LZ says…I was wondering if you could explain the difference between coconut, palm and palm kernel oils. Are they exactly the same thing? Does coconut oil penetrate the hair shaft because it’s made up of “medium chain fatty acids?” and are there any other oils with similar properties? What about oils like argan, olive, avocado, jojoba? And what about shea butter? Do they offer any meaningful benefits?
The Beauty Brains respond:
We’ve blogged before about coconut oil. Here’s how it’s different from palm oil:
Coconut oil and palm oil are very closely related. Coconut oil comes from the coconut palm tree (Cocos nucifera) while Palm oil comes from the oil palm tree (elaeis guineensis). Both types of trees belong to the general class known as “palm.” The oil expressed from the respective nuts of these trees (actually they’re considered to be fruits) are similar but with some important differences. Coconut oil is composed primarily of lauric acid with some capric and caprylic acids. The carbon chain lengths of these acids are 12, 10, and 8, respectively. Palm oil, on the other hand, is composed primarily of a mixture of palmitic acid (42%) and oleic acid (38%). Carbon chain lengths for Palmitic acid and Oleic acid are 16 and 18 respectively. What does all this mean? The shorter carbon chain length of coconut oil helps explain why it penetrates hair. (See next question.)Palm kernel oil also comes from the palm tree but is a different fraction. Its chemical composition is sort of half-way between coconut oil and palm oil.
Researchers believe that coconut oil is able to penetrate hair because of the size and shape of the molecule. As discussed above, it has a “medium chain” of 12 carbon atoms but the size of the molecule is only part of the puzzle. The shape of the molecule is also important. Coconut oil is highly saturated which means the carbon atoms are “filled up” with hydrogen atoms. In addition, the molecule is a straight chain with no branching. Palm oil is unsaturated (not all the carbons are “filled up” and the molecule is branched.) This difference in configuration allows the coconut oil molecules to slip in between the intercellular spaces in the hair’s cuticle layer so it can penetrate into the cortex. Palm oil (and most other oils) do not have this ability. While we’ve never seen the research, if we had to guess we’d say that palm kernel oil stands the best chance of penetrating like coconut oil does.
None of the other oils you asked about penetrate like coconut oil but all of them can help lubricate hair. However since they do not penetrate they need to be used in a leave on product like a hairdressing. When delivered from a conditioner or other rinse off product they will simply go down the drain.