Chapter 5 lipids

11 Metabolic syndrome:

a combination of risk factors- elevated fasting, blood glucose, htn, abnormal blood lipid, abdominal obesity increases the risk of developing coronary heart disease. 12 Abdominal obesity and insulin resistance: primary factors

The more saturated an an fat is

solid at room temperature

v Large intestine:

some fat and cholesterol in the fiber exit through feces.

AMDR 20 -35% of daily kcals

• DRIs • Saturated fat--- No more than 10% of kcals • Essential FAs ---Linoleic acid (ω6) and α-Linolenicacid (ω3) • Try to eat a ratio of closer to 1:1 ω6:ω3 • The average Western diet consumes 16:1

Blood pressure

-increased BP can cause low grade inflammatory start that stimulate plaque formation and progression.

a. Omega:

Refer to the position closest to the double bond to methyl. the FA of an omega family may have different lengths and diff number of double bonds but the location of the double bond closest to the methyl end is same in all of them.

How to calculate Personal Daily Value for fat, page 155

The % Daily Value for fat on food labels is based on 65 grams. To know how your intake compares with this recom mendation, you can either count grams until you reach 65 or add the "% Daily Values" until you reach 100 percent—if your energy intake is 2000 kcalories a day. If your energy intake is more or less, you can calculate your personal daily fat allow ance in grams. Suppose your energy intake is 1800 kcalories per day and your goal is 30 percent kcalories from fat. Multiply your total energy intake by 30 percent, then divide by 9: 1800 total kcal × 0.30 from fat = 540 fat kcal 540 fat kcal ÷ 9 kcal/g = 60 g fat (In familiar measures, 60 grams of fat is about the same as ²∕ ³ stick of butter or ¼ cup of oil.)

7 Obesity:

contribute to the increased LDL and low HDL, hypertension and diabetes. Weightloss and physical activity protect against CHD by lowering the LDL, raising HDL, improving insulin signaling and lowering BP

Increased LDL

contributes to heart disease - As LDL cholesterol accumulates in the arteries, blood flow becomes restricted and blood pressure rises. T

a. Structure of phospholipid:

has a glycerol backbone with 2 of the 3 attachment sites occupied by FA and the 3rd site occupied by a phosphate group and a molecule of choline.

chylomicrons (kye-lo-MY-cronz): t

he class of lipoproteins that transport fat from intestinal cell to the rest of the body

b. Structure of the triglyceride:

triacylglycerol, glycerol backbone. Main type of fat found in plants or animal foods and your body. i contains a glycerol backbone and three fatty acid

High LDL and low HDL cholesterol

• Total cholesterol • LDL - most atherogenic lipoproteins • Plaque instability • Inflammatory process • HDL indicate a reduced risk of atherosclerosis

♦ Major sources of omega-3 fats:

• Vegetable oils (canola, soybean, flaxseed) • Walnuts, flaxseeds • Fatty fish (mackerel, salmon, sar

Polyunsaturated fats

Vegetable oils (sesame, soy, corn, sunflower) • Nuts and seeds

Essential FA

- FA needed by the body but not made in the body and must come from diet

• % Daily Value vs. % kcals from fat page 184

- describe the amount of fat in a food. not the same as percent kal that is used in the dietary recomendation to desribe the amount of fat in diet.--- FOod levels donot provide percent kcal from fat.

ALA omega 3 food sources

- flax nuts, grass fed animal products

Plaques:

- platelets and other factors form the blood clot increased by omega 6 and decreased by omega 3. Once platelets form, a sudden spasm or surge increases the Bp and can cause tear in the fibrous coat causing rupture.

triglyceride :

-3 FA with glycerol backbone its main form of fat found in plant and animal and your body

POlyunsaturated FA

-A FA that lacks 2 or more hydrogen atoms and has 2 or more double bonds between carbons

Monounsaturated

-A fatty acid that has two hydrogen atoms lacking and has one double bone between carbons. COmposed of triglyceride in which most of the FA are monounsaturated.

What are the 2 examples of the polyunsaturated fatty acid

-Lenoleic- 2 double bond -linolenic 3 double bonds - composed of triglyceride in which the FA are unsaturated.

