Chapter 5- The Lipids- Fats, Oils, Phospholipids & Sterols

Fish Oil Supplements Concerns

- "Source of omega 3 fatty acids for the maintenance of good health" Concerns: - May raise levels of two toxic vitamins A and D, Raise levels of LDL cholesterol - May cause excessive bleeding, disrupt wound healing process, suppress immune function - Does not provide all the health benefits that fish products would such as iodine, protein and selenium - If made from real fish skins and livers, it could have bioaccumulated toxins such as: pesticides, contaminants, Hg - Expensive

Calories Contributor to Fat

- 1 gram of fat yields 9 calories - 5g of fat is 45 calories found in the following: - 1 teaspoon of oil or shortening - 1 1/2 teaspoons of margarine or butter - 1 tablespoon of salad dressing, cream cheese - 1 1/2 tablespoons of sour cream

Absorption and Transports of Fat

- 98% of fat absorbed through intestinal villi/ walls Transports: - Glycerol, which is a short-chain fatty acid travels unassisted through intestinal walls--> blood stream--> liver. - Larger lipids are incorporated into chylomicrons for transport in the lymph and blood - Chylomicrons- form one type of lipoprotein

Functions of Emulsifying agent

- Blends fat in water - Key role- they are fats in the cell membrane of every single animals - Best example of an emulsifying agent is Lecithin, which is found in the egg yolk. Lecithin has structural functions

Usefulness of Fats in the Body

- Body padding: protects the internal organs from shock through fat pads inside the body cavity - Body insulation: insulates against extreme temperatures through fat layer under the skin. Thinner people get cold easier due to less butter padding/fat - Cell membranes- fats form the major material of cell members - Raw materials- fats are raw material for bile, hormones, vitamin d. - Transports fat soluble vitamins (A, D, and K)

Saturated Fatty Acids (SAFA)

- Carries maximum amount of H atoms. (no points of unsaturation) - Found more in solids like butters, creams, etc. - Contributes to elevated LDL cholesterol (bad cholesterol) in blood which predicts disease of heart and arteries - Known to elevate risk of HD (heart disease) - Found in: coconut oils, palm oils, butter, lard, meat fat

Very Low Density Lipoproteins (VLDL)

- Carry triglycerides and other lipids made in liver to body cells for their use

1) Triglyceride/ Triglycerol's

- Chief form of fat in foods and human body (95%) - 3 units of fatty acids attached to 1 glycerol backbone - (TRI= three, glycerol is what it is attached too) glycerol + 3 fatty acid chains= triglycerol's - Fatty acids differ in chain length and degree of saturation - Within the chains is what makes them saturated or unsaturated. - Saturated chains do not have any points of unsaturation, Monounsaturated has one point of unsaturation and Polyunsaturated has multiple. (Points of unsaturation= bonding points), The more bonding points the better it is for you. The less bonding points, the more concentration of fat you can pack into it. (These fats are formed from an excess of glucose. After the liver stores all the glucose it can as glycogen, whatever is left over is turned into triglycerides)

Cholesterol and Bile

- Cholesterol serves as a raw material for bile - Bile is an emulsifying agent in fats, and is stored in the gallbladder - Emulsifies fats so enzymes in the watery fluid may contact it and split fatty acids from glycerol and then bile assist again for absorption from the GI tract - If one does not have a gallbladder then they should consume minimal cholesterol - Drinking is bad if you have cholesterol issues as the liver can only handle so much

Diet Related Health Claims

- Choose foods lower in saturated and trans fat as it will reduce the risk of heart disease - Enjoy products such as fruits and vegetables, legumes, whole grains, nuts and seeds, soy products - Lower total fat intake- no more than 35% of daily calories - Enjoy foods with little or no fat added

A Sampling of Fat Replacers- Carbohydrate based

- Fruit purees and pastes from apples- you can use unsweetened apple sauce, cherries, plums, bananas, canola oil; maltodextrins from corn. Ex: instead of using a cup of butter use 1/2 cup of apple sauce, 1/2 of canola oil... You can replace almost half the ingredients in a recipe with fruit replacers

A Sampling of Fat Replacers- Fibre based

- Gels from cellulose or starch - ***Gums from beans, sea vegetables - Oatrim from oat fibre; Z-trim from insoluble fibre.

