Lipids

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Lipids
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Lipids (Fats)?

• Lipids are a group of substances that are
  relatively insoluble in water
• Some of these substances include
• Triglyceride 95 of all Fats (body fat)?
• Cholesterol (a fat-like compound occurring in
  bile, blood, brain and nerve tissue, liver and
  other parts of the body)? Steroid hormones,
  Transport of Fat, Cell Membranes, Component of
  Cells

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Lipids (Fats)?

• Phospholipids such as Lecithin
• Cell membranes, Transport of Fat
• Vitamins A, D, E, K
• Bile acids

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Function of Dietary Fats

• Provide taste/flavor qualities to foods
• Provide fat soluble nutrients
• Provide energy in a concentrated form
• Provide satiety

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Function of Body Fat

• Provides a storage form of energy
• Provides insulation
• Provides protection to internal organs
• Provides fat for lactation

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Triglycerides

• 95 of all fat in Nature, including dietary Fat
  and Body Fat
• Stable condition of Fat for storage
• Breaks down during digestion so Free Fatty acids
  can be absorbed

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The Chemists View of Fatty Acids and
Triglycerides

• Triglycerides are lipids with three fatty acids
  attached to a glycerol.

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Lipids (Fats)?

• A Fat (Based on its composition of Fatty Acids)
  is classified as
• Saturated, or Unsaturated
• Saturated and unsaturated fats are made up of
  fatty acids (saturation refers to the number of
  hydrogen atoms in the fatty acids)?

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Lipids (Fats)Saturated Fats

• A saturated fat acid carries all the hydrogen
  atoms it can

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Fatty Acids Saturated Fatty acids
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Lipids (Fats)Saturated Fats

• saturated fats are found in whole milk, egg
  yolks, meat, meat fat, coconut and palm oils,
  chocolate, margarine, and hydrogenated vegetable
  oils

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Something to Think About

• What disease did cured ham actually have?

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Fatty Acids Unsaturated fatty acids

• Unsaturated fats are derived from plants
• Monounsaturated fats are found in olive oil and
  some nuts

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Fatty Acids Unsaturated fatty acids

• Polyunsaturated fats are found primarily in
  safflower, cottonseed, corn, soybean, and sesame
  seed oils salad dressing made from oils and
  fatty fish

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Stearic acid, an 18-carbon saturated fatty acid
Oleic acid, an 18-carbon monounsaturated fatty
acid
Linoleic acid, an 18-carbon polyunsaturated fatty
acid
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Excuse me but which is the one that practically
Kills you..polysaturated or polyunsaturated?
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Fatty Acids Unsaturated fatty acids

• Polyunsaturated fats are found primarily in
  safflower, cottonseed, corn, soybean, and sesame
  seed oils salad dressing made from oils and
  fatty fish
• There are Two different types of Polyunsaturated
  Fatty Acids.
• Omega-3-Fatty Acids
• Omega-6-Fatty Acids

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The Chemists View of Fatty Acids and
Triglycerides

• Polyunsaturated Fatty Acids
• The Location of Double Bonds
• The omega number refers to the position of the
  first double bond.
• An omega-3 fatty acid has the location of the
  double bond in the third position from the end
  carbon. An example is linolenic acid.
• An omega-6 fatty acid has the location of the
  double bond in the sixth position from the end
  carbon. An example is linoleic acid.

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Essential fatty Acids

• Linoleic acid is the only essential dietary
  lipid it is found in safflower, sunflower, and
  corn

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Omega-3 fatty acids

• Omega-3 fatty acids are Polyunsaturated Fatty
  acids classified as essential because they cannot
  be synthesized in the body they must be obtained
  from food.
• Important omega-3 fatty acids in human nutrition
  are a-linolenic acid (ALA), eicosapentaenoic
  acid (EPA), and docosahexaenoic acid (DHA).

