Nutrition Module 11: CVD - Lipoproteins Flashcards Preview

SMP - MNE Exam 2 > Nutrition Module 11: CVD - Lipoproteins > Flashcards

Flashcards in Nutrition Module 11: CVD - Lipoproteins Deck (55)
1

Where do most of the FAs in the body come from?

Dietary fat

2

What are the 3 atherogenic lipoproteins?

1. Chylomicron remnants
2. LDLs
3. VLDL remnants

3

What are the 3 non-atherogenic lipoproteins?

1. Chylomicrons
2. HDLs
3. VLDLs

4

What do people who cannot produce chylomicrons due to genetic defects usually suffer from? Why? Treatment?

Neuropathy because neurons lack vitamin E
Treatment: VE injections or oral doses that are thousand fold higher than normal

5

Describe the route of chylomicrons (5 stops)

1. Lungs
2. Muscles
3. Adipose tissue
4. Hepatic artery
5. Liver

6

How fast are chylomicrons cleared from the bloodstream? What determines the rate of clearance?

Few hours
Genetics and dietary habits (high/low-fat)

7

How does the amount of fat eaten in a typical american meal affect the rate of clearance of chylomycrons? How does this affect atherosclerosis risks?

The amount of fat saturates the clearance pathway which prolongs their circulation causing increased atherosclerosis risks

8

What is an independent risk factor of CVD?

Elevation of serum TAGs

9

What can high TAGs be caused by?

1. Obesity
2. Lack of PA
3. High carbs

10

What 3 molecules do VLDLs transport?

1. TAGs
2. Cholesterol
3. Vitamin E

11

Which is faster: chylomicrons or VLDL TAG hydrolysis?

Chylomicron

12

What is the main difference between chylomicron and VLDL remnants?

Chylomicron remnants are all cleared by receptor-mediated endocytosis vs only half of VLDL remnants are cleared like this

13

Which have longer half-lives: chylomicrons or VLDLs?

VLDLs

14

What is fatty liver? What is it caused by?

Chronic alcohol abuse impairs the liver from exporting excess TAGs via VLDLs = TAGs accumulate

15

What is the half-life of LDLs?

Few weeks

16

Which lipoproteins mediate the transport of cholesterol from arterial walls into the liver?

HDLs

17

2 components of LDLs?

1. Cholesterol
2. Vitamin E

18

What is cellular LDL cholesterol uptake regulated for?

To ensure adequate supply of cholesterol for the synthesis of membranes, hormones, and other critical compounds

19

What causes slowed LDL uptake?

Cells have enough cholesterol => fewer receptors are expressed especially on liver => LDL receptor down-regulation

20

How does dietary cholesterol intake affect the liver? What is the net effect?

Down-regulation of liver LDL receptors = high serum LDL = harder for liver to excrete as bile

21

Which cells have the highest LDL receptor activity?

Adrenal gland cells

22

Does the liver have to convert cholesterol into bile acids before it goes into bile?

NOPE

23

What kinds of FAs can lower LDLs?

Polyunsaturated FAs (eg: omega-3 FAs)

24

What kinds of FAs can increase LDLs?

Saturated and trans FAs

25

What kinds of FAs have no effect on LDL levels?

Monounsaturated FAs

26

What are the 4 factors that influence LDL levels?

1. Genes
2. Body weight
3. PA
4. Diet

27

By what % can lifestyle changes reduce excessive LDL levels?

20-40%

28

Other than polyunsaturated FAs, what 5 other foods can lower LDL levels?

1. Viscous dietary fiber
2. Soy protein
3. Plant stanols and sterols
4. Antioxidants
5. Flavonoids

29

What 4 foods are viscous fibers found in?

1. Oats
2. Barley
3. Legumes
4. Fruits

30

What 4 foods are plant stanols/sterols in?

1. Nuts
2. Seeds
3. Vegetable oils
4. Margarine

31

What 4 foods are flavonoids in?

1. Fruits
2. Vegetables
3. Wine
4. Tea

32

What are 2 viscous fibers?

1. Pectin
2. Beta-glucan

33

What is a genetic factor that increases responsiveness to dietary cholesterol?

Apolipoprotein E4

34

What kind of FA is myristic FA?

Saturated FA

35

How does the raise in LDL due to saturated FAs compare to the lowering in LDL due to polyunsaturated FAs?

Raise is bigger

36

What are polyunsaturated FAs susceptible to? What does this cause?

Peroxidation making them more atherogenic and causing a chain of free radical and lipid hydroperoxide synthesis

37

Which lipoproteins are most susceptible to peroxidation? Why?

LDLs because of high polyunsaturated FA content

38

Why do some people with excess iron stores have increased CVD and cancer risks?

Because the generation of most toxic free radicals is catalyzed by free Fe Copper

39

What happens to oxidized LDLs?

They are no longer recognized by their normal receptors but bind to the scavenger receptor on macrophages (which become foam cells) and other cells to promote atherosclerosis

40

What can explain why antioxidants in fruits and veggies are more effective than those in supplements in preventing disease? 1 example?

Because antioxidants are interdependent and complimentary

Eg: ascorbic acid regenerates alpha-tocopherol inhibiting it from becoming a pro-oxidant

41

What are normal HDL levels?

40 and above in men
50 and above in women

42

What are the 4 main functions of HDLs?

1. Transfer apoC-II and apoE to chylomicrons and VLDLs to regulate them
2. Take up cholesterol and phospholipids from VLDLs and LDLs
3. Remove cholesterol from tissues

43

What are the 2 types of factors influencing HDL levels?

1. Constitutional factors
2. Lifestyle factors

44

What are the 3 constitutional factors of HDL levels?

1. Sex: women have higher levels
2. Genes
3. Hormonal status: decrease after menopause

45

What are the 3 lifestyle factors of HDL levels?

1. PA
2. Weight
3. Alcohol (moderate intake increases HDL)

46

What are the primary prevention guidelines for CVD?

1. Maintain healthy weight
2. Sat fat intake below 10% of calories and low trans fats
3. Cholesterol intake below 300 mg/day
4. 2 servings of fish/week
5. Fruits/veggies
6. Whole grains and high fiber foods
7. Salt intake below 6g aka 2300 mg
8. Alcohol limits to 2 a day for men and 1 for women
9. Limited foods/drinks with added sugar

47

What are the 2 FAs with the greatest cholesterol-raising potential? Foods high in these?

Myristic and palmitic acid in butter, whole milk, cream and high-fat cheeses

48

Which affect serum cholesterol levels the most: types of FAs consumed or dietary cholesterol?

Types of FAs

49

Which have more unsaturated FAs: liquid or solid fats?

Liquid oils

50

Which lipoprotein delivers dietary cholesterol to the liver?

Chylomicron remnants

51

What are the most reversible vascular lesions?

Fatty streaks

52

Can carbs increase LDL levels?

NOPE

53

What will usually raise LDL levels?

Excessive VLDLs

54

What can raise VLDL levels?

Reduced fat intake because VLDLs are needed to transport TAGs and cholesterol within the body

55

What is cholestasis? What is it caused by?

Stopped bile flow caused by absence of CKK