Oil and sebum are different?

[halfgaar]

Hi,

I was wondering. The official explanation about cooked food causing acne is because of water retention causing the pores to be pinched off, in turn causing the sebum not to be able to flow out, causing infection. However, over the last few days I've been eating cooked food and I've noticed that my skin is a lot oilier (and pimplier...) than usual.

The theory and that observation seem to be in conflict. What exactly are the scientific proofs for the aforementioned theory? Could it perhaps be something else? Why would my skin be so much oiler? I eat a lot of fat usually; I can eat a jar of cashewbutter and even a lot of raw milk cheese and not have oily skin or pimples. In fact, I normally (when eating raw) put coconut oil on my skin to keep it oily..

[RRM]

The theory and that observation seem to be in conflict.

No, because there is sebum and there is oil.
Oil (colourless) excretion is not hindered by sebum canals pinched off.
Sebum, however, is more solid (and off white) and easily gets stuck.

Why would my skin be so much oiler?

To compensate for the lack of sebum reaching the surface of the skin.

I eat a lot of fat usually;

No connection.

In fact, I normally (when eating raw) put coconut oil on my skin to keep it oily..

Because your oil production is then balanced by the sebum reaching the surface of the skin.

[Kookaburra]

The theory and that observation seem to be in conflict.

No, because there is sebum and there is oil.
Oil (colourless) excretion is not hindered by sebum canals pinched off.
Sebum, however, is more solid (and off white) and easily gets stuck.

Huh? From dictionary.com

Sebum -the oily secretion of the sebaceous glands that acts as a lubricant for the hair and skin and provides some protection against bacteria

Its like saying a banana and a fruit are two separate things. There are a lot of fruits. A banana is classified as a fruit. Same goes for sebum and oil. There are a lot of oils. Sebum is classified as an oil.

Besides, I cannot find anything on the web about this separate 'oil excretion' by the body. Please show me some links to prove me wrong. I am sure all this is simply semantics.

[RRM]

There are a lot of fruits. A banana is classified as a fruit. Same goes for sebum and oil.

Exactly.
There are even different species of bananas.
We make that distinction here.
Just try to pinch some of the pores on your nose.
The white-ish stuff that may come out is sebum. You can hold it between your fingertips.
When you press it between your fingertips, it doesnt become oil.
The oil that sits on your face is pretty much like cooking oil.

Im sure you trust your own observations.

[Kookaburra]

There are even different species of bananas.

The different species of bananas are still classified as fruits.

Besides, I cannot find anything on the web about this separate 'oil excretion' by the body. Please show me some links to prove me wrong.

I found this article on Wikipedia. http://en.wikipedia.org/wiki/Oil_gland

An oil gland is a sebaceous (or sebiferous) gland that secretes sebaceous matter

This further proves that my argument about sebum and oil being the same thing is right after all.

From Wikipedia article on oil glands:

serve to protect the body against germs

In mammals they serve as a protectant and lubricant for hair and skin.

From dictionary.com on the definition of sebum:

Sebum -the oily secretion of the sebaceous glands that acts as a lubricant for the hair and skin and provides some protection against bacteria

Just try to pinch some of the pores on your nose.
The white-ish stuff that may come out is sebum. You can hold it between your fingertips.
When you press it between your fingertips, it doesnt become oil.
The oil that sits on your face is pretty much like cooking oil.

Im sure you trust your own observations.

I don't understand. Why not simply show the photos of your sebum and this 'separate' oil? After all, pictures speak a thousand words.

[RRM]

There are even different species of bananas.

The different species of bananas are still classified as fruits.

Sure, they fall in the same category, but they are not all the same.

This further proves that my argument about sebum and oil being the same thing is right after all.

If you want them to fall in the same category (sebaceous secretions), you are right, they do.
I just hope you understand that you can make a distinction.
To me, the white-ish stuff that you may push out of your pores is clearly different from the oil that sits on your skin.

Just try to pinch some of the pores on your nose.
The white-ish stuff that may come out is sebum. You can hold it between your fingertips.
When you press it between your fingertips, it doesnt become oil.
The oil that sits on your face is pretty much like cooking oil.

Im sure you trust your own observations.

I don't understand. Why not simply show the photos of your sebum and this 'separate' oil? After all, pictures speak a thousand words.

A picture doesnt prove anything (they could be a facial cream and some oil)
, whereas anyone can easily find out for him / her self.

[Kookaburra]

This further proves that my argument about sebum and oil being the same thing is right after all.

If you want them to fall in the same category (sebaceous secretions), you are right, they do.

From Wikipedia page on Sebaceous glands:

The sebaceous glands are microscopic glands in the skin which secrete an oily/waxy matter, called sebum

Sebaceous secretions are sebum and sebum only. There is nothing mentioned about a 'separate' oil.

Maybe the Wikipedia link on oil gland that I pasted isn't credible enough. I searched the National Library of Medicine database and I still found nothing about this 'separate' oil.
From http://www.nlm.nih.gov/medlineplus/maga ... 22-25.html

The small holes in your skin (pores) connect to oil glands under the skin. These glands make a substance called sebum.

