Download Lecture 4

Lecture 4
HLTH 120N
Carbohydrates
Objectives
• Differentiate between simple and complex
carbohydrates
• Know the simple and complex sugars and their
respective enzymes
• Differentiate between soluble & insoluble fiber;
know fiber requirements
• Identify which hormones are present with high
or low blood sugar
• Understand ketosis and how to prevent it
• Know differences between Type I and II diabetes
• Form an opinion on artificial sweeteners
What are Carbohydrates?
• Made of 3 atoms:
• In food, comes from _________
• Main energy source for ___________
• Most abundant form is ___________
Why do we need carbohydrates?
Daily activity
The brain
Red blood cells
To spare protein
What is simple? What’s Complex?
•
•
•
•
•
•
•
•
•
•
Green peas
Potato
Pear
Whole-grain bread
Raspberries
100% fruit snacks
Gushers fruit snacks
Black beans
Sweet potato
Cocoa Puffs cereal
•
•
•
•
•
•
•
•
•
•
Angel hair pasta
Fiber One cereal
Banana
Broccoli
Chickpeas
Rice
Popcorn
Cranberry juice
Oatmeal
Corn
Simple Carbohydrate Sugars
Monosaccharides
• Glucose
– most abundant & preferred by brain
• Fructose
– Fruit sugar w/ sweetest taste
– Processed additive:
• Galactose
– Does not occur alone
• Ribose
– Very little in foods
– In genetic material
Disaccharides
• Lactose
– Glucose + Galactose
• Maltose
– Glucose + Glucose
– Result of fermentation
• Sucrose
– Glucose + Fructose
• honey, syrup, refined into sugar
Disaccharides are attached by a
bond in nature
• β- bond
• α- bond
Complex Carbohydrates
• Oligosaccharides
3-10 linked mono-saccharides
• Polysaccharides
100’s or 1,000’s of glucose’s linked
Oligosaccharides
• Raffinose
– Beans, cabbage, sprouts, broccoli, whole grains
• Stachyose
– Beans, legumes
• No enzyme!
• Pass into large intestine undigested
Polysaccharides - Starch
• Digestion
– broken into many glucose molecules
• Amylose: straight chain
• Amylopectin: highly branched
• Resistance starches
– Linked by β- bond
– Ferment into butyrate
Polysaccharide - Fiber
• Gives plants structure
• Dietary fiber:
non-digestible plant material
• Functional fiber:
Added to foods or making up
fiber supplements
• Cellulose, psyllium, guar gum, pectin, etc.
Soluble Fiber
• Forms a gel when wet
• Fermentable
• Helps
CVD & Type 2 Diabetes
• Found in:
• Pectins, gums, mucilages
– Thickeners, stabilizers, gelling agents
Insoluble Fiber
• Does not dissolve in water
• Non-viscous & not fermented
• Found in:
• Promote regular bowel movements
–
constipation & risk of diverticulosis
• Lignins, cellulose, hemicellulose
Carbohydrate Digestion
Carbohydrate Digestion
• Mouth
– Chewing
– Salivary amylase breaks polysaccharides
• Stomach – no carb digestion!
• Small Intestine
– Disaccharides  Monosaccharides
• With maltase, sucrase, lactase
Carbohydrate absorption
• Active Transport
– Glucose
– Galactose
• Facilitated Diffusion
– Fructose
– Stays in S.I. longer, brings water in
• Blood sugar rises ________
Carbohydrate transport to liver
• First, Fructose & Galactose  glucose
• If needed, released to blood for ________
• If not, stored as __________ in the liver &
muscle
– Liver ~70 g, muscle ~120 g
– What about athletes?
The fate of fiber
• Fiber moves into the _________________
• Here, bacteria ferment certain fibers
– Products are gas and fat!
– Short Chain Fatty Acids are produced
• Used by large intestine’s cells for energy
Lactose Intolerance
• Insufficent lactase is produced
• Symptoms:
• Some born with an intolerance
• _____ of the world’s population will develop
• Glucose & Hydrogen tests
Hormones - Glucose Regulation
• Insulin
– Present when blood glucose is ______
– Activates cell transporters
• Glucagon
– Present when blood glucose is ______
– Stimulates conversion of glycogen to glucose
– gluconeogenesis
• Epinephrine/Norepinephrine
– Active with
blood glucose
– glycogen breakdown & gluconeogenesis
– Fight/flight reaction needs energy!
