Chapter 5 Nutrition The Lipids: Fats, Oils, Phospholipids, and Sterols

They help the body to absorb water-soluble vitamins

which of the following statements is not true about the role of fats in meal? They help the body to absorb water-soluble vitamins

False

A food is always made up of 100% one type of fat. For example, the olive oil would only be made up of all monounsaturated fatty acids and would not include a mixture of any other fatty acids. False

Effects of Processing on Unsaturated Fats

Effects of Processing on Unsaturated Fats Highly processed vegetable oils make up most of the added fat in the U.S. diet. Found in fryer oil, margarine, cookies, crackers, cakes, breads, dressings, sauces, etc. Safety of hydrogenated or partially hydrogenated oils is questionable.

Emulsifiers

Emulsifiers Phospholipids act as emulsifiers, because they have hydrophobic andhydrophilic regions. -Hydrophilic region •Attracts water and avoids Attracts water and avoids lipids; "water loving" -Hydrophobic region •Attracts lipids and avoids Attracts lipids and avoids water; "water fearing"

Essential fatty acids

Essential fatty acids are lipids that must be supplied by the diet. Omega-3 and Omega-6 are the two main types.

True

Fat is an important building block for cell membranes, keeping them fluid. True

True

Food sources of monounsaturated fats include olive oil, avocado, nuts, and seeds.

Low-density Lipoproteins

Low-density Lipoproteins LDL commonly called "bad" cholesterol Conveys cholesterol from the liver to tissues May become oxidized LDL and contribute to atherosclerotic plaque Lowering saturated fat and trans fat lowers LDL; substitute with monounsaturated fat like olive oil and polyunsaturated fats from nuts and seeds

Ketones

Major lipoproteins include all of the following except for Ketones.

Monounsaturated Fatty Acids(MUFAS)

Monounsaturated Fatty Acids(MUFAS) •Mono = one (they have just one double bond) •MUFAs ar a type of unsaturated fat •Food sources: olive oil, avocado, nuts and seeds •High in Mediterranean style diet; proven to be good for heart health.

Oil and Water Don't Mix Because oil is less dense than water, it floats on top unless it is emulsified.

Oil and Water Don't Mix Because oil is less dense than water, it floats on top unless it is emulsified.

Hydrophobic region

-Hydrophobic region •Attracts lipids and avoids Attracts lipids and avoids water; "water fearing"

Assessing Your Risk of Atherosclerosis

Assessing Your Risk of Atherosclerosis Blood test that determines total cholesterol, HDL & LDL cholesterol, and triglyceride levels desired levels Total Cholesterol << 200 mg/dl 200 mg/dl LDL Cholesterol << 100 mg/dl HDL Cholesterol >/=60 Triglycerides << greater equal to 150 mg/dl

Atherosclerosis

Atherosclerosis disease in which lipid-containing plaques build up inside arteries

Bile --made in the liver and stored in the gallbladder

Bile -- made in the liver and stored in the gallbladder

Dietary Fat, Cholesterol, and Health

Dietary Fat, Cholesterol, and Health High saturated fat and trans fat intakes are associated with serious diseases, especially CVD These fats are known to cause elevations in blood lipids like LDL, the bad cholesterol Replacing these fats in the diet with monousaturated and polyunsaturated fats has been shown to reduce risk.

Fats / Lipids

Fats / Lipids The broad category of fats/lipids includes: 1. Triglycerides: Fatty acids and glycerol 2.Phospholipids 3.Sterols

Fats in Protein Foods

Fats in Protein Foods Meat contains about equal amounts of protein, but saturated fat and calorie amount vary significantly depending on how much fat is present. 85% lean ground beef is 15% fat whereas 90% lean ground beef is 10% fat, making it lower in total fat, saturated fat, and calories. Choose leaner cuts of meat >90% lean ground beef Loin or round (can trim away visible fat) Chicken and turkey (skinless)

Fats in the Diet

Fats in the Diet Essential fats: fish, nuts, vegetable oils. Choose quality oils (EVOO) instead of saturated fat and trans fat. Visible vs. Invisible Solid Fats: trim visible fats from meats; reduce intake of solid fats from invisible sources (candy, cheese, burgers, homogenized milk, lunchmeat, baked goods).

