Chap2 carbohydrates

Carbohydrates in Nutrition;

Sweeteners; Diabetes Mellitus; Lactose

IntoleranceChapter 2Chapter 2

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Carbohydrates• The most abundant organic molecules in nature.The most abundant organic molecules in nature.• Are organic compounds of the elements carbon, Are organic compounds of the elements carbon,

hydrogen, and oxygen.hydrogen, and oxygen.• They provide a significant fraction of energy, They provide a significant fraction of energy,

storage energy and some intercellular storage energy and some intercellular communication.communication.

• the principal sources of energy in the diet, also the principal sources of energy in the diet, also act as starting materials for the synthesis of fatty act as starting materials for the synthesis of fatty acids and amino acids.acids and amino acids.

• Play a role in the structure of other biologically Play a role in the structure of other biologically important materials, such as glycolipids, important materials, such as glycolipids, glycoprotein, nucleic acids and heparin.glycoprotein, nucleic acids and heparin.

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Carbohydrates• The simplest and The simplest and

classified according to classified according to the number of carbon the number of carbon atoms in the chainatoms in the chain

• Most common are Most common are pentoses (five-carbon pentoses (five-carbon monosaccharides) monosaccharides) and the hexoses (six-and the hexoses (six-carbon carbon monosaccharides.monosaccharides.

• MonosaccharideMonosaccharidess

• DisaccharideDisaccharidess

• PolysaccharidesPolysaccharides

ClassificationClassification

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Pentoses (Five-Carbon Sugars)

• Are synthesized by the body, which are Are synthesized by the body, which are components of nucleic acids and components of nucleic acids and nucleotides, which acts as coenzymes in nucleotides, which acts as coenzymes in energy production.energy production.

• Two pentoses are of vital importance: Two pentoses are of vital importance: ribose and deoxyribose.ribose and deoxyribose.

• The pentose sugars most commonly The pentose sugars most commonly present in human foods are l-arabinose present in human foods are l-arabinose and D-xylose, which are widely distributed and D-xylose, which are widely distributed in nuts, fruits, and root vegetables.in nuts, fruits, and root vegetables.

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Hexoses (Six-Carbon Sugars)

• Also called dextrose, Also called dextrose, grape sugar and corn grape sugar and corn sugarsugar

• A white crystalline solid A white crystalline solid that is soluble in water that is soluble in water and is about half as sweet and is about half as sweet as sucrose (table sugar)as sucrose (table sugar)

• Is the form of Is the form of carbohydrate that the carbohydrate that the body tissue can best usebody tissue can best use

• It is oxidized in the cells It is oxidized in the cells for energy and the only for energy and the only fuel for the brainfuel for the brain

• The major food sources The major food sources are honey, fruits and corn are honey, fruits and corn syrup.syrup.

• GlucoseGlucose

• FructoseFructose

• GalactoseGalactose

TypesTypes

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Hexoses (Six-Carbon Sugars)

• Also called levulose or Also called levulose or fruit sugarfruit sugar

• Is structurally related Is structurally related to glucoseto glucose

• The sweetest of all The sweetest of all the sugars and is the sugars and is found along with found along with glucose in honey, glucose in honey, fruits and corn syrupfruits and corn syrup

• It is a constituent of It is a constituent of common table sugarcommon table sugar

• GlucoseGlucose

• FructoseFructose

• GalactoseGalactose

TypesTypes

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Hexoses (Six-Carbon Sugars

• Derived from the Derived from the hydrolysis of lactose, hydrolysis of lactose, the sugar found in the sugar found in milk and is a milk and is a constituent of many constituent of many plant polysaccharidesplant polysaccharides

• During lactation, the During lactation, the human body converts human body converts glucose to galactose in glucose to galactose in the mammary tissue the mammary tissue for the synthesis of for the synthesis of lactose in breast milklactose in breast milk

• GlucoseGlucose

• Fructose Fructose

• GalactoseGalactose

TypesTypes

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Carbohydrates• Are two joined Are two joined

monosaccharides and the monosaccharides and the simplest polysaccharidessimplest polysaccharides

• Composed of two Composed of two monosaccharides units monosaccharides units bound together by a bound together by a covalent bond known as a covalent bond known as a glycosidic linkage formed glycosidic linkage formed via a dehydration via a dehydration reaction, resulting in the reaction, resulting in the loss of hydrogen atom loss of hydrogen atom from one monosaccharide from one monosaccharide and a hydroxyl group from and a hydroxyl group from the otherthe other

• MonosaccharideMonosaccharidess

• DisaccharideDisaccharides s

• Polysaccharides Polysaccharides

ClassificationClassification

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Disaccharides• A disaccharide that is A disaccharide that is

readily hydrolyzed into readily hydrolyzed into glucose and fructose by glucose and fructose by boiling with acids or by the boiling with acids or by the action of certain enzymes action of certain enzymes (invertase) forming “invert (invertase) forming “invert sugar”sugar”

• Available as a refined Available as a refined carbohydrate in such form carbohydrate in such form as granulated, powdered, as granulated, powdered, brown and raw sugar.brown and raw sugar.

