CARBOHYDRATESCARBOHYDRATES

Learning Objectives:Learning Objectives:• Understand the different classes of Understand the different classes of

carbohydratescarbohydrates• Understand the digestion and Understand the digestion and

absorption of carbohydrates absorption of carbohydrates • Learn about the function of Learn about the function of

carbohydrates in the diet, and how they carbohydrates in the diet, and how they relate to health issuesrelate to health issues

WHAT ARE THE WHAT ARE THE CARBOHYDRATES?CARBOHYDRATES?

• Organic compounds that contain Organic compounds that contain CARBON, HYDROGEN, and OXYGEN CARBON, HYDROGEN, and OXYGEN in the ratio of 1 carbon atom and 1 oxygen in the ratio of 1 carbon atom and 1 oxygen atom for every 2 hydrogen atomsatom for every 2 hydrogen atoms

• Two Main Classes:Two Main Classes:• SIMPLE (sugars)SIMPLE (sugars)• COMPLEX (starches and fiber)COMPLEX (starches and fiber)

SIMPLE SUGARSSIMPLE SUGARS

• MONOSACCHARIDESMONOSACCHARIDES

• Glucose (or Dextrose)Glucose (or Dextrose)• GalactoseGalactose• FructoseFructose

SIMPLE SUGARSSIMPLE SUGARS

• DISACCHARIDESDISACCHARIDES

• Sucrose Sucrose (glucose+fructose)(glucose+fructose)

• Lactose Lactose (glucose+galactose)(glucose+galactose)

• Maltose Maltose (glucose+glucose)(glucose+glucose)

COMPLEX COMPLEX CARBOHYDRATESCARBOHYDRATES

POLYSACCHARIDESPOLYSACCHARIDES• Starch - long chains of glucose Starch - long chains of glucose

molecules in straight (AMYLOSE) or molecules in straight (AMYLOSE) or branching (AMYLOPECTIN) branching (AMYLOPECTIN) arrangementarrangement

• Figure 4-8, page 106Figure 4-8, page 106

COMPLEX CARBOHYDRATESCOMPLEX CARBOHYDRATES

POLYSACCHARIDESPOLYSACCHARIDES• Glycogen – animal form of starch Glycogen – animal form of starch

(highly branched and composed of (highly branched and composed of multiple glucose molecules)multiple glucose molecules)

COMPLEX COMPLEX CARBOHYDRATESCARBOHYDRATES

• FIBER – resembles starch, but cannot FIBER – resembles starch, but cannot be digested be digested

TYPES:TYPES:• CelluloseCellulose• HemicelluloseHemicellulose• PectinPectin• Gums and MucilagesGums and Mucilages• Lignans Lignans (is fiber, but not a polysaccharide)(is fiber, but not a polysaccharide)

CLASSIFICATION of FIBERCLASSIFICATION of FIBER

• SOLUBLE – dissolve in waterSOLUBLE – dissolve in water• INSOLUBLE – cannot dissolve in INSOLUBLE – cannot dissolve in

waterwater• Table 4-3, page 123Table 4-3, page 123

• Daily recommendations?Daily recommendations?

B = B = 1 cup orange juice1 cup orange juice2 scrambled eggs2 scrambled eggs1 slice white toast1 slice white toast

L =L = 1 cup chicken noodle soup1 cup chicken noodle soup1 cup iceburg lettuce 1 cup iceburg lettuce 1 Tbsp blue cheese dressing 1 Tbsp blue cheese dressing

D = D = 1 pork chop1 pork chop1 cup white rice1 cup white rice½ cup canned corn½ cup canned corn1 baked potato (no skin)1 baked potato (no skin)1 danish1 danish

S = S = 1 oz. cheddar1 oz. cheddar4 saltine crackers4 saltine crackers

• MOUTH - amylaseMOUTH - amylase• STOMACHSTOMACH• SMALL INTESTINE – pancreatic amylase, SMALL INTESTINE – pancreatic amylase,

disaccharidases, maltase, sucrase, lactasedisaccharidases, maltase, sucrase, lactase

DIGESTIONDIGESTION

• all three travel to the all three travel to the liver through the portal liver through the portal vein; galactose and vein; galactose and fructose are converted fructose are converted to glucose to glucose

CARBOHYDRATES in the CARBOHYDRATES in the BODYBODY

USE OF GLUCOSEUSE OF GLUCOSE• Energy – glucose is the primary fuel for most cells Energy – glucose is the primary fuel for most cells

in the body. The brain MUST have glucose!in the body. The brain MUST have glucose!• Sparing body protein – if glucose is scarce, the Sparing body protein – if glucose is scarce, the

body will breakdown its own protein.body will breakdown its own protein.• Preventing ketosis – with no carbohydrate, fat Preventing ketosis – with no carbohydrate, fat

breakdown produces ketone bodies. Can lead to breakdown produces ketone bodies. Can lead to ketosis.ketosis.

• Storage as glycogen – liver stores are used to Storage as glycogen – liver stores are used to maintain blood sugar, while muscle stores are used maintain blood sugar, while muscle stores are used to fuel activity. to fuel activity.

