Nutrition. Chapter 5

LDL composition

-25 percent protein and 75 percent cholesterol and other fats. -LDL is bigger (yet lighter) and richer in cholesterol than HDL

saturated fatty acid

-A fatty acid in which all carbons in the hydrocarbon tail are connected by single bonds, thus maximizing the number of hydrogen atoms that can attach to the carbon skeleton. -Solid at room temp. -fats found in chocolate (stearic acid, an eighteen-carbon saturated fatty acid is a primary component) and meat. -Palm oil, raises blood cholesterol

unsaturated fatty acid

-A fatty acid possessing one or more double bonds between the carbons in the hydrocarbon tail. Such bonding reduces the number of hydrogen atoms attached to the carbon skeleton. -C=C -Foods rich in unsaturated fatty acids, such as olive oil (oleic acid, an eighteen-carbon unsaturated fatty acid, is a major component) tend to be liquid at room temperature -Flaxseed oil is rich in alpha-linolenic acid, becomes a thin liquid at room temperature. -More beneficial than saturated fat

Cholesterol

-A lipid that forms an essential component of animal cell membranes and acts as a precursor molecule for the synthesis of other biologically important steroids. -Used in the body to make a number of important things, including vitamin D, glucocorticoids, and the sex hormones, progesterone, testosterone, and estrogens.

Lecithin

-A phospholipid manufactured by the liver and also found in many foods; a major constituent of cell membranes. - 28% of brain matter is composed of Lecithin -66% of the fat in liver is lecithin. -Lowers blood cholesterol and aids with weight loss.

Hyperlipidemia

-An increased level of lipids, triacylglycerols, and cholesterol in the blood -High cholesterol and triacylglycerol levels.

Digestion of Triacylglycerols 3

-As contents enter small intestine, BILE combines the separated fats with its own watery fluids. -Emulsification increases the surface area of lipids over a thousand-fold, making them more accessible to the digestive enzymes.

Digestion of Triacylglycerols and phospholipids 1

-Begins in mouth as lipids encounter saliva. -chewing coupled with the action of emulsifiers enables the digestive enzymes to do their tasks -The enzyme lingual lipase, along with a small amount of phospholipid as an emulsifier, initiates the process of digestion. -These actions cause the fats to become more accessible to the digestive enzymes. As a result, the fats become tiny droplets and separate from the watery components.

Prelude to Disease: When blood lipids are High

-Cardiovascular disease -Heart attack -Ischemic stroke -Congestive heart failure -Arrhythmia -Heart valve problems. -Obesity

"Good" unsaturated fats

-Contain Monounsaturated and polyunsaturated fats — lower disease risk. -Foods high in good fats include vegetable oils (such as olive, canola, sunflower, soy, and corn), nuts, seeds, and fish.

Omega 3 vs Omega 6

-Determined by counting carbons backwards from omega end to where the first double bond occurs. -3= double bond at 3rd C. 6 is the same. -both are polyunsaturated fatty acids. -The only difference is that the last double bond is six carbons from the omega end of the fatty acid molecule. -Omega-6 fatty acids are also essential, so you need to obtain them from your diet. These fats are primarily used for energy

Phospholipids 2

-Glycerol backbone. -Amphiphilic -Diglycerides (two fatty-acid molecules attached to the glycerol backbone) -Double layer in cell membranes. Protecting inside of cell from the outside environment, while allowing transport of fat and water through the membrane. -Emulsifiers

HDL composition

-HDL is 50 percent protein and 50 percent cholesterol and other fats. -HDL is smaller, more dense, and richer in protein.

Digestion of Triacylglycerols 5

-Inside the intestinal cells, the monoglycerides and fatty acids reassemble themselves into triacylglycerols. -Triacylglycerols, cholesterol, and phospholipids form lipoproteins when joined with a protein carrier. - Chylomicron transport food fats perfectly through the body's water-based environment to specific destinations such as the liver and other body tissues.

