Chap4 lipid nutrition in health and disease

Any of a group of substances Any of a group of substances that in general are soluble in that in general are soluble in organic solvents, but are not organic solvents, but are not soluble in water.soluble in water.

The term fats and lipids used interchangeably

Source of energy (9 kcal/g)Energy reserve: any excess energy from

carbohydrate, protein and lipids are stored in adipose tissues

Provide insulation to the body from coldMechanical insulation: protects vital organs

Supply Essential Fatty Acids (EFA)Linoleic acid and linolenic acid

Helps in the formation of cell membranes Phospholipids

Help carry fat soluble vitaminsFlavor and tasteThe satiety value

Fullness; fats are digested slower

 1. Fatty acids

2. Neutral fats and oils

3. Waxes

4. Phospholipid

5. Sterols

6. Fat soluble vitamins

Types of Lipids

The basic structural unit of lipidCommon in food fats and oilsHas 3 classes according to their degree of

saturationFully saturatedMonounsaturatedPolyunsaturated

Also vary in chain according to the number of atomsShort chains fatty acids 2 to 4 carbon atomsMedium chains have 6 to 10 carbon atomsLong chains have 12 to 26 carbon atoms

Linoleic and arachidonic acid are essential fatty acids

It maintain the function and integrity of cell membranes

Are used to esterify cholesterol in plasmaRequired for metabolism of cholesterol and lipidsLinoleic acid derivatives have been shown to be

precursors for a group hormone like compounds called prostaglandins

Linoleic acid deficiency: signs and symptoms of scaly skin, sparse hair growth, poor wound healing and thrombocytopenia (decrease in blood platelets)

Are a class of lipids and are a major component of all cell membranes as they can form lipid bilayers

Divided into 3 groupsPhospatides – form part of the cell walls and

mitochondriaLecithin –egg yolks and meat, used as emulsifying agent

in mayonnaise and salad dressingsCephalin – egg yolks and in brain, present in

thromboplastin which is needed in the blood clotting process

Sphingomyelins – a component of a fatlike sheath substance, tghe insulation around nerve fibers

Plasmalogens – related to the specialized function in platelets in blood coagulation

Is a waxy, fat-like substance that is made in the body by the liver

It forms part of every cell in the body and serves many vital functions:Maintain healthy cell wallsMakes hormones (the body’s chemical

messengers)Make vitamin DMake bile acids, which aid in fat digestion

Excess cholesterol circulates in blood stream can clog blood vessels and increase the risk for heart disease and stroke

Low-Density Lipoprotein (LDL) – a bad type of cholesterol that is most likely to clog blood vessels , increasing your risk for heart disease

High-Density Lipoprotein (HDL) – good type of cholesterol, helps clear the LDL cholesterol out of the blood and reduces the risk of heart disease