Food Preparation

- Grill, roast, boil, bake, broil, stir-fry, microwave, poach foods - Cut meats in half, use learn or extra lean meats, fill in bulk with soy products, veggies, legumes, grains - Rinse ground meat after cooking if it is not lean or extra lean - Slice processed meats thinly - Refrigerate meat drippings, broth and lift off solidified fat. Ex: gravy or turkey, take juice off and put into freezer so that the fat rises to top so you can scrape it off

2) Phospholipids

- Has the same structure as triglycerides BUT it has two fatty acid chains instead of three, and instead of a glycerol backbone it has a phosphorus molecule. - This phosphorus molecule makes the fat soluble in water, AND since the chain contains fatty acids, it is also soluble in fat. (Soluble in water AND fat) - This makes it an emulsifying agent, which plays a big role in cell membranes - Type of phospholipid: Lecithin

Food Cholesterol and Blood Cholesterol

- High saturated trans fatty acids and trans fat from food raises LDL blood cholesterol more than food cholesterol - Single most effective step to take is to limit the amount of SAFA and f.a in the diet so it will reduce elevated blood cholesterol levels. - High blood cholesterol- indicator of risk for cardiovascular disease - People with a genetic tendency towards high blood cholesterol must apply strict limits for fat-rich and cholesterol-rich foods - Genetic inheritance modifies everyone's ability to handle cholesterol somewhat. - For others, a limited amount of eggs, liver, and other cholesterol-containing foods poses no threat on high blood cholesterol because the body slows down cholesterol synthesis when the diet provides greater amounts. (Those with no cholesterol problems can handle as much of it as they can as the body goes through cholesterol synthesis when the body provides greater amounts then it should)

Tips for A Low Fat Diet

- Keep intakes low - Diets lower in fats are generally lower in calories - Diets low in SAFA and Trans fatty acids may reduce risk of HD - Diets lower in fat, especially SAFA may reduce risks of some cancers - Diets with fewer calories from fat allows for more intake for fruits and vegetables, fish, legumes, nuts and seeds, whole grains, low-fat milk products

3) Sterols

- Large molecules of interconnected rings of C atoms connected with C, H, O atoms - Plays important role in vitamin D, sex, and steroid hormones - Found in Cholesterol (found only in animals) and phytosterols (found only in plants) - Cholesterol is not an essential nutrient as the body is able to make it on it's own - If we wanted one to limit cholesterol in diet, then they would only be limited to plant products as all animal products contains cholesterol Way to remember cholesterols: - Atoms with side chains C, H, O - Ending in sterols

Food Sources of Omega 6

- Linoleic acid - Nuts (walnuts), leafy vegetables, grains, seeds (pumpkin and sunflower seeds), vegetable oils (corn, sesame, soybean and sunflower) Easier to get omega 6 in diet than omega 3

Polyunsaturated Fatty Acids (PUFA) and Omega 6

- Linoleic acid- EFA - Used by the body to make arachadonic acid - Used to make hormone like substances for the retina of eye and for the brain (eye and brain health) - Neutral or beneficial effects on heart disease, except when intake is too high - When replacing SAFA for omega 6, it can lead to elevated risks of heart disease - Lower levels of LDL, but lowers levels of HDL (negative effect) - Points of unsaturation- vulnerable to oxidation and free radical formation through HD or CA

Polyunsaturated Fatty Acids (PUFA) and Omega 3

- Linolenic acid which is the chemical part of omega 3 - Used to create DHA and EPA which could be found in breast milk- vulnerable to high heat/oxidation - The more unsaturated the fat is the more liquidy it will be. Ex: meats vs. oils - Moderate effects on heart functioning- prevents blood clotting, lower blood pressure, lowers LDL cholesterol, high HDL. - May enhance immune system functioning - Helps with neurological and behavioural disorders - May improve Arthritis - Prevent cataracts - Exert an anticancer effect

Food Sources of Omega 3

- Linolenic acid- oils (canola oils), flaxseed, nuts and seeds, soybeans, eggs. - DHA & EPA- human milk, eggs, cold water fatty fish (salmon, tuna, mackerel) - Omega 3 could be found in milk and eggs (animal foods) because these animals are fed flaxseeds which have omega 3 in them so what they produce leaves traces of omega 3. (Harder to get omega 3 then omega 6 in diet)

Fat Cells

- Lipids can enter and exit the blood when they want - they can enter the cells and exit the cells, etc... - We make all the fat cells we have until we are 8 years old. Once we stop making them, these fat cells just change in size either grow or shrink

Monounsaturated Fat (MUFA)