LDL function

-LDLs carry cholesterol into cells for normal usage, but LDLs can also deposit cholesterol into the walls of blood vessels, which can lead to harmful disease

LDL/HDL and inflammation

-LDLs carry lipids that are pro-inflammatory and may contribute to heart disease. -HDLs transport lipids that are anti-inflammatory and may reduce the occurrence of heart disease.

VLDLs (very low density)

-Made in the liver from remnants of chylomicrons and transport triacylglycerols from the liver to various tissues in the body. -As the VLDLs travel through the circulatory system, the lipoprotein lipase strips the VLDL of triacylglycerols. -As triacylglycerol removal persists, the VLDLs become IDL (intermediate-density lipoproteins.)

Sterols 2

-Most sterols do not contain any fatty acids but rather multiring structures. -cholesterol is present in all body cells as it is an important substance in cell membrane structure -25% of cholesterol in the body is localized in brain tissue

polyunsaturated foods

-Most vegetable and fish oils contain high quantities -plant-based foods, oils, and fish. Common sources are nuts (walnuts, hazel nuts, pecans, almonds, and peanuts), soybean oil, corn oil, safflower oil, flaxseed oil, canola oil, and fish (trout, herring, and salmon).

Fats that Lower High Cholesterol

-Omega-3 promotes lower total cholesterol and lowers triacylglycerols. -Polyunsaturated fatty acids are especially beneficial to consume because they both lower LDL and elevate HDL -

Digestion of Triacylglycerols 4

-Once the stomach contents emulsified, fat-breaking enzymes work on the triacylglycerols and diglycerides to sever fatty acids from their glycerol foundations. -As pancreatic lipase enters the small intestine, it breaks down the fats into free fatty acids and monoglycerides. -Bile salts envelop the fatty acids and monoglycerides to form micelles, which help the fats pass through the watery layer of mucous that coats the absorptive lining of the digestive tract. -Here, the fat components are released and disseminated into the cells of the digestive tract lining.

Food of saturated fats

-Red meat, butter, cheese, and ice cream. -Some plant-based fats like coconut oil and palm oil are also rich in saturated fat. -coconut oil, palm oils, or whole milk remain as liquids at room temperature but are high in saturated fat.

polyunsaturated fats

-Two or more double bonds in its carbon chain -Corn oil, sunflower oil, and safflower oil -essential fats -build cell membranes and the covering of nerves. -They are needed for blood clotting, muscle movement, and inflammation. -Two types: Omega 3 and Omega 6 -reduces harmful LDL cholesterol -improves the cholesterol profile. -Lowers triglycerides.

Insulating and protecting

-Visceral fat or adipose surrounds delicate organs. -heart, kidneys, and liver are protected by visceral fat. -

Bile

-a bitter greenish-brown alkaline fluid that aids digestion and is secreted by the liver and stored in the gallbladder. -contains bile salts, lecithin, and substances derived from cholesterol so it acts as an emulsifier. -It attracts and holds on to fat while it is simultaneously attracted to and held on to by water. -

polyunsaturated fatty acid

-a fatty acid containing two or more carbon-carbon double bonds -two or more points of unsaturation. -Soybean oil

trans fatty acids

-a kind of fat formed when hydrogen is added to vegetable oil during processing called hydrogenation. -hydrogen atoms are attached on opposite sides of the carbon chain. -not found naturally in foods. -increased risk for coronary heart disease because of the way they negatively impact blood cholesterol levels -naturally occurring trans fats do not pose the same health risks as their artificially engineered counterparts. These trans fats are found in ruminant animals such as cows, sheep, and goats, resulting in trans fatty acids being present in our meat, milk, and other dairy product supply -butter, whole milk, and baked goods

Docosahexaenoic acid (DHA)

-an omega-3 polyunsaturated fatty acid with 22 carbons and six double bonds; present in fatty fish and synthesized in limited amounts in the body from linolenic acid. -Synaptic transmission in the brain during fetal development.

