butter melting in the pan

IMPORTANT: The information on this site should never be used to self medicate or to self diagnose. Always contact your health care provider before using any kind of supplementation or making any extreme change in diet.



I thought I knew all about fat.  After all, I’ve been living with fat my whole life.  Life has been one long arduous battle to control the fat. Then I started researching and realized there was so much more to know.


Fats, as we know them, are actually triglycerides that are included in the long list of what are called lipids.


Lipids include some hormones, fat soluble vitamins, bile acids, cholesterol, monoglycerides, diglycerides, phosopholipids and waxes along with triglycerides.


When we talk about fat from food in everyday life triglycerides are what we are talking about.


Did you know that there are 36,965 molecules, and counting, that are classified as lipid molecules.  They are grouped under 8 classifications.

These are:

Fatty Acyls




Sterol Lipids

Prenol Lipids



Only some of these thousands of molecules are involved in human biology.  For a complete list of the known lipid molecules you can find them at:


This is where bio researchers go for information on lipids. 

This subject is so vast it is difficult to encapsulate it. We’re not going to talk about all those lipids just the ones that  affect humans directly.  The ones that affect humans directly are Triglycerides, Sterols and Phospholipids.  We’ll also explore what lipoproteins are and how fat is stored in our bodies.



When fat is solid it is referred to as fat but when it is liquid it is referred to as oil. Both of these forms fall under the category of triglycerides.

In medicine the word lipid is used when referring to both.

All triglycerides are made up of fatty acids plus glycerol. Glycerol better known as glycerin (the soap) is a simple sugar alcohol.

Dietary fats are found in two major categories:




When they enter our bodies they are broken down by enzymes called lipase’s   Lipase enzymes are found in our saliva, in our stomach and in our small intestines.  This is called hydrolyzing fatty acids and allows the fatty acids to cross over into our blood stream and our lymph system.


‘A triglyceride is an ester derived from glycerol and three fatty acids. Triglycerides are a blood lipid that help enable the bidirectional transference of adipose fat and blood glucose from the liver.’  Wikipedia





First the facts.

  • Saturated fats are made up of carbon, hydrogen and oxygen atoms.  For every carbon atom there are two hydrogen atoms attached.  The other end has two oxygen atoms and one hydrogen atom attached to an oxygen atom.  Saturated fats are ‘saturated’ with hydrogen atoms.
  • Saturated fats are solid at room temperature and require heat to liquify them.
  • The longer the saturated fat molecule the higher the heat needed to melt the fat.





There are 15 saturated fats that we get from food:

Butyric acid was first discovered in butter hence the name.  It is found in sour milk, rancid butter, parmesan cheese and is produced when fermentation takes place anaerobically or without air as it is in the colon or as body odour.

JILL'S-BUTYRIC-ACIDIt is known to inhibit tumours in the colon. Butyric acid is involved in the fermentation process and breakdown of dietary fibre thus helping to control inflammation in the colon.  It also promotes healthy epithelial cells (the cells that line the walls of the colon).

Its biological functions are:


Cell signaling

DNA component

Energy source

Fuel and energy storage

Fuel or energy source

Membrane integrity/stability


Its cellular locations are:


Extracellular membrane


It has 4 carbon atoms.




Caproic acid (hexanoic acid) is found in goat’s milk (thus the name as per its greek root); in various fats and oils from animals; in ginkgo and in vanilla.

Its functions in the body are:

Cell signaling

Fuel/energy storage

Fuel/energy source

Membrane integrity/stability


Its cellular locations are:


Extracellular membrane

It has six carbon atoms.

http://en.wikipedia.org/wiki/Hexanoic_acid  http://www.hmdb.ca/metabolites/HMDB00535


Caprylic acid is found in the milk of some animals, in coconut oil and in palm kernel oil.  It also is named after the goat. Caprylic acid is an antimicrobial pesticide so it is often used to combat certain bacterial infections and as a disinfectant in commercial food establishments.

Its biological functions are:

Cell signaling

Fuel and energy storage

Fuel or energy source

Membrane integrity/stability


Its cellular locations are:


Extracellular membrane

Caprylic acid has eight carbon atoms.




Capric acid (Decanoic acid)  is the third saturated fatty acid to be named after the goat not only because it is found in goat’s milk but because it smells like one.  Very popular this goat!

It is also found in coconut oil and palm kernel oil.  It is believed that capric acid played a role in RNA development and protection in the earliest life forms on earth.

Biological functions:

Cell signaling

Fuel/energy storage

Fuel/energy source

Membrane integrity/stability


Its cellular locations are:

Extracellular membrane

Capric acid has ten carbon atoms.




