Docstoc

Vitamins

Document Sample
Vitamins Powered By Docstoc
					           Carbohydrates


                Presented by
        Janice Hermann, PhD, RD/LD
OCES Adult and Older Adult Nutrition Specialist
Chemistry of Carbohydrates
 Carbohydrates Are Made Of:
 Carbon (4 Bonds)
 Oxygen (2 Bonds)
 Hydrogen (1 Bond)
Carbohydrates
 Monosaccharides
 Disaccharides
   Simple Carbohydrates (Sugars)
 Polysaccharides
   Complex Carbohydrates (Glycogen, Starch, Fiber)
Monosaccharides
 One Sugar Molecule
   Glucose
   Fructose
   Galactose
 Same Chemical Formula
 Different Structure
   Effects Sweetness And Absorption
Disaccharides
 Two Sugar Molecules
  Maltose = Glucose + Glucose
  Sucrose = Glucose + Fructose
  Lactose = Glucose + Galactose
Polysaccharides
 Many Sugar Molecules
   Glycogen
     Liver
     Muscle
   Starch
   Fiber
Digestion
 Mouth (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 Intolerance
 Lactase 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.
Absorption
 Lining Of The Mouth
 Small Intestine
   Some Fructose Converted To Glucose
   Fructose Absorbed Slower
 Liver
   Fructose and Galactose Converted To Glucose
Metabolism
 Storage Of Glucose As Glycogen
   Storage Form Of Glucose In Animals
   Liver Glycogen
     Brain, Nerve Cells, Developing Red Blood Cells
   Muscle Glycogen
   Glycogen Storage For Hours Not Days
   Lose Water When Breakdown Glycogen
Metabolism
 Using Glucose For Energy
   Primary Role Of Glucose
    38 ATP/glucose
  Brain, Nerve Cells
   and Developing RBCs
Metabolism
 Making Glucose From Protein
   Protein Converted To Glucose
   Fat Can’t Be Converted To Glucose
   If Carbohydrate Inadequate, Converts Protein To
    Glucose For Brain, Nerve Cells And Developing
    RBCs
   Adequate Carbohydrate Spares Protein
Metabolism
 Using 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 Cycle
   2-C Fragments Combine Forming Ketone Bodies,
    Can Lead To Ketoacidosis
Metabolism
 Converting Glucose To Fat
   More Glucose Than Needed For Energy Or
    Glycogen Converted To Fat And Stored
Maintaining Blood Glucose
 Important To Maintain Blood Glucose
   Too Low (Weak/Dizzy)
   Too High (Confused/Difficulty Breathing)
   Extremes Either Way Can Be Fatal
Regulating Hormones
 Glucose Too High - Insulin
   Stimulate Body Cells To Take
    Up Glucose
   Stimulates Glycogen
    Synthesis
   Stimulates Triglyceride
    Synthesis
 Glucose Too Low -
 Glucagon
   Stimulates Liver To
   Breakdown Glycogen
Falling Out Of Range
 If Blood Glucose Regulation Fails
   Diabetes
   Hypoglycemia
 Glucose May Be Modified As Part Of
 Treatment, But Hormonal Regulation Or
 Obesity (For Type 2 Diabetes) Is The Cause
 Not Glucose
Glycemic Index
 Usefulness of glycemic index controverseal
   Controversy on health impact
   Practical utility limited
   Few foods have glycemic index determined
    Those that have based on wide variations
  Glycemic 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 Index
 Effect Of Food On Blood Glucose
 Glycemic Index Differs
   Amount of carbohydrate consumed
   Nature of starch
   Type of sugar
   Preparation methods
   Fat content
   Fiber content
   Most foods are eaten in combination in a meal
   Fasting and pre-meal blood glucose
Types Of Sweeteners
 Caloric Sweeteners
   Sugars
   Sugar Alcohol
 Non-Caloric Sweeteners
Sugars (provide cal
 Includes Many Caloric Sweeteners
  Refined Sugars            Lactose
  Corn Sweeteners           Glucose
  Invert Sugars             Dextrose
  Maltose                   Honey
  High Fructose Corn Syrup  Syrups
  Concentrated Fruit Juices
Health Effects of Sugars
 Nutritional 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 Sugars
 Tooth Decay
   Sugars And Starches Contribute To Decay
   Bacteria In Mouth Ferment Sugars And Produce
    Acid That Dissolves Enamel