Oxidized LDL

-can speed up the process of plaque formation in the arteries. -It is believed to speed the process of cholesterol into the arterial walls and to induce a chronic inflammation of vessels -This activity promotes atherosclerosis and significantly increases risks for CVD

Triacylglycerols

-composed of 3 fatty acids bonded by ester linkages to glycerol - nonpolar and hydrophobic -stored as fat globules in adipose tissue -Maintains temp of body -secretes hormones, ex. adipose tissue secretes leptin (regulates appetite).

Vitamin A

-found in naturally fat-free foods such as green leafy vegetables, carrots, and broccoli. -Best absorbed with foods containing fat.

Fiber foods

-fresh fruits and veggies, whole grain breads, oats, and cereals -Fight obesity, stabilize blood sugar, and help some GI disorders -These foods bind bile salts and cholesterol to prevent their absorption and carry them out the colon.

Digestion of Triacylglycerols 2

-gastric lipase starts to break down triacylglycerols into diglycerides and fatty acids. -2-4 hours after eating a meal, 30 percent of the triacylglycerols are converted to diglycerides and fatty acids. -The stomach's churning and contractions help to disperse the fat molecules, -while the diglycerides derived in this process act as further emulsifiers. -Very little fat digestion occurs in the stomach.

Daily Cholesterol intake

-less than 300mg -Avg Female 237mg -Avg Male 358mg

LDLs

-low density lipoproteins carry cholesterol and other lipids from the liver throughout the body to tissue cells for various functions -comprised of very small amounts of triacylglycerols, and house over 50% cholesterol and cholesterol esters -Circulating LDLs in the bloodstream bind to these LDL receptors and are consumed. -Once inside the cell, the LDL is taken apart and its cholesterol is released. In liver cells these receptor systems aid in controlling blood cholesterol levels as they bind the LDLs. -A deficiency of these LDL binding mechanisms will leave a high quantity of cholesterol traveling in the bloodstream, which can lead to heart disease or atherosclerosis -Diets rich in saturated fats will prohibit the LDL receptors. Thus, LDL receptors are critical for regulating cholesterol levels.

essential fatty acids

-omega 3 and omega 6. -help regulate cholesterol and blood clotting and control inflammation in the joints, tissues, and bloodstream. -sustaining nerve impulse transmission, memory storage, and tissue structure. -help form nerve cell membranes, insulate neurons, and facilitate the signaling of electrical impulses throughout the brain.

Eicosanoids

-regulatory molecules that can be synthesized from omega-3 and omega-6 fatty acids. -Hormones that control many other hormones and important body functions.

Fats bad for Cholesterol

-saturated and trans fatty acids serve as catalysts for the increase of LDL cholesterol. -trans-fatty acids raise HDL levels, which can impact negatively on total blood cholesterol.

monounsaturated fats

-single carbon-to-carbon double bond. -has two fewer hydrogen atoms than a saturated fat and a bend at the double bond. This structure keeps monounsaturated fats liquid at room temperature. -Good sources: olive oil, peanut oil, canola oil, avocados, and most nuts, as well as high-oleic safflower and sunflower oils. - Use with polyunsaturated fats to replace saturated and trans fats.

micelles

-small transport carriers in the intestine that enable fatty acids and other compounds to be absorbed. -Fatty acid core with a water-soluble exterior -tiny spherical complexes of emulsified fat that arise during digestion; most contain bile salts and the products of lipid digestion, including fatty acids, monoglycerides, and cholesterol. -This allows efficient transportation to the intestinal microvillus -Here, the fat components are released and disseminated into the cells of the digestive tract lining.

Emulsifiers

-substances with both water-soluble and fat-soluble portions that promote the mixing of oils and fats in watery solutions -Lecithin (phosphatidylcholine), found in egg yolk, honey, and mustard, is a popular food emulsifier. Mayonnaise demonstrates lecithin's ability to blend vinegar and oil to create the stable

Chylomicrons

-the class of lipoproteins that transport lipids from the intestinal cells to the rest of the body - a large lipoprotein that now enters the lymphatic system and will soon be released into the bloodstream via the jugular vein in the neck. -transport food fats perfectly through the body's water-based environment to specific destinations such as the liver and other body tissues.

