Understanding Lipids & Fats: Types, Importance, and Health Effects

1. Lipid & Fat: Overview • What is a lipid? • Triglycerides, Phospholipids and Sterols • Triglycerides = Fat • Saturated & unsaturated • Essential fatty acids • Omega 3 & Omega 6 • Trans fat • Why do you need fat? • How does fat & cholesterol travel through your body? • LDL & HDL • How to eat to prevent heart disease • Good fat & bad fat

2. Lipids • Triglycerides • Fats and oils • Phospholipids • The body can make what it needs • Lecithin • Sterols • The body can make what it needs • Cholesterol

3. Triglycerides • Major lipid in the diet and your body • Fat in food = Triglycerides • Fat in your blood & fat cells = Triglycerides • Fat = Triglycerides • Made of glycerol and 3 fatty acids

4. Fatty Acids • 2 Types of Fatty Acids • Saturated fatty acids • Unsaturated fatty acids • Monounsaturated • Polyunsaturated • The Type of Fatty Acid Determines: • Whether the fat is solid or liquid at room temperature • Whether the fat is healthy or unhealthy for you

5. Saturated Fatty Acid • All single bonds between carbons • Saturated “full” with hydrogen atoms • Solid at room temperature

6. Saturated Fat • Sources: Animal: Beef, salami, bacon, eggs (yolk), dairy products (milk, butter, ice cream) Tropical Oils: coconut oil, palm oil & products made with these oils • Health effects: • Increases LDL “bad” cholesterol in the blood

7. Unsaturated Fatty Acids • Not saturated with hydrogen • Liquid at room temperature • 2 types • Monounsaturated • Polyunsaturated

8. Monounsaturated Fatty Acid • 1 double bond • One double bond: Not saturated “not full” with hydrogen • Liquid at room temperature

9. Monounsaturated Fat • Sources: Plant Foods: Olive oil, canola oil, peanuts, almonds, pecans, avocado, olives • Health effects: • Decreases LDL “bad” cholesterol • Increases HDL “good” cholesterol

10. Polyunsaturated Fatty Acid • 2 or more double bonds • Liquid at room temperature

11. Polyunsaturated Fat • Sources: Plant Foods: Vegetable oil (soybean, corn, sunflower, etc), walnuts, sunflower seeds, mayonnaise • Health effects: • Decreases LDL “bad” cholesterol • Decreases HDL “good” cholesterol (not good!)

12. Essential Fatty Acids • Polyunsaturated fats that can not be made in the body • Omega 3 (linolenic) double bond 3rd carbon • Omega 6 (linoleic) double bond 6th carbon

13. Polyunsaturated Fatty Acid

14. Omega 3 Fatty Acids • Benefits: • Long chain omega 3 (EPA & DHA) in fish is most beneficial! • Reduce risk of heart disease and stroke • May prevent blood clots & promote flexible blood vessels • Decrease inflammatory response • May help prevent depression • Sources: • Fish: Salmon, Sardines, Tuna, Trout, Swordfish, Halibut, Cod, Mackerel, Shrimp, Oysters, Scallops, Crab • Walnuts & Flaxseed (short chain omega 3) • Fortified eggs & milk • Fish supplements (500-600 mg/day) • Soybean & canola oil provide trace amounts of short chain omega 3 – no positive health effects

15. Triglycerides • Fat in food contains several different types of fatty acids. • Most fat contains 1 predominate type of fatty acid. • Fat is classified according to the predominate fatty acid.

