Start to end of Fats (MIDTERM 1) Flashcards
1
Q
Which is not closely related to diet?
-pneumonia, cancer, stroke, heart disease
A
Pneumonia
2
Q
Which is an organic compound?
-Vitamin C, Ca, H2O, NaCl
A
vit C
3
Q
which food is most nutrient dense?
-broccoli, onion, corn, potato
A
broccoli
4
Q
How do we describe our diet?
A
terms of food and nutrients
5
Q
1992 Canada’s food guide
A
made for 7th grade reading level
-has rainbow
6
Q
why did the food guide start?
A
WW1, people had to know what to eat to be nutritious since there wasn’t a lot of food available
7
Q
2007 food guide
A
eating well with Canada’s food guide
- rainbow = proportions
- colourful, long, many examples and food tips
- recommended servings for each age group
8
Q
2019 food guide
A
generic, tells people to get back to basics (cooking for yourself, eating with people, less fast food..), nothing about dairy products (combined with meat), no activity tips, more info online, plate = proportions
9
Q
2007 and 2019 commonalities in food guides
A
- intended to be used alongside a dietitian
- only talk about “average” general person
- miss overeating repercussions
10
Q
food guide servings for each gender/age group *EWCFG 2007
A
- women 19-50 need 7-8 V/F, 6-7 grain products, 2 milk and alternatives, 2 meat and alternatives
- men 19-50 need 8-10 V/F, 8 grain products, 2 milk and alternatives, 3 meat and alternatives
- women 51+ need 7 V/F, 6 grain products, 3 milk and alternatives, 2 meat and alternatives
- men 51+ need 7 V/F, 7 grain products, 3 milk and alternatives, 3 meat and alternatives
11
Q
food groups in EWCFG 2007
A
vegetables and fruit
grain products
milk and alternatives
meat and alternatives
12
Q
1 food guide serving of vegetables and fruit
A
1/2 cup veg or fruit but 1 cup raw leafy vegetables
13
Q
1 food guide serving of grain products
A
1 slice bread, 1/2 bagel, pita, or tortilla, 1/2 cup cooked rice/quinoa, 3/4 cup hot cereal
14
Q
1 food guide serving milk and alternatives
A
1 cup milk, 1/2 cup evaporated milk, 1 cup soy beverage, 3/4 cup yogurt, 3/4 cup kefir
15
Q
1 food guide serving meat and alternatives
A
1/2 cup cooked fish/poultry/meat, 3/4 cup cooked legumes, 3/4 cup tofu, 2 eggs, 2tbsp peanut/nut butter
16
Q
Is 1 cup of juice = to 2 food guide servings of fruit?
A
NO - processing loses nutrients!
17
Q
“other” foods?
A
salt, sugar, fats
- water, spices, coffee, granola bars, tea, raspberry jam, dill pickles
18
Q
Mediterranean food guide
A
activity is its own group
combines all plants @ bottom front (important)
fish/seafood own group
water and wine own group (probably to slow people down, encourages social eating)
protein and sweets smallest group
19
Q
Portion Distortion
A
soft drinks increased 62% in size
fries increased 57% in size
cheeseburgers increased 24%
-our societies portions way too big
20
Q
asian pyramid food guide
A
physical activity is first
no “bad” foods
practice moderation not restriction
21
Q
The nutrients
A
carbohydrates, fats, proteins (macro’s, give fuel i.e. kcal)
vitamins, minerals (micronutrients, no kcal)
dietary fibre (and water)
22
Q
DRI’s (3) - food based
A
“dietary reference intakes”
- moderation
- variety (to dilute bad stuff, eg Hg in fish)
- balance/proportion
23
Q
DRI’s (4) - nutrient based
A
meant to optimize health, not just prevent deficiency
EAR, RDA, AI, UL
24
Q
EAR
A
estimated average requirement
-amount of nutrient that meets needs of half of the population
25
qRDA
recommended dietary allowance
- found from EAR
- personal value
- average daily nutrient amount that meets needs of almost all the healthy people in the population
26
AI
adequate intake
- when EAR is unknown use AI to estimate
- less certain, set a bit higher than predicted
- average daily nutrient amount that appears to meet the needs of almost all healthy people in the population
27
UL
tolerable upper intake level
- max daily amount of nutrient that appears to be safe for most healthy people in the population
- above UL, risk for adverse affects increases
28
Essential nutrients?