Fatty Acids

Fatty Acids 1.Saturated fats (solid)-Butter, Coconut Oil, Lard 2.Mono-unsaturated -Olive oil, nuts, seeds 3.Poly-unsaturated -Omega 3s, Omega 6s

Health Effects of Omega 3s

Health Effects of Omega 3s Heart Health: reduces formation of blood clots, regulates heartbeat and blood pressure, reduces inflammation Cancer Prevention: reduces inflammation Cell Membranes: improves cell to cell communication ultimately promoting healthy tissue function Brain Function: DHA, an omega 3, makes up a large portion of the cellular membranes in brain tissue; reduces inflammation associated with aging Vision: DHA makes up a large portion of the cellular membranes in retinal tissue in the eyes. Critical for pregnant women and infants to obtain from diet during this rapid period of growth and development.

High-density Lipoproteins

High-density Lipoproteins HDL commonly called "good"cholesterol •Transports cholesterol away from tissues and to the liver where it can be eliminated by the body. •This helps to regulate blood levels, keeping cholesterol from getting too hign. Regular physical activity increases HDL •Trans fats lower HDL -not good!

Hydrophilic region

Hydrophilic region •Attracts water and avoids Attracts water and avoids lipids; "water loving"

Important Functions of Cholesterol

Important Functions of Cholesterol The body uses cholesterol to make various substances, including: Vitamin D Steroid hormones Estrogen Testosterone Bile, an emulsifier that aids in fat digestion and absorption.

Lecithin

Lecithin - major phospholipid in foods, such as egg yolks, - major phospholipid in foods, such as egg yolks, liver, wheat germ, peanut butter, and soy.

Lipoproteins and Atherosclerosis

Lipoproteins and Atherosclerosis Lipoproteins:-HDL, LDL, VLDL Transport lipids in the blood Play major role in atherosclerosis development Carry different types of lipids and can influence plaque formation differently

omega 3 and 6

Omega-3•Food Sources: Fatty fish, canola oil, walnuts, and flaxseed •Actions: Reduces inflammation, blood clotting, and blood pressure •May reduce risk of heart disease and cancer Omega-6•Food Sources: Animal fats and vegetable oils (e.g. soy, corn, safflower), nuts, seeds •Actions: Increases inflammation and blood clotting •We tend to get too much of these in our diets.

Phospholipids

Phospholipids Phospholipids are chemically similar to a triglyceride, except one fatty acid is replaced by a compound containingone fatty acid is replaced by a compound containingphosphorus, phosphorus, which makes the phospholipid soluble in which makes the phospholipid soluble in water, while its fatty acids make it soluble in fat. Lecithin - major phospholipid in foods, such as egg yolks, - major phospholipid in foods, such as egg yolks, liver, wheat germ, peanut butter, and soy.

Phospolipids in the body

Phospolipids in the body •In the body, phospholipids are major structural components of cell membranes. •Cell membranes are comprised of a double layer that is mostly phospholipids. •The chemical structure (the hydrophilic and hydrophobic caharacteristics) of phospholipids enables the cell membranes to be flexible and function properly.

Plant sterols

Plant sterols found in nuts, seeds, legumes, whole grains, vegetables, and fruits have been shown to help lower cholesterol.

Plaque

Plaque forms in an artery when something irritates the lining of the artery wall.

Polyunsaturated Fatty Acids (PUFAs)

Polyunsaturated Fatty Acids (PUFAs) •Poly = many (refers to the amount of double bonds) •They contain more than one double bond. •They are liquid at room temperature (e.g. canola oil). •There are two main types of essential fatty acids that are a subcategory of PUFAs. -Omega 3 and Omega 6

Recommendations for Lipid Intakes

Recommendations for Lipid Intakes 20 to 35% of total calories-- 2000 calorie diet = •400-700 calories from fat or 45-75 grams Fat currently contributes ~34% of the average American's daily caloric intake. < 10% of calories from saturated fats Keep trans trans fatty acid intake as low as possible

Saturated Fatty Acids

Saturated Fatty Acids Saturated Fatty Acids•Fully saturated - no double bonds •Solid at room temperature•Animal fats (butter, cheese, milk, eggs, meat) •Tropical fats (coconut oil, palm oil) •Diets high in saturated fats have been shown to increase cholesterol levels. Saturated Fatty Acids

Sterols

Sterols •Cholesterol Cholesterol is a sterol, is an animal derived sterol, more complex than most other lipids.. -IImportant structural component of every cell membrane in the body. -Cholesterol is found only in animal foods, not plant foods. -Even if you don''t eat animal foods, your body produces cholesterol because it is necessary for several important functions.