REGULATING BLOOD REGULATING BLOOD GLUCOSE LEVELSGLUCOSE LEVELS

• Insulin – lowers blood glucoseInsulin – lowers blood glucose• Glucagon – raises blood glucoseGlucagon – raises blood glucose• Epinephrine – “fight-or-flight” Epinephrine – “fight-or-flight”

hormonehormone

GLYCEMIC INDEXGLYCEMIC INDEX

• Classifies food or meals based upon their potential Classifies food or meals based upon their potential to raise blood glucose levelsto raise blood glucose levels

• Expressed as a percentage of the response to a Expressed as a percentage of the response to a standard carbohydrate, usually white bread or pure standard carbohydrate, usually white bread or pure glucoseglucose

• Useful? – decreased risk of NIDDM, heart Useful? – decreased risk of NIDDM, heart disease, and colon cancerdisease, and colon cancer

• Useless? – complex, research may not support itUseless? – complex, research may not support it

• page 116page 116

HIGH BLOOD SUGAR - HIGH BLOOD SUGAR - DiabetesDiabetes

• Type I – Insulin Dependent Diabetes Type I – Insulin Dependent Diabetes Mellitus (IDDM) or Juvenile OnsetMellitus (IDDM) or Juvenile Onset

• Type II – Non Insulin Dependent Type II – Non Insulin Dependent Diabetes Mellitus (NIDDM) or Adult Diabetes Mellitus (NIDDM) or Adult OnsetOnset

HIGH BLOOD SUGAR - HIGH BLOOD SUGAR - DiabetesDiabetes

RISK FACTORSRISK FACTORS• Type I – geneticsType I – genetics• Type II – genetics, >45 years old, Type II – genetics, >45 years old,

overweight, sedentary, low HDL or overweight, sedentary, low HDL or high triglycerides, certain racial or high triglycerides, certain racial or ethnic groups, gestational diabetesethnic groups, gestational diabetes

Page 639Page 639

HIGH BLOOD SUGAR - HIGH BLOOD SUGAR - Diabetes Diabetes

CONSEQUENCESCONSEQUENCES• Peripheral vascular diseasePeripheral vascular disease• Deterioration of the eyeDeterioration of the eye• Kidney diseaseKidney disease• Progressive nerve damageProgressive nerve damage• Heart diseaseHeart disease

CARBOHYDRATES in the CARBOHYDRATES in the DIETDIET

• RecommendationsRecommendations• Current consumptionCurrent consumption• Increasing complex carbohydrateIncreasing complex carbohydrate• Moderating sugar intakeModerating sugar intake

CARBOHYDRATES and CARBOHYDRATES and HEALTH - SugarHEALTH - Sugar

• Sugar and nutrient intake: empty Sugar and nutrient intake: empty caloriescalories

• Sugar and dental caries: ex. baby-Sugar and dental caries: ex. baby-bottle tooth decaybottle tooth decay

Sugar SubstitutesSugar Substitutes

Saccharine (Sweet & Low)Saccharine (Sweet & Low) 0 kcals/g0 kcals/g Sucralose (Splenda)Sucralose (Splenda) 0 kcals/g0 kcals/g Aspartame (Nutrasweet)Aspartame (Nutrasweet) 4 kcals/g4 kcals/g

Sugar ReplacersSugar Replacers

IsomaltIsomalt 2.0 kcal/g2.0 kcal/gLactitolLactitol 2.0 kcal/g2.0 kcal/gMaltitolMaltitol 2.1 kcal/g2.1 kcal/gMannitolMannitol 1.6 kcal/g1.6 kcal/gSorbitolSorbitol 2.6 kcal/g2.6 kcal/g

““Sugar-Free” does not necessarily mean free of Sugar-Free” does not necessarily mean free of calories!calories!

High Fructose Corn Syrup?High Fructose Corn Syrup? Produced by milling corn to produce corn Produced by milling corn to produce corn

starch, then processing that corn starch to starch, then processing that corn starch to yield corn syrup (almost entirely glucose), yield corn syrup (almost entirely glucose), and then adding enzymes which change the and then adding enzymes which change the glucose into fructoseglucose into fructose

Are all sugars the same? Page 118Are all sugars the same? Page 118

CARBOHYDRATES and CARBOHYDRATES and HEALTH – Complex HEALTH – Complex

CarbohydratesCarbohydrates

A diet rich in complex carbohydrates lowers A diet rich in complex carbohydrates lowers the risk of:the risk of:

• ObesityObesity• Type II DiabetesType II Diabetes• CancerCancer• Cardiovascular DiseaseCardiovascular Disease• Gastrointestinal DisordersGastrointestinal Disorders

Compared to Whole Wheat, White Compared to Whole Wheat, White Bread is Missing:Bread is Missing:

96% of Vitamin E96% of Vitamin E 78% of Fiber78% of Fiber 72% of Magnesium72% of Magnesium 62% of Zinc62% of Zinc 78% of Vitamin B678% of Vitamin B6 Plus PhytochemicalsPlus Phytochemicals

How Does Soluble Fiber Reduce Cholesterol?How Does Soluble Fiber Reduce Cholesterol?

Two Ways…Two Ways…

Enterohepatic Circulation of Bile (page 149 Enterohepatic Circulation of Bile (page 149 “Bile’s Routes”)“Bile’s Routes”)

Bacterial by-products of fiber fermentation Bacterial by-products of fiber fermentation in the large intestine inhibit cholesterol in the large intestine inhibit cholesterol synthesis in the liver synthesis in the liver

Fiber SupplementsFiber Supplements

Benefits?Benefits? Risks?Risks?