# Reference guide for fats and lipids



## dtlv (Jul 24, 2009)

An old nerdy post/sticky of mine from another forum briefly detailing some of the metabolic effects of specific fatty acids.

After the list follow a few notes on the basic properties of different fats and basic interactions.

*Reference for Lipids and Fats*

Below is a list of saturated, monounsaturated and polyunsaturated fats showing alternate names, the isomer, and the most common food sources where they occur as dominant fats.

Omega 3 fatty acids are in blue, omega 6 fats in red and omega 9 fats in green.

Essential fatty acids are marked with a *.

The list shows the main fats encountered in diet but is not a complete list - have chosen to miss out some of the very unusal lipids to save space.

The number before the colon, eg the (*4*:0) for Butyric acid, indicates the number of carbon atoms in the carbon chain of the molecule, the number after the colon indicates positons of double bonds or side chains or cute chemsirty stuff.

This second number is only likely of interest to any real nerds, but the first number is a good quick guide to how much of an effect that particular fat might have on cholesterol levels - a number lower than 12 will usually mean no significant effect, the higher the number gets above this the more likely the fat is to have a negative impact.

Check the notes below the list for more detail.

*Saturated Fats*

*Short Chain Saturated Fats (SCFAs or SCTs)*

*Butyric acid or butanoic acid (4:0)*

butter, cheese

*Medium Chain Saturated Fats (MCFAs or MCTs)*

*Caproic acid or hexanoic acid (6:0)*

butter, diary, goat & sheep's milk

*Caprylic acid or octanoic acid (8:0)*

baby milk formula, nuts, coconut oil, vegetable oil

*Capric acid or decanoic acid (10:0)*

baby milk formula, cheese, vegetable oil, coconut oil

*Lauric acid or dodecanoic acid (12:0) *

coconut oil, palm oil, breast milk

*Long Chain Saturated Fats (LCFAs or LCTs)*

*Tridecanoic acid (13:0)*

cheese, chicken, tomato

*Myristic acid or tetradecanoic acid (14:0)*

milk, dairy

*Pentadecanoic acid (15:0) *

cheese, meat

*Palmitic acid or hexadecanoic acid (16:0)*

palm oil, meat, poultry, fish

*Margaric acid or heptadecanoic acid (17:0)*

lamb, beef, pork

*Stearic acid or octadecanoic acid (18:0)*

meat, poultry, cocoa butter

*Arachidic acid or eicosanoic acid (20:0)*

peanuts, nuts, vegetable oils

*Very Long Chain Saturated Fats (VLCFAs or VLCTs)*

*Behenic acid or docosanoic acid (22:0)*

peanuts, nuts, veg oils

*Lignoceric acid or tetracosanoic acid (24:0) *

nuts, seeds, veg oils, seed oils

*Monounsaturated Fats*

*Myristoleic acid or tetradecenoic acid 14:1*

whale meat, red meat, dairy

*Pentadecenoic acid (15:1) *

tofu, miso, whale meat, poultry

*Palmitoleic acid or hexadecenoic acid (16:1 undifferentiated) *

whale, seal, nuts, avocado, poultry

*Heptadecenoic acid (17:1) *

tofu, cheese, meat

*Oleic acid or octadecenoic acid (18:1 undifferentiated)*

avocados, veg oil, nuts, goose fat, margarine

*Gadoleic acid or eicosenoic acid (20:1)*

seal, whale, fish

*Erucic acid or docosenoic acid (22:1 undifferentiated) *

veg oil, fish, mustard, watercress

*Nervonic acid or cis-tetracosenoic acid (24:1c)*

mustard, fish, margarine, nuts

*Polyunsaturated Fats*

*Linoleic acid (LA) or octadecadienoic acid (18:2 n-6 undifferentiated)* *

poultry, avocado, eggs, cereals, veg oils, grains

*Alpha-linolenic acid (ALA) or octadecatetraenoic acid (18:3 n-3 c,c,c)**

hemp, soya, flax

*Gamma-linolenic acid or octadecatetraenoic acid (GLA) (18:3 n-6 c,c,c )*

primrose, hemp, blackcurrant oils

*Octadecateraenoic acid (18:4 undifferentiated) *

fish, molluscs

*Eicosadienoic acid (20:2 n-6 c,c) *

pine nuts, seal, poultry

*Arachidonic acid or eicosatetraenoic acid (20:4 undifferentiated) *

fish, meat, poultry

*Eicosapentaenoic acid (EPA) or timnodonic acid (20:5 n-3)*

fish, seal, molluscs

*Docosapentaenoic acid (DPA) or clupadondonic acid (22:5 n-3)*

seal, meat, poultry

*Docosahexaenoic acid (DHA) (22:6 n-3) *

fish, seal, caviar

*Natural Trans-fats*

*Vaccenic Acid (18:1 trans-11)*

milk, dairy, human milk

...

