Lipids include fats, oils, and other compounds that do not dissolve in water. Fats and oils are made of triglycerides, which are composed of glycerol bonded to three fatty acid molecules. Fatty acids can be saturated, monounsaturated, or polyunsaturated. Lipids serve important functions in the body, including energy storage, insulation, hormone production, and as structural components of cell membranes.

1. Lipids Fats and Oils Steroids Phospholipids 03/09/10

2. Lipids Nonpolar - mostly C, H – like hydrocarbons Hydrophobic – don’t dissolve in water Feel slippery/oily Some fatty acids are ESSENTIAL 1 03/09/10

3. Fats and Oils are Triglycerides: They are built out of glycerol and fatty acids glycerol fatty acid (note hydrocarbon chain and functional group –COOH = carboxyl or acid group) 03/09/10

4. A Monoglyceride Forms glycerol + 1 fatty acid  monoglyceride + water What type of chemical reaction? Dehydration synthesis 03/09/10

5. A Triglyceride Forms 03/09/10

6. Triglycerides Types of Fatty Acids Fatty acid one is? Saturated Fatty acids 2 and 3 are? Unsaturated 03/09/10

7. Triglycerides MUFAs and PUFAs Fatty acid 2 is? Monounsaturated (MUFA) Fatty acid 3 is? Polyunsaturated (PUFA) 03/09/10

8. Trans-Fats are Unhealthy 03/09/10 Trans-fats form when unsaturated fats are partially hydrogenated They are found in many processed foods They should be avoided

9. Saturated vs. Unsaturated More dense, harder Butter, tallow, palm & coconut oil, e.g. More liquid, less dense Canola, flax, fish oils, e.g. 03/09/10

10. Essential Fatty Acids… … are always polyunsaturated … are linoleic and linolenic acid … were first found in lin (= flax ) seed oil Flax or lin is the plant that supplies us with the fibers for linen Flax – The Blue Flower of Romanticism 03/09/10

11. Essential Fatty Acids polyunsaturated found in: plant oils (especially flax seed (lin), canola, soy fish oils 03/09/10

12. Fatty Acid Composition of Oils and Fats 03/09/10

13. Lipids Function In Living Things 03/09/10

14. Function of Lipids Energy storage, insulation, shock absorption fats, oils Protection oils, waxes Component of cell membranes phospholipids, cholesterol Hormones sex hormones other steroid hormones Carriers for fat-soluble vitamins Provide Flavor to foods 03/09/10

15. Function of Lipids – Energy Storage and Insulation Energy storage Insulation 03/09/10

16. Function of Lipids – Shock Absorption Shock absorption Fat cushions inner organs like kidneys When body fat gets too low, they are at risk 03/09/10

17. Waxes For Building and Coating Bee hive They also coat (shiny) leaves, to prevent evaporation 03/09/10

18. Cell Membranes Fatty acids are used to make: Phospholipids and Cholesterol 03/09/10

19. Phospholipids Build Cell Membranes Phospholipids build them Cholesterol stabilizes 03/09/10

20. Phospholipids Depending on the fatty acids in the phospholipids, cell membranes will have different properties (fluidity e.g.) 03/09/10

21. Phospholipids form Membrane Bilayers 03/09/10

22. Cell Membrane 03/09/10

23. All cell membranes in all cells and around all cell organelles are made from phospholipids 03/09/10

24. Sidebar: Liposomes Sources: www.happi.com/special/ jan011.htm www.gilead.com/wt/tert/ liposome_tech 03/09/10 Liposomes are spherical envelopes created by mixing phospholipids and cholesterol. Liposomes can be used for targeted delivery of drugs and cosmetics to cells

25. Carriers for Fat-Soluble Vitamins Fat-soluble vitamins (A, D, E, K) can only be absorbed when consumed with fats/oils. These vitamins from salads are significantly better absorbed when the dressing contains oil. Salad dressings can contain the fats we need, in their best form: raw Conclusion: Fat-free dressings are a stupid invention If you are getting too many calories it is better to cut calories elsewhere. 03/09/10

26. Which is the fattiest organ of your body? Your brain! 03/09/10

27. The Brain Is Your Fattiest Organ It is ~60% fat DHA (ω 3) = 1/3 of the brain’s gray matter (that’s what you think with), needed for: nervous system retina ( eyes) DHA links: plant oils , fish oil, 03/09/10 Fatty membrane layers (phospholipids), long, flat cells wrapped around axon Neurons – nerve cells

28. Essential Fatty Acids Many preemies, fed on formula, ended up with visual problems, until we discovered this: DHA (docosahexaenoic acid - ω 3) and ARA (arachidonic acid - ω 6) are essential fatty acids necessary for proper brain and eye development of 3 rd trimester infants 03/09/10 See also : Formula Additives Boost Small Children's Intelligence In Study

29. Lipid Hormones Sex and other hormones 03/09/10

30. Sex Hormones are Lipids 50+ steroid hormones are made from cholesterol Not all are sex hormones 03/09/10

31. “ Male” and “Female” Sex Hormones 03/09/10

32. Hormone Production Pathways “ In the body, testosterone and some other steroids are made from cholesterol (not always a bad guy) through a sequence of chemical reactions. The chemical names next to the arrows are enzymes that catalyze the indicated reaction. Note that testosterone is produced from one female hormone (progesterone) and is the precursor to another (estradiol).”