Dodecanoic acid or Lauric acid is found primarily in coconut oil and palm kernel oil but is also found in cow’s milk, goat’s milk and human breast milk.  It is known to increase total cholesterol more than any of the other fatty acid.

The good news is that the cholesterol that it raises is the HDL or “good” lipoprotein and consequently has a more favourable affect than any other fat, saturated or unsaturated, on decreasing heart disease due to clogged arteries or so the story goes.   Lauric acid converts to a monoglyceride called monolaurin in our bodies.  Monolaurin like its counterpart caprylic acid has antimicrobial properties.

It is found primarily in palm oil, coconut oil and powdered coconut.

Biological functions:

Cell signaling

Fuel/energy storage

Fuel/energy source

Membrane integrity/stability


Its cellular locations are:

Extracellular membrane

Lauric acid has 12 carbon atoms.




Tridecanoic acid (Tridecylic acid) is a saturated fat found commonly in dairy products.

Its biological functions are:

Cell signaling


Fuel/energy source

Membrane integrity/stability


Its cellular locations are:

Extracellular membrane

It has 13 carbon atoms




Myristic acid (also called tetradecanoic acid) is a saturated fat found in nutmeg.  It is also found in palm kernel oil, coconut oil, butter and is a small component of animal fat.

Myristic acid permeates the skin easily and it acts as a lipid anchor in the plasma membrane and other bio membranes.

Its biological functions are:

Cell signaling

Fuel/energy storage

Fuel/energy source

Membrane integrity/stability


Its cellular locations are:


Extracellular membrane

Myristic acid has 14 carbon atoms.




Pentadecanoic acid is rare in nature.  It is found in cow’s milk’s butterfat and is used as a marker to record butterfat consumption.

Its biological functions are:

Cell signaling

Fuel/energy storage

Fuel/energy source

Membrane integrity/stability


Its cellular locations are:


Extracellular membrane

Pentadecanoic acid has 15 carbon atoms.




Palmitic acid is a saturated fat that is the most common one found in plants animals and even microorganisms.  It is called palmitic because of its high content in all things palm.  ie: palm oil, palm kernels and palm kernel oil.  It is found in cheeses, meats, butter and other dairy products as well.

Palmitic acid is of particular importance to us because this is what all the excess carbohydrates glucose and fructose (that has been converted to glucose in the liver) that we consume are converted into.  When the body can’t use the carbohydrate for energy it stores it in our fat cells where it is converted into palmitic acid.

In fact the World Health Organization pegs the consumption of palmitic acid from animal sources as a risk factor for cardiovascular disease because it is believed to have  the same affect as trans fats.  The W.H.O. warns against a high consumption of animal fats for this reason.  They do not however get too upset about the ingestion of too much simple carbohydrate…..? (to date)

On the positive side we do need a certain amount of palmitic acid because of its involvement in a process known as palmitoylation.  Palmitoylation is a process whereby palmitic acid is used to join certain proteins to specific membranes thus restricting them to be used only by that membrane.

Its biological functions are:

Cell signaling

Fuel/energy storage

Fuel/energy source

Membrane integrity/stability


Its cellular locations are:


Extracellular membrane

Endoplasmic reticulum


It has 16 carbon atoms.







Heptadecanoic acid occurs at low levels in the milk fat of cows, goats and other ruminants.

Its biological functions are:

Cell signaling

Fuel/energy storage

Fuel/energy source

Membrane integrity/stability


Its cellular locations are:


Extracellular membrane

It has 17 carbon atoms.




Stearic acid aka octadecanoic acid is a saturated fatty acid that is almost as common as palmitic acid in nature.  It is most abundant in animal fats but is found in much lower levels (less than 5%) in vegetable fats and oils.  The exception to the rule in plants is cocoa butter and shea butter both of which have high stearic acid content (28-45%).

Stearic acid is more likely by 2.4 times to reduce into its polyunsaturated counterpart oleic acid than palmitic acid is to reduce into its polyunsaturated counterpart palmitoleic acid.

Stearic acid is less likely to be taken up by cholesterol carriers (lipoproteins) and consequently is associated with lowered levels of LDL cholesterol compared to other saturated fats.

Its biological functions are:

Cell signaling

Fuel/energy storage

Fuel/energy source

Membrane integrity/stability


Its cellular locations are:


Extracellular membrane

Stearic acid has 18 carbon atoms.




Nonadecylic acid (aka Nonadecanoic acid) is found in fats and vegetable oils.