• Extensively used as a Extensively used as a sweetener in food sweetener in food preservation, in food preservation, in food processing, and in pill- or processing, and in pill- or tablet-making for tablet-making for pharmaceutical pharmaceutical preparationspreparations

• SucroseSucrose

• LactoseLactose

• MaltoseMaltose

TypesTypes

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Disaccharides• Or milk sugar, unique Or milk sugar, unique

to mammals and found to mammals and found in mammary glandsin mammary glands

• Makes up almost 40% Makes up almost 40% of the solids in fresh of the solids in fresh whole milkwhole milk

• A by product in the A by product in the manufacture of cheesemanufacture of cheese

• On hydrolysis with On hydrolysis with acids or enzymes acids or enzymes (galactase), lactose (galactase), lactose yields glucose and yields glucose and galactosegalactose

• SucroseSucrose

• LactoseLactose

• MaltoseMaltose

TypesTypes

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Disaccharides• Also known as malt Also known as malt

sugarsugar

• Formed by uniting two Formed by uniting two units of glucose that units of glucose that provide the first link in a provide the first link in a process that eventually process that eventually results in the creation of results in the creation of starchstarch

• An important component An important component in the process of in the process of creating fermented creating fermented barley that in turn can barley that in turn can be used to brew beerbe used to brew beer

• SucroseSucrose

• Lactose Lactose

• MaltoseMaltose

TypesTypes

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Carbohydrates• Are complex Are complex

carbohydrates made up of carbohydrates made up of many (more than 10) many (more than 10) monosaccharides linked monosaccharides linked togethertogether

• They are tasteless and They are tasteless and molecular weight ranges molecular weight ranges from 20,000 to 1,000,000from 20,000 to 1,000,000

• Some are used for storing Some are used for storing energy (starch, glycogen, energy (starch, glycogen, dextran and insulin) and dextran and insulin) and others have strutural others have strutural functions (cellulose, functions (cellulose, pectin, agar and pectin, agar and carrageen)carrageen)

• MonosaccharideMonosaccharidess

• DisaccharideDisaccharidess

• PolysaccharidesPolysaccharides

ClassificationClassificationss

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Polysaccharides• The most important The most important

carbohydrate, providing carbohydrate, providing about 50% of the total about 50% of the total carbohydrate intakecarbohydrate intake

• It is a major source of It is a major source of energy and provides energy and provides texture and consistency to texture and consistency to many food preparationsmany food preparations

• Rice, wheat, sorghum, Rice, wheat, sorghum, corn, millet and rye corn, millet and rye contain about 70% starch contain about 70% starch and are outstanding and are outstanding sources of carbohydratesources of carbohydrate

• StarchStarch

• GlycogenGlycogen

• DextransDextrans

For Storing For Storing EnergEnergyy

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Polysaccharides• The animal equivalent of The animal equivalent of

starch and provides a starch and provides a food storage system for food storage system for all forms of animal life.all forms of animal life.

• Found in highest Found in highest concentration in the concentration in the liver, where it serves as liver, where it serves as an important regulator an important regulator of blood glucose of blood glucose concentrationconcentration

• Also stored in muscles, Also stored in muscles, where it serves as where it serves as energy source for energy source for muscle contractionmuscle contraction

• StarchStarch

• GlycogenGlycogen

• DextransDextrans

For Storing EnergFor Storing Energyy

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Polysaccharides• A complex, branched A complex, branched

glucan (polysaccharide glucan (polysaccharide made of many glucose made of many glucose molecules) composed molecules) composed of chains of varying of chains of varying lengthslengths

• Form the substrate for Form the substrate for dental plaque and serve dental plaque and serve as the energy source as the energy source for potentially dental for potentially dental caries – producing caries – producing bacteria such as bacteria such as Streptococcus mutans Streptococcus mutans

• StarchStarch

• Glycogen Glycogen

• DextransDextrans

For Storing For Storing EnergyEnergy

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Polysaccharides• Provides the Provides the

fibrous framework fibrous framework for the plantfor the plant

• A good source for A good source for fiberfiber

• Aids in the Aids in the production of soft production of soft stools, in stools, in peristalsis, and in peristalsis, and in the elimination of the elimination of waterwater

• CelluloseCellulose

• Pectin Pectin

• AgarAgar

For Structural For Structural FunctionsFunctions

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Polysaccharides• A polysaccharides that A polysaccharides that

acts as a cementing acts as a cementing material in the cell walls of material in the cell walls of plant tissuesplant tissues

• Found in small quantities Found in small quantities in many fruits, young in many fruits, young green plants, and root green plants, and root vegetablesvegetables

• In the presence of sugars In the presence of sugars and a warm, slightly acid and a warm, slightly acid solution, pectin turns into solution, pectin turns into jelly.jelly.

