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Semester 2 > Nutrition > Flashcards

Nutrition Flashcards

1
Q

nutrient

A

a substance obtained from food that is used by the body.

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2
Q

essential nutrient

A

substance that MUST be obtained from food

body cannot synthesize it

or cannot synthesize in sufficient quantities

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3
Q

or supplements

A

supplements were not explicitly mentioned on notes, so pay attention to multiple choice options

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4
Q

what happens if essential nutrients not taken

A

adverse effects on health

adverse effects may disappear when essential nutrient is taken

” unless permanent damage already taken place

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5
Q

6 classes of essential nutrients

A

vitamins

minerals

carbohydrates

lipids

proteins

water

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6
Q

micronutrients

A

vitamins and minerals

required in small amounts by the body

present in small amounts in the body

not broken down for energy

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7
Q

role of micronutrients

A

structural role (some)

regulatory role (most)

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8
Q

macronutrients

A

carbohydrates, lipids, proteins

required in large amounts in body

present in large amounts in body

can be broken down in body

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9
Q

macronutrients – structural or regulatory roles?

A

can have structural/regulatory roles

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10
Q

nutrition research

A

uses scientific/academic research methodologies to obtain information about nutrition

important to replicate findings

important for peer review of findings

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11
Q

what to check for when evaluating nutritional information

A

evidence from various studies

peer reviewed info

studies replicated

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12
Q

where is reliable information about nutrition found?

A

peer reviewed journals

registered dieticians

volunteer organizations, non-profit societies

Health Canada
NIH (US)
government sources

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13
Q

beware of…

A

sales pitch

claims that sound too good to be true

(extreme claims)

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14
Q

Dietary reference intakes

A

based on scientific research on nutrient requirements

intended for use by people in health professions (NOT THE PUBLIC)

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15
Q

requirements for Dietary Reference Intakes depend on the following variables:

A

age

gender

genetics

pregnant? lactating?

environment

current diet

E.g. # calories

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16
Q

other requirement variables

A

are there current deficiencies?

establish/maximize tissue stores?

decrease chronic disease risk?

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17
Q

what happens during deficiency of a micronutrient? What are the steps?

A

Lack in diet leads to

–> decrease in tissue stores, which leads to

–> biochemical changes, which leads to

–> clinical/anatomical changes, which leads to

–> death

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18
Q

DRI (Dietary Reference Intake) is applicable to

A

applies to already healthy people

specific based on gender & age

intended to be met by food, not supplements

already adequate intake of other nutrients is expected

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19
Q

categories of dietary reference intakes

A

DRI for most nutrients

vs.

DRI for energy and macronutrients

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20
Q

subcategories of Dietary Reference Intakes (subcategories under DRI for nutrients)

A

Estimated Average Requirement (EAR)

Recommended Dietary Allowance (RDA)

Adequate Intake (AI)

Tolerable Upper Intake Level (UL)

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21
Q

subcategories of Dietary Reference Intake (under DRI for energy & macronutrients)

A

Estimated Energy Requirement (EER)

Acceptable Macronutrient Distribution Range (AMDR)

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22
Q

Estimated Average Requirement (EAR) – DRI for nutrients

A

meets the needs of 50% of healthy people

specific to age/gender

applies to groups of people

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23
Q

Recommended Dietary Allowance (RDA) – DRI for nutrients

A

meets the needs of most healthy people (98% of healthy people)

RDA is based on EAR, so only set for nutrients with EARs established

used for individuals

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24
Q

Adequate Intake (AI) – DRI for nutrients

A

estimate that will maintain health

set when there is not enough evidence to establish EAR/RDA

used for individuals

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25
Q

Tolerable Upper Intake Level (UL) – DRI for nutrients

A

highest level of regular intake of nutrient that is acceptable for most

highest level unlikely to cause adverse effects to health

applies to most healthy people (98%)

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26
Q

where do toxic levels of micronutrients usually come from?

A

supplements

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27
Q

why do many nutrients not have UL established?

A

not enough evidence to set definite UL

however, that doesn’t mean that toxic levels don’t exist for that nutrient

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28
Q

note that DRI for Energy is distinct from

DRI for macronutrients

A

see following slides

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29
Q

Estimated Energy Requirement (EER) – DRI for energy

A

estimated energy intake that will maintain energy intake/output in 50% of people

balance intake/output = no weight (fat) gain/loss

RDA not used alongside EER, because it may cause energy intake above EER

applicable to adults who are maintaining the desired body weight/composition

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30
Q

Acceptable Macronutrient Distribution Range (AMDR) – DRI for macronutrients

A

distribution/ratio b/w 3 macronutrients

E.g.
Carb 45-65% of caloric intake
Lipids 20-35% of “
Proteins 10-35% of “

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31
Q

1 Calorie =

A

1 kcal

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32
Q

macronutrient, 1gram to kcal

A

carbohydates 4kcal/g

proteins 4kcal/g

fats 9kcal/g

(alcohol 7kcal/g)

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33
Q

nutrient density

A

nutrient contribution of foods

energy/caloric density = energy supply of foods

but nutrient density also refers to energy contribution of foods

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34
Q

nutrient dense foods =

A

many nutrients/kcal relative to the amount consumed

also –>
many kcal relative to the amount consumed
—> could be called calorie-dense (?)

