Three classes of lipids:
- 1 fats or triglycerides
- 2 phospholipids
- 3 sterols
What is the largest class of lipids in foods and bodies:
Lecithin is an example of what lipid?
What are the functions of fats/triglycerides?
- -energy source
- -satiety and satiation
- -nutrient source
- -stored energy
- -organ protections
- -temp regulation
- -insulation (myelinateion of nerves)
What nutrients come from fats/triglycerides?
- -fat-soluable vitamins: A, D, E, and K
- - essential fatty acids
- -linoleic fatty acids
- -linolenic fatty acids
What are the functions of phospholipids?
- -cell membrane structure
- -emulsifier in fluids
- -part of lipoprotiens that carry fat and cholesterol away from arteries
What are the functions of sterols?
- -critical components of complex regulatory compounds
- -basic material to make bile, vitamin D, sex hormones and cells in brain and nerve tissue
What is the structure of tyiglycerides?
*all natural fats are mixtures of different types of fatty acids
What is the structure of a saturated FA?
Has a hydrogen atom attached at each available space
What is the structure of an unsaturated FA?
have double bonds between C and fewer H atoms
What are some sources of saturated fats?
- egg yolks
- milk, butter and cheese
- only plant source: tropical oils
What negative health effect is associated with saturated FA?
What is the structure of a monosaturated FA?
A carbon chain with one unsaturated double bond
What are sources of monounsaturated FA?
- olive oil
- canola oil
What is the structure of polyunsaturated FA?
contains two or more double bonds on the carbon chain
What are some sources of polyunsaturated fatty acids?
- vegetable oils -corn safflower, wheat germ, canola, sesame and sunflower
What is a linoleic acid?
- vegetable oils, prepared foods, and animal foods
What is a linolenic acid?
- fish (esp tuna, salmon, bluefish, halibut, sardines and rainbow trout)
- canola oil
decrease risk of heart disease by preventing coagulation or arterial plaques
What is the function of the essential fatty acids? (linoleic and linolenic)
- 1 skin integrity (strengthen cell membrane and prevent permeability---deficiency causes eczema and leisions)
- 2 blood cholesterol regulation
- 3 growth (brain development before and after birth)
- 4 Regulate production of enzymes needed for sythesis of nonessential FA by liver
- 5 Immune function - slows rate of infection
- 6 Prevent inappropriate blood platelet aggregation
- 7 Precursors of prostaglandins
What is a trans fat?
artificially produced fats
What is hydrogenation?
A process that changes unsaturated oils into solid fats
How are trans fats detrimental to health?
- 1 development of CAD and DMII
- 2 decrease HDL and increase LDL
- 3 Disrupt essential FA functions
Where do we find trans fats?
- frozen potato products
- frying in fast food restaurants
What is lipogenesis?
- anabolism of lipids
- results in formation of triglycerides, phospholipids, cholesterol, and prostaglandins
How is fat digested?
- -begins in mouth with lipase
- - little digestion occurs in stomach
- - bile is release when fat reaches sm. intestine
- - pancreatic lipase breaks down triglycerides into monoglycerides, fatty acids and glycerol
How is fat absorbed?
- - digested lipids bind with bile to form micelles which are absorbed by microvilli
- - inside mucosal cells, FA and monoglycerides are reassembled into triglycerides an dincorporated into chylomicrons (lipoproteins)
- -chylomicrons are absorbed into the lymph system and taken into the circulatory system
What is the DRI of fats?
- - less than 10% of cal from saturated fats
- - 20-30% kcal from fats
- - total fat intake: 40-97g
- - total saturated fat intake: 20-25g
What are high sources of cholesterol?
What is the role of lipoproteins in the body?
transort lipid-based molecules that are water insoluble through water-based blood plasma
What are LDLs and VLDLs?
- carry fats and cholesterol to body celss
- made of largest proportions of cholesterol
What are HDLs?
- carry fats and cholesterol from body cells to the liver for excretion
- made of large proportions of proteins
What is a desireable cholesterol profile look like?
- total= <200 mg/dL
- LDL= <130 mg dL
What does a borderline-high cholesterol level look like?
- total = 200-239 mg/dL
- LDL= 130-159 mg/dL
What does a high cholesterol profile look like?
- Total = >= 240 mg/dL
- LDL = >= 160 mg/dL
What doe guidlines recommend for dietary cholesterol intake per day?
less than 300mg
*if LDL is elevated, than less than 200 mg
What affets blood cholesterol?
- Cholesterol in food has little effect
- total food fat, particularly saturated fats, affect LDL
The following are all examples of what?
failure to thrive of infants
malnutrition among older adults from fear of cholesterol
Extreme fat restrictions
EFAs must be provided
How much saturated fat and cholesterol do the National Cholesterol Education Program recommend?
- 7% or less SF
- 200 mg dietary cholesterol
How does dietary fat relate to breast cancer?
Adipose tissue is the primary source of estrogen after menopause. there is an increase risk of breast cancer with an increased intake of toal fat and saturated fat
What is the association of colon cancer and dietary fat?
significant amounts of red meats and colon cancer.
stronger risk factor is consuming too many calories compared with energy expenditure
What is the associated between dietary fat and DMII and hypertension?
- indirectly related to fat intake
- both disorders are better managed when weight is healthy
- dietary fat reduction helps better manage a healthy weight