Download The Gastrointestinal System

The Gastrointestinal System
T-Talk 3.1
By Jennifer Turley and Joan Thompson
© 2013 Cengage
Presentation Overview
•  The Process
•  The Organs
•  Enzymes &
Hormones
•  After digestion:
–  absorption
–  transportation
–  utilization
–  excretion
What is Digestion?
•  The breaking down of food
•  Big food parts into smaller ones
(mechanical)
–  Involves muscles and nerves
•  Big nutrients into smaller ones
(chemical)
–  Involves acid, enzymes, and hormones
What is a Hormone?
•  Chemicals produced by
cells (typically in an
endocrine gland), and are
secreted, then affect the
behavior of cells at distal
sites in the body.
•  Examples of hormones in
digestion include:
cholecystokinin and
secretin.
What is an Enzyme?
•  Protein that catalyze metabolic reactions,
and are necessary for most biochemical
reactions to occur.
•  Digestive enzymes specifically break down
food substances.
•  Examples include: amylase for
carbohydrate, protease for protein, and
lipase for Lipids/Fat.
The journey begins in the
mouth with
•  Mechanical digestion:
chewing (mastication)
•  Chemical digestion: saliva
(lubrication) and amylase (breaks
down digestible carbohydrate)
food
becomes
bolus
1
The Stomach
The Esophagus
•  Peristalsis begins.
•  Peristalsis is: a muscular wave action that
occurs throughout the intestinal tract. It is
controlled by the central nervous system
and facilitates excretion by propelling
food stuff through the body.
The
Small
Intestine
•  Duodenum
•  Jejunum
•  Ileum
Villi & Microvilli
The Accessory
Organs
•  Is a muscular organ & storage reservoir.
•  Mechanically digests food by mixing &
churning.
•  Chemically digests food with acid and
some enzymes (pepsin).
•  Here, the bolus becomes chyme.
Signaling the
accessory organs
•  Why?
–  For assistance in digesting the food stuff.
•  How?
–  By hormones.
–  The cells of the intestinal wall produce
the hormones cholecystokinin and
secretin which enter the blood stream
and signal the accessory organs.
The Function of Bile
Emulsifier
•  The Liver
–  Makes bile
•  The Gallbladder
–  Stores bile
•  The Pancreas
–  Makes enzymes for the
chemical digestion of
carbohydrates, proteins,
and fats
–  Makes sodium bicarbonate
to neutralize stomach acid
2
Mechanisms of Absorption
Absorption
•  Passive (Simple) Diffusion (Transport):
Nutrients like water & lipid byproducts pass freely
across membranes via a concentration gradient.
•  Facilitated Diffusion (Transport): Nutrients
like water soluble vitamins diffuse across membranes
using a specific/selective transport proteins.
•  Active Transport: Nutrients like glucose & amino
acids move across membranes against a
concentration gradient using a specific/selective
transport protein & energy/ATP.
• 
• 
• 
• 
Sites of Absorption
Transportation of Nutrients
Duodenum: many nutrients
Jejunum: many nutrients
Ileum: only selected nutrients
Colon (large Intestine): water
•  Blood vessels: water
soluble nutrients
Cellular Storage
•  Short term
•  Intermediate
•  Long term
•  Lymphatic vessels:
fat soluble nutrients
Metabolic Usage
•  Catabolic reactions: Breaking down
(things get smaller). Involve hydrolysis
reactions. Are degrading or destructive in
nature.
•  Anabolic reactions: Building up (things
get bigger). Involve condensation reactions.
Are synthesizing or constructive in nature.
•  Homeostasis: The balance of catabolic
and anabolic reactions in a person so a
relatively stable internal environment or
equilibrium is achieved.
3
Metabolic Examples
Excretion
•  What action does the enzyme lipase have
on triglycerides: Anabolic, catabolic or neither?
•  What action does bile have on triglycerides:
•  The Kidney: water &
•  What action does the hormone secretin
have on the liver: Anabolic, catabolic or neither?
•  The Lung: carbon dioxide
Anabolic, catabolic or neither?
water soluble waste.
•  The Skin: water & water
soluble waste.
& water.
•  The Colon (Large
Intestine): Water is
removed & waste (bacteria,
fiber, sloughed cells, &
undigested food) is
compacted.
Summary
•  Chemical & mechanical digestion.
•  Enzymes vs hormones.
•  The gastrointestinal tract, organs, and
accessory organs.
•  Nutrient absorption & transportation.
•  Assimilation of nutrients, storage, &
metabolic usage.
•  Excretion of waste.
References for this presentation are the same as those for this topic
found in module 3 of the textbook
4
Proteins:
From Foods to Cells in the Body
T-Talk 3.2
By Jennifer Turley and Joan Thompson
© 2013 Cengage
Protein Denaturation!
•  Causes the protein to change
shape or conformation.
•  The protein and the amino acids
are still intact.
•  Can be caused by heat, alkali or
acid treatments, or metals.
•  Is required before the protein can
be digested.
Protein
Denaturation to Digestion
Presentation Overview
• 
• 
• 
• 
• 
• 
• 
Denaturation vs. Digestion
Synthesis
Character & Types
Functions
Quality
Needs (Recommended Intake)
Deficiency vs. Excess
Protein Digestion
•  The protein strand is broken and
the amino acids are released.
