What are Lipids?

• Fat
• Triglycerides
• composed of three fatty acids attached to a cental cor of 3 carbon glycerine:

• Solid fat or liquid fat (edible oils)
• depending on type of fatty acids included
• Phospholipids
• Similar to triglycerides but: replace one fatty acid with a Phosphoric acid

• Steroids
• 30 carbon cyclic compounds many of which are important hormones and are all made in the body from cholesterol;

• Steroids may be not attached to any other molecules when they are called Free Cholesterol (FC) or it may be attached to fatty acids. Then it is called cholesterol esters (CE)
• The body is able to make all it’s own cholesterol and dietary cholesterol has little influence over the amounts the occur in the blood. A diet high in saturated fats however increases the amount the body makes and can cause excess levels of blood cholesterol.
• Blood cholesterol has to be carried in lipoproteins like other lipids. Cholesterol carried in VLDLP is on it’s way to the bodies tissues and can increase cholesterol in blood vessels. Cholesterol carried in HDLP is being returned to the liver and is in the process of reducing cholesterol in the tissues.
• VLDLP and LDLP cholesterol is some times called bad cholesterol while HDLP cholesterol is referred to as good cholesterol.
• It is nor enough to just measure the total amount of cholesterol in the blood. It is the LDLP cholesterol that must be determined

• Primary store of energy
• main sauce of energy for muscles
• Protection for organs (cushioning)
• Insulation against cold
• Fat smooths body shape
• Women more than men
• Body can make most of what it needs from carbohydrates and protein
• Needed supply essential fatty acids
• Needed to supply fat soluble vitamins

• The body cannot make unsaturated fatty acids with double bonds before the 7th C
• We need fatty acids with double bond between carbon 6 and 7
• These are called w 6 fatty acids
• They are all poly unsaturated fatty acids
• having more than just the w 6 double bond
• w 3 fatty acids have w 6 as well as other double bonds total three or four
• Essential fatty acids are needed to manufacture prostaglandins
• Prostaglandinsare hormone like compounds that are needed for many activities in the body
• Many are need to allow other hormones to act.
• Cis and Trans double bonds
• Cis double bonds are the only one that occur in natural fatty acids
• 
• Trans double bonds are produced when fats are processed such as in making margarine
• Digestionand Absorption of Lipids
• Digestion
• Transport of Lipids in Blood
• Lipids are insoluble in water and body fluids
• must be carried with proteins called Lipoproteins
• These include:
• Chylomicra
• carry fat from Intestine to tissue
• VLDLP (very low density lipoprotein)
• carry lipids from Liver to tissues
• VLDLP loose fatty acids to tissues they get denser and become IDLP and eventually LDLP
• remnant LDLP and chylomicra return to liver
• HDLP
• carry cholesterol from tissues to liver
• sometimes called Revers transport
• 

• Danger of Excess Dietary Fat
• Colon Cancer
• Undigested fatty acids reaching the colon can act as a mitogen
• fatty acids make soap that wash of cells lining the gut
• This acts as a MITOGEN ie stimulates cell growth
• Cancer needs two stages to develop:
• Mutagen
• The change in genetic information that causes it to be cancerous
• and then a mitogen to start it growing
• Increases cholesterol production
• inbalance of carbohydrate and fat metabolism
• Excessive fat catabolism results in a build up of intermediates that are used to make cholesterol.
• Excess cholesterol can be deposited in the arteries causing arteriosclerosis
• Reducing blood flow and increasing the chance of a heart attack or stroke.
•  
• Obesity
• Obesity increases the chance of maturity onset (type two) diabetes
• Obesity increases the chance of hypertension
• Increased Blood cholesterol
• High blood cholesterol can lead to deposits or plaques in the arterial walls restricting the flow of blood.
• This can cause cramp in the heart called angina
• Lack of blood to the legs can result in toes dieing
• Narrowing of the arteries make it easier for blood clots to plug the artery completely stopping blood flow and causing tissue death
• Heart attacks and Strokes
• How to Reduce Lipid Intake
• Eat more fibre
• Modern "functional foods" are replacing fat with new forms of fibre and still keeping organoleptic quality
• Fat Replacements
• Fruit fibres
• Olean
• Fatty Acid Metabolism