Oil just by the sound of it feels like something our skin would like. It feels nourishing and you know that just the consistency of it would relieve the uncomfortable sensation of tight, dry skin. Skincare oils also often come in expensive, fancy looking bottles adding to the ritual of nourishment and luxury. Brands seem to have access to bottomless reservoir of exotic plants having a unique oily treasure. And we enjoy learning about a new hyped oil every season: marula, argan, jojoba, rosehip - just to name a few from the last couple of years. But what many skincare lovers do not know is that the plant oil with the most proven benefits for the skin is also the cheapest and most commonly available one: it is sunflower seed oil. You might wonder: how come this non-fancy oil is better than the expensive alternatives we hear all about from skincare brands?
Studies show that some oils, though providing an immediate relief to tight skin, can worsen the dry skin condition over time rather than remedy it. For example, in one study, volunteers have applied olive oil on one arm, and sunflower seed oil on another. Contrary to what most people would probably expect given the popularity of olive oil in skincare, the skin on the “olive oil” arms showed a worsening of barrier function. At the same time, the skin treated with sunflower seed oil improved in its hydration level. The finding that some plant oils support skin barrier function while others can worsen it has been supported by other studies as well. We also have more evidence from clinical research that confirm that sunflower seed oils can be effective in supporting and restoring skin barrier function.
Why is that? An ability of a plant oil to promote skin hydration and healthy barrier function depends on the content of one particular oily compound called linoleic acid. Oils that have a lot of it work great as moisturizers, while oils in which other compounds (e.g. oleic acid) dominate are less helpful. As you have guessed, sunflower seed oil has high content of linoleic acid, but olive oil has more of oleic acid instead.
The high content of linoleic acid in sunflower seed oil makes it useful for our skin in a number of ways. For one, it can help with a potential route cause of skin dryness: a deficiency of essential fatty acids in the upper layer of the skin. It can also help soften the upper layer of the skin and can reduce water loss from its surface. Finally, sunflower seed oil can help calm down inflammation in skin.
Another benefit of sunflower seed oil is safety: unless you have sunflower allergy, you can apply it on your skin without the fear of irritation. Safety of unoxidized sunflower seed oil in skincare is comparable to the dermatological cold standard: mineral oil. Studies have shown that sunflower seed oil is safe and helpful even for the vulnerable skin of prematurely born infants (the same is true for mineral oil, of course).
What makes sunflower seed oil stand out even more among other plant oils it its affordability. In fact, it is one of the cheapest moisturizing ingredients available. It often costs less than petroleum-derived moisturizers.
Still, while sunflower seed oil is beyond any doubt one of the best skincare gifts of nature, there is one important caveat. As all plant oils, sunflower seed oil is prone to oxidation. Oxidation is a chemical process. When a plant oil comes in contact with oxygen or sunlight, it starts a chemical reaction. As a result of it, the original compounds of the oil degrade so you can not expect the same benefits of an oxidized oil compared to the original. What is even worse is that oxidation produces new chemicals (for example, peroxydes) that are harmful and irritating to the skin.
Unfortunately, the same compound (linoleic acid) that makes sunflower seed oil helpful to the skin barrier function also makes it more prone to oxidation. The higher the linoleic acid content of an oil, the faster it oxidizes. In fact, for industrial purposes (including food), people are typically using sunflower plants that have been modified (through breeding or gene editing) to produce seeds with lower linoleic acid content - sometimes to just half of the linoleic acid content of a seed from a “conventional” sunflower. This helps improve the oil stability and make it both more affordable and convenient for food consumption. It also means though that using the sunflower seed oil from your kitchen cabinet, even if it is not oxidized, might not be as helpful to your skin as shown in the studies.
All in all, sunflower seed oil is an excellent moisturizing ingredient. It is probably the best commonly available plant oils for your skin. There are two things to keep in mind for making the best out of this oily plant goodness for the skin: 1. Linoleic acid content: not all sunflower seed oil is created equal. The type that is sold for cooking is almost certainly has less linoleic acid and will not work well as a skin moisturizer. 2. Oxidation risk: sunflower seed oil can oxidize quickly. To reduce the risk of oxidation, it’s better to avoid “pure” oil products (100% sunlflower seed oil), and go for products with a solid antioxidant and preservative system in them. Lotions and creams that have sunflower seed oil only as one of their ingredients are also more likely to oxidize less quickly. Do not be tempted to use sunflower seed oil (or any other plant oil) that you think might be oxidized: it will harm, not benefit your skin.
Explore products with sunflower seed oil here.