Let’s learn together about the plant-based oils added to moisturizing skin care products.
I. Advantages of vegetable oils as moisturizing ingredients
Vegetable oil is a fat obtained from the fruits, seeds or germ of plants, it is similar to lipids of animal origin, which are fatty acid glycerides, hydrolyzed to produce glycerol and a mixture of fatty acids. Unlike animal fats and oils, the various fatty acids in vegetable oils are more unsaturated fatty acids, the main ones being oleic acid (also called ω-9 unsaturated fatty acids), linoleic acid (ω-6 unsaturated fatty acids) and linolenic acid (ω-3 unsaturated fatty acids).
Linoleic and linolenic acids are a class of fatty acids that are essential for human skin but cannot be synthesized by the skin itself and need to be ingested into the body through the diet. Studies have found that the unsaturated fatty acids in vegetable oils are beneficial to skin health, so many moisturizing skin care products now include vegetable oils.
Linolenic acid and linoleic acid are particularly important for skin health. Linoleic acid is mainly found in the epidermal lipids ceramide and cholesterol, which are important for maintaining the skin’s moisture barrier, while linolenic acid has a role in preventing skin inflammation.
Since the body cannot synthesize linolenic acid and linoleic acid, they must be consumed from the diet. If plant-based fats rich in linolenic acid and linoleic acid are added to the diet, it will facilitate skin barrier restoration and reduce inflammatory responses. For example, evening primrose oil (Evening
Primrose oil) and borage oil (borage
oil, both of which are rich in gamma-linolenic acid, can be converted into prostaglandin E1, which has anti-inflammatory effects in the body. Some studies have found that some patients with atopic dermatitis/eczema have improved eczema symptoms after taking evening primrose oil and borage oil orally. Evening primrose oil has also been added to some moisturizing skin care products.
II. Oils of various plant sources
There are many kinds of vegetable oils that are often added to moisturizing skin care products. If you pay attention to the ingredients list of moisturizing products, you will find the following kinds of familiar vegetable oils: coconut oil, almond oil, macadamia oil, corn oil, canola oil, cottonseed oil, grapeseed oil, olive oil, tea oil, peanut oil, safflower oil, sesame oil, soybean oil, sunflower seed oil, pecan oil, castor oil, avocado oil (avocado oil) Shea butter, jojoba oil, etc.
The types of unsaturated fatty acids vary from vegetable oil to vegetable oil, and the table below lists the content of different fatty acids in some common vegetable oils.
It can be seen that
Olive oil, tea oil and almond oil are all vegetable oils with high oleic acid content;
sunflower oil, safflower oil, corn oil and soybean oil are vegetable oils with high linoleic acid content.
Evening primrose oil and borage oil, mentioned above, are vegetable oils with high linolenic acid content.
These different vegetable oils are added to moisturizers, and their efficacy will vary depending on the type and content of unsaturated fatty acids.
Third, is mineral oil really so terrible?
Let’s take a look at the differences in the physicochemical properties of mineral oil and vegetable oil added to skin care products.
Let’s take a look at the difference in moisturizing efficacy between mineral oil and vegetable oil and their effects on the skin
Through comparison, we can see that the mineral oil or vegetable oil added in the moisturizing skin care products have their own advantages and disadvantages.
Fourth, the advantages of mineral oil
Mineral oil sealing good, good skin, non-allergenic and good stability, is a lot of moisturizing skin care products and infant skin care products in the basic ingredients; In addition, the high production of mineral oil, low cost, some inexpensive and high-quality hospital-made moisturizing skin cream (such as silicone cream) are added to mineral oil to achieve the role of moisturizing.
Five, the misunderstanding of mineral oil
There are many statements on the network that mineral oil in skin care products can block pores and cause acne, but in recent years, many studies conducted in humans have not confirmed that mineral oil induces acne; about the toxicity of mineral oil, it is impossible to talk about, because the molecular structure and physicochemical properties of mineral oil determines that it is almost not absorbed by the skin, it is only in the skin surface to form a layer with a sealing oil film, blocking The loss of moisture in the skin.
Sixth, the advantages and disadvantages of vegetable oils
Vegetable oils are rich in polyunsaturated fatty acids that are beneficial to the repair of the skin barrier, and some vegetable oils also contain vitamins A, B, D, E and some trace elements, which have certain anti-inflammatory and antioxidant effects; however, these active substances are unstable and easily oxidized, and compared to mineral oil, it is more likely to have allergic or skin irritation reactions; in addition, the extraction process of vegetable oils is complex, the yield is low, and the price of moisturizing products with vegetable oils is usually higher. The price of moisturizing products with vegetable oils is usually higher.
Seven, direct use of vegetable oils can achieve moisturizing effect?
There are many patients with dermatitis eczema who often use vegetable oils directly on their skin for skin care. Some parents also use olive oil directly to massage their babies.
Eight, is this effective? Is it safe?
The unsaturated fatty acids contained in olive oil and camellia oil are mainly oleic acid. Animal studies have found that oleic acid (10%) can affect the stability of lipid membranes of normal epidermal cells and form lacunae to increase skin permeability, so oleic acid can be used to promote transdermal absorption of other drugs. If the right amount of olive oil or tea oil is added to a moisturizer, the oleic acid in it will increase the absorption of other active skin care ingredients in the moisturizer.
But on the other hand, if olive oil and camellia oil containing higher concentrations of oleic acid (79%-80%) are applied directly to the skin, there is a risk of damaging the normal lipid film of the skin, which in turn exacerbates the destruction of the skin barrier and causes skin dryness.
A recent foreign study compared the effects of olive oil and sunflower seed oil directly applied on normal skin or eczema patients’ skin on epidermal stratum corneum integrity, skin water content and pH value, and found that after 4 weeks of direct application of olive oil on skin, skin barrier function was damaged, water loss increased, and inflammatory reactions such as mild erythema appeared on skin. Another study found that direct use of olive oil as an infant massage oil may induce eczema in infants. Therefore, direct use of olive oil is not recommended for either normal infant skin care or eczema patients for moisturizing.
Camellia oil is a specialty edible oil in China with a long history of production and use. In some legends also have tea oil to promote skin healing story: According to legend, during the late Yuan Dynasty, Zhu Yuanzhang was chased by Chen You Lang army to Jianchang (now Jiangxi) a piece of oil tea forest, is picking in the oil tea forest old farmer in a hurry to Zhu Yuanzhang dressed as a farmer picking oil tea fruit, was spared a disaster. Zhu Yuanzhang deeply called the old farmer for saving his life “old table”. Old table see Zhu Yuanzhang body is wounded, with tea oil to help him coated. In a few days Zhu Yuanzhang felt the body wounds healing, redness and swelling gradually disappear, so he was happy to call this oil tea fruit.
Although there is such a beautiful legend, but according to the results of foreign research on olive oil, tea oil oleic acid content is even higher than olive oil, so should not be applied directly to the skin to skin care or massage.