•  Occurs by the protease enzymes
secreted by the pancreas and GI
mucosal cells.
•  Amino acids are absorbed,
transported to cells and then
used to build proteins.
Protein Synthesis
•  We eat protein, denature &
digest the protein, absorb &
transport the amino acids to the
cells, then within each cell,
protein is made (synthesized)
according to the DNA.
•  Protein is synthesized in a
process of converting DNA to
RNA & then protein.
1
The Gene Encodes Proteins
Protein
Character
•  Protein Character
is determined by:
–  How the 20 amino
acids are
combined
together (the
sequence).
–  The polypeptide
strand folding &
interacting.
Low & high quality dietary proteins support these
Protein Functions
1. 
2. 
3. 
4. 
5. 
6. 
7. 
8. 
Growth & tissue maintenance (replace, repair &
possibly add LBM).
Enzymes (catalysts).
Antibodies, complement proteins, circulating
components of immunity.
Fluid & electrolyte balance (free proteins).
Acid - base balance (H donors & acceptors).
Energy (4 Cals/gm, requires N removal).
Protein hormones like insulin & glucagon, secretin &
cholecystokinin.
Transportation of nutrients (lipoproteins).
Protein Synthesis inside the Cell
Types of Protein!
Fibrous
•  Uniform in structure.
•  Either exclusively
helical or sheet
formation.
•  Examples are the
proteins found in
hair, muscle fibers &
finger nails.
Globular
•  Have variation in structure.
•  Are part helical, part sheet,
part random, or completely
random.
•  Examples of globular
proteins include blood,
mucous, milk protein and
egg white.
Adult Protein Need (DRI & AMDR)
Sample Calculations
•  Eric weighs 90 Kg and ate 88 g of
protein and 3000 Calories in one day.
•  What is his DRI for protein?
–  90 Kg x 0.8 gm/Kg = 72 gm protein
•  What % of his DRI for protein did he
consume?
–  88 gm ÷ 72 gm x 100 = 122%
•  What % of Calories in his diet came from
protein?
–  88 g protein x 4 Cal/gm = 352 Cals from protein
–  352 Cals ÷ 3000 Cals x 100 = 11.7%
2
Protein Excess"
Protein Deficiency
•  Protein deficiency is called
Kwashiorkor. The individual has
peripheral edema and may not
look undernourished.
•  Protein-Energy deficiency is
called Marasmus. The individual
looks undernourished (skin &
bones, starvation).
•  Both conditions occur primarily
in 3rd world countries.
•  In the U.S. individuals who are
on starvation diets, poor,
abused, or in hypermetabolic
states can experience
Kwashiorkor or Marasmus.
•  Is most common in athletes & fad
dieters.
•  Increases risk of:
Kwashiorkor
Marasmus
Body Builders
Body Builders
sample diet
•  Meal 1: Cooked cereal, 12 egg whites,
banana, 1 piece whole wheat toast,
coffee, water, vitamin/mineral & amino
acid supplements.
•  Meal 2 (Pre-workout): Protein powder,
carbohydrate powder, amino acids.
•  Meal 3 (Post-workout): 8 oz poultry, rice,
sweet potato, corn, non-starchy vegetable,
amino acids.
•  Meal 4: 7 oz fish, rice, salad, potato,
water, amino acids.
•  Meal 5: 8 oz beef, potato, mixed
vegetable, water, amino acids.
•  Meal 6: Cooked cereal, 10 egg whites,
amino acids.
What it takes to gain muscle
7 gm/oz
7 gm/oz
7 gm/white
•  One pound muscle is: 75% water, 20%
protein, 5% other material like fat,
glycogen, minerals, enzymes.
•  One pound muscle equals 105 grams
protein.
•  To gain one pound muscle in 2 weeks
an athlete would need an extra 7-8 g
protein/day intake.
–  1 oz meat, 1 cup milk, 3 slices bread.
7 gm/oz
3 gm/0.5 c
2 gm/0.5 c
4 gm/0.5 c
–  Dehydration.
–  Liver & spleen enlargement.
–  Accelerated kidney aging.
–  Metabolic acidosis (with low carbohydrate
intake)
–  Vitamin B6 deficiency, Ca & Zn loss.
–  Heart disease & cancer.
sample diet analysis results
•  5500 Calories
•  36% Calories from protein,
49% carbohydrate, 15% fat
•  Inadequate in vitamin E (83%
DRI) and Calcium (75% DRI)
Summary
•  Dietary protein is denatured then
digested.
•  The amino acids from dietary
intake are used by cells to make
proteins by converting DNA to
RNA to protein.
•  Protein character is determined
by amino acid sequence.
3 gm/slice
3 gm/0.5 c
3
Summary
•  Proteins types: fibrous & globular.
•  Proteins have many functions in
the body.
•  Protein deficiency is called
kwashiorkor.
•  Protein excess can led to
negative health affects.
References
for this
presentation
are the same
as those for
this topic
found in
module 3 of
the textbook
4
Photosynthesis
and Fiber
T-Talk 3.3
By Jennifer Turley and Joan Thompson
© 2013 Cengage
Photosynthesis
•  The process by which
plants make
carbohydrate
structures.
•  Photosynthesis requires
chlorophyll.