• This property is This property is responsible for the setting responsible for the setting of jams and fruit preservesof jams and fruit preserves

• Cellulose Cellulose

• Pectin Pectin

• Agar Agar

For Structural For Structural

FunctionsFunctions

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Polysaccharides• Is extracted from Is extracted from

seaweeds and is used seaweeds and is used in many foods as a in many foods as a gelling agentsgelling agents

• Is used as a food Is used as a food additive to improve additive to improve the texture and the texture and consistency of such consistency of such foods as ice creamfoods as ice cream

• CelluloseCellulose

• Pectin Pectin

• AgarAgar

For Structural For Structural FunctionsFunctions

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Sugars• The refined granulated product used The refined granulated product used

for table-top purposes.for table-top purposes.• Three types of sugar mixtures for Three types of sugar mixtures for

commercial use: commercial use: Blended sugar (50% sucrose & 50% Blended sugar (50% sucrose & 50%

glucose)glucose) Pure invert sugar (50% glucose & 50% Pure invert sugar (50% glucose & 50%

fructose)fructose) Common invert sugar (50% sucrose, 25% Common invert sugar (50% sucrose, 25%

glucose & 25% fructoseglucose & 25% fructose

Why Do We Use Sugar?

•Sweet tasteSweet taste The desire The desire

for sweet for sweet taste taste increases increases with age in with age in many peoplemany people

Why Do We Use Sugar?• Preserve jams Preserve jams

and jelliesand jellies

• Volume and Volume and texture in baked texture in baked goods and goods and ice-creamice-cream

• Fermentation in Fermentation in breads breads

Types of Sweeteners

•Nutritive sweetenersNutritive sweeteners Contain caloriesContain calories

•Nonnutritive sweeteners Nonnutritive sweeteners (high intensity sweetener)(high intensity sweetener) Contain little or no caloriesContain little or no calories

Nutritive SweetenersSugars:Sugars:• GlucoseGlucose

• SucroseSucrose

• FructoseFructose

• LactoseLactose

• MaltoseMaltose

• HoneyHoney

• Corn syrupCorn syrup

• High fructose corn High fructose corn syrupsyrup

• Brown sugarBrown sugar

• All are equivalent in calories: about 4 calories per gram or about 16 calories per teaspoon

Nutritive Sweeteners

• SorbitolSorbitol

• MannitolMannitol

• MaltitolMaltitol

• ErythritolErythritol

• XylitolXylitol

• LactitolLactitol

• IsomaltIsomalt

• Hydrogenated Hydrogenated starch starch hydrolysates hydrolysates (combination of (combination of polyols)polyols)

Sugar alcohols or polyols

Sugar alcohols/Polyols

•Used in many “sugar-free,” Used in many “sugar-free,” “low-carb,” and reduced “low-carb,” and reduced calorie productscalorie products gum, candy, desserts, ice-gum, candy, desserts, ice-

cream, cough drops and syrup cream, cough drops and syrup

•Absorbed more slowly than Absorbed more slowly than “sugar”“sugar”

Sugar Alcohols/Polyols

AdvantagesAdvantages• Do not promote Do not promote

tooth decaytooth decay• May have less effect May have less effect

on blood sugar in on blood sugar in people with diabetespeople with diabetes

• Most have fewer Most have fewer calories than sugar calories than sugar (about 2 calories per (about 2 calories per gram compared to gram compared to 4)4)

DisadvantagesDisadvantages• May have May have

laxative effect laxative effect (gas, bloating, (gas, bloating, diarrhea)diarrhea)

• May be in foods May be in foods that are not that that are not that low in calories or low in calories or fatfat

High-Intensity Sweeteners

AdvantagesAdvantages• Little or no Little or no

caloriescalories

• No effect on No effect on blood sugar in blood sugar in diabetesdiabetes

DisadvantagesDisadvantages• Some have Some have

unpleasant unpleasant aftertasteaftertaste

• Cannot replace Cannot replace sugar entirely in sugar entirely in baked productsbaked products

