Does autoregulation of sebum production exist?
Lately, I’ve been thinking a lot about whether sebum can regulate sebaceous gland production. In lay terms, does the skin really know how greasy it is? Let me explain. I read a lot of articles online that say scrubbing away the grease (aka sebum) from your face causes the cells in the skin to produce more of it. Or that if you leave skin alone to its devices, it will be able to figure out the perfect amount of sebum and stop production. This perfect amount will vary among different individuals. That’s why some people have dry skin, others have extremely oily skin, and yet others have the perfect medium.
Sebaceous Gland Production
First of all, the sebaceous glands produce and secrete sebum. Sebum is made up of different oils. These include triglycerides, fatty acids, wax esters, squalene, cholesterol esters, and cholesterol. (1) Sebum helps to lubricate the skin and protect it against friction. It also makes it impervious to water. The sebaceous gland transports antioxidants to fight free radicals. It has innate antibacterial properties. Sebaceous glands can have pro- and anti-inflammatory functions.
Sebaceous gland production is especially important for those who suffer from acne. Does excessive removal of oil really cause more to build up? Not taking into account the inflammation caused by over scrubbing and cleansing, removing oil from the skin should be a good thing in theory, correct?
But, does the skin really know? Or is this sebum being constantly produced at a predetermined rate and influenced by hormones and other signals? That is the question that dermatologic scientists have been debating and trying to answer since the 1930’s.
The Feedback Theory
Termed the “Feedback Theory” back in 1958, some very prominent scientists have called it garbage; while, other (also very prominent) scientists have steadfastly defended it.
One study from 1979 set out to answer this important question. (2) The authors recruited 18 subjects as their guinea pigs and measured how much sebum their forehead was producing.
They did this by essentially transferring the sebum directly from subjects’ foreheads to a glass slide. This glass slide was then analyzed with light spectrophotometry and the results were plotted onto complicated graphs showing the kinetics of sebum excretion.
They were able to split their subjects into 3 groups: weak excretors, strong excretors, and very strong excretors. Essentially, the dry, normal, and oily skin types.
Their results showed that the sebum excretion versus time graph was not perfectly linear. Meaning that your skin’s sebaceous glands do know when they’ve excreted enough sebum and are able to adjust the rate of excretion accordingly. Hence, this was strong evidence for the sebum excretion feedback theory.
More evidence comes from the fact that whiteheads (we call them closed comedones) do not produce infinite amounts of sebum. (3) When you look at the sebaceous glands that occur underneath a whitehead under the microscope, their sebum production is shut off. There is something that is clearly telling the sebaceous gland to stop sebum production.
Opposition to the Feedback Theory
Yet, as you can imagine there are a lot of problems with studies that try to measure sebum production. It’s not easy to uniformly collect a bunch of oily material from people’s faces. It’s not easy to standardize the collection or make sure the environment is exactly the same during the collection for each subject. It seems that there is evidence in the medical literature to support both theories. (4)
Androgen receptors present on sebaceous glands increase sebum production. But a feedback mechanism by which sebum produced by sebaceous glands is able to inhibit its own production is less clear. In conclusion, you can choose which theory you want to believe.
What do you believe?
Sebaceous glands produce sebum at a rate that is determined for each individual based on hormones and other signals with no inhibition from the final product.
Sebum can inhibit sebaceous gland production in a negative feedback loop.
In conclusion, I think a feedback mechanism must be at work. Based on my personal experience, over cleansing makes my face feel more oily. In nature and biological systems, the end product almost always inhibits its own production. That’s what we call negative feedback.
And remember, too much sebum from sebaceous gland production is only one of mechanisms that can lead to acne.
- Makrantonaki, Evgenia, Ruta Ganceviciene, and Christos C. Zouboulis. “An update on the role of the sebaceous gland in the pathogenesis of acne.” Dermato-endocrinology 3.1 (2011): 41-49.
- Eberhardt, H., and G. Trieb. “Is the excretion of sebum regulated?.” Archives of dermatological research2 (1979): 127-133.
- Eberhardt, Hans. “Does a feedback mechanism work in acne?.” International journal of dermatology3 (1981): 174-174.
- Piérard, G. E., C. Piérard-Franchimont, and A. M. Kligman. “Kinetics of sebum excretion evaluated by the Sebutape®–Chromameter® technique.” Skin Pharmacology and Physiology 6.1 (1993): 38-44.