IDL (intermediate-density lipoproteins.)

-transport a variety of fats and cholesterol in the bloodstream and are a little under half triacylglycerol in composition. -While travelling in the bloodstream, cholesterol is gained from other lipoproteins while circulating enzymes strip its phospholipid component. -When IDLs return to the liver, they are transformed into low-density lipoprotein

Phospholipids

2% of dietary lipids. Water soluble. builds protective barrier, or membrane around your body's cells. I blood and body liquids, forms structures where fat is enclosed and transported throughout the bloodstream. forms cells and organelle membranes.

Triglycerides

<150 mg/dL Body converts the calories that you don't need into triglycerides and stores them in your fat cells to be used for energy later. -too many triglycerides in your blood can increase your risk of heart disease. -triglyceride troubles can lead to clogged arteries and possibly to a heart attack or stroke -Lead to metabolic Syndrome -Instead eat Naturally contain mono- and polyunsaturated fats: avocados, walnuts, chicken without the skin, canola oil, and olive oil.

fatty acids

Building Blocks of Lipids. proper reproductive health. -saturated, monounsaturated and polyunsaturated.

HDLs (high density lipoproteins)

Carries excess cholesterol out of the bloodstream from the cells back to the liver to reuse cholesterol or removed from body with bile; -Large protein composition with low cholesterol content (20 to 30%). -"good cholesterol" because high levels of HDL's in the blood are associated with a decreased risk of CVD

Phytochemicals

Chemicals in plant-based foods that are not nutrients but that have effects on the body. -Increases Bioavailability of compounds -Lycopene (found in tomatoes) and beta-carotene (carrots). -promotes health and wellbeing.

When lipoproteins enter blood and lymph what lipoprotein will they be?

Chylomicrons releasing triacylglycerols -VLDLs: Very Low-density Lipoproteins -IDLs: Intermediate-density Lipoproteins -LDLs: Low-density lipoproteins -HDLs: High-density Liproproteins

Omega-6 fatty acids (linoleic acid). foods

Eggs, poultry, most vegetable oils, wheat germ oil, whole grains, baked goods, and cereals contain these fatty acids. Omega-6 fatty acids are present abundantly in nuts and seeds such as flaxseeds, sunflower seeds, sesame seeds, and watermelon seeds.

nonessential fatty acids

Fatty acids that your body can make when they are needed. It is not necessary to consume them in the diet. -circulatory system, respiratory system, integumentary system, immune system, brain, and other organs require fatty acids for proper function.

• Omega-3 fatty acids (linolenic acid). foods

Good sources of these are canola oil, flaxseed oil, soybean oil, olive oil, nuts, seeds, whole grains, legumes, and green leafy vegetables.

DHA and EPA

Good sources of these are cod liver oil and fish such as tuna, herring, mackerel, salmon, and trout

HDL function

HDLs scavenge excess cholesterol from the cells, tissues, and blood vessels and deliver these back to the liver, where these are either reused or excreted.

5.7 key takeaways

Hydrogenation is the process of adding hydrogen to the points of unsaturation in unsaturated fatty acid chains. The resulting oil is very hard and unusable. Partial hydrogenation is the process of adding hydrogen to some of the points of unsaturation in unsaturated fatty acid chains. This produces oils that are more spreadable and usable in food products. • Food manufacturers favor the use of hydrogenated oils because they do not succumb to oxidative damage, they increase the shelf life of food products, and they have a high smoking point. • Fat replacers mimic fat but do not have the same chemical configuration as fat. Therefore the body does not process these the same way it would a naturally occurring fat. Fat substitutes such as Olestra have produced symptoms of fat malabsorption in some people.