•  CO2 + H20 + sunlight =
carbohydrate in plants.
Presentation Overview
•  Photosynthesis
•  Carbohydrate structures: sugar,
starch, fiber
•  Fiber categories & recommends
•  Fiber benefits & actions
•  Negative effects of too much
fiber
•  Food sources
Fiber Content in Foods
•  Dietary Fiber: The residue after “in vivo”
treatment. Animal tested.
•  sugars
•  starch
•  fiber
Fiber Content in Foods
•  Functional Fiber: Indigestible carbohydrate
isolated from natural sources or synthetic
indigestible carbohydrate.
•  Has beneficial physiological effects in humans.
•  An example of indigestible carbohydrate isolated
from a natural source is cellulose gel added to a
processed food.
Fiber Content in Foods
•  Total Fiber:
•  Is the combination of dietary &
functional fiber in food.
•  Is reflected as the fiber content value
on food package labels in the Nutrition
Facts panel.
1
Categories of Fiber:
Categories of Fiber:
Insoluble
Soluble
Solubility Fiber
Sources
Food
Sources
Softens &
Pectins
Gels in
Gums
water. Does Mucilages
attract
water
Fruits (like
apple
pectin),
vegetable,
legumes,
and oats
Fiber Recommendations
•  The DRI for total fiber intake:
•  Adult ♂ is 38 grams. Adult ♀ is 25 grams.
•  Personalized DRI is 1.4 grams total fiber
per 100 Calories consumed.
•  Example: A person eating 4200 Calories in
1 day should consume 59 grams of fiber.
Fiber Food Sources
Solubility
Fiber
Sources
Does not soften Cellulose Hemior gel in water. cellulose
Does attract
Lignins
water
Food
Sources
Whole grain
foods,
Celery strings
Apple peels
High Fiber Intake & Foods
•  High fiber intake is well over 2 grams/100 Calories
consumed.
•  High fiber foods provide > 2 gm fiber/serving.
•  High fiber foods are easy to assess on the food
package label by comparing the grams of fiber
with reference to the Calories provided/serving.
Fiber in Foods
Most American under consume
these types of foods and thus fiber.
The average American fiber intake is
11-13 gm/day.
2
Food Sources & Amounts of Fiber
Food
Very High
High
Good
Low
Group
>4gm
2-4gm
1-2gm
≤1gm
½ C Bran
Flakes
1 C Shredded
whole wheat
or whole
multigrain
cereal
1C
Oatmeal or
puffed
brown rice
cereal
1 Slice
Whole
Wheat
Bread
1 Slice Rye
Bread
½ C Brown
or Wild Rice
1 Corn
Tortilla
1 C Cornflakes
½ C White
Rice!
½ C Pasta
Grains
Food Sources & Amounts of Fiber
Food
Very High High
Good
Low
Group
>4gm
2-4gm
1-2gm
<1gm
N/A
1 Apple,
Banana
Orange,
Peach,
1 C Berries
2 Prunes
½C
1 C Fruit
Watermelon, Juice
Honeydew
melon,
Cantaloupe
Fruit
Food Sources & Amounts of Fiber
Food
Very High High
Good
Low
Group
>4gm
2-4gm
1-2gm
<1gm
½C
Broccoli,
Cauliflower,
Corn,
Beans,
Cabbage
1oz Nuts &
Seeds
½C
Carrots,
Green
pepper,
Celery,
Onion,
Lettuce
1 C Some
Vegetable
Juices
½C
Legumes
Vegetable (dried
beans)
Benefits-Actions of Fiber:
Bulk
•  Increases the volume of food
in the diet without adding
Calories, thus it decreases the
caloric density of the food.
•  Bulks the stool volume.
•  Both soluble & insoluble fiber
provide these benefits.
Benefits-Actions of Fiber:
Benefits-Actions of Fiber:
Stool Softener
Decreases transit time
•  Complex carbohydrate chemical
structures are hydrophillic (binds
water or attracts water) creating a
softer stool that is easier to move
along the G.I. tract.
•  Relieves constipation,
hemorrhoids, & diverticulosis.
•  Both soluble & insoluble fiber
provide these benefits.
•  Food, the bolus, chyme and feces
move through the GI tract faster,
thus the transit time is reduced.
•  Decreases time in the colon.
•  Reduces exposure time to
potential carcinogens thus
reduces colon cancer.
•  Both soluble & insoluble fiber
provide these benefits.
3
Benefits-Actions of Fiber:
Benefits-Actions of Fiber:
Improves GI tract muscle tone
Heart-Health
•  The larger volume of bulk and
the softer mass moving
through the “tube” allows the
GI tract muscles to exercise
efficiently.
•  Both soluble & insoluble fiber
provide this benefit.
•  Reduces heart disease risk by
binding cholesterol-rich bile in the
GI tract.
•  Normally, bile is reabsorbed.
•  Bile binds tightly to soluble fiber &
cannot be reabsorb.
•  Thus, a large source of
cholesterol can be excreted in the
feces.
•  Soluble fiber provides this benefit.
Benefits-Actions of Fiber:
Benefits-Actions of Fiber:
Heart-Health
Increases gastric emptying time.
