Exam #1: Nutrition and Cardiovascular Disease Flashcards
What are the causative factors of vascular disease?
- HTN
- Vascular effects of DM
- Platelet aggregation
- Hypercoaguable states from obesity and high dietary fat
- Smoking
- Insufficient regular exercise
- DIET
What fats have a deleterious effect on the heart?
1) Saturated fat
2) Cholesterol
What are elements of diet that can be cardioprotective?
- High fiber
- Folate
- Anti-oxidants
- Vitamin K
- Low Na+
- High K+ and Mg++
- Omega 3
Where do most fatty acids in the blood come from?
Diet
What are fatty acids used for in the body?
- Important membrane components
- Precursors for hormones and other complex lipids
- Precursor for eicosanoids
How are lipids transported in the blood?
As lipoproteins
List the lipoprotein classes.
- Chylomicrons & remnants
- Low Density Lipoproteins
- High Density Liporotein
- Very Low Density Lipoproteins
What are the athrogenic lipoproteins?
- Chylomicron remnants
- LDL
- VLDL remnants
What are the non-athrogenic lipoproteins?
- Chylomicrons
- HDL
- VLDL
What is a triglyceride?
Ester w/
- 3x fatty acids
- Glycerol
What is the carbon chain length for the FAs that compose TGs?
Even numbers:
16, 18, and 20
What is the function of a chylomicron?
Transport fat-soluble molecules from intestine to other organs
E.g.
- Fat-soluble vitamins
- TGs
- Cholesterol
What enzyme cleaves chylomicrons to release fat-soluble molecules?
Lipoprotein lipase
What is the function of VLDL?
Transport lipids from liver to muscles and other organs
What happens to VLDL remnants?
Re-circulation to the liver to make LDL cholesterol
What is LDL cholesterol derived from?
VLDL
How is LDL cholesterol taken up by the liver?
Receptors on hepatocytes
What happens to LDL receptors in a high cholesterol diet? Low cholesterol diet?
High= fewer receptors expressed–>more circulating LDL
Low= more receptors expressed–>less circulating LDL
How does HDL cholesterol structurally differ from the other lipoproteins?
- More protein
- More phospholipids
- Contains LCAT enzyme
- Contains apoE
What are the major functions of HDL cholesterol?
1) Transfer ApoC-II and apoE to chylomyicrons and VLDL
2) Take up cholesterole from LDL, VLDL, and phospholipids from VLDL
3) REVERSE TRANSPORT of CHOLESTEROL
What are the bad dietary fats?
Saturated fats:
- Myristic (14:0)
- Palmitic (16:0)
- Stearic (18:0)
What are the major sources of “bad” fat?
Butter Milk Meat Coconut Shortening Beef fat Chocolate
What are the cholesterol lowering fats?
- Linoleic acid (18:2)
- a-loinolenic acid (18:3)
- EPA (20:5)
- DHA (22:6)
What are the harmful effects of Trans-fats?
- Dyslipidemia i.e. high LDL, low HDL, and high TG
- Abdominal fat deposition
- Systemic inflammation
- Endothelial dysfunction
- DM
- Membrane effects (ROS)
What is a Mono-unsaturated fat?
Single double bond
*****Also called “MUFAs” and liquid at room temp. b/c of higher melting point
What are the mono-unsaturated fatty acids?
Palmitoleic acid (16:1) Oleic acid (18:1)
*****Note that the most common source is olive oil
What is a PUFA?
Fat with multiple double bonds
What are Eicosanoids?
- Signaling molecules
- Made from oxidation of 20C FA
**Include prostacyclin, thromboxane, lipoxins, and leukotrienes
What is the difference between Eicosanoids derived from FA with N6 or N3 oils?
N6= pro-inflammatory N3= less inflammatory
Outline the pathogenesis of Athersclerosis.
1) Free radicals attack PUFAs and apoB generating fragments
2) LDL is not recognized by hepatocyte receptor
3) Scavenger receptors on macrophages bind LDL fragments and makes “foam cells”
4) Dead and dying foam cells deposit cholesterol creating atherosclerosis
Note that oxidized lipids also stimulate the inflammatory response*
What are free radicals?
Unstable atoms with unpaired electrons
What are the defense mechanisms against free radicals?
- Protective cellular enzymes
- Fat-soluble anti-oxidants
- Proteins and metabolites that protect the aqueous environment of cells
What are the protective cellular enzymes that inactive free radicals?
Superoxide dismutase
Catalase
What are the cardioprotective fat-soluble anti-oxidants?
Alpha-tocopherol
Carotenoids
What proteins and metabolites protect the liquid environment of cells?
Albumin
Uric acid
Ascorbid acid
Is there a difference in the efficacy of different sources of anti-oxidants?
Generally, fruits, veggies, seeds, and nuts are better than corresponding supplements
How many servings of cold water fish per week have been shown to be cardioprotective?
2
