Fats and Lipids in
Nutrition
http://www.cwu.edu/~geed/fcsn245.htm
Dr. David L. Gee
FCSN 245 - Basic Nutrition
Fats and Lipids
 Definition
 Classes
of Fats
–Triglycerides
–Phospholipids
–Cholesterol and other Sterols
Functions of Triglycerides
Energy storage
Physical & thermal
insulator
Carrier of fat soluble
vitamins
Triglyceride Chemistry
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.
Phospholipid Chemistry

Very similar to triglycerides
– Glycerol
– TWO fatty acids
– Phosphate + nitrogen-containing
compound

Structure with two distinct parts
– Fat soluble part (FA’s)
– Water soluble part (phosphate + Ncompound)
Functions of Phospholipids
Cell
membrane
structure
Emulsifier
– fat digestion
– fat transport in blood
Cholesterol Chemistry
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning ™ is a trademark used herein under license.
Functions of Cholesterol
 Cell
membrane structure
 Precurser for:
– Bile acids
– Steroid hormones
– Vitamin D
 Sources:
– Animal fats only
– Made in liver (non-dietary essential)
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning ™ is a trademark used herein under license.
Triglycerides
Structure
Mono-
& Di- glycerides
Fatty Acids
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.
Fatty Acids
 Chain
 Long
length
chain ( C12 - C22 )
– most vegetable fats
– most animal fats
 Medium
chain ( C6 - C10 )
– butter fat
– coconut oil
– liquids/very soft at room T
Fatty Acids
Degree
 Saturated
of saturation
fatty acids (SFA)
 Monounsaturated (MUFA)
 Polyunsaturated (PUFA)
© 2002 Wadsworth Publishing / Thomson Learning™
The problem with
Saturated Fatty Acids
Raises
blood cholesterol
–Raises LDL-cholesterol (bad)
–Lowers activity of LDL-receptor
What are lipoproteins?
Particles in the blood for
transporting fat.
 Structure

– Outer coat
» Phospholipids, cholesterol,
proteins
– Core
» Fats: triglycerides, cholesterol-FA
esters
Types of lipoproteins

Triglyceride carriers
– Chylomicrons (dietary TGs)
– Very Low Density lipoproteins (VLDL,
TGs made in the body)

Cholesterol carriers
– LDL ( delivers cholesterol to tissues )
– HDL ( removes cholesterol from tissues for
excretion in liver)
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning ™ is a trademark used herein under license.
© 2002 Wadsworth Publishing / Thomson Learning™
Saturated Fatty Acids
 Raises blood cholesterol
– Raises LDL-cholesterol (bad)
 Solid
at room temperature
–High in animal fats
–Tropical plant fats
» coconut oil, palm oil, cocoa oil
Mono Unsaturated Fats
 Lowers
blood cholesterol
–Lowers LDL - cholesterol
–No effect on HDL - cholesterol
 Liquid
at room temperature
 Olive oil, canola oil, peanut oil
Major Types of Human
Nutrition Research
 Anecdotal
& Case Studies
– Individual or small # subjects
– Not controlled
– Not considered reliable research
 Epidemiological
Research
 Randomized Controlled Trials
Nutritional Epidemiological
Studies



Studies:
– Prevalence of disease/disorder in a population
– Association with nutritional factors
Observational
Time
– cross-sectional studies
– Retrospective studies
– Prospective studies
Nutritional Epidemiological
Studies

Strengths
– Significant endpoints
» mortality
» morbidity
– Free living populations
– Prospective studies over long periods of
time
Magnesium Intake and Reduced
Risk of Colon Cancer in a
Prospective Study of Women
American Journal of Epidemiology 2006 163(3):232-235

http://aje.oxfordjournals.org/cgi/content/abstract/163/3/232?maxtoshow=&HITS=10&hits=10
&RESULTFORMAT=1&title=magnesium+colon+cancer&andorexacttitle=and&andorexacttitl
eabs=and&andorexactfulltext=and&searchid=1138822446001_2635&FIRSTINDEX=0&sorts
pec=relevance&journalcode=amjepid
Nutritional Epidemiological
Studies
 Does
not prove cause and effect
– Suggests possible relationships
between nutrition and disease
 Well
known epidemiological studies
– Framingham Studies
– Physician’s Health Studies
– Nurse’s Health Studies
Randomized Controlled Trials
(RCT)
Experimental
 Groups assigned randomly
 All other factors (other than
experimental factor) controlled
 Single and double blind experiments
 Strongest evidence proving cause and
effect