Gallbladder
stores Bile
Liver Makes
Bile from
Cholesterol
Released Bile
emulsifies fat
in G.I. tract
Bile is
reabsorbed
In absence of
soluble fiber
Bile is reabsorbed,
little is excreted
In presence of
soluble fiber is
excreted
•  It takes a longer time for the
chyme to leave the stomach.
•  The rate of glucose absorption is
slowed.
•  This is beneficial with diabetes &
reactive hypoglycemia.
•  Soluble fiber provides this
benefit.
Negative Effects of too Much Fiber
Whole Grain Processing
•  Causes gas & bloating (due to decomposition of
•  Wheat kernels are refined by removing the
husk, bran, & germ.
•  The endosperm (containing mostly starch &
protein) remains.
•  Iron, thiamin, riboflavin, niacin, folate,
vitamin B6, magnesium, zinc, & fiber are lost.
fiber by gastrointestinal microbes)
• 
• 
• 
• 
• 
Too large & frequent bowel movements
Binds positively charged minerals
Binds beta-carotene
Decreases caloric value
Can cause GI tract blockages without
adequate water intake
•  Too much soluble or insoluble fiber can
cause negative effects
4
Whole Grain Processing
•  Some nutrients are added back into refined
grain products as a result of the Enrichment
act of 1942.
Processing
a Wheat
Kernel
•  Added: iron, thiamin, riboflavin, niacin, folate
•  Not Added: vitamin B6, magnesium, zinc, fiber
% Nutrients in whole grain, enriched white & unenriched white breads
Fiber Summary
•  Plants make carbohydrates via
photosynthesis.
•  Fiber is non-caloric.
•  Categories are soluble & insoluble.
•  Total fiber = functional & dietary fiber.
•  The DRI is 1.4 gm/100 Calories eaten.
•  There are health benefits for adequate
fiber intake.
•  There are negative effects from too much
fiber.
•  Whole foods provide the best source of
fiber and nutrients.
References for this presentation are the same as those
for this topic found in module 3 of the textbook
5
1/20/12
Carbohydrate Storage
and Disorders
T-Talk 3.4
By Jennifer Turley
and Joan Thompson
Presentation Overview
• 
• 
• 
• 
STORAGE
DISORDERS
Blood Sugar (glucose) •  Lactose Intolerance &
Starch vs. Glycogen
Lactose Mal-digestion
Glycogen in detail
•  Hypoglycemia
Blood sugar regulation •  Diabetes
•  Insulin & Glucagon
© 2013 Cengage
What is Glucose Used for?
•  Immediate carbohydrate energy &/or glycogen
storage (Liver & Muscle).
•  Brain, central nervous system (CNS), & red
blood cell (RBC) function (liver glycogen).
–  Requires a minimum of 100-150 grams carbohydrate day
(continuous).
•  Muscle functioning (muscle glycogen).
•  Fat synthesis (excess energy intake).
Where is Glycogen Stored?
•  The Liver (100 grams; 400 Calories).
–  Is used for blood sugar (glucose) regulation.
•  The Muscle (1-4 grams/100 grams of muscle).
–  The level increases with high carbohydrate diets &
exercise.
–  Is used for the working muscle.
What is Glycogen?
•  The storage form of glucose, “animal starch”.
•  Made from dietary carbohydrate sources.
–  All carbohydrate is converted to glucose then
stored as glycogen or used immediately.
Diets should be planned to meet the 45-65%
of Calories AMDR & minimally the DRI for
carbohydrate (130 gm/day for adults).
How Does the Body
Regulate Blood Sugar?
•  By hormones that are produced in the
pancreas.
•  The hormones effect the liver & muscle cells.
–  Insulin: decreases blood sugar levels.
–  Glucagon: increases blood sugar level.
1
1/20/12
Blood Sugar Regulation
Blood Sugar Regulation
Carbohydrate Related
Disorders
Lactose Intolerance
•  Lactose Intolerance &
Lactose Mal-digestion
•  Hypoglycemia
•  Diabetes
Lactose
Intolerance
Physiology:
•  Lactase deficiency (completely missing in
“intolerance” while low activity/levels in “mal-digestion”)
is strongly tied to evolution with several gene
mutations identified.
•  Symptoms: Gas, bloating, cramps, diarrhea.
Dairy Products and
Lactose Intolerance
•  Use a product like lactaid
•  Consume yogurt with live
cultures
•  Consume aged cheese
OR
•  Avoid dairy products
2
1/20/12
Allergy vs. Intolerance
•  Lactose intolerance & mal-digestion are
due to an inability to digest milk sugar
(lactose) not an allergic reaction to milk
protein (casein).
•  An allergy elicits an immune reaction &
involves antigens & antibodies.
Antibody and
Allergen in an
Allergic Immune
Response
–  Antibody: Protein structures produced by
immune cells that inactivate antigens
(allergens).
–  Antigen (allergen): Foreign protein
substances that elicit an immune reaction.
•  Allergic responses cause the formation
of mucous in the respiratory tract, GI
distress &/or hives.
Hypoglycemia
low blood sugar
•  Reactive: Blood sugar levels drop after eating sugar.
–  Too much insulin is secreted in response to sugar
consumption. Hyperinsulinemia.
•  Spontaneous: Liver stores of glycogen are depleted, the
ability to maintain blood sugar is diminished.