carbohydrates - glucose
protein - 9 essential amino acids: Histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine
fat - linoleic and a-linolenic acid (omega 6 and omega 3)
vitamins - all, unless by equator then D not
minerals - all
and H2O and dietary fibre
29
How do we describe nutrient intake?
amount eaten/day (g)
| as % of total calories/day
30
nutrient energy/gram
carbo - 4
protein - 4
fat - 9
alcohol -7
31
How much of each macro should we be having /day (% total kcal)?
protein - 10-35%
fat - 20-35%
carbo - 45-65%
32
Trends in the last 50 years (fats)
dropped 40-35%
| good fats replaced with bad carb, processed, low fat options
33
How much of our calories coming from other foods now?
2004, 19+
22. 7% kcal from others
26. 8% fats/day from others
34
Canadian eating trends
```
kcal dropped for fats from 40-30%
others now 25-30% of kcal and fat
200-300kcal/day more than in 1960s
obesity an epidemic
big proportions now
```
35
Why is obesity an epidemic now?
physical activity at all time low
| toxic food environment
36
Toxic Food environment?
Exposed constantly to accessible, cheap, high cal (others), low nutrient/vitamins, big portion, very tasty foods
37
Issues with Canadians eating patterns?
- people not getting minimum requirements of each food group (worried about Ca, Fe, Zn, folate, fibre)
- others replacing nutritious foods
- chronic diseases; fertility problems worrisome
38
Main 5 dietary risks associated with global mortality rates
1. High Na
2. Low whole grains
3. Low fruit
4. Low nuts/seeds
5. Low veggies
39
Main 5 dietary risks associated with global chronic disease rates
1. Low whole grains
2. High Na
3. Low fruit
4. Low nuts/seeds
5. Low veggies
40
Main chronic diseases associated with diet?
heart disease
cancer
diabetes
41
High fat foods in each food group
Veggies and fruit: avocado, coconut, veg oil
Grain products: cake, etc
Milk and alt: cheese, butter/margarine
Meat and alt: nuts/seeds, salmon, some meats (marbled steak)
42
What is fat?
most important form in nutrition
| >98% of fats are triglycerides (glycerol backbone w 3 f.a. - releases H2O in formation)
43
Important aspects of fatty acids (2)?
```
chain length: short chain = 2-4 C
medium chain *babies need these* = 6-12 C
long chain (most) = 14-22 C
degree of (un)saturation
```
44
Types of fatty acids?
saturated: ex, steric acid, 18:0 -- meat, coconut
monounsaturated (MUFA): ex, oleic acid, 18:1n-9 *omega 9 -- avocados, olive oil
PUFA: linoleic acid, 18:2n-6 *omega 6 ...
a-linolenic acid, 18:3n-3 *omega 3 -- walnuts, flax seed. any veg oil
45
Naming fatty acids
-start C numbering from omega/methyl end
-all double bonds 3C apart so only put position of 1st double bond followed by 'n' or 'w' (omega)
-put dash then the number of total double bonds in C chain
ex, 22:4n-8
46
a-linolenic acid
omega 3
essential fatty acid
18:3n-3
PUFA
47
linoelic acid
omega 6
essential fa
18:2n-6
PUFA
48
EPA (eicosapentanoic acid)
fish oil
omega 3
22:5n-3
heart health
- if this is the f.a. in membrane of platelets, will form TxA3 (thromboxane A3) when cleaved which decreases chances of myocardial infarction (heart attack) -- less aggregation/platelet adhesion
Lowers TG!
Eicosanoids suppress inflammation and clotting
49
DHA (dorosahexaenoic acid)
```
fish oil
omega 3
22:6n-3
retinal development, brain development *fetuses*
accumulates in heart
```
50
Essential fatty acid deficiency symptoms?
flakey and red skin
| -hard to diagnose
51
Role of fat in the diet?
1. calorie rich
2. provides essential fatty acids for biological messengers (eicosanoids)
3. carries fat soluble vitamins (A, D, E, K)
4. palatability (makes food taste good, gives full feeling)
52
role of fat in the body?
1. insulation
2. protection of skeleton/organs
3. energy reserve
4. precursor for biomolecules (eicosanoids, phospholipids, bile acid, steroid hormones)
53
Structure of cholesterol?
fucking confusing don't need to know what it is just know its not fatty acids
54
Hydrogenation purposes?