*General Comments*

Saturated Fats of between 12:0 and 18:0 raise LDL cholesterol.

Fats above 18:0 raise VLDL cholesterol.

Stearic Acid (18:0) has no significant effect on LDL or HDL cholesterol.

Myristic acid (14:0) increases HDL cholesterol.

Artificial trans saturated Fats (not listed) increase LDL cholesterol and lower HDL cholesterol.

Monounsaturated Fats raise HDL cholesterol.

Omega 3 Polyunsaturated Fats raise HDL cholesterol.

Omega 6 Polyunsaturated Fats weakly increase LDL cholesterol particle size compared to monounsaturated and saturated fats (beneficial effect).

Smoking lowers HDL cholesterol.

Essential fatty acids (cannot be synthesised within humans) are:

Alpha-linolenic acid (omega 3 polyunsaturated)

Linoleic acid (omega 6 polyunsaturated)

Near essential fatty acids (can be synthesised within human but to minimum rather than optimum levels) and conditionally essential fatty acids are:

Eicosapentaenoic acid (EPA) (omega 3 polyunsaturated)

Docosahexaenoic acid (DHA) (omega 3 polyunsaturated)

Gamma-linolenic acid (omega 6 polyunstaurated)

Oleic acid (omega 9 monounsaturated)

The omega 9 monounsaturated fat Oleic acid reduces total and most specifically LDL cholesterol.

The omega 6 polyunsaturated fat Linoleic acid prevents the LDL raising effects of palmitic acid when at a 1/5 ratio or better (such as in coconut oil), and may also do the same for other saturated fats (although the ratio at which this may occur is not not known).


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## defdaz (Nov 11, 2007)

Awesome, thanks Dtlv! How's the injury?


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## dtlv (Jul 24, 2009)

defdaz said:


> Awesome, thanks Dtlv! How's the injury?


Thanks mate. Am still a bit tender but much better - am thinking of giving it another week then maybe trying to lift something not too heavy!

I certainly reckon that I can get away with some light work, even if nothing that puts a heavy load through my core... we'll see anyway


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## Greenspin (Dec 27, 2010)

Ooooo you Dtlv74 beat me to it. I will alter what I have written so it can still be of some interest and relevance  Nice post though :thumbup1:


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## dtlv (Jul 24, 2009)

Greenspin said:


> Ooooo you Dtlv74 beat me to it. I will alter what I have written so it can still be of some interest and relevance  Nice post though :thumbup1:


If you've got a similar post/thread in the works add it here and we'll sticky the thread. I suspect I beat you by a while though - the above is a few years old


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## Greenspin (Dec 27, 2010)

Omega 3 (Polyunsaturated fatty acids) basic chemistry:



Above is a carbon © atom (Dramatically over simplified, but still a fair representation). You have a central 'dot' and two 'hoops' around it. The 'hoops' have 'dots' on them. These 'hoops' don't exist, they are not apart of the atom, merely another representation. I am going to call them the orbits. Now, the outer orbit is what we are going to focus on. It has four 'dots', these are called electrons. To use a metaphor, I am going to suggest you think of the central 'dot' - the nucleus, for those who wanted to know - as the sun, and the surrounding electrons - the 'dots' - as planets. Planets orbit the sun.

I won't explain why they do so, as I think it will detract from the more relative bits. So the outer shell has 4 electrons, and they are available for covalent bonding.

Next we have hydrogen (H), hydrogen has one electron on its outer orbit.



Bonding: The bonding of, in relation to the hydrocarbons in a fatty acid - see below - hydrogen and carbon is known as a covalent bond. This can be explained simple as the sharing of two electrons between atoms. This is to do with positive and negative charges within and shared between atoms, and I will leave it at that.

So, to sum up, a covalent bond between Hydrogen (H) and Carbon © in a fatty acid (hydrocarbon chain) is the sharing of two electrons, in the outer orbit. As a visual, imagine:

Figure1

What you see in figure1, is the outer orbits and there electrons. Remember carbon © has 4 electrons in its outer orbit (AKA shell), and hydrogen (H) has 1. The electrons 'pair up' by means of a covalent bond and are said to be bonded together. This bonding is what attaches them to make molecules and etc.