Its biological functions are:

Cell signaling

Enzyme cofactor

Fuel/energy storage

Fuel/energy source

Membrane integrity/stability


Its cellular locations are:

Extracellular membrane

It has 19 carbon atoms.




Arachidic acid is found in small amounts in both peanut and corn oil.

Its biological functions are:

Cell signaling

Fuel/energy storage

Fuel/energy source

Membrane integrity/stability


Its cellular locations are:


Extracellular membrane

It has 20 carbon atoms.




Behenic acid, named after the Ben-oil tree, is also found in rapeseed, canola oil, peanut oil and peanut skin. In humans it is poorly absorbed and will raise lipoprotein levels.

Its biological functions are:

Cell signaling

Fuel/energy storage

Fuel/energy source

Membrane integrity/stability


Its cellular locations are:

Extracellular membrane

Behenic acid has 22 carbon atoms.




Lignoceric acid (aka Tetracosanoic acid) is found in small amounts in peanut oil and in most fatty substances.

Its biological functions are:

Cell signaling

Fuel/energy storage

Fuel/energy source

Membrane integrity/stability


Its cellular locations are:


Extracellular membrane


It has 24 carbon atoms.




Trans Fats

Artificially created transfats are detrimental to our health and are associated with heart problems and other health issues.  Transfats are produced by injecting hydrogen atoms into a non saturated oil molecules to produce a saturated fat;  that is a fat that has a full complement of hydrogen atoms.





The second category of fats is called unsaturated fatty acids and it falls into two sub categories: monounsaturated and polyunsaturated. Neither have a complete complement of 2 hydrogen atoms for every carbon atom.

Unlike saturated fats the composition of unsaturated fats allows them to bend and become flexible so they present usually as liquid but in the case of monounsaturates can be hardened by refrigeration.

Mono and polyunsaturates are more easily destroyed by heat than saturates.  In fact it is good not to cook with polyunsaturates at all as they are far more unstable than monounsaturates. Poly and mono unsaturates should be kept refrigerated to maintain freshness.

Once an oil reaches its smoking point it degrades and starts to oxidize and partially hydrogenate.  It is best not to overheat oils.






The facts:

Monounsaturates also have chains of carbon atoms but none of their carbon atoms have two hydrogen atoms.  There are always two missing hydrogen atoms and there is always one double bond between two carbon atoms.

So what does that mean for us?

Both the thickness of the oil or fat and the melting temperature are affected by the number of double bonds.

Saturated fats have no double bonds and every carbon atom is attached to two hydrogen atoms.  This makes them very rigid so that they are solid at room temperature and have a high melting point.

Monounsaturates, on the other hand, are more susceptible to heat but still maintain their integrity when heated at moderate temperatures.  They have one double bond and are liquid at room temperature but tend to turn solid when refrigerated.  Olive oil for instance, if it is pure olive oil, will solidify when refrigerated.

Canola oil does not have as much monounsaturated fat as olive oil so does not solidify as easily but still maintains its structure at medium cooking heat because it contains a fairly high level of monounsaturated fat.




These are monounsaturated fatty acids found in the human diet:

Palmitoleic acid is found in animal, vegetable and marine oils as well as in macadamia nuts.

What does it do for us?

In humans it is found in adipose tissue and in high amounts in the liver.  It increases insulin sensitivity and helps prevent the destruction of insulin secreting beta cells thus it is important in preventing and controlling type ll diabetes. Palmitoleic acid appears to have hormone like effects.

It is an omega 7 fatty acid and has sixteen carbon atoms and one double bond. 16:1 w7



Oleic acid occurs naturally in both animal and vegetable fats and oils. It constitutes about 50% of chicken fat and 47% of lard.

What does it do for us?

Its name is derived from olive oil which is mostly composed of oleic acid.  Oleic acid has been associated with lowering levels of LDL cholesterol and increasing levels of HDL cholesterol. The latter is still being debated.  It is believed to lower blood pressure but is also believed to increase breast cancer risk.  It is classified in chemistry as an omega-9 fatty acid and has 18 carbon atoms and one double bond.18:1 w9



Gondoic acid, a form of Eicosenoic acid is a monounsaturated and is found in plant oils and nuts

It is an omega 9 fatty acid and has 20 carbon atoms and 1 double bond  20:1 w9



Erucic acid is an oil found in members of the brassicaceae family which includes turnip, kale, broccoli, brussel sprouts, mustard and rapeseed.

What does it do for us?

It is helpful in preventing coronary heart disease when ingested in small amounts.

Erucic acid is an omega 9 fatty acid and has 22 carbon atoms and 1 double bond.

22:1 w9



Nervonic acid is an oil found in Chinook salmon, yellow mustard seed, flaxseed, Sockeye salmon, sesame seeds and macademia nuts.