How many types of lipoproteins are there

4

Saturated Fatty acid

A fatty acid carrying max possible hydrogen atoms and contain only single bonds between its carbon atom

Omega 3:

A polyunsaturated fatty acid with its closest double bond three carbons away from the methyl end is an omega-3 fatty. i lenileic - 18 carbon omega 3 fatty acid

Explain the relationships among saturated fats, trans fat, and cholesterol and chronic diseases, noting recommendation

Although some fat in the diet is necessary, too much fat adds kcalories without nutrients, which leads to obesity and nutrient inadequacies. Too much saturated fat, trans fat, and cholesterol increases the risk of heart disease and possibly cancer. For these reasons, health authorities recommend a diet moderate in total fat and low in saturated fat, trans fat, and cholesterol

• Fat replacers • Types

Artifical fat- offering sensory and cooking abilities of fat but none of the calories examples- olestra- made of sucrose molecule with 6-8 FA

atherosclerosis development

Atherosclerosis Development • Accumulation of fatty streaks along inner arterial walls • Streaks enlarge and harden • Encasement in fibrous connective tissue • Plaques stiffen arteries and narrow passages • Well-developed plaques by age 30

6 Diabetes:

BV that often become blocked and circulation diminishes. AtheroS progresses rapidly.

iv Small intestine:

CCK, pancreatic lipase, hydrolysis 1 CCK signals the gall bladder to release bile via bile duct. The pancreatic lipase flows from the pancreas. 2 Emulsified fat (triglyceride) after being exposed to --- < pancreatic lipase <- breaks down to monoglyceride, glycerol, and the Fa are absorbed.

c. Discuss the role of nutrition in the prevention and treatment of cardiovascular disease.

Cholesterol screening: total cholesterol, LDL HDL and triglyceride. ii Lifestyle changes: physical activity, dietary changes, lose weight, reduce exposure to cig. iii Diet: 1 Balance energy intake and physical activity. 2 limit saturated fat to less than 7 percent 3 trans fat to less than 1 percent cholesterol to less than 300 mg a day 4 increase soluble fiber intake: potassium and sodium - increase in potassium and low sodium 5 minimize added sugars and consume omega 3 fish 6 increase plant sterols and stanols consume- soy food, 7 limit alcohol 8 Sodium restrictor: reduce sodium intake to less than 2300 mg sodium per day 9 phsycal activity 30 min per day.

Role of omega 3 linolenic acid 18:3 (n3) ALA

Converted to EPA and DHA if now in the diet. e. Eicosapentaenoic acid (20:5) n3 aka EPA i produces anti-inflammatory molecules f. Docosahexaenoic acid 22:6 n 3 AKA DHA i brain health, fetal brain development

• Risks Fat replacers

Enzymes in the digestive tract cannot break the bonds of olestra, so unlike sucrose or fatty acids, olestra passes through the digestive system unabsorbed.When olestra passes through the digestive tract unabsorbed, it binds with some of the fat-soluble vitamins, A, D, E, and K, and carries them out of the body, robbing the person of these valuable nutrients.

ic. Describe the absorption of lipids into the intestine and the formation of chylomicrons.

Few lipids go directly into the blood stream- such as glycerol, short and medium FA chains. ii Most enter the lymphatic system 1 Miceles diffuses into the intestinal wall, reassemble of triglycerides, packed with proteins called chylomicrons, by pass the liver first. iii Large lipid such as monoglyceride and long chain combine with bile forming micelles that are water soluble to penetrate the watery solution that bathes the absorption cells. The lipid content of the micelles diffuse into the cell where mono and long chain are reassembled into triglycerides. within the cell, the newly made triglyceride and other lipid chains , cholesterol and phospholipid are packed into chylomicrons—the intestinal cells than release the chylomicrons into the lymphatic system. 1 Chylomicrons circle through the lymph until they reach a point of entry into the blood steam at the thoracic duct near the heart. The blood takes these lipids to the rest of the body for immediate storage.

advantages of hydrogenation

First, it protects against oxidation (thereby prolonging shelf life) by making polyunsaturated fats more saturated. Second, it alters the texture of foods y making liquid vegetable oils more solid (as in margarine and shortening). Hydrogenated fats improve the texture of foods, making margarines spreadable, pie crusts flaky, and puddings creamy.

f. Sterols in foods: i

Foods derived from both plants and animals contain sterols, but only those from animals contain significant amounts of cholesterol—meats, eggs, seafood, poultry, and dairy products. Sterols other than cholesterol are naturally found in plants. Being structurally similar to cholesterol, plant sterols interfere with cholesterol absorption.