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Omega-3 fatty acids

• Health benefits
• U.S. FDA gave "qualified health claim" status to
  eicosapentaenoic acid (EPA) and docosahexaenoic
  acid (DHA) omega-3 fatty acids, stating that
  "supportive but not conclusive research shows
  that consumption of EPA and DHA omega-3 fatty
  acids may reduce the risk of Coronary Heart
  Disease

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Omega-3 fatty acids
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Omega-3 fatty acids

• Fish oils and plant oils are the primary dietary
  source of omega-3 fatty acids.
• Another potential source of omega-3 fatty acids
  is New Zealand green lipped mussels.
• EPA and DHA are found in cold-water fish such as
  salmon, mackerel, halibut, sardines, and herring.
• ALA is found in flaxseeds, flaxseed oil, canola
  (rapeseed) oil, soybeans, soybean oil, pumpkin
  seeds, pumpkin seed oil, purslane, perilla seed
  oil, walnuts, and walnut oil

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Fats-Dietary Guidelines

• Keep total fat intake between 20 to 35 percent of
  total calories
• Most from poly and mono fatty acids (fish, nuts,
  vegetable oils, etc.)?
• Consume lt 10 of calories from saturated fatty
  acids,
• Consume lt 300 mg/day of cholesterol,
• Keep trans fatty acid consumption low

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Fats-Dietary Guidelines

• Eat lean, low-fat, or fat-free meat, poultry, dry
  beans, and milk or milk products
• Limit intake of fats, oils, and products high in
  sat/trans fatty acids

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Fats and Health Concerns

• Diets high in cholesterol and saturated fat are
  believed to increase the risk of coronary heart
  disease, some cancers and obesity
• Polyunsaturated fatty acid (PUFA) polyunsaturated
  fats tend to lower blood cholesterol

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The Chemists View of Fatty Acids and
Triglycerides

• Degree of Unsaturation Revisited
• Firmness
• Saturated fats are solid at room temperature.
• Polyunsaturated fats are liquid at room
  temperature.
• Shorter fatty acid chains are softer at room
  temperature than longer chains.

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Something to Think About

• If the professor on Gilligan's Island can make a
  radio out of a coconut, why can't he fix a hole
  in a boat?

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The Chemists View of Fatty Acids and
Triglycerides

• Degree of Unsaturation Revisited
• Stability
• Saturated fat is more resistant to oxidation.
• Monounsaturated fat is slightly less susceptible
  to spoilage.
• Polyunsaturated fat spoils most readily.
• Protection from rancidity
• Sealed in airtight containers away from light
• Add antioxidants
• Hydrogenation

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The Chemists View of Fatty Acids and
Triglycerides

• Degree of Unsaturation Revisited
• Hydrogenation
• Protects against oxidation therefore prolonging
  shelf life
• Alters texture
• Trans-Fatty Acids
• Changed from cis to trans configuration and act
  like saturated fats in the body
• Heart disease connection is being researched.
• Conjugated linoleic acid is a naturally occurring
  trans fat that may be beneficial to health.

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What is Trans Fat?

• Basically, trans fat is made when manufacturers
  add hydrogen to vegetable oil--a process called
  hydrogenation.
• Hydrogenation increases the shelf life and flavor
  stability of foods containing these fats.

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Trans fat

• Trans fat can be found in vegetable shortenings,
  some margarines, crackers, cookies, snack foods,
  and other foods made with or fried in partially
  hydrogenated oils. Unlike other fats, the
  majority of trans fat is formed when food
  manufacturers turn liquid oils into solid fats
  like shortening and hard margarine.

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Trans fat

• Trans fat, like saturated fat and dietary
  cholesterol, raises the LDL cholesterol that
  increases your risk for CHD.
• Americans consume on average 4 to 5 times as much
  saturated fat as trans fat in their diets.

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The Chemists View of Phospholipids and Sterols

• Phospholipids and sterols have unique chemical
  structures that allow them to have unique roles
  in the body.
• Sterols have a multiple-ring structure.