Read the Label!• Foods with high Foods with high

intensity intensity sweeteners may be sweeteners may be combined with combined with other ingredientsother ingredients

• Check the Nutrition Check the Nutrition Facts label for Facts label for calories, calories, carbohydrate, and carbohydrate, and fatfat

Nonnutritive Sweeteners (high-intensity)

• Acesulfame Acesulfame potassium potassium Sunette, Sweet-Sunette, Sweet-

OneOne• Aspartame Aspartame

Equal, Equal, NutraSweetNutraSweet

• NeotameNeotame

• SaccharinSaccharin Sweet ‘n Low, Sweet ‘n Low,

etcetc

• SucraloseSucralose SplendaSplenda

Approved by Food and Drug Administration (FDA):

When Can You Use a High-Intensity Sweetener?

• BeveragesBeverages• Cooking and baking Cooking and baking

when sugar is not when sugar is not needed for volume, needed for volume, texture, structuretexture, structure

Fruit cobblers Fruit cobblers and piesand pies

SaucesSauces PuddingsPuddings

What Foods Work Better With Sugar?

•CakesCakes

•CookiesCookies

•Yeast breadsYeast breads

Sugar’s Role in Baked Goods

Sugar provides to baked Sugar provides to baked goods:goods:

• browningbrowning

• tendernesstenderness

• structurestructure

• volume volume

• texturetexture

Why Reduce Sugar Intake?

• Contains calories, Contains calories, but no nutritional but no nutritional valuevalue

• Medical conditions:Medical conditions: Overweight/Overweight/

obesityobesity DiabetesDiabetes High High

triglyceridestriglycerides

How Can You Cut Back on Sugar?• Reduce added sugar by up to Reduce added sugar by up to

½½

• Replace some or all of the Replace some or all of the sugar with a high-intensity sugar with a high-intensity sweetenersweetener

Check guidelines for Check guidelines for specific sweeteners specific sweeteners for use in recipesfor use in recipes

• Use canned fruit packed in Use canned fruit packed in juicejuice

How Can You Cut Back on Sugar?

• Replace high-sugar Replace high-sugar beverages with sugar-beverages with sugar-free beveragesfree beverages

Size Size CaloriesCalories

Super-size Super-size 410410

Large Large 320320

MediumMedium 220220

Points to Remember• High-sugar foods and beverages are High-sugar foods and beverages are

usually high in calories and low in usually high in calories and low in nutritional valuenutritional value

• Cut back on sugar by using less added Cut back on sugar by using less added sugar or substituting high-intensity sugar or substituting high-intensity sweetenerssweeteners

• Many “sugar-free” foods are not “calorie-Many “sugar-free” foods are not “calorie-free”free”

• Baked products often require some sugar Baked products often require some sugar for acceptable qualityfor acceptable quality

Diabetes Mellitus

•This is a disorder of carbohydrate metabolism in which the ability to oxidize and utilize carbohydrates is lost as a result of disturbances in the normal mechanism

The disorder is characterized by:

• Elevated blood sugar (hyperglycemia) Polyuria-excessive urination Polydipsia-increased thirst Polyphagia-increased appetite

• Involuntary weight loss• Visual disturbances

(retinopathy/osmotic lens shape changes)

• Candidal pharyngitis/vaginitis• Acute ketotic illness

Diabetes Mellitus : a group of diseases characterized by high levels of blood glucose resulting

from defects in insulin production, insulin action, or both

• 20.8 million in US ( 7% of population)20.8 million in US ( 7% of population)

• estimated 14.6 million diagnosed (only 2/3)estimated 14.6 million diagnosed (only 2/3)

• Consists of 3 types:Consists of 3 types:

1) Type 1 diabetes1) Type 1 diabetes

2) Type 2 diabetes2) Type 2 diabetes

3) Gestational diabetes3) Gestational diabetes

Complications :- Stroke- Heart attack- Kidney disease- Eye Disease- Nerve Damage

Diabetes Mellitus• Type 1 DiabetesType 1 Diabetes

- cells that produce insulin are - cells that produce insulin are destroyed destroyed

- results in insulin dependence- results in insulin dependence

- commonly detected before 30- commonly detected before 30

• Type 2 DiabetesType 2 Diabetes

- blood glucose levels rise - blood glucose levels rise due to due to

1) Lack of insulin 1) Lack of insulin productionproduction

2) Insufficient 2) Insufficient insulin insulin action (resistant action (resistant cells)cells)