1. transform liquid oil into a harder fat for spreadability/baking
2. enhances/extends shelf life (vending machines) bc less double bonds
55
Hydrogenation process?
take any MUFA/PUFA (vegetable oil) and put it in H2 gas/high pressure and temperature until new bond formed (ex, 18:t)
56
Trans fatty acid basic info?
result of hydrogenation
| natural cis double bond now trans bonds so molecule is linear = harder
57
Which are legumes? walnuts, lentils, chickpeas, pinto beans, almonds, peanuts, pecans
lentils, chickpeas, pinto beans, peanuts
58
Food sources of trans fats?
minority is dairy products
majority is processed foods made of original margarine, veg oil shortening, anything hydrogenated
- 33% baking, 13% fast food, 9% original margarine/shortening
59
Digestion means?
enzymatic breakdown of food into its smallest absorbable unit (AA, glucose..)
60
Absorption means?
transfer of digested food components across absorptive surface (mucosa) of GI tract into blood/lymph
61
Metabolism means?
various pathways that take nutrients from digestion and absorption and store them/use them in anabolism
62
Small Intestine details
convoluted
microvilli increase SA to increase absorption
each villi has lymph vessels (lacteals), veins and arteries
63
Hepatic Portal System in digestion
H2O soluble molecules from SI cross mucosal cells of villi -> hepatic portal vein -> liver for nutrient absorption -> general circulation
64
Lymphatic system in digestion
Fat soluble molecules from SI cross mucosal cells as chylomicrons -> lacteals in villi -> larger lymph vessels -> thoracic duct -> blood
-if theres bacteria in these molecules, lymphocytes and phagocytes in lymph fluid trigger immune response
65
GI parts and functions
1. mouth - chews and mixes food w saliva
2. salivary glands - make saliva w starch digesting enzyme
3. pharynx - swallows chewed food w saliva
4. esophagus - moves food to stomach
5. liver - makes bile acid
6. gall bladder- stores and releases bile acid
7. stomach - churns food, secrete acid and protein digesting enzyme
8. pancreas - secretes HCO3- to neutralize intestinal contents, makes lipase
9. large intestine - absorbs H2O, some vitamins and minerals (good bacteria here)
10. small intestine - completes digestion and absorbs nutrients into HPC or lymph
11. Anus
66
Fat digestion and absorption steps
1. TG enter SI
2. Bile enters SI, emulsifies fat into small liquid drops (micelles - made of fats, bile acid)
3. Lipases empty into SI and break down fats into f.a., glycerol, mono/disaccharides
4. micelles (bubbles w fat-soluble inside and H2O soluble outside) move around, bump mucosa walls
5. if f.a. <12 C = H2O soluble, enter HPC and go to liver
6. if f.a. >14 C *most* = reform into TG inside intestinal cells
7. TG's packaged into chylomicrons, enter lymphatic system and go to blood
7. bile reabsorbed/recycled into gallbladder **entero-hepatic circulation
67
Bile Acid characteristics
made from cholesterol in liver
required for fat emulsification and micelle formation
amount needed/day is much greater than amount made/day because it has efficient reabsorption/recycling
68
Is cholesterol essential?
NO
| liver can make all we need
69
How does soluble fibre help maintain healthy (low) cholesterol levels?
- soluble fibre binds to dietary cholesterol in SI (along with bile), takes it to feces
* *less cholesterol being taken to the blood as chylomicrons!
- since the bile is taken to feces, liver must make more bile from existing cholesterol (takes it from blood) thus **lowering blood cholesterol even more
70
Lipoproteins: fat metabolism
consist of protein, cholesterol, TG's, and phospholipids
only exist in lymph and blood (H2O sol enviros)
transport fat around body
4 types: Chylomicrons, VLDL, LDL, HDL
71
Chylomicrons
- formed in SI, rich in TG
- found in blood 2-10 hours after meal (why blood cholesterol levels taken when fasted)
- drop off f.a. and cholesterol at tissues
- decreases in size to become chylo-reminant
- back to liver *proteins let it in*
72
VLDL
TG rich
excess fat that comes from chylomicrons is turned into VLDLs in liver
-drops off f.a. and cholesterol at tissues, then becomes LDL
73
LDL
Chol rich - 'bad' cholesterol
- drops cholesterol off at tissues
- goes back to liver for degradation but if liver at capacity for cholesterol, will stay in blood and increase blood (serum) cholesterol
74
HDL
made in liver, protein rich
picks up extra chol at tissues and brings back to liver, always let back into liver
'good' cholesterol
75
Total cholesterol (serum) = ?
