Transcript CARBOHYDRATES - University of Akron

CARBOHYDRATE FAMILY
CARBOHYDRATES
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Hydrated Carbon atoms
Organic Compounds
Ratio (C H2 O)
Hexoses = 6 Carbon sugars***
Bonds
Monosaccharides = 1
Disaccharides = 2
Oligosaccharides = 3-10
Polysaccharides = 10 - thousands
MONOSACCHARIDES
• GLUCOSE
• part of every disaccharide
• main component of polysaccharide
• body’s final form of fuel
• GALACTOSE – rarely free in nature
• FRUCTOSE
• sweetest sugar
• converted to glucose in small intestine/liver
• requires insulin
MONOSACCHARIDE
STRUCTURES
CONDENSATION OF
MONOSACCHARIDES
DISACCHARIDES
• MALTOSE
2 Glucose units
Malt sugar
Intermediate product of starch digestion
• LACTOSE
Glucose + Galactose
Milk sugar
• SUCROSE
Glucose + Fructose
Table sugar
SWEETNESS OF
SUGARS
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FRUCTOSE …………...170
SUCROSE……………...100
GLUCOSE………………70
MALTOSE……………...46
LACTOSE………………35
GALACTOSE…………..32
OLIGOSACCHARIDES
• OLIGO = Scent
• 3-10 single glucose units
• Raffinose and Stachycose  beans,
legumes
• No digestive enzymes large
intestinegas
COMPLEX
CARBOHYDRATES
POLYSACCHARIDES
GLYCOGEN
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Storage form of energy for animals
Not found in plants
Humans store glucose as glycogen
Released with hormone signal
STARCH
• Storage form of glucose for plants
• Found in grains, legumes, tubers
• Long, branched or unbranched chains
(amlyopectin or amylose)
• Hydrolyze starch  glucose  energy
FIBER
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Structural part of plants
Polysaccharide but not starch
Not digested by human enzymes
Contribute little or not energy
Nonstarch polysaccharides
Nonpolysaccharides
Resistant starches – starches classified
as fiber, resist digestion
FIBER BY SOURCE
• Dietary fibers – found naturally intact in
plants
• Functional fibers – extracted from plant or
manufactured, beneficial health effects
• Total fiber – sum of dietary fiber and
functional fiber
PHYSICAL
CHARACTERISTICS
SOLUBILITY
SOLUBLE FIBERS
• Form gels – viscous, hold water
• Fermentable- bacteria in colon
• Protect against heart disease by lowering blood
cholesterol levels – traps bile which is then
excreted
• Protect against diabetes by lowering blood
glucose levels
• Delays transit time and stomach emptying
• Provides feeling of fullness
EXAMPLES
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Gums and Mucilages
Guar gum
Psyllium
Carrageenan
Barley
Oats
• Used as stabilizers in
food industry
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Pectins
Apples
Citrus fruits
Strawberries
Carrots
• Used in food industry
as thickeners, control
texture and
consistency
WATER INSOLUBLE
FIBER
• Do not form gels
• Less readily fermented
• Promote bowel movements and prevent
constipation
• Provide feeling of fullness and satiety
• Delays gastric emptying
EXAMPLES
• Cellulose from fruits,
vegetables, legumes,
bran
• Hemicellulose-main
part of plant fiber,
bran and whole
grains
• Lignin
• Found in fruits with
edible seeds
(strawberries,
tomatoes)
• Woody structure of
plants
DIGESTION
 Mouth  SALIVARY AMYLASE
Some starch digestion, chewing high fiber
foods
 Stomach ACIDS – NO ENZYMES
Chyme – NO starch digestion
 Small Intestine PANCREATIC AMYLASE
Most starch digestion 
Dextrins and Disaccharides (Maltose)
 Intestinal Mucosa (Villi) – fibers attract water to soften
stool
 Bacteria in large intestine ferment fibers
 Sugars and most starches digested within 1-4 hours
HYDROLYSIS
ABSORPTION
 Nutrient absorption in small intestine
 Blood from intestines circulates through
liver
 Liver  Converts sugars to glucose to
cells for fuel or storage