What does it do for us?

It is important to our health because of its involvement in the biosynthesis of the nerve cell myelin. It is found in the sphingolipids of the white matter in our brains and is used to treat diseases such as multiple schlerosis.

It is an omega 9 fatty acid and has 24 carbon atoms and one double bond. 24:1 w9




Polyunsaturated fats are the other sub category of unsaturated fats.  Polyunsaturated fats have more than one double bond in their backbone:

Polyunsaturates fall into several categories:

  1. Omega-3
  2. Omega-6

  3. Omega-9

Conjugated fatty acids






18:3 n-3 c,c,c,  Alpha-Linolenic acid  is an omega 3 fatty acid found in nuts, seeds and their respective oils.  It is an essential fatty acid having to be acquired in the diet.  Chia seeds, kiwi seeds, flaxseeds, perilla seeds, lingonberry seeds, as well as walnuts.  All have high levels of ALA.

What does it do for us?

ALA competes with Omega 6 fatty acids in our cell membranes.  High levels of alpha-linolenic acid are associated with lowered levels of cardiovascular disease, anxiety, stress, and cortisol.  It is also known to produce a significant reduction in depression.

There is a very small positive association between ALA and prostate cancer although it is believed that this originates from flaxseed consumption.  Flaxseed contains cyanogen glycosides which are neurotoxic and nonapeptides which are immunosuppressive.




20:5 n-3 Eicosapentaenoic acid (timnodonic acid)

Eicosapentaenoic acid, EPA, (icosapentainoic acid) or as it’s commonly called timnodonic acid is an omega -3 fatty acid.  It has 20 carbon atoms and 5 cis double bonds. EPA acts as a precursor to 3 different eicosanoids: leukotriene -3, prostaglandin – 3 and thromboxane -3. It is also a precursor to docosahexaenoic acid or DHA.

EPA is not only found in certain foods but is also synthesized using ALA or alpho-linolenic acid.   The foods from which it can be obtained include cod liver, herring, mackerel, salmon, menhaden, sardine, various types of seaweed and human breast milk.

What does it do for us?

Research on EPA has revealed that it is beneficial in treating schizophrenia, depression and improves the response of chemotherapy patients.  It also has been shown to play a role in protecting against liver damage from the anticonvulsant drug valproate and from cell death from toxins.  As well, it helps to prevent an abnormal fat buildup and retention in fat cells.



Docosapentaenoic acid  is an omega 3 fatty acid.  Docosapentaenoic acid  (DPA) is called clupanodonic acid in popular language.

What does it do for us?

It acts as an intermediary between EPA and DHA.



  22:6 n-3   Docosahexaenoic acid  (DHA)  is either made from alpha-linolenic acid or gotten directly from mother’s milk or fish oil.  Its common name is cervoic acid.

What does it do for us?

Docosahexaenoic acid (DHA) is an omega 3 fatty acid.  Our brains are primarily made up of DHA.  It is the most important structural component of the human brain, particularly the cerebral cortex as well as the retina in our eyes, testicles, skin and sperm.




Omega 3 Polyunsaturates with limited available information:

Tetracosapentaenoic acid http://www.ncbi.nlm.nih.gov/pubmed/9870906

Tetracosahexaenoic acid

Stearidonic acid  An omega 3 fatty acid which is synthesised by alpha linolenic acid. http://en.wikipedia.org/wiki/Stearidonic_acid

Eicosatrienoic acid http://www.ncbi.nlm.nih.gov/pubmed/8869885

Heneicosapentaenoic acid http://en.wikipedia.org/wiki/Heneicosapentaenoic_acid




Omega 6 fatty acids are a group of fatty acids that have a double carbon to carbon bond in the n-6 position from the methyl end.

Inflammation is our bodies response to damage, irritants or pathogens within our cells.  When inflammation occurs it signals the immune system to  go into action to fight and or repair the offended cells.

Although inflammation is extremely important to the survival of our cells it can also become chronic and chronic inflammation can lead to diseases such as hay fever,  heart disease (blocked arteries),  tooth decay,  rheumatoid arthritis and even cancer.  Because of the dangers of chronic inflammation our bodies fight to closely regulate it.

Eicosanoids are signalling molecules.  Eicosanoids control many of our bodies activities.  Inflammation and immunity are two of the main systems eicosanoids exert complex control over.  They also act as messengers within the central nervous system.  The controls that are dependant on eicosanoids are extremely complex.

Eicosanoids are created from both omega 6 and omega 3 fatty acids as needed.