- MUFA- contains 1 point of unsaturation - Mono= one - May help lower levels of LDL cholesterol, but doesn't affect HDL cholesterol levels - Fairly resistant to damaging in oxidation, but cautious to presence of heat. Ex: canola oil better in baking and olive oil better used in dressings/not in heat due to the possibility of oxidation. - Found in: olive oil, canola oil, peanut oils

Cholesterol

- Made by body - Makes bile, emulsifying agent - Part of the cell membrane and necessary for body functions - Excess intakes of cholesterol elevates blood cholesterol in healthy people - Genetically susceptible people must limit cholesterol-containing foods. - 20% of high cholesterol can be controlled by diet, 80% controlled by genetics

PUFA- Ecosanoids

- Made from omega 3 and 6 - They have hormone like functions such as: - Muscle relaxation or contraction, blood vessel dilation or constriction, blood clot formation and regulation, immune response, etc. - Play important roles that can benefit body and protect us in nature. Ex: cancer prevention

A Sampling of Fat Replacers- Protein based

- Microparticulated protein from milk or egg whites - Types Simpless, K Blazer - Depends on purpose of protein in recipe - Do not used artificial protein for the whole entire recipe

Fats in Milk/ Milk Products/ Cheese/ Grains

- Milk, ice cream, yogurt- all fat is saturated - Cheese- single biggest contributor to saturated fat in diet. Choose cheeses that have less % Milk fat and %BF - Yogurt- varies depending on the type. Ex: greek 9% regular could be 0% - Grains- usually low in saturated fat but fat is often added in during processing. Whole grain brain has a high caloric content due to it's germ in the product but it's the healthiest

Digestion of Fat

- Mouth: lingual lipase- digestion of milk fat from infants--> - Stomach: fat floats at the top layer, separating from watery fluid. Some gastric lipase/enzymes digests some fats--> - Pancreas: pancreatic lipase break down fats into smaller particles for absorption into the small intestine. (breaks down from fatty acids, to glycerols, etc...)--> - Small intestine: fat triggers the release of bile from gallbladder and emulsifies fat particles. The hormone cholecystokinin is the trigger that calls upon the bile to release to emulsify and absorb fat

Trans Fatty Acids

- New fatty acids formed by the process of hydrogenation of unsaturated fats; hydrogen introduced into liquid form (Hydrogenation- makes fats stay fresher for longer, gives it a higher smoking point/less vulnerable to oxidation) - Found mostly in stick butters, margarine, fast food, baked goods, chips - May have more negative health benefits on heart then SAFA - Raises levels of LDL cholesterol and lowers levels of HDL - Contributes equal energy to other fats

Usefulness of Fat in Food

- Nutrient- provides essential fatty acids - Energy- provides a concentrated energy source (lipids provide more energy per gram than pro and cho) - transport- carries fat-soluble vitamins A, D, E, K and some phytochemical - Raw materials- provides raw materials for needed products - Sensory appeal- contributes to taste and smell of foods but do not sacrifice health for it - Appetite- smell stimulated the appetite. - Satiety- contributes to feeling of fulness. Fibre, fat and protein contribute to staying full - Texture- help makes food tender- hydrogenation - DRI recommendation- 20- 35% of daily calories comes from healthy fat choices

Lipids

- Organic (carbon-containing) compound - Soluble in other organic solvents - Not soluble in water because water is not organic. We need an emulsifying agent in the body if we have oil and water combined. - Most mixtures are SAFA, MUFA and PUFA Two types: Fat: lipids that are solid at room temperature Oils: lipids that are liquid at room temperature THREE TYPES: triglycerides, phospholipids, sterols

Polyunsaturated Fatty Acids (PUFA)

- PUFA- contains 2 or more points of unsaturation - Poly= plural - Essential fatty acids= omega 3 and 6 (body cannot make these, therefore they are essential to consume) - Omega 3+6 are the raw materials for Ecosanoids

Chylomicrons

- Protein and lipid clusters - Emulsifiers attracting both water and fat- help carry lipids through blood - Body fat extracts triglycerides they need from the chylomicrons passing by in the bloodstream then chylomicrons remnants are carried back to liver

Lowering LDL Cholesterol

- Reduce saturated and trans fat and increase monounsaturated and polyunsaturated fats Strategies include: - Limit butter, salad dressings, sour cream - Cook with limit or no added fats - Ensure adequate intake of dietary antioxidants vitamins c and e, phytochemical and selenium

Raising HDL Cholesterol

- Regular physical activity

Omega 3 and 6 Contributes..

