What Is Grape Seed Oil, What Does It Do? Linoleic Acid

The name of grape seed oil often carries a wrong expectation. The polyphenols and the strong "anti-ageing" antioxidants that come to mind with grapes are largely the subject of the seed extract, not the oil. The oil's real property is different: among common vegetable oils it has one of the highest linoleic acid shares, and that is why it is used in cosmetics. In measurements, about 66-75% of the fatty acids were linoleic, 14-20% oleic, 7-8% palmitic, and 4% stearic acid.

Oil or extract? The most common confusion

Only about 0,01-0,02% of the polyphenols pass into the oil; the rest remains in the press cake. Be cautious of texts that present a study of the extract as if it were a benefit of the oil. The oil contains more tocotrienols than the vitamin E family's tocopherols, and the amount varies widely by variety, from 1 to 53 mg per 100 g.

What does linoleic acid do to the skin?

Linoleic acid is an essential fatty acid from the omega-6 family and plays a direct role in the water impermeability of the skin barrier. The low level of linoleic acid in the sebum of acne-prone skin is discussed as a factor that makes the comedo wall permeable. In a small study, microcomedone size in the area where linoleic acid was applied fell by about 25% over 1 months, and did not change in the placebo area.

The point to watch: in that study it was linoleic acid that was applied, not grape seed oil. We do not know a good study testing the oil itself on acne-prone skin. It is premature to say "good for acne"; it is more honest to say "reasonable to try on oily skin". For the general routine, you can look at the oily skin care article.

Has it really been tested on skin?

Very little. A review of vegetable oils clearly says the oil has not been studied enough in human skin. In a rat wound model, a connective tissue marker rose and the wound closed faster. The closest human data is a foot-massage study in 90 pregnant women: massage with grape seed oil and sweet almond oil was better than no intervention for leg swelling, but the two oils were indistinguishable. This suggests the effect may come from the massage rather than from the oil.

Light texture claim and quick spoilage

The description "light, absorbs quickly into the skin" is common in the sector, but there is no measured standard for it. The perception varies with the formula and the person. What is measured is oxidation: in a comparison with refined oils, grape seed oil, which has many double bonds, had the shortest resistance time to spoilage. It is also known that oxidised oils can lead to sensitisation.

• Choose a small bottle, keep it away from light and heat, and do not leave it open for a long time after opening.
• If you notice a change in colour or a sour smell, do not apply it to your skin.
• A note on food: drying of seeds with combustion gases can increase polycyclic aromatic hydrocarbons in some oils, and refining generally reduces this. This finding was measured for cooking oil; its importance in an applied product is not known.