LIPIDS:

1. LIPIDS: • 1) Fats = • 2) Oils =

2. Functions of Lipids: • 1) • 2) • 3) • 4) • 5) • 6)

3. Types of Lipids: • 1) Triacylglycerols: (triglycerides, TG’s) • 2) Phospholipids: • 3) Isoprenoids:

4. 3 Types of Fatty Acids: • 1) • 2) • 3)

5. Chain Length • 2-6 C’s = • 8-10 C’s = • 12 or more C’s =

6. Saturated Fatty Acid (SFA)

7. MUFA’s

8. PUFA’s

9. Further Classification of PUFA’s • Omega 3 (w-3) vs. Omega 6 (w-6)

10. Linoleic Acid = a- Linolenic Acid =

12. Synthesizing a FattyAcid: • The body can synthesize all the fatty acids it needs from dietary CHO, fat and protein except for: ESSENTIAL FATTY ACIDS: 1) 2)

14. Fatty Acid Synthesis • Not all steps are equally efficient in humans, elongation and desaturation of 18:3w-3 to EPA and DHA appear somewhat restricted in humans. • w-3 and w-6 f.a.’s that we eat become a part of the phospholipids of our cell membranes.

17. Effects of eicosanoid families: • 1) Raise or lower BP (vasoconstrict or vasodilate • 2) Increase or decrease platelet aggregation (bld. Clotting) • 3) Increase or decrease immune response • 4) Increase or decrease inflammatory response (asthma, arthritis)

18. Hydrogenation: • Can chemically alter a MUFA or PUFA -->

20. Cis vs. Trans • 1) In nature • 2) • 3)

21. Reasons for hydrogenation: • To change the physical properties of a product: • To make a product with fat more stable:

22. Effects on Lipoprotein Levels (Lipid Profile) SFA MUFA w-3PUFAw-6PUFATrans

23. Triglycerides (triacylglycerols) • TG = • TG’s =

24. Triglyceride

25. Phospholipids (PL): Lecithin

26. Sterols Cholesterol Cholesterol ester

27. Sterols made from cholesterol: • 1) • 2) • 3)

28. Types of Lipoproteins • Function = • 1) Chylomicrons • 2) Very Low density Lipoprotein (VLDL) • 3) Low density Lipoprotein (LDL) • 4) High density Lipoprotein (HDL)

29. Types of Lipoproteins • 1. Chylomicron made by the small intestines, is absorbed into the lymph vessel then moves into the bld. • Function is to: a. b.

30. Types of Lipoproteins • 2. VLDL: after a meal the liver converts excess carbohydrate and excess protein into fat. • The liver will then assemble all this fat, including the fat from the chylomicron remnants into VLDL (very low density lipoprotein)

31. Continuing VLDL: • VLDL is secreted into the blood stream. • The function of VLDL: • 1) • - • - • -

32. Types of Lipoproteins • 3. LDL: LDL arises from VLDL once it has lost a lot of its TG. • LDL function:

33. Types of Lipoproteins • 4. HDL: HDL (high-density lipoprotein) is secreted into blood. • The function of HDL: • Does “Reverse cholesterol transport”

34. CHD (coronary heart disease, atherosclerosis) • Atherosclerosis (AS): LDL circulating in the blood stream contains fat (PUFA’s) that can become oxidized, termed oxLDL. It is oxLDL that is readily taken up and retained in the artery wall. Specifically, macrophages (immune cells residing in the artery wall) take up the oxidized LDL. This results in a build up of LDL and other material = AS plaque.

35. Oxidation • Oxidation is the process that occurs normally and in certain pathological conditions in the body. It is not a rare event. When compounds in the body get oxidized they are damaged. DNA, proteins, PUFA’s in cell membranes and LDL are all possible targets of oxidant attack and damage.

36. Antioxidant Defense Systems • 1. Prevent oxidation from being initiated • 2. Halt oxidation once it has begun • 3. To repair oxidative damage

37. Antioxidant Mechanisms: • 1. Antioxidant vitamins (vitamins C, E, carotenoids) • 2. Other non-essential antioxidants chemicals in foods (flavonoids, and other phytochemicals) • 3. Antioxidant enzyme systems that are made by the body and often require various minerals for normal functioning (super oxide dismutase (SOD), which requires Mn, Cu, Zn; glutathione peroxidase (GPX), which requires Se; and catalase).

38. Factors associated with LDLaccumulation in artery wall and oxidized LDL: • Factors that aren’t dietary or are genetic: • Being male • Being post-menopausal female • Family history of heart disease before the age of 55 (some are associated with genetic defects in LDL receptors)

39. Factors associated with LDL accumulation in artery wall and oxidized LDL: • Factors that are affected by diet: • Elevated levels of LDL • More LDL around to potentially oxidize and accumulate in artery wall • High blood pressure • Damages the artery wall, allowing LDL to enter the wall more readily

40. Continued Dietary Factors • Factors that are affected by diet: • Cigarette Smoking • Damages the artery wall • Cigarette smoke products are oxidants and can oxidize • Cigarette smoking compromises the body’s antioxidant vitamin status, especially vit. C • Low levels of HDL • HDL carries cholesterol from artery walls back to the liver

41. Continued Dietary Factors • Factors that are affected by diet: • Low levels of antioxidant vitamins E and C, ß-carotene • E especially and C protect LDL from oxidation • Low levels of other dietary antioxidants • Phenolics, flavonoids, red wine, grape juice, vegetables, fruits • Sedentary (exercise is the most potent factor to raise HDL levels) • Obesity promotes a lowered HDL, whereas attaining ideal body weight promotes higher HDL

42. Elevated Homocysteine Levels: • Homocysteine is normally produced in the body during certain metabolic pathways and is normally metabolized to other products. If homocysteine is not properly metabolized the elevated levels of homocysteine occur and this damages artery walls, increasing the oxidation of LDL. Elevated homocysteine levels are significantly correlated with increased risk to heart disease. Vitamins B6, B12, and folic acid greatly help to normalize homocysteine levels and increase HDL

43. Dietary/Lifestyle Prevention/Intervention of Heart Disease