Just try to pinch some of the pores on your nose.
The white-ish stuff that may come out is sebum. You can hold it between your fingertips.
When you press it between your fingertips, it doesnt become oil.
The oil that sits on your face is pretty much like cooking oil.

Im sure you trust your own observations.

I don't understand. Why not simply show the photos of your sebum and this 'separate' oil? After all, pictures speak a thousand words.

A picture doesnt prove anything (they could be a facial cream and some oil)
, whereas anyone can easily find out for him / her self.

Huh? Facial cream? I am asking you to show a photograph of the sebum and 'separate' oil on your face, not to find one from the internet.

The white-ish stuff that may come out is sebum. You can hold it between your fingertips.
When you press it between your fingertips, it doesnt become oil.
The oil that sits on your face is pretty much like cooking oil.

Just because you observed the white-ish stuff didn't become oil when you squeezed it between your fingertips, you came to the conclusion that it is a different substance?

As an analogy:
I squeeze the water in the cup between my fingertips. It did not become ice. So I say the ice and water are two separate things?

The stuff that you squeeze out from the pores of your nose and the stuff sitting on your face are the same thing. They are sebum.

To sum up, based on sources from NLM, Wikipedia and other general acne sites on the web, I have come to the realization that sebaceous glands are also known as oil glands. They secrete sebum only. There is no 'separate' oil that is secreted.

I really like to believe you RRM but where's your scientific source? You say that anyone can easily find out for him/her self but it seems to me you are the only one who tried it. What works for you might not work for others. Are there any testimonials from anyone regarding this little 'experiment'?

(Wow this entry took me more than an hour to organise. All the quotes are driving me nuts.)

[RRM]

Sebaceous secretions are sebum and sebum only. There is nothing mentioned about a 'separate' oil.

Sure, they are the same, in the sense that they come from the same source.
In as much as oil originates from an oil well under the earth's surface.
That oil, however, can be very thick, or more watery.
The watery stuff gets out most easily.
The same is true for the skin; its all sebum, but we make a distinction between
oil (the more watery stuff) and sebum (the white-ish stuff).
Sure, you can say its all sebum, but then you cannot make that distinction.
Saying that its all exactly the same, is ignoring the more or less subtle differences.

Why does the body make both watery (oil) and solid sebum?
Because its not a machine, making always exactly the same product.
Its extremely adaptive and has a solution for all usual circumstances.
The pores in your skin dont all have the same size.
When the pores are too small (or 'pinched off') the body still needs to be able to protect the skin
against dehydration; hence the watery version (oil), for those circumstances.
On the sides of my nose, the skin pores are biggest, so that is where i can push out the sebum.
On my forehead, the pores are smaller, and i can only occasionally push out any sebum.
But my forehead can get oily, due to the oil 'leaking' from those small pores.

Huh? Facial cream? I am asking you to show a photograph of the sebum and 'separate' oil on your face, not to find one from the internet.

I understood that.
In order to show you the sebum that i push out of my nose-pores,
I have to push it out first, right?
How does the picture of that pushed out sebum show you that it is exactly that,
and that i have not replaced it with something else white-ish? (such as some facial cream)

[Kookaburra]

In as much as oil originates from an oil well under the earth's surface.
That oil, however, can be very thick, or more watery.

I know nothing about oil well. How do you know the oil under an oil well can be thick or watery? Have you actually been to an oil well? Do you have any sources to support what you said? Else, it's just your opinion and not a fact.

How does the picture of that pushed out sebum show you that it is exactly that,
and that i have not replaced it with something else white-ish? (such as some facial cream)

If you say that you did not replace it with cream, I just have to take your word for it. Why would you lie about things like that anyway?

Here's the thing. You said the white-ish stuff that may come out is sebum. Here's an article on sebum written by Heather Brannon, MD http://dermatology.about.com/od/glossarys/g/sebum.htm

Sebum is a light yellow, oily fluid.

Based on her description, I don't know what that white-ish stuff is. It can be pus or something else but it's definitely not sebum. Sebum is not white-ish.

Sebum produced by the sebaceous gland combines with cells being sloughed off within the hair follicle and "fills up" the hair follicle. When the follicle is "full," the sebum spreads over the skin surface giving the skin an oily appearance. When this process works correctly, the skin is moisturized and remains healthy.

Sebum is supposed to be oily. The oil sitting on your face is sebum. That white-ish stuff is not sebum.

Why does the body make both watery (oil) and solid sebum?
Because its not a machine, making always exactly the same product.
Its extremely adaptive and has a solution for all usual circumstances.
The pores in your skin dont all have the same size.
When the pores are too small (or 'pinched off') the body still needs to be able to protect the skin
against dehydration; hence the watery version (oil), for those circumstances.
On the sides of my nose, the skin pores are biggest, so that is where i can push out the sebum.
On my forehead, the pores are smaller, and i can only occasionally push out any sebum.
But my forehead can get oily, due to the oil 'leaking' from those small pores.

