The Scalp and Its Function part 2

Sebum

A healthy scalp produces approximately an ounce of sebum every one hundred days. Sebum comes from the natural breakdown of small cells within the sebaceous glands. Sebum’s main function is to condition the skin and act as a barrier to prevent internal moisture loss. Sebum is made up of a highly variable mixture of fatty lipids including glycerides, fatty acids, wax esters, squalene and cholesterol. (Hint: You may recognize many of these ingredients in deep conditioning treatments). The hair care industry has found ways to duplicate the composition of natural sebum as the best way of returning hair to its proper condition.


Scalp dryness is a common issue and much if it is related to genetics. But, while some of us produce normal amounts of sebum, the cause of the majority of challenges anyone with curly or wavy hair faces is due to the nature of the hair’s cuticles with all the bends, coils and kinks which are more susceptible to damage and are more likely to lift or raise, especially around the bends. Complete sebum coverage virtually cures all of that for two main reasons:

  1. First it's 100% organic and moderately hydrophobic, so it stabilizes the amount of moisture your strands take in and hold on to.

  2. The second reason why sebum is so special is because of its acidic pH. Ph plays an important role in hair health (more to come on that). Did you know that sebum’s acidity helps your cuticles to lay flat? And the reason we want this is because the sebum coverage works to retain moisture, thus it doesn’t need to lift your cuticles as much to achieve moisture penetration. I know this sounds a little confusing so let me try to explain.


As we curly and wavy heads know, we have a lot of deep conditioning sessions. Many of us use heat to help our cuticles lift so the moisture can penetrate our hair strands in order that the moisture will last for a few days. So in essence, we are constantly disturbing our cuticles to maintain some level of moisture in our hair.

But, with complete sebum coverage moisture retention is stabilized so there's no need to disturb your cuticles. I'm not saying you won't need a deep conditioning session, but with sebum coverage, you need them less often. The sebum’s coating is doing the work that we are most often forcing our cuticles to do. So the fact that sebum is acidic is an added bonus. But, because the sebum has a hard time working its way down the bends of our hair, that’s where oils come to play. I’ll talk more about that at a later time. 

Sebum production is ultimately controlled by hormones and therefore fluctuate over time. I found this information interesting; Certain stressors such as dietary deficiencies, prescription medicine and puberty may increase or reduce normal sebum production. (“The Role of Sebaceous Gland Activity and Scalp Microfloral Metabolism in the Etiology of Seborrheic Dermatitis and Dandruff”. Journal of Investigative Dermatology Symposium Proceedings).

Some of us may have naturally low sebum production, which can be a strong contributor to chronic scalp dryness. And for others, scalp dryness may be self-inflicted. For example, when products are placed directly on the scalp and allowed to build up and extremely heavy oils, grease, pomades, are the common culprits that can clog the scalp’s pores. But even sebum build up can cause an issue.

When sebum is present in the scalp, it is initially very flexible and moist. But, as the days go by, sebum begins to harden like wax which when combined with flaking scalp cells and heavy oils/greases can create obstruction around the entrance of the hair follicle. When it happens on our face, a pimple results. In some cases, this blockage can lead to scalp dryness and itchiness, inflammation and shrinkage of the hair follicles and decrease in the quality of hair that emerges from the clogged follicles. (“The Role of Sebaceous Gland Activity and Scalp Microfloral Metabolism in the Etiology of Seborrheic Dermatitis and Dandruff”. Journal of Investigative Dermatology Symposium Proceedings. “Nadifloxacin: A Quinolone for Topical Treatment of Skin Infections and Potential for Systemic Use of Its Active Isomer, WCK 771,” Expert Opinion on Pharmacotherapy. “Hormonal Changes and Acne Breakouts”. Acne Treatment Guide).

The scalp like our skin needs to be able to breathe. Our scalp is essentially an extension of our face. Just as pores on the face can become clogged, so can hair follicles.

I will stop here. Feel free to drop a comment, share with your friends, Invite! See you on next week's post!