TC = LDL + HDL + VLDL
| *not chylomicrons!
76
mmol/L =
__ mg/dL / 38.67
77
CHD risks associated with LDL levels ____ and HDL levels ____.
LDL > 3.36 mmol/L
| HDL < 1.03 mmol/L
78
A __% decrease in TC = ___% decrease in CHD risk
1% mg/dL ; 2%
79
TC cutoff when blood cholesterol medications needed
> 5.2 mmol/L
80
Coronary Heart Disease Steps (2)
Atherosclerosis - decades; gradual plaque accumulation in coronary artery leading to decreased blood flow or blockage
Thrombosis - minutes; injury to arterial plaque causing thrombis (clot formation) and blockage = heart attack (Myocardial infarction)
81
Ischemic stroke
same CHD steps, just in carotid artery
82
Atherosclerosis early steps
1. healthy artery: macrophages in monolayer
2. fatty streak formation: ~20 years of excess LDL oxidizes, macrophages become foam cells
3. plaque formation (foam cells*)
4. monolayer injury: chemicals, sudden BP spike, fibrous cap forms over plaque
5. thrombus (platelets aggregate/adhere): blockage
6. myocardial infarction
83
Atherosclerosis prevention
- decrease LDL by decreasing sat fats/trans fats and cholesterol
- more antioxidants
- keep safe/healthy environment
- exercise regularly to prevent BP spike
- have fish (eicosanoids, less platelet aggregation/adherence)
84
How can I raise HDL levels?
- avoid supplements that say they increase HDL
- loose weight if overweight (every 10lb dec = 2mg/dL inc in HDL)
- limit refined sugars/carbs
- avoid smoking
- aerobic exercise
- alcohol (red wine, but can inc TG)
85
Sat fat impact on TC, blood LDL, blood HDL. ex?
inc TC, inc LDL, inc/no effect HDL
palm oil, steak
exception: dark chocolate - 18:0
86
PUFA fat impact on TC, blood LDL, blood HDL. ex?
dec TC, dec LDL, dec HDL
| fish oils
87
MUFA fat impact on TC, blood LDL, blood HDL. ex?
dec TC, dec LDL, no effect HDL
| avocado, seeds, nuts, olive oil
88
Trans PUFA fat impact on TC, blood LDL, blood HDL. ex?
inc TC, inc LDL, dec HDL
| everything that tastes amazing :(
89
How do free radicals cause PUFA membrane damage
breaks 2x bond in PUFA's (oxidizes)
PUFA now oxidized = rancidity of oils
breakdown of oxidized PUFA leads to short chain aldehydes (malondialdehyde, cancer promoter)
90
Sources of antioxidants
whole grains, nuts, seeds, vegetables, fruit (vitamin C, E) *Selenium
91
Stages of Cancer
1. Initiation: DNA damage to cell (UV rays, Rº, PAH)
2. Promotion: damage replicates, promoted by malondialdehyde or 2º bile acids
3. Progression; damage spreads, replication speeds up
4. Metastasis
92
PAH
polyaromatic hydrocarbon
| potent liver carcinogen
93
Free radical prime conditions
heat, light, O2
94
Dietary cholesterol Key Points
- structural component of membranes in animals
- precursor for bile, vit D, steroid hormones
- not essential
- only found in ANIMAL products
- DRI - keep chol as low as possible
95
What foods contain cholesterol?
```
milk (22mg/cup)
cheddar cheese (53mg/50g)
pork/chicken/beef/turkey (~70mg/75g)
shrimp/lobster (55mg/75g *low in sat)
egg yolk (213mg *low in sat)
margarine (0mg *low in sat)
```
96
Dietary strategies to lower TC
reduce sat/trans fats (animal products)
inc soluble fibre intake
decrease dietary chol intake
97
Fish oils - EPA and DHA interest origin and fish they come from
very PUFA, come from phytoplankton
-greenland inuit have 2x bleeding time than mainland Danish ppl and had way lower CHD rates as well as main intake of food was fish
(lots of EPA and DHA)
-found that inc bleeding time = less clotting = less likely to have thrombosis
98
Fish high in EPA/DHA
mackerel (best), salmon, herring, sardines, trout
99
Arachidonic acid
Omega 6, 20:4n-6
needed for normal brain development
- if f.a. in platelet is this, cleaves off to form TxA2 which is a STRONG promoter of inflammation and clotting
100
Soluble fibre found in?
citrus fruits, oats, legumes, psyllium, most vegetables and fruit - 1/3 is soluble, 2/3 is insoluble)
101
What if I don't like fish?