All this is simply your opinion, your observation. How can I believe you when there are no scientific sources to support you? In order for a theory to be accepted as fact, you got to test it. Have you done that? Like I asked in an earlier post, do you have testimonials of people doing that little pinching the nose pore experiment? Of all those people who have stuff coming out of their pore, are they all white-ish? That white-ish stuff that you experienced may be unique to you only. What makes you think that the white-ish stuff is sebum in the first place?

[RRM]

All this is simply your opinion, your observation.

Its your observation too, if you just try.
Virtually everybody who is acne prone will confirm the following to you.
Please ask anyone.
Somebody with acne always has a few 'hot-spots', and also areas where (s)he will hardly ever break out.
These non-acne areas may be oily at times though.
This indicates pores with sebaceous activity, and yet no acne.
This means that not all sebum/oil has exactly the same properties.
With acne, the pores get blocked. Oil does not get stuck. Just try to stick it between your fingers.
With acne, the pimple always contains a solid core that got stuck in the sebum canal, which is not oil.
The sebum that you can push out of specific pores, is not oil, its a bit more solid.

[Kookaburra]

Once again, you provide no sources to back up your explanations. Sentences like

This indicates pores with sebaceous activity, and yet no acne.

and

This means that not all sebum/oil has exactly the same properties.

...

It's anecdotal evidence. It's like saying my grandpa smokes everyday since 20 years old and lives to the age of 100. This means that smoking is good for your health.

What's your stand actually? First you said that there is sebum and there is oil in your initial reply to halfgaar. Then you said that both oil and sebum are in the same category as sebaceous secretions, meaning that the sebaceous gland secrete both oil and sebum. Then you said its all sebum in your analogy of the oil well. Then you said that there is a watery(oil) and solid sebum, meaning that the sebum has two states, solid and water. The water state is called oil. And the solid state is called sebum. Then in your last post you said that not all oil/sebum has the same properties. So by putting a "/", you are now saying that oil and sebum are the same thing? It's so confusing. I am sure I am not the only one who is confused.

You should have stated first and foremost in your reply to halfgaar that what you are about to say is simply your theory. If not there are people who will take it as fact seeing you are the administrator and co-creator of the diet.

Having said that, it's pointless to continue this discussion anymore until you can provide scientific sources to back you up.

[Oscar]

Let me interject here...I haven't followed the discussion very closely, but it seems to me that the main confusion (in this thread, but maybe also in literature) is caused by the terminology.
As I understand it (correct me if I'm wrong):
There is one gland, the sebaceous gland, which produces two versions of basically the same substance. Like ice and water, they occur in different states and have (some) different properties.
Because they are basically the same substance they are both sebum. To clarify which version he's talking about, RRM uses the terms 'oil' and 'sebum' to distinguish the 'water' and 'ice' versions.

[RRM]

Basically, it comes down to this:
Is all sebum exactly the same?
Or does it come in different varieties of thickness / solidness?

The sebaceous glands are microscopic glands in the skin which secrete an oily/waxy matter, called sebum

Why does it say oily/waxy?
Because it may be both.
Still dont believe sebum comes in varieties?

Sebum
In the eyelids, meibomian sebaceous glands secrete a special type of sebum into tears.
...
Earwax is partly composed of sebum.
...
The sebaceous glands of a human fetus in utero secrete a substance called Vernix caseosa, a "waxy" or "cheesy" white substance coating the skin of newborns.
...
In males, sebaceous glands begin to appear predominantly on the penis, on the shaft and around the rim of the penile head during and after puberty.

The last one requires thorough cleansing of the penis.
If not, you get a (non-oily) stinking "cheese-head".
(I recall 2 guys who were nicknamed "mozzarella and gorgonzola" because of this,
as they were exposed by the girls they had sex with)

Are all pores the same?
Definitely, no.
The pores on your nose are the biggest. Thats because the nose needs most vigorous
protection against dehydration.
And thats because the skin on the nose is most exposed to sunlight, followed by your forehead.
(which also contains large pores).

So, why the bigger pores?
Because the excretion of lots of thick sebum (sebum plus keratin) requires bigger pores.
Oil can be squeezed through the most narrow pores.
You may compare it to the maintenance of engines; those huge engines require a thick petroleum wax,
whereas for a tiny engine a drop of oil will suffice.

[halfgaar]

Sorry for my late reply, but I was gone for a while.

Anyway, I don't really know what to contribute except that RRM's 'experiment' is has the same effect on me, and I've known this for a long time (after being on raw though). I can squeeze a light-yellow/off-white (depends on the interpretation I guess) substance from the pores on my nose, but not really anywhere else. This substance is so thick, the strands I push out don't fall or trickle down, they just stick out from the pore.

[B-Rad]

The composition of sebum varies between species. In humans, the lipid content is as follows:[6]
Percent composition Substance
25% wax monoesters
41% triglycerides
16% free fatty acids
12% squalene

sebum is not a homogenous substance