The case for oils
Oils are emollients: they fill the tiny gaps between skin cells and slow down water loss from the surface. For dry hands, elbows and shins in winter, a simple oil does a respectable job, and plenty of people find it more pleasant than a heavy cream. Fans of coconut oil often cite a 2008 randomised trial by Verallo-Rowell and colleagues, in which virgin coconut oil improved mild to moderate atopic dermatitis in children more than mineral oil did. Lauric acid, coconut's main fatty acid, also shows antibacterial activity in the lab.
Jojoba fans have a neat argument too. Jojoba (from Simmondsia chinensis, native to the Sonoran Desert) is a liquid wax ester rather than a true triglyceride oil, and it is chemically closer to some components of human sebum. Many oily-skinned readers tell us it feels lighter than they expected.
The case against
The sceptics have receipts. Coconut oil scored high on the old rabbit-ear comedogenicity tests popularised by Fulton in the 1980s. Those tests are crude and do not translate perfectly to human faces, yet the pattern matches what many acne-prone readers report: coconut oil on the body is fine, coconut oil on the chin is trouble.
Olive oil has a more surprising problem. In a 2013 study by Danby and colleagues published in Pediatric Dermatology, four weeks of olive oil on adult forearms weakened the skin barrier, while sunflower seed oil left it intact. The likely culprit is oleic acid, which can loosen the lipid layers in the outer skin. That matters for anyone with eczema, and it is why "just use olive oil on the baby" is no longer standard advice in the UK.
"The oil is not good or bad. It is a fatty acid profile meeting a particular skin."Roundtable summary, oils thread
Side by side
Here is the table we keep coming back to. "Linoleic" and "oleic" refer to the dominant fatty acids; linoleic-rich oils tend to feel lighter and suit breakout-prone skin better.
| Oil | Pros | Cons |
|---|---|---|
| Coconut | Rich, inexpensive, one positive paediatric eczema trial, lovely on dry body skin and hair ends. | Often clogs pores on the face; solid below about 24 °C; strong scent in virgin versions. |
| Olive | Widely available, nourishing feel, traditional soap base (Castile). | High oleic acid; shown to weaken the barrier on adult skin; not ideal for eczema-prone skin. |
| Sunflower seed | High linoleic acid; preserved barrier function in the Danby study; light and cheap. | Oxidises fairly quickly; buy small bottles and store away from heat. |
| Jojoba | Wax ester similar to parts of sebum; very stable; suits many oily and combination skins. | Pricier; a small number of people still find it congesting. |
| Argan | Balanced oleic and linoleic profile; light finish; produced by women's cooperatives in south-west Morocco. | Frequently diluted or mislabelled; evidence for "anti-ageing" claims is thin. |
| Rosehip | Very linoleic-rich; popular for dull or uneven-looking skin; dries quickly. | Spoils fast; vitamin A content is small and variable, so it is not a retinoid substitute. |
| Shea butter | Excellent occlusive for cracked hands, lips and heels; West African staple for centuries. | Heavy on faces; quality varies between refined and unrefined. |
What the room agreed on
- Oils seal in water; they do not add it. Apply them over damp skin or over a water-based moisturiser.
- Body skin forgives almost any oil. Facial skin, especially if it breaks out, deserves a lighter linoleic option.
- Eczema-prone skin should skip olive oil and talk to a pharmacist or dermatologist before experimenting.
- Rancid oil smells like crayons or old nuts. Bin it; oxidised fats can irritate.
- Oil is not sunscreen, whatever the label on a market stall says.
Plain take: plant oils are useful, honest emollients, but "one oil for everything" doesn't hold up. Coconut and shea are great below the neck; sunflower and jojoba are kinder to faces; olive oil is best kept in the kitchen if your barrier is fragile.
Disagree, or have an oil we skipped? Start a thread. Next on the table: does the plant live up to the label?