Lecture 4 HLTH 120 N Carbohydrates Objectives Differentiate
Lecture 4 HLTH 120 N Carbohydrates
Objectives • Differentiate between simple and complex carbohydrates • Know the simple and complex sugars and their respective enzymes • Differentiate between soluble & insoluble fiber; know fiber requirements • Identify which hormones are present with high or low blood sugar • Understand ketosis and how to prevent it • Know differences between Type I and II diabetes • Form an opinion on artificial sweeteners
What are Carbohydrates? • Made of 3 atoms: • In food, comes from _____ • Main energy source for ______ • Most abundant form is ______
Why do we need carbohydrates? Daily activity The brain Red blood cells To spare protein
What is simple? What’s Complex? • • • Green peas Potato Pear Whole-grain bread Raspberries 100% fruit snacks Gushers fruit snacks Black beans Sweet potato Cocoa Puffs cereal • • • Angel hair pasta Fiber One cereal Banana Broccoli Chickpeas Rice Popcorn Cranberry juice Oatmeal Corn
Simple Carbohydrate Sugars
Monosaccharides • Glucose – most abundant & preferred by brain • Fructose – Fruit sugar w/ sweetest taste – Processed additive: • Galactose – Does not occur alone • Ribose – Very little in foods – In genetic material
Disaccharides • Lactose – Glucose + Galactose • Maltose – Glucose + Glucose – Result of fermentation • Sucrose – Glucose + Fructose • honey, syrup, refined into sugar
Disaccharides are attached by a bond in nature • β- bond • α- bond
Complex Carbohydrates • Oligosaccharides 3 -10 linked mono-saccharides • Polysaccharides 100’s or 1, 000’s of glucose’s linked
Oligosaccharides • Raffinose – Beans, cabbage, sprouts, broccoli, whole grains • Stachyose – Beans, legumes • No enzyme! • Pass into large intestine undigested
Polysaccharides - Starch • Digestion – broken into many glucose molecules • Amylose: straight chain • Amylopectin: highly branched • Resistance starches – Linked by β- bond – Ferment into butyrate
Polysaccharide - Fiber • Gives plants structure • Dietary fiber: non-digestible plant material • Functional fiber: Added to foods or making up fiber supplements • Cellulose, psyllium, guar gum, pectin, etc.
Soluble Fiber • Forms a gel when wet • Fermentable • Helps CVD & Type 2 Diabetes • Found in: • Pectins, gums, mucilages – Thickeners, stabilizers, gelling agents
Insoluble Fiber • Does not dissolve in water • Non-viscous & not fermented • Found in: • Promote regular bowel movements – constipation & risk of diverticulosis • Lignins, cellulose, hemicellulose
Carbohydrate Digestion
Carbohydrate Digestion • Mouth – Chewing – Salivary amylase breaks polysaccharides • Stomach – no carb digestion! • Small Intestine – Disaccharides Monosaccharides • With maltase, sucrase, lactase
Carbohydrate absorption • Active Transport – Glucose – Galactose • Facilitated Diffusion – Fructose – Stays in S. I. longer, brings water in • Blood sugar rises ____
Carbohydrate transport to liver • First, Fructose & Galactose glucose • If needed, released to blood for ____ • If not, stored as _____ in the liver & muscle – Liver ~70 g, muscle ~120 g – What about athletes?
The fate of fiber • Fiber moves into the _________ • Here, bacteria ferment certain fibers – Products are gas and fat! – Short Chain Fatty Acids are produced • Used by large intestine’s cells for energy
Lactose Intolerance • Insufficent lactase is produced • Symptoms: • Some born with an intolerance • _____ of the world’s population will develop • Glucose & Hydrogen tests
Hormones - Glucose Regulation • Insulin – Present when blood glucose is ______ – Activates cell transporters • Glucagon – Present when blood glucose is ______ – Stimulates conversion of glycogen to glucose – gluconeogenesis
• Epinephrine/Norepinephrine – Active with blood glucose – glycogen breakdown & gluconeogenesis – Fight/flight reaction needs energy! • Cortisol – When blood glucose is. – gluconeogenesis & use of glucose • Growth Hormone – When blood glucose is – glucose uptake & FA use .