 Storage – liver, muscle, adipose tissue
 Heart, kidney, brain, liver – No insulin
 Muscle, adipose tissue – Insulin required
DIGESTION AND
ABSORPTION
METABOLISM
• Glucose – major in metabolism
• Stored as glycogen in liver – about 1/3 of body’s
supply
• 2/3 stored in muscles
• Glycogen made when blood glucose is high
• Glycogen dismantled when blood glucose is low
– from liver
• Muscle glycogen used for muscle usage
• Glycogen is bulky because of water – limits
storage
GLUCOSE FOR
ENERGY
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Fuels most of body activities; energy for brain and CNS
Frequent replenishing due to low storage amounts
Gluconeogenesis-Carbohydrates are protein sparing
Fat for energy – need carbohydrates to release energy
Fat + glucose  energy + CO2 + H2O
Fat + fat  Ketones (ketosis)  upsets acid/base
balance
• Glucose  fat; excess glucose stored as fat after
glycogen stores are filled
BLOOD GLUCOSE
LEVELS
• Normal blood glucose level = 80-120
mg/dl (FBS)
• INSULIN – Beta cells of the Pancreas
respond to HIGH blood glucose levels
• GLUCAGON – Alpha cells of pancreas
respond to LOW blood glucose levels
• EPINEPHRINE – Adrenal glands 
“flight” or “fright” – glucose released from
glycogen
REGULATION OF
BLOOD GLUCOSE
GLYCEMIC RESPONSE
• Glycemic response – how fast glucose is
absorbed after a person eats, how high blood
sugar rises, how fast returns to normal
• Glycemic index – classifies food according to
their potential to raise blood sugar levels
• May help control diabetes, heart disease and
weight management
• Not many foods have been analyzed, values
vary greatly, eat foods in combination
DIABETES
• Normal blood sugar 80-120 mg/dL
• Type 1 diabetes – pancreas doesn’t make
insulin – unsure why
• Type 2 diabetes – cells not reacting to
insulin due to age, obesity
• Type 2 epidemic in children and
adolescents in US
• Type 2 most common form of diabetes
ORAL GLUCOSE
TOLERANCE TEST
• Nothing by mouth for at least 12 hours before test
• Administer CHO load 75-100 gms CHO
• Blood draws:
Normal range
Fasting
<140 mg/dl
30, 60 minutes
<115 mg/dl
120 minutes
<200 mg/dl
180 minutes
<140 mg/dl
• If two high values – one must be at the 2 hour interval > 200 mg/dL diagnose DM
• 2 hours post prandial (pp) =138-205 mg/dl is normal
NORMAL HORMONE
BALANCE
GLYCOSYLATED
HEMOGLOBIN (HbA1C)
 Provides accurate, long term index of average
blood glucose levels
 With high blood glucose levels certain
Hemoglobins become glycosylated-glucose
attaches to hemoglobinsugar coated
 Irreversible average blood sugar level 100120 days prior to test
 Adult/elderly…………..2.2-4.8%
 Good Diabetic control….2.5-6%
 Fair Diabetic control……6.1-8%
 Poor Diabetic control…..>8%
HYPOGLYCEMIA
• Normal blood sugar rises after eating then
returns to normal
• Hypoglycemia – blood sugar drops quickly
– below normal
• Caused by too much insulin, strenuous
physical activity, illness, inadequate food
intake
• Some people do have hypoglycemia and
must regulate carbohydrate intake
HYPOGLYCEMIA
LACTOSE INTOLERANCE
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Missing adequate amount of lactase
Lactase  Glucose + Galactose
Amount produced decreases as we age
Deficiency due to intestinal villi are
damaged (disease, medication,
malnutrition, surgery)
• May be temporary
• May be genetically determined
TREATMENT
• Limit – not necessarily avoid milk and milk
products
• Read labels for milk, milk solids, whey,
casein, lactose in medications as filler
• Symptoms – diarrhea, gas, abdominal
discomfort
• Can use lactaid pills or “milk”, acidophilus
milk, yogurt
TESTING
• Give lactose load – 50-100mg of lactose
• Blood draws to check glucose levels at 1 min.,
15 min., 30, 60, 120 min.
