Food and Nutrition Chapter 6

Which of the following is a lipoprotein?

Chylomicron. HDL LDL

Coronary Calcium

Coronary calcium consists of calcium deposits in the arteries of the heart. Associated with smoking and elevated total cholesterol.

Health Benefits of Alcohol

- Although there may be some benefits to modest alcohol consumption, there are risks with moderate to excessive intake. - Moderate to excessive intake of alcohol is associated with: • Increased risk of addiction • Hypertension • Heart failure • Cancer • Liver cirrhosis • Motor vehicle accidents

Alcohol and Physical Performance • American College of Sports Medicine

- Athletes should learn about alcohol's effects on health. - Avoid excessive alcohol during the 48 hours before an event. - After exercise, and until his or her body recovers its normal fluid status, the athlete should focus on consuming nonalcoholic beverages

What is Arteriosclerosis?

- Condition that results from atherosclerosis - Characterized by loss of arterial flexibility - Commonly referred to as "hardening of the arteries" - Contributes to hypertension What is Hypertension? - Chronic condition characterized by abnormally high blood pressure levels - May cause hardened arteries to tear or burst

Ethanol ("Alcohol")

- Simple 2-carbon compound - In beer, wine, vodka, whiskey, sake, koumiss, and kefir

Dietary fats provide approximately ______ kilocalories per gram.

9

Which of the following statements is TRUE?

A polyunsaturated fatty acid has two or more double bonds between carbons in the hydrocarbon chain.

Alcohol Production

Alcohol production requires: • Microbes (e.g., yeast) • Warm conditions • A source of simple sugar Typical sugar sources for common alcohol-containing beverages are in grains, fruits, potatoes, and milk. • Koumis is made from mare's milk. • Kefir is made from camel's milk

How the Body Processes Alcohol at High Doses

At high doses, the liver's ability to metabolize alcohol using the dehydrogenase pathway is overwhelmed. - Under these conditions, the microsomal ethanol oxidizing system (MEOS) is used. - MEOS wastes energy as the heat produced dissipates into the environment.

Bile

Bile is made in the liver and stored in the gallbladder. Bile contains bile salts that aid in lipid digestion. Without bile, lipids clump together in large fat globules.

Lipids and Health: Cardiovascular Disease (CVD)

CVD: diseases of the heart and blood vessels Most common forms of CVD are: Heart disease ("coronary artery disease") Stroke 1 in 3 adult Americans have some form of CVD. Responsible for ~28% of deaths in the U.S. in 2011

Alcohol and the Cardiovascular System and Cancer

Cardiovascular system: Excess consumption can damage heart muscle and elevate blood pressure. Cancer: Chronic drinkers are more likely to develop cancers of oral cavity, esophagus, stomach, liver, pancreas, breast (women), and colon/rectum.

Phospholipids

Chemically similar to a triglyceride; 1 fatty acid is replaced by a compound that contains phosphorus and, often, nitrogen. • Lecithin - the main phospholipid in foods, such as egg yolks, liver, wheat germ, peanut butter, and soy.

Reducing Your Risk of Atherosclerosis: Dietary Changes

Effects of dietary fat & cholesterol on blood lipids: - Saturated fats increase LDL and HDL. - Trans fats increase LDL but lower HDL. - Monounsaturated fats lower LDL but not HDL. - Polyunsaturated fats lower LDL and lower HDL in some people.

Part of an atherosclerotic plaque that has broken free of an arterial wall is a(n):

Embolus

Recycling Bile Salts

Enterohepatic Circulation: After bile salts are used to aid lipid digestion, the salts are absorbed in the ileum and returned to liver for the production of new bile. Soluble fibers and plant sterols/stanols interfere with bile and cholesterol absorption. This causes the liver to remove cholesterol from the bloodstream for making "new" bile.

Lipids Includes

Fatty acids Triglycerides Phospholipids Cholesterol

Saturation

Fatty acids also vary by saturation. • Saturated - Each carbon atom within the chain holds 2 hydrogen atoms. • Unsaturated - One or more carbon atoms within the chain lacks 2 hydrogen atoms, and as a result, the molecule has 1 or more double bonds.

Fatty Acids

Fatty acids contain a hydrocarbon chain (carbon and hydrogen atoms) with a methyl group (CH3) at one end and an acid group (COOH) at the other. • Fatty acids vary in their number of carbons: • Short chain fatty acids — 2 to 4 carbons • Medium chain fatty acids — 6 to 12 carbons • Long chain fatty acids — 14 to 24 carbons

High-density Lipoproteins (HDL)

HDL is commonly called "good" cholesterol. • Smallest and densest type of lipoprotein • Transports cholesterol away from tissues and to the liver, where it can be eliminated.

Very Low-density Lipoproteins

High levels may contribute to atherosclerosis. • VLDL primarily carries triglycerides. • Excessive alcohol and refined carbohydrate intakes stimulate VLDL production in the liver.