What increases the likelihood of these conditions? • Renal disease • Blindness • Low Circulation • Amputation of extremeties • Seizures • Stroke • Heart Disease • Ketoacidosis
What is Diabetes? • 11 % of Americans have been diagnosed with Type II (formerly called adult onset) – 35% are pre-diabetic – Up to 5. 7 million cases are undiagnosed
Type I • The body cannot produce enough insulin – Excess glucose _________ – Confusion, lethargy, & breathing problems • Why? • Average diagnosis age: 10 -14 – Infants & adults less common • Genetic Link – Autoimmune? • Blood glucose monitored & insulin injected
Type II • Body’s cells are resistant to insulin – Pancreas secretes increased amounts to deal with ___________ – Result is impaired fasting glucose – Pancreas becomes incapable of secreting insulin – Blood Glucose is dangerously high • Insulin insensitivity • Pancreas is not producing
Type II - causes • Most common cause: ______ 80 -90% of diabetics • Genetics • Poor diet • Inactivity
Type II - treatment • Lose weight – 5 -10% of body weight • Controlling carbohydrate intake – Avoid alcohol, which causes _________ • Regular exercise most effective • Oral medications – Increase insulin sensitivity – Decrease glucose production by liver • Insulin injections
Hypoglycemia • Fasting blood glucose is ______ • May be excessive _____ production • If diabetics inject too much insulin • 1 -4 hours post meal – Shakiness, nervousness, anxiety, sweating, headaches, weakness, irregular heartbeat • Treatment -
Low Carb & Ketoacidosis • Ketosis: the breakdown of _____ to produce ketones • Ketones suppress appetite, cause dehydration and acetone breath • Excessive ketone production = ketoacidosis – We need ____ g/day of carbohydrate to prevent – What happens with too much acid in the body?
Health Benefits of Complex Carbs • Nutrients – vitamins & minerals • Fiber – Likely reduces the risk of colon cancer – Prevents hemorrhoids, constipation, and other intestinal problems – Reduces the risk of diverticulosis – Reduces the risk of heart disease – May enhance weight loss – May lower the risk of type 2 diabetes
What should we eat? • Carbohydrates should be high in fiber, whole grain, and unprocessed • Most Americans eat too many simple • Diets high in simple sugars – Can cause tooth decay – May impact cholesterol – Contribute to obesity and diabetes • Added sugar intake should be <150 calories/day for adult men and <100 calories/day for adult women – Per the American Heart Association (AHA)
• Most American eat too little complex carbs – Average 2 servings total of fruits and vegetables • Refined grains – Stripped of fiber Some are enriched • Lost nutrients added back Others are fortified • New nutrients added
How much fiber? • 14 g for every 1, 000 calories • 50 g/day or more may be too much • Sources: “whole grain”– not just “wheat” Fresh fruits/veggies… or frozen! Legumes – peas, beans, lentils Canned?
Sweeteners • Nutritive Sweeteners – Honey, sugar, fructose – Sugar alcohols • Non-nutritive Sweeteners – ADI: ___________ – Amount a person can consume per day for a lifetime without adverse effects
Saccharin • Sweet n’ low • 300 x sweeter than sucrose • Causes bladder cancer in rats – 20 years of research on humans • National Toxicology Program removed it from the list of products that may cause cancer • No ADI is set
Aspartame • Equal and Nutrasweet • Phenylalanine + aspartic acid • 200 x sweeter than sucrose • ADI: 50 mg/kg/day – Kids may exceed on poor diet • Who cannot consume it? • Common side effects:
Sucralose • aka Splenda • Cl atoms replace H and O on sucrose • 600 x sweeter and can be heated • ADI 5 mg/kd/day – 340 mg for 150 lb person – 1 packet has 12 mg
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