Cholesterol, blood pressure, and heart disease:
Soft, fat-like, waxy substance
Bloodstream and cells
Needed for cell membranes and hormones and to make vitamin D
Comes from 2 sources
Body produces it (mostly genetic) in liver (1000 mg day)
Food sources (animal products – meats, poultry, fish, eggs, butter, whole milk, and cheese, not from
plant sources) (100 – 500 mg day)
Foods with trans fats or saturated fats may cause the body to produce more cholesterol
Must be transported through blood
Carriers are called lipoproteins
Low-density lipoprotein (LDL)
High-density lipoprotein (HDL)
Lipoprotein = protein + fat
LDL, more fat, less protein
HDL, more protein, less fat
LDL = “bad”
Too much can clog arteries by forming plaque
Atherosclerosis can cause heart attack or stroke
HDL = “good”
Tends to carry cholesterol away from arteries
and back to liver.
May also remove excess cholesterol from
plaque in arteries, slows buildup.
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Total cholesterol
LDL
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Optimal – under 200 mg/dL
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Borderline high risk – 200-239 mg/dL
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High risk – 240 mg/dL and up
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Optimal – less than 100 mg/dL
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Near/Above optimal – 100-129 mg/dL
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Borderline high – 130- 159 mg/dL
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High – 160 – 189 mg/dL
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Very high – 190 mg/dL
HDL
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Low - less than 40 mg/dL
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High – above 60 mg/dL (may lower risk for heart disease)
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Women tend to have higher HDL due to estrogen (needs to be over 50 mg/dL)
Triglycerides
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Normal – less than 150 mg/dL
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Borderline high – 150 – 199 mg/dL
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High – above 200 mg/dL
What affects cholesterol?
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Diet
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Poly and monounsaturated fats may help lower cholesterol when used in place of
saturated fats, but still limit
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High carbohydrates, excessive alcohol may increase triglycerides
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Soluble fiber may lower LDL, not HDL
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Weight
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Physical activity
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Age
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Gender
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Heredity
Prevention of high cholesterol
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Get it checked
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Watch fats, eat healthy
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Consume less than 300 mg of cholesterol a day
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Be active
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Quit smoking
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Some may need medication
–
Lipitor, Crestor, Zocor
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Vytorin
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Zetia
Processes that determine the cholesterol balance
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intestinal uptake of dietary cholesterol
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de novo cholesterol synthesis
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synthesis of steroid hormones from cholesterol
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synthesis of bile acids from cholesterol, and their biliary secretion
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biliary secretion of surplus cholesterol in unmodified form
Overview of cholesterol synthesis
Triglycerides:
Formation of Triglycerides:
Triglycerides form by condensation (dehydration) reactions between the hydroxyl (OH) groups of the
glycerol and the carboxyl (COOH) group of three
fatty acids.
Triglycerides are esters
being derived from an
alcohol and a fat.
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Glycerol (blue) is an alcohol derivative of
glyceraldehyde and has three hydroxyl
groups. It acts as the backbone of the
structure.
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Fatty acids (red) – there are more than 70 types of fatty acid but they all have
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long hydrocarbon tails and
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a terminal carboxyl group (COOH). The variety of fatty acids determine the
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properties of each triglyceride.
Functions of Triglycerides:
Energy storage - triglycerides contain twice the energy/gram of carbohydrates or proteins. During
aerobic respiration triglyceride is broken into 2C portions which are fed into the Krebs cycle.

Source of metabolic water
– water is released on the breakdown of triglycerides and this property is used efficiently is by
desert mammals.
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Insulation – triglycerides are found in the blubber of whales and other aquatic animals.
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Buoyancy – aquatic animals use triglycerides to help them float as they are less dense than
water.