–  Happens to everyone in between meals or when food has
not been consumed. 4-6 hours during the day, 10-12 hours
with sleep.
•  Drug Induced: Low blood sugar from a drug reaction.
–  Improper insulin or oral hypoglycemic drug use with
diabetes.
–  Anti-inflammatory and thyroid medications are
known to cause hypoglycemia.
Type 1
Less common
• 
• 
• 
• 
~5% of cases
Juvenile onset
Is more difficult to control
Insulin administration is essential in the control
of blood sugar (Insulin-dependent diabetes)
•  Is due to a genetic and/or viral factor causing
auto immunity directed against the pancreatic
beta cells
Diabetes
A chronic disease
•  Is characterized by hyperglycemia (high blood
sugar).
•  Affects >20 million Americans, many unaware.
•  Increases heart disease, stroke, kidney disease,
retinopathy, and neuropathy.
•  Decreases life expectancy.
•  Occurs as type 1 or type 2
diabetes.
Physiology of Type 1 Diabetes
Blood
Stream
1.  Antibodies attack the
insulin producing
cells of the pancreas.
2.  No insulin is made.
3.  Blood glucose/sugar
levels are high.
4.  Liver & muscle cells
cannot take up
glucose because
there is no insulin to
bind the cell
receptor.
3
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Type 2
Physiology of Type 1 Diabetes
Very common
Blood
Stream
•  ~95% of cases
•  Typically adult onset
•  May be controlled with lifestyle changes
& oral hypoglycemic agents
•  Is caused by insulin resistance (decreased
Insulin is injected
into soft tissue &
works its way into
the blood stream
insulin receptor response)
5. Insulin is injected.
6. The insulin receptor on
liver and muscle cells
bind to insulin &
take up glucose.
7. Blood sugar levels decline.
•  Is predisposed by obesity & genetics.
Physiology of Type 2 Diabetes
Physiology of Type 2 Diabetes
Blood
Stream
Drug
1. Oral Hypoglycemic
drugs are used to make
the cells respond to the
insulin.
2. Blood sugar levels decline.
Glucose Tolerance Test
Indications of Diabetes
•  Fasting glucose level ≥ 126 mg/dl.
•  2 hour post prandial (fed) blood glucose
level ≥ 200 mg/dl.
Drug pill is taken
orally & works it’s
way into the blood
stream
Blood
Stream
1. The pancreas produces
insulin.
2. Blood glucose/sugar
levels are high.
3. The insulin receptor
on the liver and muscle
cells are insensitive to
the insulin.
Measures Carbohydrate Metabolism
• 
• 
• 
• 
Normal diet for 3 days prior to test.
Baseline fasting blood sugar level. (Levels ≥126 mg/dl indicate diabetes).
Glucose load. 1 gm carbohydrate /Kg body weight or a max of 100 gm
for adults.
Monitor blood sugar every half hour for six hours.
Normal Blood Glucose is 70-99 mg/dl
Pre-Diabetes is 100-125 mg/dl
4
1/20/12
Overweight
Contributes to
Hyperglycemia
type 2 diabetes
Case Studies: Dick & Jane
DICK
JANE
300
250
200
Dick's Blood
Sugar (mg/dl)
Dick's Weight (lbs)
150
100
50
0
-12
-9
-6
-3
0
months
Dick’s blood sugar dropped from >600
mg/dl to 90-100 mg/dl over 12 months
with weight loss from 262 to 233 lbs.
Food Composition
The Glycemic Response/Index
months
Jane’s blood sugar went up from 128 mg/dl to
240 mg/dl after gaining an extra 10lbs. Over 24
months she gradually lost 100 lbs and brought
her blood sugar to normal.
What is the
Glycemic Response/Index?
•  Simple sugars & foods with a high
glycemic index burn up fast & elicit an
insulin response.
•  Complex carbohydrates sustain energy
better.
•  The rise in blood sugar in response
to food as compared to glucose.
•  Glucose is assigned 100.
•  The Glycemic Index of a food can be
useful to anyone concerned with
blood sugar control.
Glycemic Response of Foods
Glycemic Index of Foods
•  Those with diabetes should eat foods
that have a lower glycemic response or
slower entrance of glucose into the blood
stream.
•  Foods with high protein, fat, & fiber lower
the glycemic response.
5
1/20/12
Summary
•  Glucose is required by the brain, RBCs & CNS
for energy (ATP).
•  Carbohydrate is the preferred energy source of
the body.
•  All carbohydrate is converted to glucose for
energy.
•  Excess carbohydrate is stored as glycogen.
(liver & muscle)
•  If glycogen stores are full, excess
carbohydrate is stored as fat.
Summary
•  Lactose intolerance occurs when the enzyme
lactase is missing.
•  Milk allergy involves immunity.
•  Hypoglycemia is low blood sugar. Can be
reactive, spontaneous, or drug induced.
•  Hyperglycemia is a sign of diabetes.
Summary
•  Liver glycogen maintains blood sugar
for brain, RBCs & CNS function.
•  Muscle glycogen maintains the
working muscle in high intensity
exercise.
•  The hormones insulin & glucagon
regulate blood sugar levels.
•  Insulin decreases while glucagon
increases blood sugar.
Summary
•  Diabetes occurs as type 1 & type 2.