Now we know how they fatty acid is held together, we can look at the chemical structure of our fatty acids and what defines it as a polyunsaturated fatty acid (AKA omega 3)

Figure 1A

Above, what you see is the basic structure of a fatty acid (Figure 1A). It is comprised of the elements (raw materials - check out the periodic table) Carbon ©, Hydrogen (H) and oxygen (O). Broken down, you can say it is a hydrocarbon chain (A chain of hydrogen and carbon atoms, you can see why they call it that  ) with a carboxylic group (the bit on the right end that looks different to the rest) on one end.

The above illustration shows a line of carbon atoms, these are bonded together by sharing electrons. The first carbon atom from the left is bonded to one other carbon atom. It uses one of it's 4 electron to bond to the next carbon atom along, which means it has 3 electrons left free for bonding. And for each of the free electrons, it's bonded to a hydrogen atom, the hydrogen atom using its 1 'free' electron. The next carbon along is bonded to a carbon on the left and the right, using two electrons, leaving two 'free'. These two free electrons are bonded to hydrogen, and so on so on. In figure 1A all of the carbon © atoms has a hydrogen (H) atom attached (it is attached by a covalent bond) - the last being an exception, but that is not important at this point - so that would make this a saturated fatty acid. It literally means that the carbon atoms are saturated with hydrogen atoms, nice and simple.

Figure 2A

Above is an illustration of a polyunsaturated fat (Figure 2A). As you can see, it differs from figure 1A as it has less hydrogen atoms. This means the carbon atoms have electrons that are not bonded with hydrogen (H). So, it is safe to say the carbon atoms are not saturated by hydrogen, they are unsaturated. And as there is not just one (mono = 1) carbon electron free of hydrogen, it is safe to say it has many, or poly (poly = many), unsaturated carbon atoms. So it is a carbon chain that has many free of hydrogen, carbon atoms, or, it is polyunsaturated.

- A note, atoms 'like' to have 'full' outer orbits. An atom can have more than 2 orbits, as you can see, hydrogen has one and carbon has 2. And these orbits like to have a certain number of electrons to become more stable, I won't indulge this point as, but it's important to know that they do.

In figure 2A there appears to be two lines between some of the carbon © atoms. If you remember that a carbon atom has 4 electrons, and as said above, they like to have a certain amount of electrons in there orbits to be more stable, well, when a carbon atom has a free of hydrogen (H) electron, it holds onto the carbon © atom next to it (AKA the double bond). If you look at the first, from the left, carbon © atom in the chain, it has four lines coming off it - the electrons- and they are attached to three different hydrogen (H) and 1 carbon © atom (=4 electron and so four bonds), then the next carbon along is only attached to 2 carbon and 1 hydrogen (=3 bonds) so the last electron bonds to the carbon next to it to make its self more stable. If you count how many bonds there are for each atom, carbon will have 4 and hydrogen will have 1, in the figure 2A you will see how the hydrocarbon chain balances out.

You may have seen Polyunsaturated fatty acids (omega 3) is written in plural form, i.e fatty acids <-- s  . This is important, and very easy to understand. The hydrocarbon chain (figures 1A and 2A) are like codes, if you take a saturated fat (look at figure 1A) and take away 2 hydrogen atoms from one place in the chain, it changes the code. If you take two away, but from a different part of the chain, it changes the code again, even though it has the same amount of hydrogen atoms as when we took the two away from a different place in the chain. We don't have to indulge this to much, but just understand that the code is changed.

As the poly in polyunsaturated simply refers to the fact it has many carbon electrons free of hydrogen, we then are left with the many possible places that the hydrogen could be 'missing' and many possible codes. Two factors (looked at simple of course) come into play hear to determine the type of polyunsaturated fatty acid it is. Factor 1 is where the unsaturated carbons are in the chain (the hydrocarbon chain), and factor 2 is the length of the chain.

Chain length: Put simple, if you look at figure 2A it has 10 carbon atoms ©, so this is a 10 carbon hydrocarbon chain. But they can differ. Chain length is what is being referred to when people speak of medium chain, long chain, short chain etc triglycerides. A triglyceride is simple 3 fatty acids (tri=3) attached to the backbone of glycerol. So you get, triglyceride (this is a the most abundant type of lipid (fat) in the body)

Put these factors together and we get the formula to workout what polyunsaturated fat you have.