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The Chemists View of Phospholipids and Sterols

• Phospholipids
• Phospholipids in Foods
• Phospholipids contain glycerol, two fatty acids
  and a phosphate group with a molecule of choline.
• Used as emulsifiers in food industry
• A well-known phospholipid is lecithin.
• Food sources of lecithin include eggs, liver,
  soybeans, wheat germ and peanuts.

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• Do the Alphabet song and
• Twinkle, Twinkle Little Star have the same
  tune?
•  

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• Do the Alphabet song and
• Twinkle, Twinkle Little Star have the same
  tune?
•  Did you just try singing the two songs above?

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The Chemists View of Phospholipids and Sterols

• Roles of Phospholipids
• Enable transport of lipids across cell membranes
• Emulsifiers
• Lechithin is made by the liver. Supplements
  increase energy intake and can cause GI symptoms.

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The Chemists View of Phospholipids and Sterols

• Sterols A well-known sterol is cholesterol.
• Sterols in Foods
• Found in plant and animal foods
• Cholesterol is found in animal foods onlymeat,
  eggs, fish, poultry and dairy products
  (exogenous).

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The Chemists View of Phospholipids and Sterols

• Sterols
• Roles of Sterols
• Starting material for bile acids, sex hormones,
  adrenal hormones and vitamin D
• Structural component of cell membranes
• Liver produces 800-1500 mg cholesterol per day
  (endogenous).
• Atherosclerosis is a disease that causes heart
  attacks. It occurs when cholesterol forms
  deposits in the artery wall.

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Transport of Lipids

• Lipid transport is made possible by a group of
  vehicles known as lipoproteins.
• Chylomicrons
• Largest of the lipoproteins
• Least dense
• Get smaller as triglyceride portion is removed by
  the cells

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Transport of Lipids

• Lipid Transport
• VLDL (Very-Low-Density Lipoproteins)
• Composed primarily of triglycerides
• Made by the liver
• Transport lipids to the tissues
• Get smaller and more dense as triglyceride
  portion is removed

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Transport of Lipids

• Lipid Transport
• LDL (Low-Density Lipoproteins)
• Composed primarily of cholesterol
• Transport lipids to the tissues
• HDL (High-Density Lipoproteins)
• Composed primarily of protein
• Transport cholesterol from the cells to the liver

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Transport of Lipids

• Lipid Transport
• Health Implications
• High LDL is associated with higher risk of heart
  attack and is known as bad cholesterol.
• High HDL seems to have a protective effect and is
  known as good cholesterol.

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Transport of Lipids

• Lipid Transport
• Health Implications
• Factors that lower LDL and raise HDL
• Weight control
• Replace saturated fat with monounsaturated fat
  and polyunsaturated fat in the diet
• Soluble fibers
• Phytochemicals
• Moderate alcohol consumption
• Physical activity
• Genes influence lipoprotein activity.

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Two types of blood cholesterol

• Low-density lipoproteins (LDL) sometimes
  referred to as bad cholesterol, causes
  cholesterol to build up on the walls of your
  arteries increasing your risk of heart disease

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LDL Cholesterol-Recommended Range
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Two types of blood cholesterol

• High-density lipoproteins (HDL) sometimes
  referred to as good cholesterol, helps your
  body get rid of cholesterol in your blood the
  higher your HDL the better as it helps reduce the
  risk of heart disease

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Hyperlipidemia
After 12 Weeks of Exercise Total Cholesterol
-- decreases HDLs -- increase LDLs --
decrease
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This is the left coronary artery from the aortic
root on the left. Extending across the middle of
the picture to the right is the anterior
descending branch. This coronary shows severe
atherosclerosis with extensive calcification..
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This aorta shows severe atherosclerosis
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Fats-Dietary Guidelines

• Keep total fat intake between 20 to 35 percent of
  total calories
• Most from poly and mono fatty acids (fish, nuts,
  vegetable oils, etc.)?
• Consume lt 10 of calories from saturated fatty
  acids,
• Consume lt 300 mg/day of cholesterol,
• Keep trans fatty acid consumption low

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YOU WANT BY-PASS SURGERY WITH THAT
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LDL Cholesterol- Recommended Range