Both lecithin and hydrogenated lecithin are generally considered safe cosmetic ingredients.
However, based on the EWG's evaluation and some research papers, some people should be cautious when using it.

People with soy or egg allergies

Lecithin is found in a variety of plants and animals, but most of the lecithin used in cosmetics is soybean lecithin or egg yolk lecithin.
Therefore, if you have a soy or egg allergy, it is best to avoid it just to be safe. If you want to use it, do a patch test or consult a dermatologist beforehand.

People with sensitive skin

I wrote that lecithin promotes the penetration of ingredients into the skin. This may seem like a good effect at first glance, but if it penetrates too much, it can irritate the skin. People with sensitive skin or thin skin should be especially careful.
One study in mice showed that 30% of lecithin penetrated into the subcutaneous tissue.

About percutaneous absorption: Differences between percutaneous absorption and penetration of cosmetic ingredients

The risks of lecithin that promotes penetration

When the following ingredients are mixed with lecithin, they may penetrate deep into the skin and pose unexpected dangers.

• Ingredients that are considered safe because they are not absorbed through the skin
• Ingredients that have been identified as posing risks when absorbed through the skin

No matter what cosmetic ingredient, it is not expected that it will pass through the epidermis and dermis and reach the subcutaneous tissue. What if an ingredient that is considered safe because it is not absorbed through the skin reaches the subcutaneous tissue due to the action of lecithin?

No one knows what the impact will be.

Potential to produce carcinogens

Another concern is the generation of by-products.

Lecithin can react with certain substances to produce nitrosamines, which are suspected to be strong carcinogens and have been detected in pharmaceuticals, which are subject to stricter controls than cosmetics.

To avoid the risk of nitrosamine contamination, you must be careful about the ingredients you use together.
A report from the Cosmetic Ingredient Safety Research Institute , a global organization that evaluates the safety of cosmetic ingredients, also warns that ingredients that have the potential to produce nitrosamines should not be mixed with lecithin.

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