Fats and Lipids in Nutrition http://www.cwu.edu/~geed/fcsn245.htm

1. Fats and Lipids in Nutritionhttp://www.cwu.edu/~geed/fcsn245.htm Dr. David L. Gee FCSN 245 - Basic Nutrition

2. Fats and Lipids • Definition • Classes of Fats • Triglycerides • Phospholipids • Cholesterol and other Sterols

3. Functions of Triglycerides • Energy storage • Physical & thermal insulator • Carrier of fat soluble vitamins

4. ©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license. Triglyceride Chemistry

8. Phospholipid Chemistry • Very similar to triglycerides • Glycerol • TWO fatty acids • Phosphate + nitrogen-containing compound • Structure with two distinct parts • Fat soluble part (FA’s) • Water soluble part (phosphate + N-compound)

9. Functions of Phospholipids • Cell membrane structure • Emulsifier • fat digestion • fat transport in blood

11. ©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license. Cholesterol Chemistry

12. Functions of Cholesterol • Cell membrane structure • Precurser for: • Bile acids • Steroid hormones • Vitamin D • Sources: • Animal fats only • Made in liver (non-dietary essential)

13. ©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.

14. Triglycerides • Structure • Mono- & Di- glycerides • Fatty Acids

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16. Fatty Acids • Chain length • Long chain ( C12 - C22 ) • most vegetable fats • most animal fats • Medium chain ( C6 - C10 ) • butter fat • coconut oil • liquids/very soft at room T

17. Fatty Acids • Degree of saturation • Saturated fatty acids (SFA) • Monounsaturated (MUFA) • Polyunsaturated (PUFA)

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19. The problem with Saturated Fatty Acids • Raises blood cholesterol • Raises LDL-cholesterol (bad) • Lowers activity of LDL-receptor

20. What are lipoproteins? • Particles in the blood for transporting fat. • Structure • Outer coat • Phospholipids, cholesterol, proteins • Core • Fats: triglycerides, cholesterol-FA esters

21. Types of lipoproteins • Triglyceride carriers • Chylomicrons (dietary TGs) • Very Low Density lipoproteins (VLDL, TGs made in the body) • Cholesterol carriers • LDL ( delivers cholesterol to tissues ) • HDL ( removes cholesterol from tissues for excretion in liver)

22. ©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.

23. © 2002 Wadsworth Publishing / Thomson Learning™

24. Saturated Fatty Acids • Raises blood cholesterol • Raises LDL-cholesterol (bad) • Solid at room temperature • High in animal fats • Tropical plant fats • coconut oil, palm oil, cocoa oil

25. Mono Unsaturated Fats • Lowers blood cholesterol • Lowers LDL - cholesterol • No effect on HDL - cholesterol • Liquid at room temperature • Olive oil, canola oil, peanut oil

26. Major Types of Human Nutrition Research • Anecdotal & Case Studies • Individual or small # subjects • Not controlled • Not considered reliable research • Epidemiological Research • Randomized Controlled Trials

27. Nutritional Epidemiological Studies • Studies: • Prevalence of disease/disorder in a population • Association with nutritional factors • Observational • Time • cross-sectional studies • Retrospective studies • Prospective studies

28. Nutritional Epidemiological Studies • Strengths • Significant endpoints • mortality • morbidity • Free living populations • Prospective studies over long periods of time

29. Magnesium Intake and Reduced Risk of ColonCancer in a Prospective Study of Women American Journal of Epidemiology 2006 163(3):232-235 • http://aje.oxfordjournals.org/cgi/content/abstract/163/3/232?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=1&title=magnesium+colon+cancer&andorexacttitle=and&andorexacttitleabs=and&andorexactfulltext=and&searchid=1138822446001_2635&FIRSTINDEX=0&sortspec=relevance&journalcode=amjepid

30. Nutritional Epidemiological Studies • Does not prove cause and effect • Suggests possible relationships between nutrition and disease • Well known epidemiological studies • Framingham Studies • Physician’s Health Studies • Nurse’s Health Studies

31. Randomized Controlled Trials (RCT) • Experimental • Groups assigned randomly • All other factors (other than experimental factor) controlled • Single and double blind experiments • Strongest evidence proving cause and effect

32. Modification of lymphocyte DNA damage by carotenoid supplementation in postmenopausal women.American Journal of Clinical Nutrition, Vol. 83, No. 1, 163-169, January 2006 http://www.ajcn.org/cgi/content/abstract/83/1/163

33. Randomized Controlled Trials • Limitations • Short period of time • Clinical trials can be longer, but more difficult to control • Subjects not free-living • # subjects small • Endpoints measured related to, but does not measure morbidity or mortality

34. Mono Unsaturated Fats • Lowers blood cholesterol • Lowers LDL - cholesterol • No effect on HDL - cholesterol • Liquid at room temperature • Olive oil, canola oil, peanut oil

36. Mediterranean DietProtection Against Heart Disease? • High in Olive Oil (MUFA) • French Paradox • Northern vs Southern France • But other possible contributing factors: • High Red Wine consumption • Rich in fiber, fruits, vegetables • More active lifestyle • Recent changes in diet and lifestyle 

37. Polyunsaturated Fats • Lowers LDL-cholesterol • But also lowers HDL-cholesterol • Dietary Sources • Vegetable oils • Fish oils

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39. Essential Fatty Acids • PUFA’s required in diet • Two classes of EFA’s • Omega-6 PUFA’s • Linoleic acid • Omega-3 PUFA’s • Linolenic acid • 3-6 g/day (1 tsp veg. oil)

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41. Essential Fatty Acids • Deficiency Syndrome • Rare • fat malabsorption in infants • Dermatitis, hair loss, poor wound healing • Bigger concerns of relative amounts of w-3 & w-6 in US diet

42. Essential Fatty Acids • Functions • Component of phospholipids in cell membranes • Synthesis of Eicosanoids • Potent hormone-like chemicals • Prostaglandins • Leukotrienes

43. Eicosanoid Functions:role in heart disease • Regulates • smooth muscle contractions • blood pressure • Omega-3 eicosanoids tend to lower BP • Omega-6 tend to increase BP • blood clotting • Omega-3 eicosanoids tend to inhibit blood clotting • Omega-6 tend to increase blood clotting

44. Intake of Fish and Omega-3 Fatty Acids and Risk of Stroke in Women • JAMA, Jan. 2001 • Nurses’ Health Study • Prospective epidemiological study • 14 year follow up on 79,839 women • 574 strokes • Relative Risk related to fish consumption

45. Risk of Stroke on Fish Consumption

46. Stroke and Fish Intake (cont.) • Risk of ischemic stroke 49% in women consuming fish > 2/wk • Risk related to intake of omega-3 PUFA • No association between fish intake or omega-3 intake with hemorrhagic stroke

47. Dietary Effects on Eicosanoids • Omega-6 PUFA (Veg Oils) • Produce eicosanoids that tend to: • increase blood clotting • increase blood pressure • May tend to increase risk of heart disease

48. Dietary Effects on Eicosanoids • Omega -3 PUFA’s (fish oils, canola) • Produce eicosanoids that tend to: • decreases blood clotting • decreases blood pressure • decreases blood viscosity • decreases risk of heart disease

49. Essential Fatty Acids and Inflammation • Inflammation: injury that results in increased immune system activity and blood flow • Inflammation may play a role in heart disease and cancer • Omega-3 PUFA may reduce inflammatory response

50. Hydrogenation of UFA • Conversion of PUFA to MUFA & SFA • Process • Purposes: • Produce solid fats from oils • Produce more chemically stable fats (resists oxidation, rancidity)