Carbohydrates

Presented by Janice Hermann, PhD, RD/LD

OCES Adult and Older Adult Nutrition Specialist

Chemistry of CarbohydratesCarbohydrates Are Made Of:

Carbon (4 Bonds)Oxygen (2 Bonds)Hydrogen (1 Bond)

Carbohydrates

MonosaccharidesDisaccharides

Simple Carbohydrates (Sugars)Polysaccharides

Complex Carbohydrates (Glycogen, Starch, Fiber)

MonosaccharidesOne Sugar Molecule

GlucoseFructoseGalactose

Same Chemical FormulaDifferent Structure

Effects Sweetness And Absorption

Disaccharides

Two Sugar MoleculesMaltose = Glucose + GlucoseSucrose = Glucose + FructoseLactose = Glucose + Galactose

PolysaccharidesMany Sugar Molecules

GlycogenLiverMuscle

StarchFiber

DigestionMouth (salivary amylase)Stomach (HCl and pepsin)Small Intestine (pancreatic amylase)Intestinal Wall (disaccharidases)

Maltase (maltose to glucose + glucose)Sucrase (sucrose to glucose + fructose)Lactase (lactose to glucose + galactose)

Lactose IntoleranceLactase activity declines with age and for

certain racial groups. Lactose remains undigested and is not absorbed.

Undigested lactose moves into the large intestine where it absorbs water causing bloating, abdominal discomfort and diarrhea.

Undigested lactose becomes food for intestinal bacteria which produce irritating acid and gas, further contributing to discomfort and diarrhea.

AbsorptionLining Of The MouthSmall Intestine

Some Fructose Converted To GlucoseFructose Absorbed Slower

LiverFructose and Galactose Converted To Glucose

MetabolismStorage Of Glucose As Glycogen

Storage Form Of Glucose In AnimalsLiver Glycogen

Brain, Nerve Cells, Developing Red Blood CellsMuscle GlycogenGlycogen Storage For Hours Not DaysLose Water When Breakdown Glycogen

MetabolismUsing Glucose For Energy

Primary Role Of Glucose38 ATP/glucose

Brain, Nerve Cells and Developing RBCs

MetabolismMaking Glucose From Protein

Protein Converted To GlucoseFat Can’t Be Converted To GlucoseIf Carbohydrate Inadequate, Converts Protein To

Glucose For Brain, Nerve Cells And Developing RBCs

Adequate Carbohydrate Spares Protein

MetabolismUsing Fat for Energy

Inadequate Carbohydrate, Fat Used For Energy For Other Cells

Fat Broken Into 2-C Fragments And Converted to Acetyl CoA

Overloads TCA Cycle2-C Fragments Combine Forming Ketone Bodies,

Can Lead To Ketoacidosis

MetabolismConverting Glucose To Fat

More Glucose Than Needed For Energy Or Glycogen Converted To Fat And Stored

Maintaining Blood GlucoseImportant To Maintain Blood Glucose

Too Low (Weak/Dizzy)Too High (Confused/Difficulty Breathing)Extremes Either Way Can Be Fatal

Regulating HormonesGlucose Too High - Insulin

Stimulate Body Cells To Take Up Glucose

Stimulates Glycogen Synthesis

Stimulates Triglyceride Synthesis

Glucose Too Low - GlucagonStimulates Liver To

Breakdown Glycogen

Falling Out Of RangeIf Blood Glucose Regulation Fails

DiabetesHypoglycemia

Glucose May Be Modified As Part Of Treatment, But Hormonal Regulation Or Obesity (For Type 2 Diabetes) Is The Cause Not Glucose

Glycemic IndexUsefulness of glycemic index controverseal

Controversy on health impactPractical utility limitedFew foods have glycemic index determined

Those that have based on wide variationsGlycemic index may be unnecessary

Current guidelines already suggest many low glycemic index choices; whole grains, legumes, vegetables, fruits and milk products.

Eating frequent, small meals spreads glucose absorption across the day and thus offers similar metabolic advantages to eating foods with a low glycemic response

Glycemic IndexEffect Of Food On Blood GlucoseGlycemic Index Differs

Amount of carbohydrate consumedNature of starchType of sugarPreparation methodsFat contentFiber content Most foods are eaten in combination in a mealFasting and pre-meal blood glucose

Types Of SweetenersCaloric Sweeteners

SugarsSugar Alcohol

Non-Caloric Sweeteners

Sugars (provide calIncludes Many Caloric Sweeteners

Refined Sugars LactoseCorn Sweeteners GlucoseInvert Sugars DextroseMaltose HoneyHigh Fructose Corn Syrup SyrupsConcentrated Fruit Juices

Health Effects of SugarsNutritional Deficiencies

Sugar Can Only Contribute To Deficiencies By Displacing Nutrients

Sugars Are Not “Bad” But Nutrient Dense Foods Must Come First

Amount Of Sugar Depends On Calories Available Beyond Those Needed For Nutrients

Health Effects of SugarsTooth Decay

Sugars And Starches Contribute To DecayBacteria In Mouth Ferment Sugars And Produce