The omega 6 fatty acids are the most active in creating inflammation where as the omega 3 fatty acids reduce inflammation. Omega 6 fatty acids do not always act to create inflammation. The amounts and the proportions of each of these fatty acids affect the way the body controls inflammation.  Too much omega 6 fatty acid in the diet can lead to chronic inflammation resulting in heart disease, arthritis and other chronic inflammatory diseases.  We get large amounts of omega 6 fatty acids from processed and fast foods.

In our bodies the effects of omega 6 fatty acids can be felt because of their bonding to eicosanoids.  In this form they bind to large numbers of receptors in every tissue throughout our bodies.




http://en.wikipedia.org/wiki/Omega-6_fatty_acid http://www.ncbi.nlm.nih.gov/pubmed/21688154



18:2 undifferentiated Linoleic acid is an omega 6 fatty acid.  Our bodies cannot make linoleic acid on their own so we must get it from our diets.

It is found in most oils, almonds, chicken fat, egg yolk, lard and butter.

Linoleic acid has a double bond at the sixth carbon atom from one of the ends of the molecule.  In all there are 18 carbon atoms and two double bonds.

What does it do for us?

It is used in the biosynthesis of arachidonic acid and consequently some prostaglandins which are a type of hormone that is found throughout the body. They have many functions in the body such as constriction and relaxation of heart muscles the sensitisation of neurons to pain and the regulation of calcium, movement, hormones and cell growth

Linoleic acid is also metabolized into gamma linolenic acid.




18:3 (n−6) Gamma Linolenic acid is found mostly in vegetable oils such as GLA safflower oil, evening primrose oil, blackcurrant seed oil, borage and hemp oils.  It is also found in oats, barley and spirulina.


What does it do for us?

GLA is an omega 6 fatty acid.  It is used by our bodies to form DGLA (dihomo-y-linolenic acid) which is one of three ‘eicosanoids’ .   (Ecosanoids are signalling molecules that control some of our bodies most complex systems such as the inflammatory and immune systems and they act as messengers in the central nervous system.)

Although gamma-linolenic acid is an omega 6 fatty acid, which are generally pro inflammatory, it actually has anti inflammatory properties.

Our bodies produce GLA using linolenic acid which uses an enzyme that creates a double bond on the sixth carbon atom.  As we get older or when we have certain dietary deficiencies the special enzyme called D6D does not convert well and we do not get enough GLA.


Omega 3 Polyunsaturates with limited available information:

Eicosadienoic acid

Dihomo-Y-linolenic acid (DGLA)


Eicosatetraenoic acid (arachadonic acid)


Docosadienoic acid


Docosatetraenoic acid (Adrenic acid)


Docosapentaenoic acid (Osbond acid)


tetracosatetraenoic acid








Eicosatrienoic acid (Mead acid)





18:4 Parinaric acid is a polyunsaturated fatty acid with 18 carbon atoms and 4 conjugated (it has double bonds seperated by a single bond) double bonds.  These repeating single/double bonds make it different from other polyunsaturates which have their double bonds separated by a methylene unit.   This form of alternating double bond has fluorescent properties and consequently is used to study biomembranes and lipoprotein interactions.

What does it do for us?

Alpha parinaric acid is primarily found in the Pacific Islands in the seeds of the makita tree.  Its toxicity to human leukemia cells and to malignant gliomas in cell cultures makes its anti cancer potential of interest to science.


18:3 Catalpic acid is a polyunsaturated fatty acid with 18 carbon atoms and 3 double bonds.

What does it do for us?

It decreases abdominal fat deposits, lowers blood glucose levels and insulin levels while decreasing white adipose tissue.  It increases HDL cholesterol and upregulates gene expression to decrease plasma triglyceride levels.


















Podocarpic acid





Sterols or steroid alcohols are special forms of steroids.   Sterols and stanols from plants are called phytosterols and sterols from animals are called zoosterols.

Campesterol, sitosterol, stigmasterol and ergosterols are phytosterols.

Cholesterol is the most important zoosterol.



Plant sterols are broken down into two classes: sterols and stanols.  Stanols makeup only about 10% of all dietary phytosterols while sterols make up the most abundant source.


Stanols are the saturated form of phytosterols as they have no double bonds and therefore no openings for more hydrogen atoms to attach themselves to the molecule.  They are therefore saturated or filled up with hydrogen atoms and there is no room for more.


Phytosterols unlike cholesterol cannot be synthesized inside the body.  They must be consumed.  The blood levels of phytosterols are usually a fraction of the concentration of cholesterol in the blood.   Only about 10% of phytosterols are absorbed into our bodies as opposed to 50 to 60% of dietary cholesterol.