What are atherogenic Diet:

food high in saturated fat, transfat and cholesterol low in vegetables fruits and whole gains- elevates ldl cholesterol.

VLDL

In the liver , the most active site of lipid synthesis, cells are making cholesterol, FA, and other lipid compound. the lipid made in the liver and those collected from the chylomicrons are packaged as VLDL and shipped to other parts of the body. -As VLDl travel through the body, cells remove triglyceride -As they remove TGS, bldl shrinks and propoertion of lipdis shifts. -cholesterol become predominant lipid and lipoiortion becomes smaller and more dense. VLDL becomes LDL

FUnction of the sterols

Many vitally important body compounds are sterols. Among them are bile acids, the sex hormones (such as testosterone), the adrenal hormones (such as cortisol), and vitamin D, as well as cholesterol itself. Cholesterol in the body can serve as the starting material for the synthesis of these compounds ♦ or as a structural component of cell membranes; more than 90 percent of all the body's cholesterol is found in the cells. D

Dietary cholesterol ♦

May also raise blood cholesterol

Example of monounsaturated

Oleic Acid- abundant in olive in canola oil

Major sources of unsaturated fats: Monounsaturated fats •

Olive oil, canola oil, peanut oil, safflower oil • Avocados

Describe the chemistry, food sources, and roles of phospholipids and sterols.

Phospholipids, including lecithin, have a unique chemical structure that allows them to be soluble in both water and fat. The food industry uses phospholipids as emulsifiers, and in the body, phospholipids are part of cell membranes. Sterols have a multiple-ring structure that differs from the structure of other lipids. In the body, sterols include cholesterol, bile, vitamin D, and some hormones. Animal-derived foods are rich sources of cholesterol. Table 5-2 (p. 138) summarizes the lipid family of compounds.

Blood clots

Platelets and other factors form blood clots • Increased by ω6, decreased by ω3

c. What affect does saturation have on physical property: the degree of saturation influences the firmness of fat at room temperature i

Polyunsaturated : liquid at room temperature ii More saturated animal fats are solid at room temperature, and some oils such as cocoa butter, palm oil, coconut oil are saturated. they are firmer than vegetable oil because of their saturation but softer than animal fat because of their shorter carbon chains. d. shorter the carbon chain, softer the fat is e. The degree of unsaturation also influences the stability: i Polyunsaturated- spoil readily because their double bonds are unstable. Saturated fats= are resistant to oxidation and are least likely to become rancid. f. Saturated tend to slack together, become solid at room temperature.

Recommendation:

Selecting lean cut meat, skinless poultry, fat free milk products help to lower the saturated fat intake and the risk of heart disease. the DRI and Dietary Guidelines suggest a diet that provides 20 to 35 percent of the daily energy intake from fat, ♦ less than 10 percent of daily energy intake from saturated fat, as little trans fat as possible, and less than 300 milligrams cholesterol.

8 Cigarette smoking:

Smoking damages the heart directly• Toxins in cigarette smoke damages vessels

Explain the relationships between monounsaturated and polyunsaturated fats and health, noting recommendations.

Some fat in the diet has health benefits, especially the monounsaturated and polyunsaturated fats that protect against heart disease and possibly cancer. For this reason, Dietary Guidelines recommend replacing saturated fats with monounsaturated and polyunsaturated fats, particularly omega-3 fatty acids from foods such as fatty fish, not from supplements. Many selection and preparation strategies can help bring these goals within reach, and food labels help to identify foods consistent with these guidelines.

