Lipid & Fat: Overview What is a lipid? Triglycerides, Phospholipids and Sterols Triglycerides = Fat Saturated & unsaturated Essential fatty acids ü 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 v Monounsaturated v 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 (cheese, butter, milk, 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, olives, peanuts, peanut butter, avocado, almonds, almond butter, canola oil, pecans Health effects: Decreases LDL bad cholesterol in blood Increases HDL good cholesterol in blood
Polyunsaturated Fatty Acid 2 or more double bonds Liquid at room temperature
Polyunsaturated Fat Sources: Plant Foods: Vegetable oil (soybean, corn, sunflower, etc), sunflower seeds, mayonnaise Health effects: Decreases LDL bad cholesterol in blood Decreases HDL good cholesterol (not good!) May be pro-inflammatory
Essential Fatty Acids 2 types of polyunsaturated fats can not be made in the body Omega 3 first double bond 3 rd carbon Omega 6 first double bond 6 th carbon
Polyunsaturated Fatty Acid
Health Benefits of Omega 3 Heart health (EPA & DHA) ü Reduce risk of heart attack and stroke. ü Prevent blood clots & promote flexible blood vessels ü Decrease inflammation Brain health (DHA) ü 5-10% of human brain is DHA omega 3 fatty acids ü May help prevent depression
What Foods Supply Omega 3? Fish & Seafood: Long chain omega 3 (EPA & DHA) Fish: Herring, salmon, anchovies, sardines, caviar, bluefish, tuna, catfish, bass, trout, swordfish, halibut, pollock, flounder, cod, crab, mackerel, shrimp, oysters, scallops, mussels Plants: Short chain omega 3 (ALA) need to be converted to long chain (EPA & DHA). Plants: Flax oil & seeds, chia seeds, walnuts, sea vegetable, (leafy greens) Fortified foods: eggs & milk
Omega 3 Supplements What s the latest scientific findings? Observational Studies: No effect on hearth health for people with high risk of heart disease. Experimental Studies: No benefit of supplement How are omega 3 supplements created? Harvest small fish, boiled down to form supplements. So what happens to the big fish that eat the smaller fish? Overtime, there will have less big fish in the oceans
Triglycerides Fat in food contains several different types of fatty acids. Most fat contains 1 predominate type of fatty acid. Fat is named according to the predominate fatty acid.
Fats and fatty acid composition
Trans Fat Hydrogenation makes Trans Fat Transfat created by adding hydrogens to a polyunsaturated fat. Creates partially hydrogenated or hydrogenated oil Makes an unsaturated oil more solid at room temperature, thus more shelf stable 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
Challenge Questions: FAT 1. Omega 3, 6 & 9 are all important to consume. a. True b. False 2. Which is the healthiest oil? a. Coconut oil b. Olive oil c. Canola oil 3. A food that is monounsaturated (such as nuts) does not have any saturated fat. a. True b. False
Why do you need fat? Energy Source ü Provides 9 calories per gram ü Supplies 60% of body s energy needs during rest ü Form of stored energy in adipose tissue Insulation & Protection Carries fat-soluble vitamins Flavor & Satiety
Challenge Questions: FAT 1. Can a food be cholesterol free & raise your LDL bad cholesterol in your blood? Yes or No? 2. Heart disease is #1 cause of death in this country what role does fat play?
How does fat become a part of you? (digestion & absorption) 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. 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) Delivers excess cholesterol to cells High LDL -risk factor for heart disease HDL: High-density lipoproteins (good) Removes excess cholesterol protective High HDL reduces risk for heart disease LDL & HDL referred to as cholesterol Lipoprotiens Only in blood!
The Good vs Bad Fat The Good: Unsaturated Fat Monounsaturated Fat ü Lower harmful LDL cholesterol ü Raise the helpful HDL cholesterol ü Foods: Olive oil, olives, peanuts, almonds, nut butters, pecans, avocado, canola oil and peanut oil Polyunsaturated Fat ü Lower harmful LDL cholesterol ü Decrease the helpful HDL cholesterol (not good) ü May be pro-inflammatory (not good) ü Foods: Soybean & corn oil (and foods made with these oils), mayonnaise, sunflower seeds
The Good vs Bad Fat The Bad: Trans & Saturated Fat Trans Fat ü Increases harmful LDL cholesterol ü Decreases helpful HDL cholesterol ü Foods with partially hydrogenated oil: Check ingredients in microwave popcorn, crackers, cookies, peanut butter, margarine Saturated Fat ü Raises harmful LDL cholesterol ü Foods: Beef, bacon, dairy (except fat free), butter, cheese, ice cream, coconut & palm oil (cookies, crackers, cakes and donuts)
How to Eat to ê 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) Choose fiber-rich foods Aim for 25-35 grams per day
How to Eat to ê Heart Disease Include Omega-3 foods Eat fatty fish 1-2 times/week (most helpful!) Walnuts, flax, chia, seaweed, fortified eggs & milk Monterey Bay Aquarium Seafood Watch app. Guide to sustainable seafood Fish oil supplements 500 600 mg/day recommended (EPA & DHA) Limit cholesterol <300 mg per day