- Structural and functional parts of the cell membranes - Contributes lipids to the brain and nerves - Promotes normal growth and vision - Assists in gene regulation, genetic activities affective metabolism - Maintains outer structures of skin, protecting against water loss - Support immune cell functions - Do not consume too much mercury when taking in these, change the types of foods consumed - Brain health- dementia, ADD, ADHD

Olestra (Olean)

- Sucrose polyester - Non-caloric artificial fat made from sucrose and fatty acids - Fatty acids bonded with sugar or sugar alcohol - Not recognized by body there it goes undigested; passes through GIT intact - This causes digestive distress such as diarrhea, gas, cramps, strong urge to defecate. it can leak through the anus and leave smelly dark yellow stains in undies. - Most successful artificial fat, used for cooking, frying, baking - Causes loss of nutrients vit. A, D, E, K and phytochemicals - No long term studies to show health effects on consumers, especially children. - Currently not allowed in Canada

How to Apply Recommendations

- Take steps to reduce levels of LDL-c - Choose a diet with 20-35% of cals from fat - Keep as low as possible of SAFA (<10% of total cal) and trans fat (<1%) - Consume foods and oils with MUFAs and PUFas - Consume more vegetables, fruits, nuts and seeds, whole grains - Add fatty fish at least twice a week - Consume in moderation sources of cholesterol: eggs, liver, shellfish - Try the "Mediterranean Diet"- people in this area have lower rates of heart disease. Many reasons hypothesized for this, one which is typical dietary intake patterns

Lecithin

- This is manufactured by the liver and found in many foods (egg yolk) - **plays key role in the structure of cell membranes - Helps fat travel across lipid-containing membranes of cells into the watery fluids - Lecithin in egg yolks keep the emulsified substance stable. Ex: mayonnaise - Lecithin supplements- have no special ability to promote health. The body can make all the lecithin it needs

Low Density Lipoproteins (LDL)

- This is the bad cholesterol - Carries cholesterol and other lipids to body's tissues - LDL made from VLDL after they have transported many of their triglycerides to body cells - Elevated LDL cholesterol- leads to higher risk of heart disease, more susceptible to oxidation - Lipid protein carries cholesterol out of body (BAD) - Larger, lighter, and richer in cholesterol - High blood LDL cholesterol concentration is a predictor for suffering a fatal heart attack or stroke. The higher the levels, the earlier the episode.

High Density Lipoproteins (HDL)

- This is the good cholesterol - Carries cholesterol and phospholipids away from body cells to the liver for disposal- this is good - High levels of HDL lowers levels of heart disease - Increase good cholesterol with healthy lifestyle factors- quit smoking, workout, eat well - Smaller, denser and packaged with more proteins. - Higher levels of HDL cholesterol will lower levels of receiving diseases

Fats in the Diet- In food and Added fats- Visible and Invisible Fats

- Visible: easy to trim out. ex: fats on meats - invisible: marbling of meats, blending into processes - meats or sauces, fats in some food (avocado, nuts, olives, cheese, coconuts) Added fats: -Visible: consciously adding butter, margarine, oil or shortening to recipes, salad dressings, dessert toppings - Invisible: hidden in fried foods, baked goods, sauces, mixed dishes and dips and spreads.

How is Stored Fat Used as Energy?

- When the body does not consume enough CHO and it needs energy, it draws on it's stored fat for energy. - Fatty acids combine with glucose and energy which releases carbon dioxide and water. (Glycolysis cycle) - CHO is needed in the body so that it prevents the build up of incomplete fat breakdown in blood and urine (ketosis).

Milk Fat Classifications

- Whole milk- 3.25% - Reduced fat- 2% - Low fat- 1% - Fat free, zero fat, no fat, skim milk (0.5%) - Fat is the only nutrient being reduced, all the rest stay the same

Fish Oil Supplement Health Benefits

1. Prevents Heart Disease - Omega 3- ecosanoids: prevents blood clotting, inflammation and ensures normal heartbeats. - Hardening of arteries - Reduced blood pressure (relaxed blood pressure) 2. Infant growth and development - Normal brain (cortex) and vision (retina) development 3. Prevent Cancers - Some anticancer effects - Cell development inhibits cancer development

Why are Fats Hydrogenated?