   Sugar Only One Of Many Factors
     How Long Food On Teeth
     How Often Food Eaten
     Dental Hygiene
Health Effects of Sugars
 Diabetes
   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 Sugars
 Hyperactivity/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 Sugars
 Heart Disease
   Normal Sugar Intakes Do Not Raise Triglycerides, If
    Calories In Balance
   Very High Intakes Of Sucrose And Fructose Can
    Increase Triglycerides
      Glucose Causes Insulin Release
      Some People Over Produce Insulin In Response To
       High Glucose Or Carbohydrate
   Other dietary factors such as total fat, saturated
    fat, and obesity have a much stronger association
    with heart disease than sugar intake.
Health Effects of Sugars
 Obesity
   Obesity Due To Energy Imbalance
   No Direct Connection Between Sugar And Obesity,
    Unless Excess Sugar Containing Foods Leads To
    Energy Imbalance
      Foods High In Sugar Often High In Fat
   Increase In Calorie Intake Has Come From
    Carbohydrates, And Primarily Soft Drinks
Sugar Alcohols
 Provide Calories, But Fewer Than Sugars
 Because Not Completely Absorbed
   Products With Sugar Alcohols Can Be Labeled
   “Sugar Free” or “Reduced Calorie”
 Incomplete Absorption Can Cause Gas,
  Abdominal Discomfort and Diarrhea
 Real benefit of using sugar alcohols is that
  they do not contribute to dental caries
Non-Caloric Sweeteners
 FDA Approved Non-Caloric Sweeteners
Name                    Sweetness ADI
Saccharin   Sweet & Low 450x      5 mg/kg
Aspartame NutraSweet 200x         50 mg/kg
             Equal
Acesulfame K Sunette    200x      15 mg/kg
Sucralose   Splenda     600x       5 mg/kg
Neotame                8,000x     18 mg/day
Non-Caloric Sweeteners
 FDA Petitioned Non-Caloric Sweeteners
   Cyclamate
   Alitame
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 Sweeteners
 All Compounds Toxic At Some Dose
 Question Is Whether Non-Caloric
 Sweeteners Are Safe In Quantities People
 Normally Consume And Potentially Abuse
Saccharine Safety
 Used Over 100 Years In US
 Not Metabolized By Body, Rapidly Excreted,
  Does Not Accumulate In Body
 Originally on GRAS List
 Safety Questions Arose In 1977
 Rat Study Suggested Large Doses Increased
  Risk Of Bladder Cancer
Saccharine Safety
 Large Human Studies Do Not Support An
 Association Between Saccharine And Cancer
 For Population As A Whole
  Subgroup May Have Increased Risk
Aspartame Safety
 Composed Of:
   Phenylalanine
   Aspartic Acid
   Methyl 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 Damage
 Aspartame Products Carry A Warning
 Someone With PKU Can Handle Aspartame In
  A Diet Soda, But Children With PKU Need
  Phenylalanine From Nutrient Rich Foods
Methyl Group
 During Metabolism:
Methyl Group ⃗ Methanol ⃗ Formaldehyde ⃗ Carbon Dioxide
 Amount Produced Fall Below Levels That
  Would Cause Harm
 Many Juices Produce More Methanol Than
  Aspartame In A Diet Soda
Other Accusations
 No Credible Evidence Links Aspartame To:
   Multiple Sclerosis
   Lupus
   Seizures
   Brain Tumors
   Birth Defects
Other Accusations
 Some People Claim They Have Unusual
  Sensitivity To Aspartame
 Double Blind Studies Have Failed To
  Reproduce Reactions
 In Conclusion, Except For People With PKU,
  Aspartame is Safe.
Acesulfame K Safety
 FDA Approved Acesulfame K In 1988 After
  Reviewing 90 Safety Studies
 Some Groups Believe Acesulfame K Caused
  Tumors In Rats
 FDA Concluded Tumors Were Not Caused By
  Sweetener
Sucralose Safety
 FDA Approved Sucralose In 1998 After
 Reviewing 110 Safety Studies
Neotame Safety
 FDA 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 absorbed
 Neotame does not have to carry a warning
  for people with PKU

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:13
posted:6/24/2012
language:English
pages:44