Emulsifiers are

Hydrophobic and hydrophilic

Which is an advantage of using hydrogenated fats in packaged foods?

Increased shelf life.

Low-density Lipoproteins

LDL commonly is called the "bad" cholesterol. • Conveys cholesterol to tissues • May become oxidized LDL and contribute to atherosclerotic plaque

Digested fats are absorbed into _____ surrounding the _____.

Lacteals, Small intestine.

Dietary Recommendations

Limit: - Saturated fats to <10% of total kcal - Trans fats limited to as little as possible Choose unsaturated fats to replace saturated and trans fats.

Assessing Your Risk of Atherosclerosis

Lipid (Lipoprotein) Profile: Blood test that determines total cholesterol, HDL & LDL cholesterol, and triglyceride levels Desirable Cholesterol and Triglyceride Levels: • Total Cholesterol • LDL Cholesterol • HDL Cholesterol • Triglycerides < 200 mg/dl < 100 mg/dl > 60 mg/dl < 150 mg/dl

________ are proteins that transport lipids through the bloodstream.

Lipoproteins

Emulsifiers

Phospholipids act as emulsifiers because they have hydrophobic and hydrophilic regions. - Hydrophobic region: • Attracts lipids and avoids water - Hydrophilic region: • Attracts water and avoids lipids

Hydrogenation

Process that adds hydrogen atoms to liquid vegetable oils Partial hydrogenation: - Not all double bonds are hydrogenated. - Natural cis double bonds convert to the unhealthy trans form.

Major Functions of Lipids in the body

Providing and storing energy (fat) Maintaining cell membranes Producing certain hormones Insulating the body against cold temperatures Cushing the body against bumps and blows Contributing to body contours Absorbing fat - soluble vitamins and phytochemical

What Happens to Lipids in the Body?

The duodenum, or upper small intestine, is the primary site of lipid digestion. In the duodenum, pancreatic lipase digests triglycerides, forming primarily: - Monoglycerides - Free fatty acids

Modifiable risk factors for atherosclerosis include

Tobacco use

Consuming margarines with plant sterols may interfere with cholesterol absorption.

True

What are trans fats

Unsaturated fats with at least 1 trans double bond rather than the more common cis double bond.

Risk factors for developing cardiovascular disease include:

Use of tobacco products. Hypertension. Being male

Trans Fats and Health

Used in many processed foods: - High amounts of trans fats in diet increase heart disease risk by raising blood cholesterol levels. - In 2013 the FDA announced a ban on the addition of trans fats to foods (there will be a gradual phase out of trans fats).

Lips Are:

generally, insoluble in water • less dense than water

The end products of triglyceride digestion include

monoglycerides fatty acids glycerol

Fats that are solid at room temperature have a high proportion of _________________ fatty acids.

saturated

Digestion of fats and lipids begins in the _____, but the primary site for digestion of fats and lipids is _______.

stomach; small intestin (Some lipid breakdown occurs in the stomach, but the primary site for digestion and absorption of lipids is the small intestine. Although the digestive enzyme lipase is present and mixes with the food in the mouth, no digestion of lipids occurs in the mouth because the lipase is inactive until it is activated by the stomach acid.)

Alcohol Dependence and Abuse

• A person who is dependent on alcohol (an alcoholic) has an uncontrollable need to drink; is unable to limit alcohol consumption; suffers withdrawal symptoms; and experiences tolerance. • About 17% of men and 8% of women become dependent on alcohol at some point in their lives.

Using Triglycerides for Energy

• Adipose cells (also known as fat cells) remove fatty acids and glycerol from circulation and reassemble them into triglycerides for storage. • When the body needs energy, adipose cells can break down triglycerides into fatty acid and glycerol molecules before releasing them into bloodstream. • Liver can convert glycerol to glucose— another energy source. • Triglycerides provide 9 kcal/g (carbohydrate & protein provide 4 kcal/g).

Nonmodifiable Risk Factors for Atherosclerosis

• Age - risk increases for men after age 45 and for women after age 55 • Genetics (family history) cannot be modified - Genes may: • code for physical conditions that increase risk of hypertension and diabetes • influence the way circulatory and immune systems respond to diet

Alcohol and the Gastrointestinal Tract

• Alcohol irritates the lining of the GI tract. • It contributes to ulcers of the esophagus and stomach. • Chronic alcoholism contributes to alcoholic pancreatitis.

Alcohol and Body Water

• Alcohol is not a "thirst quencher." • It is a diuretic that suppresses the production of antidiuretic hormone (ADH). - As a result, kidneys excrete more urine, which is mostly water, and certain minerals and vitamins.

Essential Fatty Acids

• Precursors of prostaglandins - Hormone-like substances formed from EPA, DHA, and arachidonic acid • Effects of prostaglandins: - Stimulate uterine contractions - Regulate blood pressure - Promote immune system response

Alcohol and Drug Interactions

• Prescriptions and over-the-counter medications may amplify effects of alcohol. • Alcohol may interact with certain drugs, causing serious side effects.