33. Sex Hormones Fat cells produce the enzyme aromatase, which converts testosterone to estrogen: testosterone aromatase  estrogen This may have a feminizing effect on fat men. Some of these men actually grow breasts that produce milk. 03/09/10

34. Cholesterol  Vitamin D With enough sun exposure, vitamin D becomes non-essential 03/09/10 in skin cells UV

35. Sidebar: Bone Density 50% out of 100,000 women with hip fractures due to osteoporosis never get back on their feet 03/09/10

36. Osteoporosis 03/09/10 Source and more info: http://www.mrc-hnr.cam.ac.uk/research/bone_health/bone_health.html

37. When is the Best Time to Increase Peak Bone Mass? 03/09/10 ____________ risk zone See which sport enhances bone density in which part of the body: This is a great site on bone health

38. Factors in Bone Density Nutritional calcium (take Ca: Mg in 2:1 ratio) vitamin D (sun exposure) vitamin K 2 ( menaquinone ) vitamin C boron (?) silica (?) essential fatty acids Other exercise (weight bearing) sun exposure estrogen (requires proper essential fatty acid intake) 03/09/10

39. Bone Health See which sport enhances bone density in which part of the body This is a great site on bone health 03/09/10

40. Sources of Calcium and Vitamin K 03/09/10

41. Lipid Requirements Which lipids do we need? Essential, unsaturated fatty acids How much should we get? 20 -35 % of total calories consumed should be from fats Max. 1/3 of total fat calories (=1/10 of total calories) from saturated FAs 2/3 from unsaturated fats (MUFA and PUFA) 5 MUFA : 1 PUFA 4 ω ( omega) 6 : 1 ω 3 03/09/10

42. Fish Oils and Health For a meat-eating man, replacing 1 meat meal a week with a fish meal reduces his chance of stroke by 20% 03/09/10

43. Should You Eat Fish Caught in the Waters Around New York City? See next page or click here for Dept. of Health Info 03/09/10

44. Wave of Fish Advisories New figures released by the U.S. EPA show that 35% of lake acreage in the United States and 24% of river miles contain enough pollution to warrant consumption advisories for fish caught in those waters. The advisories cover some 40 different substances ; 98% of them involve PCBs, chlordane, dioxins, DDT, or mercury . Though the number of advisories rose from 2,814 in 2002 to 3,094 in 2003, EPA administrator Mike Leavitt attributed that increase to more monitoring rather than an increase in pollution. .. 1 03/09/10

45. 03/09/10

46. 2003 –Advisories for 86 Water Bodies 03/09/10

47. Sample Page 03/09/10

48. Sad - The Skinny On The Fish Oil 1 What the Government Recommends for Fish You Catch 03/09/10

49. Should You Still Eat Fish? 03/09/10

50. Find Fish that Are Safe to Eat Click here for lists of mercury contents in fish The figures on these lists apply to wild salmon. Also, tuna has since been added to the high mercury list. The authors of one study on contaminants in farmed salmon conclude that, because of chemical contaminants, farmed salmon should not be eaten more often than 0.25 to 1 times per month, but see next page 03/09/10

51. Mercury in Fish What Women Should Know About Mercury In Fish Avoid If Pregnant Shark Swordfish King mackerel Tilefish Tuna steaks Canned tuna Sea bass Gulf Coast Oysters Marlin Halibut Pike Walleye White croaker Largemouth bass Data From The 1970s Show High Concentrations (No Recent Data Available) Porgy Orange Roughy Snapper Lake Trout Bluefish Bonito Rockfish Eat No More Than One Serving From This List Per Month Mahi mahi Blue mussel Eastern oyster Cod Pollock Great Lakes salmon Gulf Coast blue crab Channel catfish (wild) Lake whitefish Lowest In Mercury Blue crab (mid-Atlantic) Croaker Fish Sticks Flounder (summer) Haddock Trout (farmed) Salmon (wild Pacific) Shrimp * * Shrimp fishing and farming practices have raised serious environmental concerns. ** Farmed catfish have low mercury levels but may contain PCBs in amounts of concern for pregnant women. 03/09/10

52. The Environmental Working Group’s Tuna Calculator Click here to find out how much tuna a week you can safely eat 03/09/10

53. Risk-Benefit Analysis of Eating Farmed Salmon The effects were estimated for the European Economic Area countries (population 387 million). Here are the estimates: 03/09/10 In a population of 387 million (Europe) Estimated Resulting Change in Deaths per Year Excess cancer mortality due to pollutants in farmed salmon + 210 The number of cancer deaths that could be prevented by the restrictive recommendation on farmed salmon use to 1 meal/month + 40 Lost net health effect (cancer and cardiac deaths combined) of unrestricted salmon consumption - 5200

54. Yes !!! But … The EPA’s advisories for pregnant and breastfeeding women This site has lots of info regarding breast-feeding, go to the reference articles on the bottom 03/09/10

55. ω 3 fatty acids (EPA, DHA) vs. methylmercury (MeHg) contents in fish 03/09/10 avoid

56. Last Not Least - ??? The major changes in the essential fatty acid composition of the food supply, including increased availability of the omega-6 linoleic acid, may be correlated not only with increased risks of homicide, but also increased risks of suicide and suboptimal social cohesion. 03/09/10

57. Bioaccumulation see also  Ecology Toxic mud: The Hudson River, a Superfund Site 03/09/10

58. The End Next => Proteins 03/09/10