•  Unmanaged diabetes has health implications.
•  Individuals with diabetes should consider the
glycemic response of foods for diet planning.
•  Selecting low glycemic index foods is useful in
controlling blood sugar rises.
References for this presentation are the same as
those for this topic found in module 3 of the textbook
6
1/20/12
Presentation Overview
Lipids in Heart
Disease & Cancer
Lipids in Heart Disease
•  Incidence
•  Contributing factors
•  Prevention
•  Blood lipids
•  Dietary fat
•  Oxidation & antioxidants
•  Trans & omega 3 fatty
acids
•  Other factors
T-Talk 3.5
By Jennifer Turley and Joan Thompson
© 2013 Cengage
Heart Disease
Lipids in Cancer
•  The cancer process
•  Diet & lifestyle &
disease risk
•  P:S ratio
•  Dietary lipids &
disease risk
Atherosclerosis
•  #1 cause of death in America.
•  1/3 die of atherosclerosis.
•  Myocardial infarction and stroke risk
increase with atherosclerosis.
•  Plaques:
Deaths per 100,000
•  Occlude arterial vessels.
•  Form from arterial wall injury.
•  Contain cholesterol (oxidized LDL), platelets, etc.
Diet
Related
Alcohol
Related
Non-Diet
Related
Hypertension
•  Is high blood pressure.
•  Is a leading cause of arterial wall
injury.
•  Synergizes with atherosclerosis to
cause heart disease and stroke.
Blood Pressure
Classification of Measurements
Category
Systolic1
Optimal
<120
Pre-hypertension
120-139
or
80-89
Stage 1 hypertension
140-159
or
90-99
Stage 2 hypertension
≥ 160
or
≥ 100
1 Systolic
Conjunction
and
Diastolic2
<80
Blood Pressure in mm of mercury (Hg)
Blood Pressure in mm of mercury (Hg)
2 Diastolic
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Reducing Blood Pressure
•  DASH Diet (The Dietary Approach to
Stop Hypertension)
•  Increase calcium, potassium and magnesium
•  Low-fat, fiber-rich, moderate protein &
carbohydrate
•  Aerobic exercise
•  Healthy Body Weight
What are the Risk
Factors?
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
Elevated serum cholesterol
Genetics
Smoking tobacco & drinking alcohol
Hypertension
Diabetes
Obesity
Sedentary lifestyle
Stress
Male gender
Consuming a low fiber & high fat diet
Elevated Serum Cholesterol &
Increased Deaths from Heart Disease
Who is Dying of Heart
Disease?
• 
• 
• 
• 
• 
25-34 years: Men at 3X rate as Women
35-44 years: Men at 2X rate as Women
45-64 years: Women catching up to men
65-75 years: Women catching up to men
75-80 years: Women = Men
How can it be prevented?
•  Lifestyle changes
•  Less stress, no smoking
•  Healthy diet
•  Healthy fats, nutritionally adequate
•  Regular aerobic exercise
•  An hour a day
•  All positively affect blood lipid
values and blood pressure
Blood Lipids!
Serum Triglycerides
•  VLDL
•  CHYLOMICRONS
mg/dl total cholesterol
Serum Cholesterol
•  LDL (Bad, 77.5%)
•  HDL (Good, 17.5%)
IDL (Neutral, 5%)
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Serum Triglycerides!
Lipid Carrier Molecules
•  Elevated levels are associated with heart disease.
•  High triglyceride levels thicken the blood causing
hypertriglyceridemia.
•  Triglycerides are packaged primarily in
Chylomicrons and Very Low Density Lipoproteins
(VLDL).
•  A fasting 12 hour blood test is needed to
determine an accurate triglyceride level.
•  <150mg/dl is normal.
•  450 mg/dl is like pumping ketchup, causes arterial
damage contributing to heart disease and stroke.
Serum Cholesterol
•  Elevated levels are associated with
atherosclerosis if 2 other risk factors exist.
•  Cholesterol is packaged as Low Density
Lipoproteins (LDL) and High Density Lipoprotein
(HDL). Intermediate Density Lipoprotein (IDL) is
present to a minor extent.
•  HDL’s return cholesterol to the liver for synthesis
of bile, hormones, and vitamins.
•  LDL’s delivers cholesterol to tissue and therefore
have a higher plaque effect.
Blood Cholesterol Levels & Disease Risk
Blood Cholesterol Levels & Disease Risk
Total Cholesterol LDL Cholesterol
< 100 mg/dl
< 200 mg/dl
Desirable/Low Risk
200-239 mg/dl
Borderline High Risk
≥ 240 mg/dl
Optimal
100-129 mg/dl
Near optimal
130-159 mg/dl
Borderline high
High Risk
160-189 mg/dl
High
≥ 190 mg/dl
Very high
HDL Cholesterol
< 40 Low (indicates risk)
> 60 High
Therapeutic Lifestyle Changes (TLC) Diet
Summary of the TLC Diet
Metabolic Syndrome:
If Three or More of These Factors
1. 
2. 
3. 
4. 
5. 
