Fats and Lipids in Nutrition http:www'cwu'edugeedfcsn245'htm

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Fats and Lipids in Nutritionhttp//www.cwu.edu/g
eed/fcsn245.htm

• Dr. David L. Gee
• FCSN 245 - Basic Nutrition

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Fats and Lipids

• Definition
• Classes of Fats
• Triglycerides
• Phospholipids
• Cholesterol and other Sterols

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Functions of Triglycerides

• Energy storage
• Physical thermal insulator
• Carrier of fat soluble vitamins

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Triglyceride Chemistry
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Phospholipid Chemistry

• Very similar to triglycerides
• Glycerol
• TWO fatty acids
• Phosphate nitrogen-containing compound
• Structure with two distinct parts
• Fat soluble part (FAs)
• Water soluble part (phosphate N-compound)

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Functions of Phospholipids

• Cell membrane structure
• Emulsifier
• fat digestion
• fat transport in blood

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Cholesterol Chemistry
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Functions of Cholesterol

• Cell membrane structure
• Precurser for
• Bile acids
• Steroid hormones
• Vitamin D
• Sources
• Animal fats only
• Made in liver (non-dietary essential)

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Triglycerides

• Structure
• Mono- Di- glycerides
• Fatty Acids

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Fatty Acids

• Chain length
• Long chain ( C12 - C22 )
• most vegetable fats
• most animal fats
• Medium chain ( C6 - C10 )
• butter fat
• coconut oil
• liquids/very soft at room T

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Fatty Acids

• Degree of saturation
• Saturated fatty acids (SFA)
• Monounsaturated (MUFA)
• Polyunsaturated (PUFA)

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The problem with Saturated Fatty Acids

• Raises blood cholesterol
• Raises LDL-cholesterol (bad)
• Lowers activity of LDL-receptor

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What are lipoproteins?

• Particles in the blood for transporting fat.
• Structure
• Outer coat
• Phospholipids, cholesterol, proteins
• Core
• Fats triglycerides, cholesterol-FA esters

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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)

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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

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Mono Unsaturated Fats

• Lowers blood cholesterol
• Lowers LDL - cholesterol
• No effect on HDL - cholesterol
• Liquid at room temperature
• Olive oil, canola oil, peanut oil

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Major Types of Human Nutrition Research

• Anecdotal Case Studies
• Individual or small subjects
• Not controlled
• Not considered reliable research
• Epidemiological Research
• Randomized Controlled Trials

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Nutritional Epidemiological Studies

• Studies
• Prevalence of disease/disorder in a population
• Association with nutritional factors
• Observational
• Time
• cross-sectional studies
• Retrospective studies
• Prospective studies

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Nutritional Epidemiological Studies

• Strengths
• Significant endpoints
• mortality
• morbidity
• Free living populations
• Prospective studies over long periods of time

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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?maxtoshowHITS10hits10RESULTFORMAT
  1titlemagnesiumcoloncancerandorexacttitlean
  dandorexacttitleabsandandorexactfulltextandse
  archid1138822446001_2635FIRSTINDEX0sortspecre
  levancejournalcodeamjepid

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Nutritional Epidemiological Studies

• Does not prove cause and effect
• Suggests possible relationships between nutrition
  and disease
• Well known epidemiological studies
• Framingham Studies
• Physicians Health Studies
• Nurses Health Studies

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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

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Modification of lymphocyte DNA damage by
carotenoid supplementation in postmenopausal
women.American Journal of Clinical Nutrition,
Vol. 83, No. 1, 163-169, January 2006

• http//www.ajcn.org/cgi/content/abstract/83/1/163

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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

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Mono Unsaturated Fats

• Lowers blood cholesterol
• Lowers LDL - cholesterol
• No effect on HDL - cholesterol
• Liquid at room temperature
• Olive oil, canola oil, peanut oil

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Mediterranean DietProtection 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 ?

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Polyunsaturated Fats

• Lowers LDL-cholesterol
• But also lowers HDL-cholesterol
• Dietary Sources
• Vegetable oils
• Fish oils

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Essential Fatty Acids

• PUFAs required in diet
• Two classes of EFAs
• Omega-6 PUFAs
• Linoleic acid
• Omega-3 PUFAs
• Linolenic acid
• 3-6 g/day (1 tsp veg. oil)

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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

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Essential Fatty Acids

• Functions
• Component of phospholipids in cell membranes
• Synthesis of Eicosanoids
• Potent hormone-like chemicals
• Prostaglandins
• Leukotrienes

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Eicosanoid Functionsrole 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

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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

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Risk of Stroke on Fish Consumption
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Stroke and Fish Intake (cont.)

