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

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

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

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

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

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

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

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

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

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

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!)

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

Polyunsaturated Fatty Acid

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 ( mg/day) Soybean & canola oil provide trace amounts of short chain omega 3 – no positive health effects

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.

Fats and fatty acid composition

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

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

CQ FAT: Revised Answers 1.Omega 3, 6 & 9 are all important to consume. a.True b.False 1.Which is the healthiest oil? a.Corn oil b.Olive oil c.Canola oil 2.A food referred to as “monounsaturated” (such as nuts) does not have saturated fat. a.True b.False

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

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

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

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

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…)

Composition of Lipoproteins

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!

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

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)

Eating Guidelines for Healthy Blood Cholesterol Levels (  HD) 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 grams per day

Eating Guidelines for Healthy Blood Cholesterol Levels (  HD) Include Omega-3 foods Fatty fish 1-2 times/week (most helpful!) Walnuts, flaxseed, fortified eggs & milk Sustainable seafood A-Z: Mercury calculator for Tuna- Consider Fish oil supplements 500 – 600 mg/day recommended (EPA & DHA combined) Limit cholesterol <300 mg per day

CQ FAT: Write “revised” ideas on back of notecard 1.Can a food be “cholesterol free” & raise your “bad” cholesterol? Why or why not? 2.Heart disease is #1 cause of death in this country…what role does fat play?