Module 2 Flashcards
Lipids
Include fat and other substances that are dissolvable in organic substances (ethanol)
What are some high fat foods?
Vegetables:
- Avocado
- Coconut
- French fries
Milk and alternatives:
- Cheese
- Ice cream
- Regular milk
Grains:
- Doughnut
- Muffins
Meat and alternatives:
- Salmon
- Bacon
- Ground beef
Other:
- Butter
- Margarine
- Oil
- Potato chips
- Fudge
Are potatoes a high-fat food?
Only when you deep fry them (depends how you prepare them)
Triglyceride
Over 98% of fat is in this form that we eat
- structure dictates health or health risk
What are the two important aspects of fatty acids?
- chain length (how long or short)
- degree of saturation (as full as it can be of hydrogen)
What are the different lengths of fatty acid chains?
Short chain: 2-4 carbons
Medium: 6-12 carbons
Long (majority of what we’re eating: 14-122 carbons
What makes a fatty acid saturated?
In the carbon chain the carbons have to be attached to 4 things (not double bonds, as full of hydrogen as it can be)
Ex palmitic acid 16:0
Monounsaturated fatty acid (MUFA)
- only one double bonded carbon
Ex. oleic acid 18:1n-9 (omega-9)
Polyunsaturated fatty acids (PUFA):
two or more double bonded carbons
- linoleic acid 18:2n-6 (omega-6)
- alpha-linolenic acid 18:3n-3 (omega 3)
What are the two fish oils?
These are highly unsaturated
- Eicosapentaenoic acid (EPA) 20:5n-3 (reduces heart rate)
- Docosahexaenoic acid (DHA) 22:6n-3 (important for brain and eyes)
How can you tell if something is a unsaturated or saturated fatty acid?
- solids are going to be saturated fats since there’s less double bonds (butter)
- Unsaturated is going to be in a liquid state since it has many kinks due to the double bonds
- coconut oil has highest amounts of saturates
Why are fats and oils that have more omega-3 fats worse for cooking with?
- since it as a lot of double bonds it is more susceptible to oxidation and worse for health
- try to store these in tight containers, dark places
- monounsaturated fats are better for cooking with
Why are the polyunsaturated essential?
deficiency of fatty acids could cause:
- scaly dermatitis (inflammation of skin
- excess loss of water through skin
- impaired growth
How does fat play a role in our diet?
- Important source of energy (kcal)
- Provides essential fatty acids (linoleic and linolenic)
- brings along fat soluble vitamins (ADEK) to absorb it
- Palatability (mouth feel and taste) - allows for taste and aroma of foods
How does fat play a role in our body?
- Insulation - helps keep body warm
- Protection - protects skeleton and vital organs from falls
- Energy reserve - store kcal in adipose (fat) cells (reduce levels only by oxidizing/burning fat)
- Precursor for other biomolecules in body:
- fatty acids make eicosanoids (biological messengers) and phospholipids for cell membrane
- cholesterol makes bile acids for steroid hormones
Hydrogenation
Manufacturing/food processing practice
What is the purpose of hydrogenation?
- Transform an oil (liquid fat) into harder fat (margarine)
- purpose for spreadability
- good for use in baking (vegetable oil, shortening) - To enhance shelf life of processed foods (will not oxidize)
Trans fatty acids (TFA)
Category of fatty acids produced during hydrogenation
What’s the difference between naturally-occuring fatty acids and trans fatty acids structurally?
Naturally-occuring:
- have cis double bonds (kinks)
- more kinks makes the fat more liquidy
Hydrogenation produced fats:
- turns the cis double bonds into double linear trans bonds (not kinks)
- makes the fat solid
- similar structure to saturated fatty acids
Food sources of Trans Fatty acis:
Processed foods containing:
1. Margarine
2. Hydrogenated/partially hydrogenated vegetable oil
3. Vegetable oil/shortening
Examples of food that have trans fats:
- Margarine (want to purchase non-hydrogenated)
- Peanut butter
- deep fried foods
- pastry or batter (fish sticks, chicken nuggets)
- most cookies and crackers
Where are we getting most of our trans fats
- mostly from baked foods
- also fast food
What does trans fats contribute to?
coronary heart disease
What are the 3 processes after consuming fats?
Digestion: an enzymatic process - breakdown of whatever we’re eating to the smallest absorbable units
Absorption: take smallest units across absorptive surface of GIT into vascular (blood) or lymphatic system
Metabolism: various pathways nutrients take following digestion and absorption
Bile acids
Made form cholesterol (made from liver, all you will ever need)
- Recycled 3-5x/meal
What are bile acids required for?
- emulsification of fat (suspending of fat in watery environment)
- leads to formation of micelles
What are lipoproteins?
carry/transport fats + cholesterol (fat package)
- exist only in blood/lymph
What 4 things are all lipoproteins going to have?
- cholesterol
- triglycerides
- proteins
- phospholipids
Important info about the chylomicron:
- only present in blood particular period after eating meals (2-10hrs after eating, reflects how much fat was eaten)
Important info about VLDL:
- Made by/in the liver from excess carbohydrate and protein
- becomes LDL
Important about LDL:
- circulates in blood and carries cholesterol to all body tissue
- in healthy person should not rise (return to liver)
- will not be taken up by liver if not needed
- diet high in cholesterol = saturated fats + trans fats
What is total blood cholesterol
Total cholesterol levels = LDL, VLDL, HDL (in mmoles/litre)
- if HDL<1.03mM or LDL>3.36mM, then increased heart disease
When does the patient have to be aware of risk of coronary heart disease?
When total blood cholesterol reaches 5.2mM
Hemorrhagic stroke
burst blood vessels (less common)
Ischemic stroke
lack of oxygen (same pathogen of heart disease)