Fasting Blood Triglycerides: ≥150 mg/dl
HDL: <50 mg/dl ♀ <40 mg/dl ♂
Blood Pressure: ≥130/85 mm Hg
Fasting Blood Glucose: ≥110 mg/dl
Waist Circumference: >35” ♀ >40” ♂
Total Fat
SFA
PUFA
MUFA
Trans Fatty Acids
Carbohydrates
Proteins
Cholesterol
Plant stanols/sterols
Soluble Fiber
Total Calories
25%-35% of Calories
<7% of Calories
≤10% of Calories
≤20% of Calories
As low as possible
50%-60% of Calories
~15% of Calories
<200 mg/day
2 g/day
10g-25g/day
Balance energy intake and expenditure to maintain
desirable body weight and prevent weight gain.
Expend 200 Calories/day in moderate physical activity.
Examples of Food in a 2200 Calorie One Day TLC Diet
Grains
Vegetables
Fruits
Low Fat Dairy
Lean Meat/Fish/
Alternatives
Eggs
Oils
7 ounce equivalents with ½ whole grains
3 cup equivalents
2 cup equivalents
3 cup equivalents
6 ounce equivalents, soy protein may replace some
animal product
<2 yolks/week
6 teaspoon equivalents
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Dietary Fat & Lipoproteins
Fatty Acid Composition of Common Fats
•  SFA:
Increase LDL
•  PUFA :
Decrease LDL & HDL
•  MUFA:
Decrease LDL
•  Cholesterol:
Can Increase LDL
•  Phospholipids:
Not indicated in
heart disease
Oxidation of Fat
Antioxidants
•  Antioxidants: Prevent oxidation reactions, react
•  The double bonds of polyunsaturated
fatty acids are targets for oxidation
(damage by oxygen species).
•  The double bond breaks with oxidation
generating lipid fragments that are very
sticky.
(-CH2CH=CHCH2- to CH2CHO + CH2CHO).
with oxygen radical species directly, & prevent
heart disease
•  Antioxidants vitamins include: vitamin E
(alpha-tocopherol), vitamin C (L-ascorbic acid),
beta-carotene (provitamin A)
•  Minerals with antioxidant cofactor functions
include: Zinc, Copper, & Iron
•  The sticky fragments contribute to
atherosclerotic plaque formation.
Hydrogenation of Fat
•  Trans fatty acids levels are high in
processed foods containing partially
hydrogenated oils.
•  The double bonds from PUFA & MUFA are
removed by hydrogenation (adding hydrogen).
•  The fatty acid becomes more saturated.
•  Is used in the process of making
margarine.
•  The softer the margarine the less trans fat.
•  Stick margarine & shortening are highly
hydrogenated and partially hydrogenated.
Hydrogenation of Fat
H+ H+ H+
H+ H+ H+
H+ H+
spotlight
Unsaturation
Saturation
+H2
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Partial Hydrogenation
of Fat
•  Is done in the food industry.
•  Many of the double bonds from
PUFA & MUFA are removed and
many can be chemically modified
to a trans fatty acid (TFA)
configuration.
•  TFAs contribute to heart disease.
Cis vs. Trans Fatty Acids
•  Cis:
•  The naturally occurring configuration in PUFA &
MUFA.
•  Hydrogen atoms are on the same side of the double
bond in the fatty acid Carbon chain.
•  Trans:
•  Form during the partial hydrogenation process.
•  A chemical “Fluke”
•  Hydrogen atoms are on the opposite side of the
double bond in the fatty acid Carbon chain.
Trans Fatty Acids are
Detrimental to Health
The Chemical Structure of
Cis & Trans Fatty Acids
spotlight
Consumer Keys for
Avoiding Trans Fatty Acids
•  Read the nutrition facts panel. TFA free is defined
as ≤0.5 gm/serving.
•  Avoid foods with partially hydrogenated oils in the
ingredient list (such as cookies, chips,
doughnuts) on the food label.
•  Bake with vegetable oils.
•  Use margarines that are soft. Choose margarines
that are trans fatty acid free.
•  Avoid deep-fat fried foods like french fries, corn
chips, doughnuts, & chicken nuggets.
•  Avoid high meat and dairy product intake as a
natural TFA source from bacterial action on
unsaturated fatty acids in the ruminants stomach.
•  TFAs contribute to heart disease by
increasing LDL & decreasing HDL
cholesterol & increasing triglycerides.
•  An intake of 2-3% of energy from TFAs
has greater than predicted negative
effects from the marked adverse blood
lipid changes. TFAs may also contribute to
inflammation, endothelial cell dysfunction,
and diabetes (insulin resistance).
•  Intake should be < 1% of energy to as low
as possible.
Omega-3 Fatty Acids
Heart Healthy
Omega carbon
Linoleic Acid
An Omega-6 fatty acid
Omega carbon
Alpha-Linolenic Acid
An Omega-3 fatty acid
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How Do Omega-3
Fatty Acids Work?
•  They affect the synthesis of eicosanoid hormone
like compounds such as prostaglandins &
leukotrienes.
•  The compounds produced from omega 3 fatty
acids:
•  Decrease blood clotting (prevent plaque build-up)
•  Decrease blood pressure (prevent atherosclerosis)
•  Decrease blood total cholesterol, LDL cholesterol, &
triglycerides & increase HDL cholesterol)
•  Decrease inflammation (prevent arthritis, asthma)
•  Increase immunity (prevent cancer)
Omega-3 Fatty Acids in Fish
•  Best Sources:
• 
• 
• 
• 
• 
•  Good Sources:
Salmon
Herring
Mackerel
Tuna
Whitefish
To avoid mercury contamination,
eat fish that live closer to the surface
and have a shorter lifespan.