Read food labels •

Total fat, saturated fat, trans fat, and cholesterol • Compare products

What happens during the hydrogenation process

Total hydrogenation rarely occurs during food processing. Most often, a fat is partially hydrogenated, and some of the double bonds that remain after processing change their configuration from cis to trans

Health Effects of Saturated Fats,

Trans Fats, and Cholesterol • Standard American diet • Blood lipid profile • Heart disease • Elevated blood cholesterol • Saturated fat - increase LDL cholesterol, promote blood clotting • Trans fats - increase LDL cholesterol • Dietary cholesterol

Essential Fatty acids:

We cannot added double bonds in our body thus we must eat 1 lenoleic omega 6 and lenolENIC omega 3- can be used to make other critical fatty acids to an extent. by using desaturation and lengthening ii The human body cannot make linolenic 18 carbon omega 3 fatty acid and 18 carbon omega 6 fatty acid. -they must be supplied by diet.

h y d r o g e n a t i o n (HIGH-dro-jen-AY-shun or high-DROJ-ehNAY-shun):

a chemical process by which hydrogens are added to monounsaturated or polyunsaturated fatty acids to reduce the number of double bonds, making the fats more saturated (solid) and more resistant to oxidation (protecting against rancidity). Hydrogenation produces trans-fatty acids

i Choline:

a nitrogen containing compound found in te foods and made in body from AA. part of phospholipid lecithin and acetylcholine.

1 Chylomicrons circle through the lymph until they reach a point of entry into the blood steam at the thoracic duct near the heart. The blood takes these lipids to the rest of the body for immediate storage.

are the largest and least dense lipoproteins/ transport diet derived lipids (mostly triglyceride) from small intestine via lymph to the rest of the body. Cell from all over the body remove triglyceride from the chylomicrons as they pass by so the chylomicrons get smaller and smaller. The remnants are taken up by liver which remove the remnants from blood.

ii Compounds made from cholesterol are :

bile, steroid hormone such as testosterone, cortisol , vitamin D

blood lipid profile ♦ reveals the

concentrations of various lipids in the blood, notably triglycerides and cholesterol, and their lipoprotein carriers (VLDL, LDL,and HDL). b

9 Atherogenic Diet:

elevated LDL, cholesterol, BP and inflammation. 10 Other risk factors: elevated triglyceride- due to the role they pay in lipoprotrien metabolism

role of fat in the body:

energy source, cell membrane, signal molecule, insulation, shock absorption. b. most efficient form of energy storage, unlimited ability to store fat, adipose tissue , protein sparring, kb in times of starvation. i Adipose tissue secretes hormone adipokines that regulate energy balance and influence several body function

Fat replacers

fat replacers—ingredients that provide some of the taste and texture of fats, but with fewer kcalories. Because the body may digest and absorb some of these fat replacers, they may contribute energy, although significantly less energy than fat's 9 kcalories per gram

omega 3 EPA and DHA

fish, algae

LDL:

loaded with cholesterol and few tryglcerine. -circulates throughout the body. making their contents avaibale to the cells of all tissue, muscle fat stores and mamamarry gland. - the cell takes cholesterol, TGS and phospholipid and use them fr energy, making hormones, and building new membranes

omega 3 eicosanoid:n.

lower Bp, prevent blood clot, protect against the irregular heart beat and reduce inflammatio

b. Function of phospholipid:

membrane bilayer, micelles, emulfiers- helping to keep fat suspended in the blood ad body fluids.

i By the middle age,

most adults have atleast one risk factor. Increased age, male gender, and early CHD in immediate family member << non modifiable 1 modifiable risk factors: a Increased blood LDL cholesterol, low blood HDL cholesterol, high blood pressure, Diabetes.

Docosahexanoic acid

omega 3 poly unsaurated with 22 carbon and 6 double bonds. made from linolenic acid

Arachinoic FA

omega 6 poly unsaturated with 20 and 4 double dobs present in meat and other animal fat synthesized from linoleic acid

FA

organic compounds composed of carbon chain with hydrogens attached and acid group (cooh) at the one end and an methyl group at the other end (CH3)

h. Eicosanoids: 20 carbon poly unsaturated FA

participate to immune response to injury and inflammation, producing fever, inflammation and pain. i

i Example: lecithin:

phospholipid: it has two FA chain and third position is occupied by a phosphate group and a molecule of choline.

Omega 6:

poly unsaturated fatty acid with its closest double bond 6 carbons away from the mythl end is omega 6 fatty acid. i linolenic: 18 carbon omega 6 fatty acid.