16. Fats and fatty acid composition

17. Trans Fat • Hydrogenation: • Transfat created by adding hydrogens to a polyunsaturated fat. • Creates “partially hydrogenated” & “hydrogenated” oil • Makes an unsaturated oil more solid at room temperature, thus a more shelf stable product • Yields TRANS FAT • Negative Health Effects: • Increases LDL “bad” cholesterol • Decreases HDL “good” cholesterol • Most harmful of all the fats • Must be included on food labels

18. Cis vs Trans Fatty Acids • Cis fatty acids • Chain is bent • Occur naturally • Trans fatty acids • Chain is straighter • Produced by hydrogenation

19. CQ FAT: Revised (back of card) • Omega 3, 6 & 9 are all important to consume. • True • False • Which is the healthiest oil? • Coconut oil • Olive oil • Canola oil • A food referred to as “monounsaturated” (such as nuts) does not have any saturated fat. • True • False

20. Why do you need fat? • Energy Source • Provides 9 calories per gram • Supplies 60% of body’s resting energy needs • Form of stored energy in adipose tissue • Insulation & Protection • Carries fat-soluble vitamins • Flavor & Satiety

21. How does fat become a part of you? • Stomach breaks down about 30% of fat • MOST DIGESTION occurs in SMALL INTESTINE • Bile and pancreatic lipase break fat into monoglycerides and free fatty acids • After absorption inside intestinal wall, the triglyceride is remade • Fat, cholesterol and phospholipds (all lipids) join with protein to form a lipoprotein carrier – chylomicron. • Fat travels via lipoproteins in the bloodstream

22. “Packages” that transport lipids in the blood to cells and liver Lipoproteins

23. Phospholipids • Glycerol with 2 fatty acids and a phosphate nitrogen component • Compatible in fat and blood (water) • Major component of cell membranes allowing fatty & water soluble substances into cell • Coat the surface of lipoproteins

24. Cholesterol • Used to make bile (needed for digestion of fat) • Abundant in cell membranes, nerve & brain tissue • NOT ESSENTIAL - The body makes it • Made in liver. Only found in animal products. • Food with high saturated fat & trans fat increases blood cholesterol MORE THAN food that has cholesterol (shrimp, egg yolks…)

25. Composition of Lipoproteins

26. Lipoproteins in the Body • LDL: Low-density lipoproteins (bad) • Deliver cholesterol to cells • High LDL -risk factor for heart disease • HDL: High-density lipoproteins (good) • Removes cholesterol – protective • High HDL–reduces risk for heart disease • Lipoprotiens – NOT in foods, ONLY in blood!

27. The “Good” vs “Bad” Fat • The Good: Unsaturated Fat • Monounsaturated Fat • Lower harmful LDL cholesterol • Raise the helpful HDL cholesterol • Foods: Peanuts, olives, avocado, almonds, pecans, olive oil, canola oil and peanut oil • Polyunsaturated Fat • Lower harmful LDL cholesterol • Decrease the helpful HDL cholesterol (not good) • Foods: Soybean & corn oil (and foods made with these oils), mayonnaise, sunflower seeds, walnuts

28. The “Good” vs “Bad” Fat • The Bad: Trans & Saturated Fat • Trans Fat • Increases harmful LDL cholesterol • Decreases helpful HDL cholesterol • Foods with partially hydrogenated oil: margarine, crackers, cookies, peanut butter, fast food, popcorn…check label! • Saturated Fat • Raises harmful LDL cholesterol • Foods: All dairy (except fat free), butter, cheese, ice cream, beef, bacon palm & palm kernel & coconut oil (in cookies, crackers, cakes and donuts)

29. How to Eat to  Heart Disease • Fat • Less than 10% calories from saturated fat • Choose products with 0 trans fat. • Choose monounsaturated fats (olive oil, avocado, nuts) • Minimize omega 6 polyunsaturated oils (soy & corn oil, mayo and processed foods with these ingredients) • Choose fiber-rich foods • Aim for 25-35 grams per day

30. How to Eat to  Heart Disease • Include Omega-3 foods • Fatty fish 1-2 times/week (most helpful!) • Walnuts, flaxseed, fortified eggs & milk • Sustainable seafood A-Z: www.seafoodwatch.org • Mercury calculator for Tuna- www.ewg.org • Consider Fish oil supplements • 500 – 600 mg/day recommended (EPA & DHA combined) • Limit cholesterol • <300 mg per day

31. CQ FAT: Write “revised” ideas on back of notecard • Can a food be “cholesterol free” & raise your “bad” cholesterol? Why or why not? • Heart disease is #1 cause of death in this country…what role does fat play?