Acid That Dissolves EnamelSugar Only One Of Many Factors

How Long Food On TeethHow Often Food EatenDental Hygiene

Health Effects of SugarsDiabetes

Hormonal regulation or obesity (in case of type 2 diabetes) causes diabetes - not sugar

Carbohydrate intake, including sugar, may be modified as part of the treatment for diabetes but it is not a cause

For people with diabetes, attention is first given to total amount of carbohydrate in the diet rather than the source

Health Effects of SugarsHyperactivity/Misbehavior In Children

Controlled Studies Failed To Show An Adverse Relationship Between Sugar And Hyperactivity Or Misbehavior In Children

Carbohydrates, Including Sugars, Stimulate Production Of Serotonin, Makes A Person Sleepy And Sluggish

Health Effects of SugarsHeart Disease

Normal Sugar Intakes Do Not Raise Triglycerides, If Calories In Balance

Very High Intakes Of Sucrose And Fructose Can Increase TriglyceridesGlucose Causes Insulin ReleaseSome People Over Produce Insulin In Response To

High Glucose Or CarbohydrateOther dietary factors such as total fat, saturated

fat, and obesity have a much stronger association with heart disease than sugar intake.

Health Effects of SugarsObesity

Obesity Due To Energy ImbalanceNo Direct Connection Between Sugar And Obesity,

Unless Excess Sugar Containing Foods Leads To Energy ImbalanceFoods High In Sugar Often High In Fat

Increase In Calorie Intake Has Come From Carbohydrates, And Primarily Soft Drinks

Sugar AlcoholsProvide Calories, But Fewer Than Sugars

Because Not Completely AbsorbedProducts With Sugar Alcohols Can Be Labeled

“Sugar Free” or “Reduced Calorie”Incomplete Absorption Can Cause Gas,

Abdominal Discomfort and DiarrheaReal benefit of using sugar alcohols is that

they do not contribute to dental caries

Non-Caloric SweetenersFDA Approved Non-Caloric SweetenersName Sweetness ADISaccharin Sweet & Low 450x 5 mg/kg Aspartame NutraSweet 200x 50 mg/kg

EqualAcesulfame K Sunette 200x 15 mg/kgSucralose Splenda 600x 5 mg/kg Neotame 8,000x 18 mg/day

Non-Caloric SweetenersFDA Petitioned Non-Caloric Sweeteners

CyclamateAlitame

Accepted Daily Intake (ADI)Amount a Person Can Safely Consume

Everyday Over A Lifetime Without Risk Conservative Level with a wide margin of

safety

Safety Of Non-Caloric SweetenersAll Compounds Toxic At Some DoseQuestion Is Whether Non-Caloric

Sweeteners Are Safe In Quantities People Normally Consume And Potentially Abuse

Saccharine SafetyUsed Over 100 Years In USNot Metabolized By Body, Rapidly Excreted,

Does Not Accumulate In BodyOriginally on GRAS List Safety Questions Arose In 1977Rat Study Suggested Large Doses Increased

Risk Of Bladder Cancer

Saccharine SafetyLarge Human Studies Do Not Support An

Association Between Saccharine And Cancer For Population As A WholeSubgroup May Have Increased Risk

Aspartame SafetyComposed Of:

PhenylalanineAspartic AcidMethyl Group

Extensive Studies Document Safety, Except For People With PKU

Phenylketonuria (PKU)Inherited Disease Were Can’t Handle Excess

Phenylalanine (1:10-15,000)Accumulation Of Excess Phenylalanine and

By-Products Can Cause Irreversible Brain Damage

Newborns Screened For PKU

Phenylketonuria (PKU)Strict Diet Providing Phenylalanine For

Growth But Not DamageAspartame Products Carry A WarningSomeone With PKU Can Handle Aspartame

In A Diet Soda, But Children With PKU Need Phenylalanine From Nutrient Rich Foods

Methyl GroupDuring Metabolism: Methyl Group Methanol⃗ ⃗⃗ Formaldehyde Carbon Dioxide ⃗Amount Produced Fall Below Levels That

Would Cause HarmMany Juices Produce More Methanol Than

Aspartame In A Diet Soda

Other Accusations

No Credible Evidence Links Aspartame To:Multiple SclerosisLupusSeizuresBrain TumorsBirth Defects

Other AccusationsSome People Claim They Have Unusual

Sensitivity To AspartameDouble Blind Studies Have Failed To

Reproduce ReactionsIn Conclusion, Except For People With PKU,

Aspartame is Safe.

Acesulfame K SafetyFDA Approved Acesulfame K In 1988 After

Reviewing 90 Safety StudiesSome Groups Believe Acesulfame K Caused

Tumors In RatsFDA Concluded Tumors Were Not Caused By

Sweetener

Sucralose SafetyFDA Approved Sucralose In 1998 After

Reviewing 110 Safety Studies

Neotame SafetyFDA approved neotame in 2002 after

reviewing 110 safety studies Neotame also contains phenylalanine,

aspartic acid , a methyl group and an additional side group which blocks digestive enzymes from separating phenylalanine and aspartic acid

As a result, the amino acids are not absorbedNeotame does not have to carry a warning for

people with PKU