Emulsifation of Fat by bile

process that makes fat soluble in water, requires a helper molecule such as bile or phospholipid. In the stomach, the watery GI juice tend to seperate. the enzyme in the GI juice cant get at the fat. -when the fat enters the small intestine, pancreas secretes bile -bile emulsifying action converts the fat globules into small droplets that repel one another. -after emulsifation- more fat is exposed to the enzyme making fat digestion for efficient.

the shorter the chain is

the softer the fat is

Replacing saturated fats with unsaturated fats

♦ reduces LDL cholesterol and lowers the risk of heart disease.29 To replace saturated fats with unsaturated fats, sauté foods in olive oil instead of butter, garnish salads with sunflower seeds instead of bacon, snack on mixed nuts instead of potato chips,

HDL

-HDL made by the liver to remove the cholesterol from the cells an carry it back to the liver for recycling or disposal -by efficiently removing choleric from the boof stream, the HDL lowers the risk of heart disease

What are the 4 types of proteins

-chilomicrons -VLDL -lDL HDL

Transient ischemic Attack

-a temporary reduction in the blood flow to the brain, which causes temporary symptoms that vary depending on the part of the brain affected.

Standard american Diet

-current american diet elivers excess fat, 1/5th of the total kcal

Major source of solid fat

-desert, pizza cheese processed meat

food sources omega 6

-linoleic acid - palm oil, conventional animal products

Food sources of omega 9

-monounsaturated fat,- olive oil and avacado

eicosapentanoic

-omega 3 poly unsaturated with 20 carbon 5 double dbond present in fish and syntehsized in limited amount from linolenic acid

function of the special LDL receptors

-on the liver plays a crucial role in the control of blood cholesterol by removing LDL from the circulation.

whats so bad about trans fat?

-packages like saturated fat, likely to oxidize like unsaturated fat. -behave like saturated fat at increase cholesterol in the blood, risk of heart disease. -typically occur in partially hygrogenated food when hydrogen shift around some double bonds can chage their config from cis to trans.

Blood clots

-platelets and other factors form blood clots. Abnormal blood clotting can trigger death. Thrombosis- a clot that grew large enough to restrict or close off a blood vessel (thrombosis). Embolism: when clot begs free and enters the circulatory system and until it lodges in a small artery and stop the bloof flow to the tissue- embolism

ii Mouth and salivary glands:

1 Some fats begin to melt as they reach body temperature. The sublingual salivary gland in the base of the tongue secrete lingual lipase. The degree of hydrolysis by lingual lipase is slight for most fat but may be appreciable for milk fats.

Enteropathic circulation of bile

1. in the liver, bile is made from cholesterol 2. in the gall bladder, the bile is stored. 3. in the small intestine: bile emulsifies fat 4. in the colon: bile that has been trapped by the soluble fiber is excreted in feces 5. bile absorbed in the blood and goes back to the liver

ipoproteins (LIP-oh-PRO-teenz)

: clusters of lipids associated with proteins that serve as transport vehicles for lipids in the lymph and blood.

emulsifiers:

: substances with both water-soluble and fatsoluble portions that promote the mixing of oils and fats in watery solutions.

Unsaturated Fatty acid

A FA that lacks hydrogen atoms and has at least one double bond between carbon. An unsaturated fat composed of triglyceride in which most of te FA are unsaturated

c. What contributes to FA accumulation:

A diet high in saturated fat is major contributor to the development of plaques and progression. In general, the more saturated fat in the diet, the more LDL cholesterol in the blood. IN addition to raising blood cholesterol saturated fat also contribute to heart disease by promoting blood clotting. Fas from animal sources( meats, milk and milk products) are main sources of saturated fat. INcreased LDL also causes blood flow t o become restricted and causes an increase in blood pressure.

The degree of saturation influences stability

Polyunsaturated fats spoil most readily because their double bonds are unstable; monounsaturated fats are slightly less susceptible. Saturated fats are most resistant to oxidation and thus least likely to become rancid

Eicasanoid

derivatives of 20 FA acid

Linoleic acid (omega-6) AI:

e. Men: f. • 19-50 yr: 17 g/day g. • 51+ yr: 14 g/day

c. Foods that contain phospholipid:

eggs, liver, soyabeans, wheat germs, peanuts.