Phytosterols are known to lower low density lipoproteins while increasing high density lipoproteins.



Cholesterol is the sterol produced in animals.  It is essential to the structure of the membranes of our cells and their ability to allow fluids and nutrients to flow in and out of the cell.  Cholesterol is one of the most important elements in our bodies. Not only does it:

  • Maintain proper fluidity and permeability in the cell but
  • It is a major factor in the creation of steroid hormones  a. the sex hormones, progesterone, estrogen and testosterone and b. the adrenal gland hormones, cortisol and aldosterone.  Steroid hormones help control the metabolism, inflammation, immune function, salt and water balance, the development of sexual characteristics, the fight or flight response and the fight against illness and injury.
  • It is involved in the creation of bile acids
  • And the synthesis of Vitamin D.
  • Within the cell membrane cholesterol functions by assisting in the transport of cell signals and nerve conduction.
  • It helps in the production of lipid rafts in the membranes of plasma which increases the transfer of cellular information.
  • It is a major part of the myelin sheath which protects the axons inside the neurons in our central nervous system.  This increases the efficiency of the transfer of cellular information within the neuron.
  • Cholesterol is produced by all animals in all cells, however, the liver is responsible for producing larger amounts than any of the other cells throughout the body.
  • Cholesterol is also ingested into our bodies through our food supply, specifically from eating animal products.  Most of the cholesterol that we get from our diet is bonded together with fatty acids.  This is called esterification.  Esterified cholesterol is not absorbed well by the body consequently it gets rejected and is excreted.  This is one of the reasons that dietary cholesterol has little effect on our bodies total cholesterol levels.  The other reason is that any amount of dietary cholesterol that is taken up into our bodies triggers a reaction that causes the body to reduce its internal synthesis of cholesterol.

In fact each of us has our own genetically coded level for cholesterol over which we have little control except by using drugs or eating phytosterols.




The next major question is:

“How do lipids including cholesterol get transported around our bodies to the right destinations”?

Cholesterol is carried around the body in packages called lipoproteins. These lipoproteins fall into five categories: chylomicrons, very low density lipoproteins (VLDL), intermediate lipoproteins (IDL), low density lipoproteins (LDL) and high density lipoproteins (HDL).

Lipoproteins are packages made up of proteins and lipids that act as transporters.   The lipoproteins we are discussing here are those used to transport cholesterol, phospholipids and triglycerides to the cells in our bodies.

First we need to understand what an amphiphile is.

Both apolipoproteins and phospholipids are amphiphiles.  That is they are both water loving and fat loving.

Apolipoproteins (APO) are special proteins that can bind to fats and other lipids while being able to move through water based solutions.

When these apolipoproteins attach themselves to chains of phospholipids they form lipoproteins.   These lipoproteins surround the lipid molecules, cholesterol and triglycerides, so that they can be transported in the liquid environment of the blood stream or the lymphatic system.

ApoA1 is involved in clearing triglycerides and cholesterol from the white blood cells within the artery walls thus reducing the amount of cell death and foam or plaque buildup on the artery walls.

ApoA2 is involved in the transference of phospholipids to HDL particles and is involved in the regulation of the size of HDL particles.

ApoB100 is the key that locks into a cell so that the cell will allow cholesterol to enter.

Apo E engineers the transport of lipoproteins into the lymph system and then into the blood.

ApoC activates lipase which is an enzyme that hydrolyzes fat into free fatty acids so that they can be used by the cells that they are being distributed to.

Each lipoprotein has different apolipoprotein (APO’s) in its outer wall.

Chilomicrons have Apo A, Apo E, Apo B and Apo C attached to the phospholipids on the outside of their lipoproteins.

Very Low Density Lipoproteins have Apo B100, ApoC1,and ApoE attached to the phospholipids on the outside wall of their lipoproteins.

Intermediate density lipoproteins (IDL) have multiple copies of Apo E and a single copy of Apo 100.

Low Density Lipoproteins (LDL) have only one apolipoprotein and that is ApoB100.

High Density Lipoproteins (HDL) have Apo1, Apo A2, Apo E and Apo C



Chylomicrons are small particles that carry lipids (triglycerides, cholesterol and phospholipids) and proteins from the small intestines and from the liver to the cells in our bodies.

The proteins in chylomicrons connect with cells in the liver, muscles in the skeleton and heart and to the storage cells in adipose tissue thus delivering lipids to these areas of the body.

The remnants of the chylomicrons are taken up by the liver where they are broken down and excreted.

Chylomicrons deal with dietary fats and other lipids which we have been ingested from food.