• Risk of ischemic stroke 49 in women consuming
  fish gt 2/wk
• Risk related to intake of omega-3 PUFA
• No association between fish intake or omega-3
  intake with hemorrhagic stroke

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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

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Dietary Effects on Eicosanoids

• Omega -3 PUFAs (fish oils, canola)
• Produce eicosanoids that tend to
• decreases blood clotting
• decreases blood pressure
• decreases blood viscosity
• decreases risk of heart disease

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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

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Hydrogenation of UFA

• Conversion of PUFA to MUFA SFA
• Process
• Purposes
• Produce solid fats from oils
• Produce more chemically stable fats (resists
  oxidation, rancidity)

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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

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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 gt
  0.5g/serving (Jan. 2006)
• Currently, trans fats are included with all
  unsaturated fats

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Diet and Heart Disease

• Incidence
• Leading cause of death
• 1,250,000 myocardial infarctions/yr
• 750,000 MI deaths/yr

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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

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History of a Heart AttackInitiation

• Fatty Streaks
• Initiated by
• hypertension
• cigarette smoke
• Inflammation
• C-reactive Protein a marker for chronic
  inflammation (CRP)
• other causes?

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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

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C-reactive Protein in Overweight Children
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History of a Heart AttackAtherosclerotic Plaque
Development

• Macrophages attach
• LDL-cholesterol accumulates
• Fibrous cells grow
• Calcification

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History of a Heart AttackEnd-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

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History of a Heart Attack

• Warning signs
• Angina shortness of breath
• Often no warning!
• Treatment
• Angiogram
• Angioplasty
• Coronary bypass surgery

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Treatment of late-stage CHDSecondary Prevention
of CHD

• Testing
• Stress test
• Angiogram
• Angioplasty
• Balloon angioplasty
• stents
• Coronary Bypass Surgery
• Grafting of healthy veins around diseased
  coronary arteries

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Primary Prevention of CHD

• Know your risk factors
• Make dietary changes
• Start/continue exercise
• Stop smoking
• Stress reduction
• Use medication if necessary

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CHD Risk Factors( modifiable)

• High LDL-cholesterol
• Low HDL-cholesterol
• High blood pressure
• Family history of early CHD
• Current cigarette smoking
• Diabetes
• (Obesity )

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Risk Factors for CHD

• High Total Blood Cholesterol
• gt200 mg/dl borderline high risk
• gt240 mg/dl high risk
• High LDL-C
• gt130 mg/dl borderline high
• gt160 mg/dl high risk

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Lowering your LDL-C

• Decrease dietary saturated fat
• lt 10 calories (Step 1)
• lt 7 calories (Step 2)
• Decrease dietary cholesterol
• lt 300 mg/day (Step 1)
• lt 200 mg/day (Step 2)

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Lowering your LDL-C

• Replacing dietary SFA with MUFA
• Canola oil, olive oil
• Increase dietary fiber
• Whole grains, oats, fruits, vegetables

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Lowering your LDL-C

• Decrease dietary Trans-FA
• hydrogenated fats
• Medication
• Plant stanols/sterols
• Statin drugs
• Bile acid binding resins
• Niacin (pharmacological doses)

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Risk Factors for CHD

• Low HDL-C
• lt 40mg/dl high risk
• gt 65mg/dl protective

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Increasing your HDL-C

• Exercise
• Alcohol
• 1-2 servings/d males
• 1 serving/d females

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2nd ExamTuesday, 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

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Risk Factors for CHD

• Hypertension
• Cigarette smoking
• quit/dont start
• Diabetes
• lose weight if overweight (type 2)
• control blood sugar

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Non-modifiable Risk Factors

• Age
• males over 45
• female post-menopause
• Family History
• premature CHD
• males under 55
• females under 65

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Risk Reduction
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Reversal of Heart Disease ?

• Heart Disease Reversal Program
• Dean Ornish, MD
• Semi-vegetarian
• NF dairy
• egg whites
• lt10 cal from fat

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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

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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