What is the goal of digestion?

i Goal of fat digestion: dismantle triglyceride to monoglyceride, FA, and glycerol.

c. Role of omega 6 FA ( 18-2) n6

i. linoleic acid-(18-2) n6 - cell membrane, production of AA ii Arachidonic acid 20:4 n 6 1 Produces pro inflammatory molecules. Things that require inflammation such as wound healing. iii vegetables and meat supply enough omega 6 to meet the body nee

Women:

i. • 19-50 yr: 12 g/day j. • 51+ yr: 11 g/day k. ♦ Linolenic acid (omega-3) AI: l. • Men: 1.6 g/day • Women: 1.1 g/day

2 Men are more at risk than women due the estrogen protecting women. level of AA homocysteine increases damage of the artery walls.

ii Risk factor High LDL and Low HDL. 1 Total cholesterol: most atherogenic lipoprotein. 2 Increased HDL means that cholesterol returning from the cells to the liver where it will be used to make bile and excreted in the GI track. 3 Any low LDL cholesterol that remains in the blood after body cell take up the amount they need = oxidize—trigger plaque formation and contribute to plaque instability.

Trans and the heart disease,

in the body, Trans fats alter blood cholesterol the same way some saturated fats do: they raise LDL cholesterol and at high intakes, lower HDL cholesterol, limiting the intake of Tran's fats can improve blood cholesterol and lower the risk of heart disease.

size and compsotion of lipoprotein

inerior of triglycerdie and cholesterol surrouned by phospholipid. -tail interior- where the lipids are protein near the outer ends of the phospholipid cover the structure -hydrophilic ouside and hydrophobic inside

ii omega 6 eicosanoids:

promote clot formation, inflammation, BV constriction.

iii Stomach:

the stomach churning mixes fat with water and acid. A gastric lipase hydrolyses fat. little fat digestion here but most of the Fat digestion happens in the SI

Inflammation

• Damage to cells lining the blood vessels elicits inflammatory response • Immune system sends in macrophages • LDL cholesterol becomes trapped and engulfed by macrophages • Macrophages swell; eventually become foam cells of plaque

Dietary Guidelines

• Diet low in saturated fat • Zero trans fat • Diet low in cholesterol • AMDR 20 -35% of daily kcals • Daily Values (DV) on food labels0 based on 65 grams • Saturated fat and cholesterol --- saturated fat 10 percent and cholesterol less than 300 mg • How to calculate Personal Daily Value for fat, page 155

Groceries

• Fat-soluble vitamins • A, D, E, and K • Flavor, texture, and palatability • Protein foods--- Selections such as fish • Milk and milk products--- Selections such as reduced fat

The Mediterranean Diet

• Low in saturated fat • Very low in trans fat • Rich in unsaturated fat • Rich in complex carbohydrate and fiber • Rich in nutrients and phytochemicals • Benefits for heart disease risk

Sources of saturated fat in the American diet

• Meats • Whole milk products • Tropical oils- coconut, palm Zero saturated fat is not possible Trans fat ------ >Limit/eliminate hydrogenated foods

Health

• Olive oil • Benefits for heart health • Replace saturated fats-- resude the LDL cholesterol Regular consumption of omega-3 fatty acids helps to prevent blood clots, protect against irregular heartbeats, improve blood lipids, and lower blood pressure, especially in people with hypertension or atherosclerosis.31 In addition, omega-3

• Blood pressure

• Plaques increase pressure (self-accelerating) The results • Rupture and embolism • Heart attack • Transient ischemic attack (TIA) or stroke • Aneurysm

Heart disease

• Replace saturated fats with unsaturated fats • Regular consumption of omega-3 fatty acids suppresses inflammation

Major sources of saturated fats:

• Whole milk, cream, butter, cheese, ice cream • Fatty cuts of beef and pork • Coconut, palm, and palm kernel oils (the tropical oils and products containing them such as candies, pastries, pies, doughnuts, and cookies)

recommendation

•Vegetable, fruit and grain- Lowers consumption of various fats in the diet • Solid fats and oils- Fried and baked goods • Choose wisely----More unprocessed foods

• Cancer

•ω3 fatty acids from food • Supplements Promotion rather than initiation of cancer • Dietary fat and cancer risk-----Differs for various types of cancer and combinations of fats as well. The increased risk in cancer from fat appears to be due primarily to saturated fats or dietary fat from meats (which is mostly saturated). Fat from milk or fish has not been implicated in cancer risk.