- commonly detected after - commonly detected after 4040

- effects > 90%- effects > 90%

- eventually leads to - eventually leads to ββ-cell -cell failure failure (resulting in insulin dependence)(resulting in insulin dependence)

Gestational Diabetes 3-5% of pregnant women in the US develop gestational diabetes

Testing :

Fasting Plasma Glucose Test

(FPG) - (cheap, fast)

*fasting B.G.L. 100-125 mg/dl signals pre-diabetes

*>126 mg/dl signals diabetes

Oral Glucose Tolerance Test

(OGTT)

*tested for 2 hrs after glucose-

rich drink

*140-199 mg/dl signals pre-

diabetes

*>200 mg/dl signals diabetes

80 to 90 mg per 100 ml, is the normal fasting blood glucose concentration in humans and most mammals which is associated with very low levels of insulin secretion.

A.K.A.: Glycated Hemoglobin tests A1C

Management of DM

•Diet

•Oral Hypoglycemic Agents

•Insulin

Diet • Cornerstone of diabetic therapy• Individualized, tailored to the needs

of the patient• The goal is proper growth and

development (for the young diabetics) and normalization of weight in the normal work or school setting without hyperglycemia or hypoglycemia

Oral Hypoglycemic Agents

• The oral agents sulfonylureas and arysylfonylureas are indicated for Type II DM patients

• Side effects include: toxic reactions Nausea, vomiting, Dyspnea, Palpitations

Insulin • Indicated (together with dietary

manipulation as the primary mode of metabolic control for: Newly diagnosed Type I diabetics Type II diabetics failing to maintain

adequate glycemic control on oral hypoglycemic medications

Preoperatively Drug pregnancy

Dental Correlations• Generally accepted that there is a

direct relationship between DM and dental diseases

• Symptoms can be related to salivary and dental changes, periodontal and mucosal abnormalities, opportunistic infections, acetone or diabetic breath and altered wound healing

Dental Management• Obtain a comprehensive medical history from

the known or suspected diabetic patient• Establish the severity and degree of control

before instituting any dental management When the patient’s diabetes is well controlled and

there are no concurrent medical problems, he may receive appropriate dental therapy without modification of accepted dental protocols

When the patient’s diabetes is uncontrolled, or when there is a serious underlying organic disease, elective care or surgical procedure should be delayed until blood glucose level has been regulated

When the severity of diabetics or the degree of control is not known, treatment should be limited to palliation

• In the dental treatment of all diabetics, reduce pain as much as possible. The stress stimulates the release of epinephrine, which in turn, increases the blood glucose level

• Be careful with antimicrobial therapy, excessive use of unnecessary antibiotics can lead to oral or systemic fungal infections

Lactose intolerance

Overview

Lactose intolerance is the inability to digest lactose (a type of sugar found in milk and other dairy products).

Symptoms

*Abdominal bloating& Abdominal cramps

*Diarrhea

*Floating stools & Foul-smelling stools

*Gas (flatulence)

*Malnutrition

*Nausea*Slow growth

*Weight loss

Causes

Lactose intolerance happens when the small intestine does not make enough of the enzyme lactase. Babies' bodies make this enzyme so they can digest milk, including breast milk. Beforehumans became dairy farmers, most people did not continue to drink milk, so their bodies did not make lactase after early childhood. Lactose intolerance is more common in Asian, African, African-American, Native American, and Mediterranean populations than it is among northern and western Approximately 30 million American adults have some amount of lactose intolerance by age Not having enough lactase (lactase deficiency) may also occur as a result of intestinal diseases such as celiac sprue and gastroenteritis, or after bowel surgery. Temporary lactase deficiency can result from viral and bacterial infections, especially in children, when the cells lining the intestine are injured.

Tests & diagnosis

*Enteroscopy

*Lactose-hydrogen breath test

*Lactose tolerance test

*Test for stool-reducing substances

Prevention

There is no known way to prevent lactose intolerance. If you have the condition, avoiding or restricting the amount of milk products in your diet can reduce or prevent symptoms.

Treatment

*Buttermilk and cheeses (they have less lactose than milk

*Fermented milk products, such as yogurt

*Goat's milk (but drink it with meals, and make sure it is supplemented with essential amino acids and vitamins if you give it to children)

*Ice cream, milkshakes, and aged or hard cheeses

*Lactose-free milk and milk products

*Lactase-treated cow's milk for older children and adults*Soy formulas for infants younger than 2 years

*Soy or rice milk for toddlers

*Take calcium supplements

*Eat foods that have more calcium (leafy greens, oysters, sardines, canned salmon, shrimp, and broccoli)

*Drink orange juice that contains added calcium

Complications

Weight loss and malnutrition are possible complications.