Modification of lymphocyte DNA
damage by carotenoid supplementation
in postmenopausal women.
American Journal of Clinical Nutrition, Vol. 83, No. 1, 163169, January 2006
http://www.ajcn.org/cgi/content/abstract/83/1/163
Randomized Controlled Trials
 Limitations
– Short period of time
»Clinical trials can be longer, but more
difficult to control
– Subjects not free-living
»# subjects small
– Endpoints measured related to, but
does not measure morbidity or
mortality
Mono Unsaturated Fats
 Lowers
blood cholesterol
–Lowers LDL - cholesterol
–No effect on HDL - cholesterol
 Liquid
at room temperature
 Olive oil, canola oil, peanut oil
Mediterranean Diet
Protection Against Heart Disease?
High in Olive Oil (MUFA)
 French Paradox

– Northern vs Southern France

But other possible contributing factors:
– High Red Wine consumption
– Rich in fiber, fruits, vegetables
– More active lifestyle
– Recent changes in diet and lifestyle 
Polyunsaturated Fats
 Lowers
LDL-cholesterol
–But also lowers HDLcholesterol
 Dietary
Sources
–Vegetable oils
–Fish oils
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning ™ is a trademark used herein under license.
Essential Fatty Acids
 PUFA’s
required in diet
 Two classes of EFA’s
–Omega-6 PUFA’s
»Linoleic acid
–Omega-3 PUFA’s
»Linolenic acid
 3-6
g/day (1 tsp veg. oil)
© 2002 Wadsworth Publishing / Thomson Learning™
Essential Fatty Acids
 Deficiency
Syndrome
– Rare
» fat malabsorption in infants
– Dermatitis, hair loss, poor wound
healing
 Bigger
concerns of relative
amounts of w-3 & w-6 in US diet
Essential Fatty Acids
 Functions
 Component
of phospholipids in cell
membranes
 Synthesis of Eicosanoids
– Potent hormone-like chemicals
»Prostaglandins
»Leukotrienes
Eicosanoid Functions:
role in heart disease
 Regulates
– smooth muscle contractions
»blood pressure
Omega-3 eicosanoids tend to lower BP
 Omega-6 tend to increase BP

– blood clotting
Omega-3 eicosanoids tend to inhibit blood
clotting
 Omega-6 tend to increase blood clotting

Intake of Fish and Omega-3 Fatty
Acids and Risk of Stroke in
Women


JAMA, Jan. 2001
Nurses’ Health Study
– Prospective epidemiological study



14 year follow up on 79,839 women
574 strokes
Relative Risk related to fish consumption
Risk of Stroke on Fish
Consumption
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
<1/mo
1-3/mo
1/wk
2-4/wk
>4/wk
Stroke and Fish Intake (cont.)
 Risk
of ischemic stroke 49% in
women consuming fish > 2/wk
 Risk related to intake of omega-3
PUFA
 No association between fish intake
or omega-3 intake with
hemorrhagic stroke
Dietary Effects on Eicosanoids
 Omega-6
PUFA (Veg Oils)
–Produce eicosanoids that tend to:
»increase blood clotting
»increase blood pressure
–May tend to increase risk of
heart disease
Dietary Effects on Eicosanoids
 Omega
-3 PUFA’s (fish oils,
canola)
–Produce eicosanoids that tend to:
»decreases blood clotting
»decreases blood pressure
»decreases blood viscosity
–decreases risk of heart disease
Essential Fatty Acids and
Inflammation
Inflammation: injury that results in
increased immune system activity and
blood flow
 Inflammation may play a role in heart
disease and cancer
 Omega-3 PUFA may reduce
inflammatory response

Hydrogenation of UFA
 Conversion
of PUFA to MUFA &
SFA
 Process
 Purposes:
– Produce solid fats from oils
– Produce more chemically stable fats
(resists oxidation, rancidity)
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning ™ is a trademark used herein under license.
Hydrogenation of UFA
 “cis”
and “trans” UFA
 ‘trans’ formed as a side/reverse
reaction of hydrogenation
 Trans fats mainly found in foods
with partially hydrogenated fats
– Trace amounts in milk fat & tallow
– Current average intake ~2.6% of calories
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning ™ is a trademark used herein under license.
Health Concerns of Trans Fatty Acids

Epidemiological Studies
– Several show association between consumption of
trans fats and risk of coronary heart disease

Randomized Controlled Trials
– Several show that increased consumption of trans
fats increase LDL-C, possibly by decreasing LDL
receptor activity