• Watch for 20-30mg/dl ^ in blood glucose levels
• No increase in glucose levels and positive
symptoms  lactase deficient
• Second method is Breath H test-Check
hydrogen level in breath after lactose challenge
HEALTH EFFECTS OF
SUGAR
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Nutrient deficiencies
Dental caries
Causes obesity
Causes heart disease
Causes behavior problems
Causes cravings and addictions
RECOMMENDED INTAKE
• Carbohydrate = 130 gms/day (45-65% of
calories)
• Daily value = 300 gms/day (60% of 2000 cal)
• Added sugar = empty calories
• Discretionary calories
• Hard to distinguish between naturally occurring
or added
• Read label – HFCS, sugar, lactose, glucose,
honey, corn syrup, corn sweetener
HEALTH EFFECTS OF
FIBER
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Heart disease
Diabetes
GI health
Cancer
Weight management
Causes abdominal discomfort
Nutrient bioavailability may be affected
FIBER FORM
DIVERTICULA
RECOMMENDATIONS
FOR FIBER
• Intake of 25-35 Grams /Day (14 gms/1000
calories)
• Using fiber rich foods – not supplements
• Use fruits, vegetables, legumes, whole
grains
• Increase gradually over several weeks to
give GI tract time to adapt
• Drink adequate fluids
FIBER
EXCHANGE LISTS
• Introduced in 1950 by American Diabetes
Association and American Dietetic Association
• 3 groups based on the macronutrients
• Carbohydrate group (CHO)
• Meat and meat substitute group (protein)
• Fat
• Portion sizes adjusted so that CHO, Fat, Protein
and Kcals are approximately equal
• Does not consider micronutrients
MEMORIZE
GOOD DIABETIC
CONTROL
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DIET
MEDICATION
SKIN AND FOOT CARE
VISIT DOCTOR REGULARLY
BLOOD/URINE TESTING
EXERCISE
EDUCATION
INSULIN ACTIVITY
DIABETES CONTROL AND
COMPLICATIONS TRIAL
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FOOD PYRAMID
EXCHANGE LISTS
CHO COUNTING
TAG SYSTEM (TOTAL AVAILABLE
GLUCOSE
• TO INCREASE COMPLIANCE MUST
INDIVIDUALIZE
CARBOHYDRATE
COUNTING
Need to identify the carbohydrate to insulin ratio:
 Insulin through CSII (Continuous subcutaneous
insulin infusion)
 Most closely resembles body
 Need to count grams of carbohydrate in food
items
 Builds on knowledge of food exchange lists and
portion sizes
 Multiple daily injections
ESTIMATED INSULIN-TOCARBOHYDRATE RATIO
WEIGHT (LB)
100-109
110-129
130-139
140-149
150-169
170-179
180-189
190-199
200+
RATIO INSULIN TO CHO
1:16
1:15
1:14
1:13
1:12
1:11
1:10
1:9
1:8
ARTIFICIAL SWEETNERS
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Non-nutritive – no energy
Saccharin – oldest, no more warning label
Aspartame – amino acids, PKU
Acesulfame-K – tumors and rat studies
Sucralose – changed structure of sugar, used in
cooking, not digested
Neotame – newest
Tagatose – fructose related
Alitame and Cyclamate – approval pending
Stevia – herbal, no FDA approval needed
SWEETENERS
• Acceptable daily intakes – amount
considered safe if stable throughout
lifetime
• Weight control – confusing studies
SUGAR ALCOHOLS
• Sugar relatives – sugar replacers, nutritive
sweeteners
• Yield energy – less than glucose
• Low glycemic response
• Used extensively in food processing – provide
bulk and sweetness
• Examples:
Mannitol
Sorbitol (diarrhea)
Xylitol
lactitol
isomalt