Figure 2A

The above fatty acid is an omega 3. Omega 3 fatty acids have there first double bond at the third position in the hydrocarbon chain from the methyl group (Methyl group = 1 carbon © and 3 hydrogen (H), written like this CH3 ) end of the hydrocarbon chain. The methyl group end is the end of the chain that has 1 carbon atom bonded to 3 hydrogen atoms. If you look at figure 2A, you can see the methyl group is on the left side, and if you count the bonds, the first double bond is in the third position on the chain between the 3rd and 4th carbon atom (3rd position = an omega 3 <--- notice the three).

To identify the 'type' of omega 3, you then look at chain length and number of double bonds. In physiological literature, omega 3 Eicosapentaenoic acid (EPA for short) is given the name 20:5(n-3)

Lets take this name apart. The 20 part refers to the amount of carbon atoms in the hydrocarbon chain (20:5(n-3)) then after the 20 you have the number 5 (20:5(n-3)) this is the number of double bonds the hydrocarbon chain has, and lastly you have (n-3) (20:5(n-3)) this is how they write the position of the first double bond, in this case it is position 3. We know that if the first double bond from the methyl group is in position 3, then it is an omega 3 fatty acid. The n in n-3 can also be written like ω-3 and omega-3

-A note, if it was n-6, it would be an omega 6 unsaturated fatty acid. As the first double bond would be at the sixth position on the chain. See how it works 

 Figure 3A (EPA)

Figure 3A shows EPA's (omega 3 Eicosapentaenoic acid) chemical formula (the carbon, hydrogen and oxygen layout if you will) written in a slightly different way to figures 1A and 2A.

It does not show you the hydrocarbon chain as C's and H's rather just the carbon bonds of the chains. So where there is a double bond (shown as two lines) there is not going to be a hydrogen atom present, and where there is a single line, there will be hydrogen atoms bonded to the carbons 'free' electrons. Think of (in this illustration) the beginning point of the line (from the right, below the red '1') as a carbon, there after each corner is a carbon, and lastly, the end point where the O has two bonds is the last carbon in the hydrocarbon chain. Now count the beginning and end points, along with all the corners between, and you should have 20. That 20 carbons is the 20:5(n-3). Each line represents a bond, so from right side to the left, count three lines (as this is and omega 3 fatty acid) and the third should have a double bond (two lines) that is the 20:5(n-3) Then excluding the O with the two lines, as this is essentially not apart of the hydrocarbon chain (it is not hydrogen (H) or carbon ©, it is oxygen (O), so is part of the fatty acid, but not the bit be are taking about) and you will have 5 double bonds, so the 20:5(n-3) part 

(Omega 3 DHA)

Above, Omega 3, Docosahexaenoic acid (DHA) 22:6(n-3)

(Omega 3 EPA)

Above, Omega 3 Eicosapentaenoic acid (EPA) 20:5(n-3)

(Omega 3 ALA)

Above, Omega 3 Alpha-Linolenic acid 18:3(n-3)

-DHA, is abundant in the brain and has a 22 carbon hydrocarbon chain with 6 double bonds.

-EPA is involved in anti inflammatory responses etc and has a 20 carbon chain with 5 double bonds.

These two omega 3's are very important! They are found in animal sources. Fish in particular contain high levels of these types of omega 3 fats.

-ALA is a form of omega 3 found in plant sources (including flaxseed/oil, canola oil, vegetable oils in general and etc). It is a shorter chain fatty acid than EPA and DHA with only 3 double bonds. Our body however, can convert a small amount of this fat into the longer chain fatty acids EPA and DHA, but at a conversion of only around 5% in men and a little more in women! That is not to say it is not important in its original form.

GS


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## dtlv (Jul 24, 2009)

That must have taken you a fair bit of time to put together Greenspin - nice work, especially if done just for the forum.

I know many people find the details of nutritional chemistry very daunting and/or find it a level too deep for something to think about practically, but it can aid the understanding of many nutritional interactions no end if combined with a knowledge of how the body uses fats (and amino acids and carbohydrate molecules) structurally and metabolically - and it's not actually that complex once you get your head around the ideas, it can just be hard and lengthy to explain.

Am going to sticky this thread as it's a good geeky thread for reference. If anyone has any good science based information about lipids and their effects on health or their interactions that they want to add please feel free to do so.


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