VLDL is a package with apolipoproteins and phospholipids that contain triglycerides and cholesterol as well as cholesterol esters.  It is formed in the liver.

Both VLDL and Chylomicrons are the least dense with cholesterol of the five lipoproteins. They have the least cholesterol and the most triglyceride.

Once in the blood stream VLDL acquires two more apolipoproteins called apoC and apoE from HDL ( high density lipoproteins).

As it circulates around the body it comes in contact with a lipoprotein lipase or LPL, an enzyme that removes triglycerides from VLDL to use for energy or for storage. Once this is accomplished VLDL returns  apoC back to HDL but keeps apoE and HDL trades some cholesterol esters with VLDL for phospholipids and more triglycerides.

More and more triglycerides are removed from VLDL by the LPL enzyme and by HDL. VLDL then turns to IDL intermediate density lipoprotein to get more triglycerides.




Intermediate density lipoproteins are formed because of the loss of triglycerides from VLDL.  When VLDL transfers triglycerides into storage cells or to use for energy it returns to the blood stream and resumes as IDL (intermediate density lipoproteins).

At this point the IDL particles have lost most of their triglycerides but retain some cholesterol.

IDL like LDL can contribute to atherosclerosis.    About half of the IDL particles are taken up by the liver and the other half are changed into low density lipoproteins or LDL after having even more triglycerides removed through hydrolysis. The protein called apoE that was acquired from the HDL by VLDL now is used to bind to the LDL receptor until the IDL is converted to LDL and then apoE is discarded and IDL remnants are returned to the liver.




So finally we have lipoprotein molecules that have much less triglyceride and lots of cholesterol both esterified (bonded to a fatty acid) and non esterified and one large  apolipoprotein APO B100.

LDL continues to circulate throughout the body connecting with various cells and connecting with their receptors to transfer cholesterol for use by the cell.

Scientists are just beginning to discover that there are different types of LDL. LDL, they are finding, comes in 2 forms: pattern A which are larger and less dense and pattern I which are smaller and fit into the walls of the arteries quite nicely.  This information is just beginning to be explored but appears to be giving us much greater insight into the role lipoproteins play in our lives.

LDL comes in varying sizes.  Larger particles travel through the blood stream without incidence.  Smaller particles, however, have a tendency to lodge in the walls of arteries creating irritation and inflammation that attract macrophages.  The smaller particles are closer in size to the normal gaps in the layer of cells on the artery walls so tend to settle into them.

Macrophages are cells that are released through the immune response to engulf pathogens and unwanted debris in the body and destroy them.  Fixed macrophages will remain at the site of inflammation. These macrophages called ‘foam cells’ increase the plaque buildup in the artery walls leading to problems with blocked arteries and atherosclerosis.



HDL helps to

  • Inhibit inflammation and oxidisation
  • Inhibit coagulation and the aggregation of platelets as well as inhibiting the activation of the endothelium which are the layer of cells that line the artery walls.
  • HDL delivers cholesterol to the adrenal glands, the ovaries and the testes so that they can synthesis steroid hormones.
  • HDL also transports cholesterol away from the macrophages or ‘foam cells’  attached to artery walls as a result of the immune response to the imbedding of LDL particles in the lining of the wall.  This is called reverse cholesterol transport, a protective action of HDL against clogged arteries.
  • HDL exchanges triglycerides for cholesteryl esters with VLDL thus changing VLDL into LDL particles.
  • HDL transports cholesterol back to the liver where it is excreted into bile and finally into the intestines in bile acids.
  • There is a parasite called trypanosoma brucei brucei that is a specialized protein that HDL protects us against.
  • Triglycerides degrade in HDL.

As with LDL scientists are just beginning to discover that there are different types of HDL. HDL apparently has 5 subfractions that have been identified.  These range from large to small.  The largest ones are the most effective in removing cholesterol and the smallest the least effective.  This information is just beginning to be explored but appears to be giving us much greater insight into the role lipoproteins play in our lives.

Fatty acids (or as their salts) do not often occur as such in biological systems. Instead fatty acids like oleic acid occur as their esters, commonly the triglycerides, which are the greasy materials in many natural oils. Via the process of saponification, the fatty acids can be obtained.

http://en.wikipedia.org/wiki/High density_lipoprotein















Phospholipids are lipids which are a major component of all cell membranes which form bilayers within the cell.  Phospholipids were first discovered in 1847 by a French chemist, Theodore Gobley, in the form of lecithin found in the yolk of an egg.  Phospholipids along with sterols provide membrane fluidity and mechanical strength to our cells.  Another naturally forming phospholipid is sphingomyelin which also plays a role in cell structure of the myelin sheath that protects nerve cell axons.