• 
• 
• 
• 
• 
• 
• 
• 
Cod
Flounder
Halibut
Mahi Mahi
Orange Roughy
Sea Bass
Clams
Scallops
Other Factors in Heart Disease
•  High doses of Niacin: Increases HDL, decreases
LDL.
•  Statin type cholesterol lowering drugs: Reduce
the synthesis of cholesterol in the liver.
•  Cholesterol absorption inhibitor drugs.
•  Benecol spreads: Contain plant stanol esters that
reduce the absorption of cholesterol in the
digestive tract.
•  Wine: Reduces blood viscosity. Red wine and/or
grape juice increases HDL.
•  Alcohol: 1 serving per day decreases risk of a
cardiovascular accident. It is an anticoagulant.
•  Aerobic Activity: Increases HDL, decreases LDL.
•  Soluble Fiber: Decreases LDL.
•  Soy Protein: Increases HDL, decreases LDL.
American Heart Association
omega 3 fatty acid recommend
•  Consume 0.5-1.8 grams of omega-3 fatty
acids per day as fatty fish or supplements.
•  The omega-3 fatty acids in fish are called
EPA & DHA.
•  Consume 1.5-3.0 grams alpha-linolenic
acid (an omega-3 fatty acid) per day.
•  Plant sources of omega-three fatty acids flax
seed, walnuts, & canola oil.
Homocysteine in Heart Disease
•  Homocysteine is an amino acid intermediate of
cysteine & methionine metabolism.
•  Elevated levels of homocysteine cause arterial
wall damage & contribute to heart disease.
•  Folic acid (folate), B6 & B12 function as cofactors
for the enzymes driving the inter conversion of
cysteine & methionine, thus adequate intakes
prevent hyperhomocystemia.
methionine
homocysteine
cysteine
Lipids in Cancer
•  Cancer is the 2nd leading cause of death
in Americans.
•  It is characterized by uncontrolled cell
growth.
•  It occurs through a process of initiation,
promotion, and progression.
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Carcinogenesis
Cancer Risk
•  Increased Cancer Risk by Lifestyle
Practices
–  Smoking tobacco, UV light, Obesity,
Sedentary Lifestyle
•  Increased Cancer Risk by Dietary
Practices
–  ~ 45% of all cancer deaths are diet-related
–  Low F&V, antioxidant nutrient, & fiber intake
–  High total fat and PUFA, sodium intake
–  P:S ≥3:1 + high fat diet = cancer risk
–  P:S ≤0.33:1 (or ≤1:3) + high fat diet = heart
disease risk
Sample P:S Ratio Calculation
•  Kathy ate a high fat diet.
–  104 gm PUFA & 30 gm SFA
•  What is her P:S ratio?
Dietary Lipids & Disease Risk
Dietary Factor
Heart Disease Cancer
Low fat intake
Prevents
disease
Prevents
disease
Does not
contribute to
disease
Does not
contribute to
disease
Contributes to
disease
Contributes to
disease
(20-25% of total Calories)
Ø 104 ÷ 30 = 3.47. This # is placed in the P
position of the ratio
–  The S position is always assigned the # 1
•  The P:S is 3.47:1
•  Is the ratio increasing disease risk?
–  This P:S ratio is increasing risk for cancer
–  Remember that you do want enough PUFA to
get your essential (linoleic and alpha-linolenic)
fatty acid needs met.
Fatty Acids & Disease Risk
Moderate fat
intake
(25-35% of total Calories)
High fat intake
(>35% of total Calories)
Summary
How to prevent heart disease
High SFA
Low MUFA
Low PUFA
Increases total blood
cholesterol, LDL
(is not ideal)
Is associated with
heart disease
(is atherogenic)
Low SFA
Low MUFA
High PUFA
Decreases total blood
cholesterol, HDL &
LDL (is not ideal)
Increases cancer risk
(is tumorgenic)
Low SFA
High MUFA
Adequate PUFA
Decreases total blood
cholesterol, LDL
(is ideal)
Is not associated with
cancer or heart
disease risk (is not
tumorgenic or
atherogenic)
•  Avoid dietary cholesterol & saturated fat.
•  Avoid hydrogenated or partially
hydrogenated fat (trans-fatty acids).
•  Consume MUFA and omega 3 fatty acids.
•  Protect PUFA, MUFA, & LDL with
antioxidants.
•  Consume adequate folate to prevent
hyperhomocystemia.
•  Consume soluble fiber, soy, and plant
stanols/sterols.
•  Avoid cigarette smoking.
•  Exercise (especially aerobic).
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Summary
How to prevent cancer
•  Choose to eat mostly plant foods.
–  Eat plenty & a variety of whole
grains, fruits, & vegetables!
•  Avoid high fat diets especially saturated
fat & omega-6 fatty acids.
•  Consume an antioxidant-rich diet.
•  Practice all aspects of a sound diet:
Calorie control, adequacy, balance,
moderation, and variety.
References for this presentation are the same as those for this topic found in module 3 of the textbook
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