Post on 03-Jan-2016
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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