Cholesterol Absorption

Increased amounts of fat in the diet results in the increase of mixed micelles, which in turn allows for more ___? -Is aided by an increase in dietary fat components -Is hindered by high fiber content (more beneficial) -poorly absorbed when compared to phospholipids and triacylglycerols

Sterols

Least common Lipid. Cholesterol is the most common sterol. Body produced most cholesterol, not so much from food. Cholesterol important component of cell membrane. Required for synthesis of sex hormones, Vitamin D, and Bile Salts.

cis fatty acids

Naturally occurring unsaturated fatty acids in which carbon moieties lie on the same side of the double bond.

Monounsaturated foods

Olive oil and canola oil -Found in plant oils. Common sources are nuts (almonds, cashews, pecans, peanuts, and walnuts) and nut products, avocados, extra virgin olive oil, sesame oil, high oleic safflower oil, sunflower oil, and canola oil.

monounsaturated fatty acid

One double bond Ex. Oleic acid in olive and canola oil. -Helps regulate blood cholesterol levels. (reduces stroke or cardiovascular diseases.)

monounsaturated fats and polyunsaturated fats

Provide essential nutrition for normal cell development and healthy skin.

Action to fight likelihood of Diseases

Remember that saturated fats are found in large amounts in foods of animal origin. They should be limited within the diet. Polyunsaturated fats are generally obtained from nonanimal sources. While they are beneficial for lowering bad cholesterol they also lower good cholesterol. They are better for you than saturated fats but are not to be consumed in excess. Monounsaturated fats are of plant origin and are found in most nuts, seeds, seed oils, olive oil, canola oil, and legumes. Monounsaturated fats are excellent because they not only lower bad cholesterol, but also they elevate the good cholesterol. Replace current dietary fats with an increased intake of monounsaturated fats.

Trans fatty acids

Stick margarines, fast foods, commercial baked goods, and some snack foods contain trans fats. Limit your consumption of these products to keep trans fats to less than 1 percent of your fat consumption

The largest influence on blood cholesterol levels

The largest influence on blood cholesterol levels rests in the mix of saturated fat and trans fat in the diet.

Saturated fat foods

This fat is found in animal products, dairy products, palm and coconut oils, and cocoa butter. Limit these products to less than 10 percent of your overall dietary fat consumption.

Excess Fat

Too much adipose tissue. impact on health. Like Cholesterol in arterial wall. Leads to Cardiovascular disease.

Fat soluble vitamins

Vitamins A, D, E, K. Carries these vitamins through the digestive process and intestinal absorption is improved

What performs emulsification?

When bile enters the small intestine, it will mix with the fat globules and will cause them to break down into smaller units called emulsion droplets. This process is called emulsification. Emulsification greatly increases the surface area of the fat on which the lipase can actually act on.

Healthy amounts of Lipids

a low amount of LDL and a high amount of HDL prevents excess buildup of cholesterol in the arteries and wards off potential health hazards. Increased LDL = Bad Increased HDL = Good

Amphiphilic

attracted to both water and fat - containing hydrophobic(dislike water) and hydrophilic (likes water) parts

cis fatty acids vs. trans fatty acids

cis - hydrogens on same side of the double bond, U formation. most are unsaturated acids trans - hydrogens on opposite sides of double bond. linear

Lipoproteins

clusters of lipids associated with proteins that serve as transport vehicles for lipids in the lymph and blood. -Inner core made up of traicylglycerols and cholesterol esters (a cholesterol ester is a cholesterol linked to a fatty acid). -The outer envelope is made of phospholipids interspersed with proteins and cholesterol. -Together they form a chylomicron

Omega 3 food sources

cold water fish, walnuts, flaxseed, canola oil, chia seeds, Soybeans, Tofu, Kale, Brussel sprouts, Cauliflower, Cabbage, Cloves, Flaxseeds Spinach Kale Brussels sprouts Salad greens Beans

Fat Gram

densely concentrated. Stored energy. 9 calories per gram. Good for energy needed for exercise.

steatorrhea

fat malabsorption resulting in severe diarrhea -can result from diseases that affect absorption, such as Crohn's disease and cystic fibrosis.

essential fatty acids

fats needed by the body that must be consumed in the diet because the human body cannot manufacture them -Omega 3 and 6 -Must be obtained from food

omega-3 and omega-6

fish, flaxseed oil, hemp, walnuts, and leafy vegetables

Foods that takes away fat-soluble vitamin content.

grain and dairy are processed, these essential nutrients are lost. Manufacturers replace these nutrients by enrichment.