• Cortisol
– When blood glucose is
.
– gluconeogenesis & use of glucose
• Growth Hormone
– When blood glucose is
– glucose uptake & FA use
.
What increases the likelihood
of these conditions?
• Renal disease
• Blindness
• Low Circulation
• Amputation of extremeties
• Seizures
• Stroke
• Heart Disease
• Ketoacidosis
What is Diabetes?
• 11 % of Americans have been diagnosed with
Type II (formerly called adult onset)
– 35% are pre-diabetic
– Up to 5.7 million cases are undiagnosed
Type I
• The body cannot produce enough insulin
– Excess glucose _________________
– Confusion, lethargy, & breathing problems
• Why?
• Average diagnosis age: 10-14
– Infants & adults less common
• Genetic Link
– Autoimmune?
• Blood glucose monitored & insulin injected
Type II
• Body’s cells are resistant to insulin
– Pancreas secretes increased amounts to deal
with ______________________
– Result is impaired fasting glucose
– Pancreas becomes incapable of secreting
insulin
– Blood Glucose is dangerously high
• Insulin insensitivity
• Pancreas is not producing
Type II - causes
• Most common cause: ___________
80-90% of diabetics
• Genetics
• Poor diet
• Inactivity
Type II - treatment
• Lose weight
– 5-10% of body weight
• Controlling carbohydrate intake
– Avoid alcohol, which causes __________________
• Regular exercise most effective
• Oral medications
– Increase insulin sensitivity
– Decrease glucose production by liver
• Insulin injections
Hypoglycemia
• Fasting blood glucose is ___________
• May be excessive __________ production
• If diabetics inject too much insulin
• 1-4 hours post meal
– Shakiness, nervousness, anxiety, sweating,
headaches, weakness, irregular heartbeat
• Treatment -
Low Carb & Ketoacidosis
• Ketosis: the breakdown of _____ to produce
ketones
• Ketones suppress appetite, cause dehydration
and acetone breath
• Excessive ketone production = ketoacidosis
– We need ____ g/day of carbohydrate to prevent
– What happens with too much acid in the body?
Health Benefits of Complex Carbs
• Nutrients – vitamins & minerals
• Fiber
– Likely reduces the risk of colon cancer
– Prevents hemorrhoids, constipation, and other
intestinal problems
– Reduces the risk of diverticulosis
– Reduces the risk of heart disease
– May enhance weight loss
– May lower the risk of type 2 diabetes
What should we eat?
• Carbohydrates should be high in fiber, whole grain,
and unprocessed
• Most Americans eat too many simple
• Diets high in simple sugars
– Can cause tooth decay
– May impact cholesterol
– Contribute to obesity and diabetes
• Added sugar intake should be <150 calories/day for
adult men and <100 calories/day for adult women
– Per the American Heart Association (AHA)
• Most American eat too little complex carbs
– Average 2 servings total of fruits and vegetables
• Refined grains
– Stripped of fiber
Some are enriched
• Lost nutrients
added back
Others are fortified
• New nutrients
added
How much fiber?
• 14g for every 1,000 calories
• 50 g/day or more may be too much
• Sources:
“whole grain”– not just “wheat”
Fresh fruits/veggies… or frozen!
Legumes – peas, beans, lentils
Canned?
Sweeteners
• Nutritive Sweeteners
– Honey, sugar, fructose
– Sugar alcohols
• Non-nutritive Sweeteners
– ADI: _____________________
– Amount a person can consume per day for a
lifetime without adverse effects
Saccharin
• Sweet n’ low
• 300x sweeter than sucrose
• Causes bladder cancer in rats
– 20 years of research on humans
• National Toxicology Program removed it from
the list of products that may cause cancer
• No ADI is set
Aspartame
• Equal and Nutrasweet
• Phenylalanine + aspartic acid
• 200x sweeter than sucrose
• ADI: 50 mg/kg/day
– Kids may exceed on poor diet
• Who cannot consume it?
• Common side effects:
Sucralose
• aka Splenda
• Cl atoms replace H and O on sucrose
• 600x sweeter and can be heated
• ADI 5mg/kd/day
– 340 mg for 150 lb person
– 1 packet has 12 mg