We live in a world where millions of men and women are desperately seeking new ways to protect and nourish their skin. Lotions and potions line bathroom cabinets across the globe, and there’s a distinct trend for organic products that draw from the earth’s natural bounty to deliver supposedly impressive results.
Olive oil is one of the so-called miracle products which is endorsed and recommended by natural health and beauty sites all over the web. Those worried about their skin are urged to slather this oil all over their face and reap the benefits of this wonderful substance. Olive oil is said to moisturize without blocking the pores, as well as exfoliating and improving the skin’s natural elasticity. What more could you ask for in a skincare solution?
Thousands of people have applied olive oil to their faces on the recommendations of these health and beauty ‘experts’ – but a closer look at the scientific evidence shows that putting olive oil on your skin is a really, really bad idea. Here are three reasons why you absolutely should not use olive oil on your skin.
Olive oil can cause acne when used topically
To date, there haven’t actually been any studies on whether olive oil directly causes acne in humans – but in animal studies, applying oleic acid (the main fatty acid in olive oil) has been shown to cause acne, rather than offering any skincare benefits.
One study published in the British Journal of Dermatology actually used oleic acid to induce acne in rabbit ears, so that they could study various anti-acne drugs. The study discovered that oleic acid and its peroxides were able to induce large comedones (the skin-colour bumps and papules that will be familiar to those who have experienced acne in their lives). The more oleic acid was applied, the larger the comedones grew.
This graph shows the average size of the biopsied comedones over time. The line B represents pure, undamaged oleic acid – the kind found in olive oil.
Source: Motoyoshi, K. Enhanced comedo formation in rabbit ear skin by squalene and oleic acid peroxides. Br. J. Dermatol.109, 191–8 (1983). https://www.ncbi.nlm.nih.gov/pubmed/6223652
Oleic acid vs. olive oil
Though it should be stated that olive oil itself was not used in this particular study, the fact that oleic acid is the main fatty acid in olive oil still renders the results significant. Fatty acids like oleic oil are bound to triglycerides, which are usually too large to penetrate the skin – but olive oil (and many other oils recommended for skincare purposes) also contains some amount of free fatty acids.
Also, the bacteria in the skin produce enzymes that break triglycerides into their constituent fatty acids. The combination of free fatty acids in the oil and those released by bacteria provides a steady supply of oleic acid to the skin.
Put simply: one of the key substances found in olive oil has been proven to cause acne, and was used to induce comedones in rabbits.
Olive oil feeds acne-causing bacteria on the skin
One of the main reasons why oleic acid (and by proxy, olive oil) causes acne, is that it feeds the acne-causing bacteria on the skin’s surface. We’ve already established that certain bacteria on the skin (known as P. Acnes lipases) can break down triglycerides into free fatty acids, so that the skin can absorb them. A significant study from 1993 also discovered that the addition of oleic acid boosts the growth of P. Acnes by between 50% and 100% – depending on how much oleic acid was present in the petri dish.
The authors of the study also concluded that oleic acid helped the bacteria to anchor itself into the wall of the skin follicle, making it even harder to remove. This is called ‘colonizing’, and it’s a key factor in the ongoing presence of acne.
Olive oil disrupts the protective skin barrier and leaves the skin exposed to breakouts
There’s also strong evidence to suggest that olive oil, as well as causing acne and increasing the presence of bacteria, can disrupt your skin’s natural protective barrier and leave the skin exposed to further irritation. So much for this miraculous natural remedy!
One study, which examined the impact of topical oils on the skin barrier, discovered that olive oil slowed down the healing of the skin. The research was carried out on mice, which have almost identical skin barriers as humans, and the results showed that olive oil (as well as mustard and soybean oils) ‘significantly delayed recovery of barrier function compared with untreated skin’.
Another study took place in 2013, which involved a team of researchers asking adult volunteers to apply six drops of olive oil to their forearms twice a day for five weeks. When the five weeks was over, the results showed a weakening of the skin barrier function and mild skin irritation.
The team concluded that ‘topical treatment with olive oil significantly damages the skin barrier, and therefore has the potential to promote the development of, and exacerbate existing, atopic dermatitis’. The researchers also stated that their findings challenge ‘the unfounded belief that all natural oils are beneficial for the skin’.
What oils should be used instead?
To be honest, I’m not a fan of putting oil on the skin. But for those that are drawn to it, fortunately, there are some natural oils out there which can benefit the skin and won’t cause acne or disrupt the skin’s barrier function. Researchers in Germany tested a range of different vegetable oils, including sunflowers, hemp, grapeseed, sesame, almond, flaxseed, argan and pumpkin seed oil, and discovered that oils with less oleic acid and lots of linoleic acid are the most suitable for skincare purposes.
This graph shows the proportion of oleic and linoleic acids of total fats in selected oils. If you want to use oils on your skin, go for something where the green bar is long and the red bar is short.
Best skincare oils to try
Olive oil is certainly one of nature’s great creations, and it makes for a fantastic salad dressing. Unfortunately, the presence of such high levels of oleic acid make it a horrible choice for skincare, and it should be avoided at all costs.