Omega 6 fatty acids

increase blood pressure, immune response, and inflammation.

plant sterols

inhibits dietary cholesterol absorption. Lowers cholesterol levels.

Adipose Tissue

is called fatty tissue, is excess energy from food we eat is digested and incorporated into this ______. Lipids function as an energy reserve. Stored tightly without water and stores more energy amounts in a reduced space.

Unabsorbed fats

not absorbed properly as is seen in some medical conditions, a person's stool will contain high amounts of fat.

unsaturated foods

nuts, olives, avocado

omega-3 fatty acids

polyunsaturated fatty acids commonly found in fish oils that are beneficial to cardiovascular health.

subcutaneous fat

protects against extreme temperatures and provides padding during physically demanding exercises. Like horseback riding.

bad fatty acids

saturated (bad) and trans fat (worse)

Blood Cholesterol Recommendations

total: <200mg (healthy = under 200) LDL: <100mg (less than 100 =good, >160mg = high HDL: >40mg men & >50mg women

Replace red meat and butter with...

with fish, beans, nuts, and healthy oils instead of refined carbohydrates.

Measures cholesterol

• Desirable. Under 200 milligrams per deciliter • Borderline high. 200-239 milligrams per deciliter • High risk. 240 milligrams per deciliter and up

lipid profile

• LDL. Less than 160 milligrams per deciliter (if you have heart disease or diabetes, less than 100 milligrams per deciliter) • HDL. Greater than 40-60 milligrams per deciliter • Triacylglycerols. 10-150 milligrams per deciliter • VLDL. 2-38 milligrams per deciliter

5.5 Key takeaways

• The recommended fat intake for adults is 20-35 percent of your total caloric intake. Saturated fat must be less than 10 percent of your total caloric intake, and lowering this to 7 percent can further reduce the risks for heart disease. Trans fat should be less than 1 percent of total caloric intake. • Nuts, seeds, whole grains, legumes, and vegetable oil such as soybean, canola, and flaxseed are excellent sources of monounsaturated and polyunsaturated fats. • The polyunsaturated fatty acids linolenic and linoleic acids are used by the body to make substances that carry out many vital functions in the body. • The omega-3 fatty-acid family includes linolenic acid, EPA, and DHA. The omega-6 fatty-acid family includes linoleic acid and ARA. DHA and ARA play crucial roles in brain and eye development. EPA and DHA found in fatty fish play important roles in inflammation reduction and disease prevention. • Many people consume too many omega-6 fatty acids and not enough omega-3 fatty acids. Omega-3 fats and omega-6 fats are precursors to hormones that have opposing properties. A proper balance between both must be obtained to avoid health problems.

5.8 Key Takeaways

• To reduce saturated fat in your diet, eat less red and processed meat and more fish and chicken. Choose lean cuts of meat and white meat portions. Bake, broil, or grill instead of fry. Avoid deep-fried foods, cheeses, and creamy cheese sauces. Remove the skin from chicken and remove as much fat from meat as possible. Choose low-fat milk and lower fat cheeses, such as mozzarella, where possible. Use liquid vegetable oils such as olive oil or canola oil instead of shortening or butter. • In order to reduce blood cholesterol, restrict the consumption of eggs, chicken livers, beef, pork, shrimp, crustaceans, fast foods, pastries, butter, cheese, and ice cream. • To gain the most benefit from reducing your saturated fat intake, substitute unsaturated fats in the place of saturated fats and trans fats. Do not add unsaturated fats to an already fatty diet. Fill your plate with plant-based foods and use the foods containing fat more as an accompaniment.