- try frozen cod and Haddock (less fishy smell, good texture)
- supplements (still have 9kcal/g)
- microalgae (plant source of omega 3), seaweed, DHA rich eggs
102
a-linolenic sources
flax seeds, walnuts, canola oil
103
fish oil recommendations
- w/o CHD - 2 f.s./week (herring, salmon, trout)
- w CHD - ~1g EPA and DHA/day from fish
- needing to lower TC: 2-4g EPA and DHA/day
104
Concerned about contaminants in fish?
- have variety in kinds of fish
- limit top of the food chain fish (bioaccumulation; shark, marlin, tilefish, king mackerel, bluefin tuna, swordfish)
- canned tuna is good unless albacore
105
Albacore f.s/week
women pregnant/trying to get pregnant: 4
1-4 yrs old: 1 (1/2 can)
5-11 yrs old: 2
Ppl where its main source of protein: 10
106
Should doctors "prescribe" fish oils to dec CHD risk?
no -> no evidence to say this works same/has no side effects
107
Dietary Fats and Cancer
main cancers - prostate, breast, colorectal
- know little about the link b/n diet and cancer
- correlation b/n fat intake and 3 cancers
- mechanisms as to how f.a. causes cancer -> oxidized fats - malondialdehyde
- difficulty in separating fat intake from total kcal (since all diet related) -> western nations have increased fat, but also total kcal (which could have more impact than just the fats) .. in animals INJECTED with PUFA oil, it increased promotion since more opportunity for oxidation, but not able to conclude bc we don't inject oil
108
What happened if animals were given 80% of their ad libitum (all food they could eat)?
death rates dramatically decreased
109
How to reduce cancer risk (diet)?
dec overall fats, inc fibre, inc plant based foods (cruciferous veggies, colourful berries, citric fruits), inc whole grains, inc legumes/nuts/seeds
110
How to reduce cancer risk (lifestyle)?
don't smoke, inc physical activity, keep healthy body weight, dec exposure to enviro hazards
111
DRI recommendations of total fat intake from Health and; Welfare (1990) to 2002 DRI on Macros?
under 30%
| now, 20-35%
112
DRI recommendations of saturated fat intake from Health and Welfare (1990) to 2002 DRI on Macros?
under 10%
| was as low as possible, but American Heart Association in 2006 changed it to ~7%
113
DRI recommendations of trans fat intake from Health and Welfare (1990) to 2002 DRI on Macros?
little discussion on it
| low as possible!
114
DRI recommendations of MUFA fat intake from Health and Welfare (1990) to 2002 DRI on Macros?
```
majority
still majority (good for heart)
```
115
DRI recommendations of a-linolenic and linoleic acid intake from Health and Welfare (1990) to 2002 DRI on Macros?
Before, all PUFA under 10% because of oxidizability
Now, 1:10 ratio however most ppl are having more of a 1:17 ratio. They think we should try for 1:4 to actually get the 1:10 ratio
116
In class review: Role of free radicals in cancer process?
- Directly: damages DNA (directly; initiation)
- Indirectly: takes e- from PUFA leading to PUFA free radicals which eventually become short chain aldehydes -- malondialdehyde (cancer promoter)
117
In class review: TxA2 vs TxA3
Eicosanoids made from platelet fatty acids
TxA2: thromboxane made from arachidonic acid. Powerful aggregatory agent. More likely to result in thrombus (clot)
TxA3: thromboxane made from EPA (omega 6). 1/20th aggregatory strength (moderate). Still clots, but less chance of myocardial infarction
118
In class review: How does chylomicron get from lymph fluid to blood?
Reaches thoracic duct, fluids enter into blood
- doesn't go to liver once in the blood!
- goes everywhere in body once in blood
119
```
In class review:
What is notation of arachidonic acid?
Has 20 carbons, 4 double bonds, and is an omega 6.
```
20: 4n-6
120
In class review: Where is linoleic acid found?
any vegetable or grain oil
olive oil too
any oil is combo of many fatty acids