FDA requires Trans fat labeling containing >
0.5g/serving (Jan. 2006)
– Currently, trans fats are included with all
unsaturated fats
Diet and Heart Disease
 Incidence
 Leading
cause of death
 1,250,000 myocardial
infarctions/yr
 750,000 MI deaths/yr
Diet and Heart Disease
 Incidence
of early heart disease
(under age 65)
 Males:
– 300/100,000 fatal MI
– 80/1,000 MI
 Female:
– 125/100,000 fatal MI
– 45/1,000 MI
History of a Heart Attack
Initiation
Fatty Streaks
–Initiated by:
»hypertension
»cigarette smoke
»Inflammation
 C-reactive
Protein: a marker for
chronic inflammation (CRP)
»other causes?
Low-grade Systemic
Inflammation in Overweight
Children




Pediatrics, Jan. 2001
cross-sectional epidemiological study
3,561 children, 8-16 yrs old
C-reactive protein
– Associated with inflammation
– linked with development of heart disease in
overweight adults
C-reactive Protein in Overweight
Children
History of a Heart Attack
Atherosclerotic Plaque Development
 Macrophages
attach
 LDL-cholesterol accumulates
 Fibrous cells grow
 Calcification
© 2002 Wadsworth Publishing / Thomson Learning™
History of a Heart Attack:
End-Stage: Symptoms Appear

Myocardial Infarction
– Heart attack

Angina
– Chest pain

Thrombosis:
– growth of stationary clot

Embolism:
– sudden closure by loose clot

Ischemia
– Lack of blood flow and oxygen delivery to tissue
History of a Heart Attack
 Warning
signs
– Angina & shortness of breath
– Often no warning!
 Treatment
– Angiogram
– Angioplasty
– Coronary bypass surgery
Treatment of late-stage CHD
Secondary Prevention of CHD

Testing
– Stress test
– Angiogram

Angioplasty
– Balloon angioplasty
– stents

Coronary Bypass Surgery
– Grafting of healthy veins around diseased
coronary arteries
Primary Prevention of CHD
 Know
your risk factors
 Make dietary changes
 Start/continue exercise
 Stop smoking
 Stress reduction
 Use medication if necessary
CHD Risk Factors
( * modifiable)
High LDL-cholesterol *
 Low HDL-cholesterol *
 High blood pressure *
 Family history of early CHD
 Current cigarette smoking *
 Diabetes *
 (Obesity *)

Risk Factors for CHD
 High
Total Blood Cholesterol
–>200 mg/dl: borderline high risk
–>240 mg/dl: high risk
 High
LDL-C
–>130 mg/dl: borderline high
–>160 mg/dl: high risk
Lowering your LDL-C
 Decrease
dietary saturated fat
–< 10% calories (Step 1)
–< 7% calories (Step 2)
 Decrease
dietary cholesterol
–< 300 mg/day (Step 1)
–< 200 mg/day (Step 2)
Lowering your LDL-C
 Replacing
dietary SFA with
MUFA
–Canola oil, olive oil
 Increase
dietary fiber
–Whole grains, oats, fruits,
vegetables
Lowering your LDL-C
 Decrease
dietary Trans-FA
– hydrogenated fats
 Medication
–Plant stanols/sterols
– “Statin” drugs
– Bile acid binding resins
– Niacin (pharmacological doses)
Risk Factors for CHD
Low
HDL-C
–< 40mg/dl : high risk
–> 65mg/dl : protective
Increasing your HDL-C
Exercise
Alcohol
–1-2 servings/d males
–1 serving/d females
2nd Exam
Tuesday, Feb 13, 2005

The Lipids: Fats and Oils
– Chapter 5

Nutrition and Disease Prevention
– Chapter 11
» Cardiovascular Disease
» Hypertension and Stroke
» Nutrition and Cancer Prevention

Nutrition Research
– Chap 1: 11-14
Risk Factors for CHD
 Hypertension
 Cigarette
smoking
–quit/don’t start
 Diabetes
–lose weight if overweight (type 2)
–control blood sugar
Non-modifiable Risk Factors
 Age
–males over 45
–female post-menopause
 Family
History
–premature CHD
»males under 55
»females under 65
Risk Reduction
100
80
60
40
20
0
smoke, hiBP, hiTC
hiBP, hiTC
hiTC
none
Reversal of Heart Disease ?
 Heart
Disease Reversal Program
 Dean Ornish, MD
 Semi-vegetarian
– NF dairy
– egg whites
 <10%
cal from fat
Reversal of Heart Disease ?
 JAMA 1998
5
year study - mod-severe CHD
 20 patients on Ornish diet
 15 patients on AHA Step 2 diet
 Average % stenosis
– Ornish - 8% improved
– AHA - 28% worse
Reversal of Heart Disease ?

Cardiac Events
– heart attacks
– angioplasty
– coronary bypass surgery
Ornish - 25 events in 5 years
 AHA - 45 events in 5 years
 More CHD regression, half the number
of cardiac events