1. Stays fresher longer - When unsaturated points are oxidized, it gives the food an "off" taste. Therefore, they hydrogenate these unsaturated points into saturated points so the food does not have an "off" taste due to saturated fats being good with oxidation 2. Higher smoking point - Allows for fats to be cooked at a higher smoking point such as deep frying foods. - Less resistant to high temperature and oxidation 3. Makes fats harder, stronger, more spreadable Alternative-Keep them refrigerated; antioxidant BHA and BHT used as additives

Lipoproteins

4 types: VLDL, LDL, HDL and Chylomicrons

Artificial Fats and Fat Replacers

Artificial fats: zero-energy fat replacers - They mimic sensory and cooking qualities of naturally-occuring fats - They are resistant to digestion Fat replacers: must contribute little food energy; non-toxic; not stored in body tissues - Ex: Olestra a brand named Olean - (Contributes a very small amount of calories to diet but smaller than actual fat. Ex: an apple sauce containing 4 cals instead of 9) - Most of fat replacers used in baked goods, chips, salad dressing, spreads and dips, cereal, baked bars, etc.

Recipe Modifications

Cooking: Replace solid fats with oils: - canola oil and vegetable oil better for low heats or salad dressings - Avocado oil and grape seed oil for high heats. Choose larger portions of salads greens, other veggies and dress lightly: - Choose olive oil based dressings - Cook in water then add oil based sauces - Choose low fat milk products Baking: - Replace butter with margarine or canola oil - Replace 1/2 cup of butter with apple sauce - 1 egg for 2 egg whites - Replace egg with ground flaxseed and water Ex: instead of using butter you can take 1/2 a cup of apple sauce and then 1/2 cup of canola oil.

Exchange System Classification of Lean Meat

Extra lean ground - 10% fat or less Lean ground- 17% fat or less Medium- 23% or less High- 30% or less

Major Risk Factors for CVD (Cardiovascular disease)

Genetics 80%: - Age, gender, family history Modifiable/ lifestyle- 20% - High LDL levels, low HDL levels - "Athrogenic diet" a diet high in saturated and trans fat while very low in whole grain products, vegetables and fruits, legumes. This diet will lead to increased risk of heart disease - Limit bad fats which will reduce risk of heart disease - Physical inactivity; cigarette smoking - Diabetes (insulin resistant) type 2- obesity- eat healthy to prevent the onset.

Attributes of the Mediterranean Diet

Greece, Spain, Portugal, Israel, France... - High in grain products, fibre, fruits and vegetables, legumes - Low in saturated fats (butter, meat fats) but high in MUFAS (olive oil) - Very very little trans fat consumed - Moderate in milk and milk products, alcohol - Low in meat products

Finding how Many Calories From Fat in Food

If we want to find how much percentage of a food should be fat: • We know that DRI is 20-35% of total calorie should be from fat. o Ex: a label that has: 260 calories, 13G of fat • Take 20% of 260 and multiply to find out lowest range of calories from fat: .20x260=52 calories from fat. • .35%x 260=91 calories from fat- highest range. If something has more than 91 calories, you know this food is too high in fat/bad for you and you will have to decrease the fat in food. o To find total fat take 13g of fat x 9=117g of fat. o If you are not given calories in a food, to find it you take protein, fat and carbohydrates and multiply them by their number like carbs and protein= 4 and fats are 9 and then find that result, add them together and you get total calories from that food.

Fats in Meat/ Poultry & Fish

Meats: - Meat is very high in saturated fat - Dark meat has more fat then light meat Poultry: - Majority of fats is in and under the skin - Added moisture to turkey contributes to fat Fish: - Generally low in fat and contains "healthy" fats omega 3

DRI for Healthy Fats

Polyunsaturated fats: - Consume food and oils that contain PUFA - omega 3- flaxseed, nuts and seeds, canola oil - Consume more monounsaturated fats- olive, canola, peanut and sesame oils Omega 6 DRI: - 5-10% - 17 grams per day for males, 12 grams per day for females Omega 3 DRI: - .6-1.2% - 1.6 grams per day for males - 1.2 grams per day for females

DRI for Unhealthy Fats- SAFA and Trans

SAFA: -DRI: Less than 10% a day Trans Fat: - Less than 1 percent a day

Recommendation: Intakes of Fat For Healthy People

Total Fat: - Choose a diet low in fats - DRI: 20-35% of total cal from fat - Heart and stroke foundation: 45-75 grams per day for female, 60-105 g/p/d for males Cholesterol: - Those with preexisting cvd problems do not take in more than 300ml a day - Choose a diet low in fats