Is sunflower oil a comedogenic oil?

The term comedogenicity refers to the ability of an ingredient to create an occlusive film on the skin's surface, blocking the pores and potentially promoting the appearance of skin imperfections. The sebum released on the skin's surface then has difficulty evacuating, leading to an accumulation that results in the formation of comedones, or skin blemishes. Comedogenic oils can be an aggravating condition for skin disorders such as acne. However, the comedogenicity of an oil does not necessarily guarantee the appearance of skin imperfections.

Indeed, reactions following the application of comedogenic products vary from one individual to another. In a study conducted by DINARDO on six people with blemish-prone skin, the application of a patch saturated with comedogenic cosmetic products did not lead to the formation of comedones in the entire group. These results show a high intra-group variability. Thus, depending on the skin type and the concentration of comedogenic actives, the effects of a comedogenic oil vary.

Furthermore, thecomedogenicity index is a parameter that allows the evaluation of an ingredient's comedogenicity, or its potential to clog pores. It is measured on a scale of 0 to 5. A score of 0 indicates that there is no pore obstruction. A score of 5 means that the oil can cause pore occlusion, leading to the appearance of comedones, or blackheads. On average, an ingredient is considered comedogenic as soon as its comedogenicity index is at least 2. The comedogenicity index of a vegetable oil can be influenced by various criteria, such as the speed of the oil's penetration into the epidermis, oxidative stability, rancidity, and the quality of the oil.

A scientific review published in 1989 by FULTON, a renowned dermatologist, classified sunflower oil as a non-comedogenic oil. This review provides a list of ingredients ranked according to their comedogenicity. It assigns sunflower oil a comedogenicity index of 0. Furthermore, several scientific data on sunflower oil allow for the evaluation of its comedogenicity.

1. Sunflower oil exhibits a good rate of penetration: Its rich composition of polyunsaturated fatty acids such as linoleic acid allows the sunflower oil to easily penetrate the skin. Indeed, thanks to its numerous double bonds, linoleic acid is flexible, which facilitates the oil's penetration into the skin barrier. Moreover, linoleic acid is a natural component of the stratum corneum, which further enhances penetration.

2. Sunflower oil exhibits good oxidative stability: Sunflower vegetable oil notably contains Vitamin E, which acts as an antioxidant and combats oxidation reactions. The Vitamin E content in the oil (about 60 mg per 100 g) thus allows sunflower oil to have a good stability to oxidation.

3. Sunflower oil is a high-quality oil: There are different methods of extracting sunflower oil, the cold-press method remains the least risky in terms of composition. The virgin sunflower oil obtained does not contain impurities and retains its compositional characteristics.

Finally, proper storage of the oil, protected from heat and moisture, is crucial in order to maintain its essential composition. Heat could promote the oxidation of the oil. Thus, all the data regarding the comedogenicity of sunflower vegetable oil tends to suggest that it is a non-comedogenic oil.

Note: There are several types of sunflower vegetable oil on the market, which differ in terms of composition. The "linoleic" type sunflower oil has a composition enriched with polyunsaturated fatty acids, and the "high oleic" type has a composition much richer in monounsaturated fatty acids. Thus, the "high oleic" type sunflower oil will slightly diverge from regular sunflower oil in terms of its oxidative stability.

• FULTON J. E. Comedogenicity and Irritancy of Commonly Used Ingredients in Skincare Products.Journal of the Society of Cosmetic Chemists (1989).

• DiNARDO J. C. & al. A Reassessment of the Comedogenicity Concept. Journal of the American Academy of Dermatology (2006).

• KHARRAT M. & al. Biochemical Characterization of Seed Oil from Tunisian Sunflower (Helianthus annuus L.) Varieties with Particular Emphasis on Its Fatty Acid Composition and Oil Content. Journal of Food Quality (2022).

• TURSUNOVA N. & al. Physiological and biochemical composition of sunflower (Helianthus annuus L.). Journal of Breeding and Genetics (2023).