Adipose tissue Is loose connective tissue which we refer to as body fat.

Free fatty acids are delivered to adipose tissue by lipoproteins and are freed by the enzyme lipoprotein lipase through the gateway unlocked by an apoliprotein.

There is a constant flow of free fatty acids going into and leaving the adipose tissue.  This flow is controlled by insulin and leptin. If there is too much insulin the fatty acids go into the adipose tissue.  If there is not enough then they come out.  They come out because low insulin signifies that glucose levels in the blood are low and the body will need another energy source – fat.

Adipose Tissue is made up of adipocytes which are cells that hold fatty acids and is considered to be a major endocrine organ as it produces hormones.  The following are the hormones produced by adipose tissue:

Leptin: This hormone is believed to be an anti starvation hormone.  When leptin levels decrease hunger increases. It also controls hunger in other ways.

Leptin levels are elevated in the obese because leptin is produced in adipose tissue.  When weight is lost leptin levels decrease and that signals hunger to increase.  This explains why dieters develop the yoyo diet effect where they loose weight then gain it right back and then some.

Resistin:  has been shown to increase the risk of heart disease by increasing the production of LDL in the liver and it degrades LDL receptors in the liver.  Resistin is believed to enhance inflammation but is also thought to have a role in energy homeostasis.

Estrogen: the primary female sex hormone.

Cytokine TNFa (tumour necrosis factor alpha): signal cell death (apoptosis) in cells that are damaged.

Adipose tissue contains fibroblasts which synthesis the materials for the structural framework for tissues and plays a critical role in wound healing.

It contains blood vessel endothelial cells – the cells line the walls of the blood vessels

It stores immune cells such as macrophages- cells involved in tissue repair

Preadipocytes are also stored in the adipocyte tissue to be used as needed in case of the need for further fat storage.

Its main role is to store lipids to be used for energy.

Adipocytes come in various colours: white, brown, beige, pink.  They never reduce in numbers and can add more if needed.

White adipose tissue is is used to store energy for use by the cells energy factory ATP.  They contain a single large fat molecule in each cell and have receptors for specific hormones: insulin, norepinephrine (the fight or flight hormone), glucocorticoids (control the metabolism of glucose) and human growth hormone (stimulates growth and cell reproduction)

Brown adipose tissue is a specialised tissue that can generate heat through a specialised process within the mitochondria that generates heat instead of ATP (adenosine tryphosphate).

It is found in abundance in infants who can’t move or shiver to keep warm.  It is also found in abundance in animals that hibernate which is why they can stay alive in extremely cold temperatures.  Brown adipose tissue is found in very small amounts in adult humans.

Beige adipose tissue has just recently been discovered.  It has a gene expression that is not the same as either the white or brown tissues but little is yet known about it.

Pink adipose tissue is presently being studied and appears to be involved in the development of mammory gland development.

Genetic predisposition controls the formation of adipose tissue.

Adipose tissue in humans is found:

Beneath the skin ( subcutaneous)

In the abdomen and surrounds internal organs (visceral fat)

In bone marrow (yellow bone marrow)

In breast tissue

It provides insulation from heat and cold

Contains many small blood vessels.

Surrounds organs to provide protective padding

Its main function is to store lipids for use as energy and to protect the body from excess glucose by storing  excess glucose as the triglyceride, palmitic acid, a saturated fat.

Abdominal fat

Visceral fat is semi fluid and is found inside the abdominal cavity surrounding the stomach, liver, intestines, kidneys and over organs.

The Panniculus is excessive adipose tissue hanging down from the abdomen and is a mark of obesity.

Sex differences in fat storage are programmed by our hormones. Females tend to store fat on the thighs, hips and buttocks and men on the belly.


Epicardial fat

A form of visceral fat that is deposited around the heart and has molecules that are thought to significantly affect the heart.


Subcutaneous fat

Found just under the skin. It is not involved in any illnesses caused by obesity such as cancer, stroke or heart disease.

It is resonsible for the secretion of leptin and resistin.


Ectopic fat

Ectopic fat is the term used to describe fats that are not stored in adipose tissue. Not a visceral fat but stored around and even in the liver, skeletal muscles, heart and pancreas and in higher amounts around the organs of the abdominal cavity.

It interferes with the function of the organ and is part of the cause of insulin resistance in type 2 diabetes.  Ectopic fat is caused when the adipose tissues cannot contain anymore fat molecules and cannot for what ever reason produce more adipocytes.  The overflow of fat molecules is deposited in the places that require very little fat and are not meant for storage.


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