Storing and Using Fats

Storing and Using Fats Triglycerides eaten in foods are transported to body's fat stores by chylomicrons. When needed for energy, stored fat molecules can release fatty acids to be used by cells. Carbohydrates help with this process

all of the above

The body uses cholesterol to make bile steroid hormones Vitamin D All of the above

Fats / Lipids

The broad category of fats/lipids includes: 1.Triglycerides: Fatty acids and GlycerolTriglycerides: Fatty acids and Glycerol 2.Phospholipids (e.g. Lecithin)Phospholipids (e.g. Lecithin) 3.Sterols (e.g. Cholesterol)Sterols (e.g. Cholesterol)Lipids are •insoluble in water (they don't dissolve/mix) in water (they don't dissolve/mix) •less denseless dense than water (they float when than water (they float when mixed with water)

Trans Fatty Acids

Trans Fatty Acids A primarily man-made fat man-made fat produced by saturating produced by saturating carbons through carbons through hydrogenation. Hydrogenation: a process that adds hydrogen atoms to liquid vegetable oils to make them solid at room temperature. This makes these oils have a longer temperature. This makes these oils have a longer shelf life.

Transport of Fats

Transport of Fats Glycerol and shorter-chain fatty acids pass directly through the cells of the intestinal lining unassisted into the bloodstream. Larger lipids are assembled into lipoproteins, which serve as transport vehicles for lipids in the blood and lymph. Major lipoproteins include: chylomicrons, VLDL, LDL, and HDL

Triglycerides

Triglycerides •Composed of 3 fatty acids Composed of 3 fatty acids (mono, poly, or saturated (mono, poly, or saturated fatty acids) fatty acids) attached attached to a to a glycerol "backbone"glycerol "backbone" •Fatty acids in food influence the composition of fats in the body. •The body stores energy as The body stores energy as triglycerides (fat).

Very Low-density Lipoproteins

Very Low-density Lipoproteins High levels may contribute to atherosclerosis VLDL primarily carries triglycerides

WHAT IS THE ROLE OF FAT IN A MEAL?

WHAT IS THE ROLE OF FAT IN A MEAL? •Fat provides a pleasant "mouth feel" and allows flavors to glide across your taste buds, making foods taste more appetizing. •Helps body to absorb fat soluble vitamins(A, D, E, and K), phytonutrients, and other nutrients like CoQ10 .•Slow the rate at which foods leave the stomach, which slows the rate at which carbohydrates in the meal are released into the bloodstream. Provides a feeling of satiety.

Diets low in saturated fats have been shown to increase cholesterol

Which of the following statements is not true about saturated fats? Diet low in saturated fats have been shown to increase cholesterol

It is recommended to eat a diet high in trans fats to prevent heart disease

Which of the following statements is not true about trans fat? It is recommended to eat a diet high in trans fat to prevent heart disease.

major lipoproteins

chylomicrons, VLDL, LDL, HDL

True

fat deposits in the abdominal region play an important role in cushioning our vital organs, however too much fat tissue in this area is associated with increased risk of chronic illness. True

All of the above are true

which of the following statements is not true about phospholipids? Phospholipids found in food act as emulsifiers our cell membranes are made up of a double layer of phospholipids that helps to keep our cells flexible and fluid. Phospholipids are critical for healthy nerve cell and brain function. All of the above are true

• Plaque narrows arteries, interfering with circulation.• Plaque may also result in the formation of a fixed clot— a thrombus.

• Plaque narrows arteries, interfering with circulation.• Plaque may also result in the formation of a fixed clot— a thrombus.

THE ROLE OF FAT IN THE BODY

•Fat provides a concentrated source of energy in the diet -9 calories per gram •It is an important building blocks for cell membranes and keeps them fluid. •It is also an important raw material for hormones and hormone-like substances. •Certain fats (omega-3s) can help to reduce inflammation in the body.

THE ROLE OF FAT IN THE BODY

•The layer of fat under your skin (subcutaneous fat) stores energy, insulates you against cold temperatures, and protects against bruising. •Fat deposits in abdominal region cushions your vital organs.