Alcohol and the Liver

Excessive amounts of alcohol are converted to fatty acids in the liver. Fatty liver - condition is reversible, if the person avoids alcohol. Continued alcohol consumption results in fat buildup in liver. • destroys liver cells and results in scar tissue Liver cirrhosis - irreversible hardening of the liver; can cause liver failure

Bile salts are digestive enzymes.

False

Food Selection and Preparation

Strategies to reduce dietary fat include: • Reduce intake of fried foods. • Purchase lean cuts of meat and trim visible fat. • Replace some fatty foods with reduced-fat or fat-free alternatives. • Replace high-fat sandwich meats with nut butters. • Choose low-fat snack foods. • Use less salad dressing on salads.

Functions of Cholesterol

The body uses cholesterol to make various substances, including: - Vitamin D - Steroid hormones • Estrogen • Testosterone - Bile

Health Benefits of Alcohol

• Light to moderate alcohol intakes: - Raise HDL cholesterol - Reduce blood levels of fibrinogen • Decrease platelet stickiness • Controversy over the health benefits of alcohol: - Benefits of drinking red wine and beer rather than white wine and liquor • Alcohol itself or the antioxidants and certain vitamins in beer and red wines may provide health benefits.

Lipoproteins and Atherosclerosis

• Lipoproteins: - Transport lipids in the blood - Play major role in atherosclerosis development - Carry different types of lipids and can influence plaque formation differently

Effects of Alcohol on Nutritional Status

• Moderate alcohol stimulates appetite. • Excessive alcohol: - displaces intake of nutrient-dense foods - interferes with body's absorption of certain vitamins, minerals, and fat - increases excretion of certain nutrients

Which is an essential lipid?

Omega 3 fatty acid.

Which is an important component of cell membranes?

Phospholipids

Omega-3 and Omega-6 Fatty Acids

Omega-3 Sources: Fatty fish, canola oil, walnuts, and flaxseed (See Table 6.6) Actions: Reduces inflammation, blood clotting, and blood pressure. May reduce risk of heart disease. Omega-6 • Sources: Animal fats and vegetable oils • Actions:Increases inflammation and blood clotting. • May also reduce risk of heart disease.

Lecithin is the major ______ in food, and is found in egg yolks, liver, wheat germ, and peanut butter.

Phospholipid

Which fatty acid has the most hydrogens?

Saturated

Information on food labels includes amounts of:

Trans fat. Monounsaturated fat. Cholesterol

C-reactive Protein

•High-sensitivity C-reactive protein (hs-CRP) Protein produced primarily by liver in response to inflammation •Marker for CVD and hypertension Note: A "marker" is an early physiological warning sign that can be measured in blood.

Fetal Alcohol Spectrum Disorders

• Alcohol is toxic to cells, including embryonic cells. • An infant born with a fetal alcohol spectrum disorder ( FASD ) has some degree of developmental abnormalities as a result of its mother's consumption of alcohol during pregnancy.

How the Body Processes Alcohol

• Alcohol requires no digestion. - Rapidly absorbed in the mouth, esophagus, stomach, and small intestine • Detoxification begins in stomach where alcohol dehydrogenase metabolizes ~20% of alcohol consumed - Most alcohol is absorbed in small intestine. - It travels to the liver, where it is metabolized.

Alcohol and the Brain

• Effects on the CNS appear within a few minutes after consumption. • Acts as a depressant, slowing transmission of messages between nerve cells. • Effectsonthebrainvaryanddependonthe blood alcohol concentration (BAC).

Alcohol and Health

• Effectsvaryfrompersontopersondueto: - Differences in overall health - Drinking habits - Genetic backgrounds • Alcohol affects every cell in the body, and excesses can damage every organ system

Major Functions of Lipids

• Enhance the intestinal absorption of fat-soluble vitamins and phytochemicals • Contribute to rich flavor, smooth texture, and appetizing aroma of foods

Plant Sterols and Stanols

• Plants make small amounts of sterols (plant sterols and stanols) that have chemical structures similar to cholesterol. • Although plant sterols and stanols are not well absorbed by the human intestinal tract, these substances compete with cholesterol for absorption. • This competition reduces the amount of cholesterol that is absorbed, which may help lower elevated cholesterol levels.

Factors that Influence Alcohol Metabolism

• Sex Men typically have • more gastric alcohol dehydrogenase • larger livers that can metabolize more alcohol at a time • more water in their bodies As a result, a man's blood alcohol concentration (BAC) rises more slowly than a woman's. • Prior Drinking History Regular drinkers develop tolerance - Level of alcohol-detoxifying liver enzymes increase. As tolerance increases, alcohol dependence (alcoholism) is more likely to occur.

Modifiable Risk Factors for Atheroscierosis

• Smoking • Hypertension* • Diabetes* • Excessbodyfat* • Elevated blood cholesterol (LDL)* • Physical inactivity *Influenced by diet