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35
Q

DIETARY GUIDLINES (vs. Dietary Reference Intake)

A

intended for use by general public

E.g.
Canada’s Food Guide

–> helps improve health, meet nutrition needs, reduce chronic disease risk

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36
Q

2019 Canada Food guide

A

less prescriptive approach

based on flexibility

gives tips for healthy eating habits

recommends variety of healthy food choices

shows proportions of food (e.g. plate)

no prescriptive amounts

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37
Q

4 components of food labels

A

1) ingredient list

2) nutrient content claim

3) health claims

4) Nutritional facts table

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38
Q

1) ingredient list

A

in descending order by weight

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39
Q

2) nutritient content claim

A

must be measured

meet specific criteria
E.g.
low in fat, high in fibre, excellent source of…

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40
Q

3) Health claims

A

statements relating a food or “ component to risk of disease

only certain “Health Claims” are accepted in Canada

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41
Q

4) Nutrition Facts table

A

lists total amount of energy as well as amount of 13 core nutrients:

oTotal fat
o Saturated fat
o Trans fat
o Cholesterol
o Sodium
o Carbohydrates
o Fibre
o Sugar
o Protein
o Vit. A
o Vit. C
o Calcium
o Iron

% Daily Value (%DV) – based on 2000kcal/day diet and average
DRI values

general tool for comparing foods as nutrient sources

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42
Q

digestion

A

process of breaking down food into small molecules that can be absorbed

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43
Q

mechanical/chemical digestion

A

Mechanical digestion – breakdown … teeth and peristalsis

Chemical digestion – breakdown … acid (HCl) and digestive enzymes

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44
Q

absorption

A

Absorption – process by which small molecules enter the cells of the gastrointestinal tract (GI)

Lumen of intestine –> intestinal epithelial cell –> blood or lymph

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45
Q

mouth

A

mechanical and chemical digestion

  • Saliva secreted from salivary glands
    o enzymes for carbohydrate digestion
    o mucous for lubrication
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46
Q

esophagus

A

food to stomach with peristalsis

no digestion technically (?)

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47
Q

stomach

A

mechanical and chemical digestion

  • gastric juice containing HCl and enzymes
    (prot digestion)
  • pH ~2
  • secrete mucous …
    protect lining of stomach
  • Little/no absorption
  • Food + Secretions = Chyme
  • in stomach for 2-4hrs
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48
Q

chyme

A
  • Food + Secretions = Chyme
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49
Q

how long in stomach

A
  • in stomach for 2-4hrs
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50
Q

absorption in stomach?

A
  • Little/no absorption
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51
Q

what secrete in stomach?

A

mucous – protect lining

HCl/enzymes – digest food

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52
Q

small intestine

A

mechanical/chemical

Primary site of absorption

Upper part (duodenum) receives BILE, PANCREATIC JUICES

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53
Q

Bile

A

§ Formed by liver and stored in gallbladder

§ Contains bile salts to emulsify fats (aids in lipid digestion/absorption)

§ Contains bicarbonate ions (HCl3-) to neutralize acidic chyme

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54
Q

pancreatic juice

A

§ contains bicarbonate ions

§ contains digestive enzymes (for starches, fats, & proteins)

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55
Q

small intestine continued

A
  • cells lining intestine also secrete brush border enzymes – important for disaccharide and protein
    digestion
  • muscle action continues mechanical digestion and mixes chyme with bile and pancreatic juice
  • pH ~5-7
  • stays here for 3-10hrs
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56
Q

how long in small intestine

A

3-10hrs

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57
Q

pH small intestine

A

pH 5-7

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58
Q

what happens to chyme

A

mix with BILE & PANCREATIC JUICES

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59
Q

WHY BILE?

A

neutralize acidic chyme (BICARBONATE IONS)

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60
Q

WHY BILE? (2)

A

bile salts emulsify fats

lipid digestion/absorp

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61
Q

WHERE BILE FORMED?

A

liver

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62
Q

WHERE BILE STORED?

A

gallbladder

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63
Q

Pancreatic juices also contain …

A

BICARBONATE IONS

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64
Q

pancreatic juices contain …

A

digestive enzymes

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65
Q

WHAT ARE BRUSH BORDER ENZYMES

A

enzymes from BRUSH BORDER

ENZYMES FOR DISACCHARIDE & PROTEIN DIGESTION

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66
Q

WHAT IS BRUSH BORDER?

A

microvilli covered surface of epithelial tissue

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67
Q

Large intestine (colon)

A

little digestion, some absorption

stays 24-72hrs

do not secrete enzymes

has bacteria – have enzymes that digest food

secrete mucous for lubrication

absorption – water and some minerals
(e.g. Na & K)

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68
Q

large intestine how long?

A

stays 24-72hrs

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69
Q

large intestine what absorb?

A

water and some minerals
(e.g. Na & K)

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70
Q

how is GI tract regulated?

A

secretion of enzymes and peristalsis

under nervous system and endocrine system control

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71
Q

water

A

Carries nutrients throughout body

Solvent for minerals, vitamins, amino acids, glucose, etc

Removes waste from tissues/blood

participates in many chemical reactions

Joint lubricant

Shock absorber (eyes, spinal cord, joints, amniotic sac)
E.g.
CSF

maintain body temperature

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72
Q

dehydration

A

Water loss > water intake

heavy exercise or high temps

Increased risk for infants & elderly

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73
Q

micronutrient

A

substance obtained from food that is used by the body

for normal function, growth, and maintenance of body tissues

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74
Q

why RDA / AI

A

prevent deficiency disease

maintain tissue stores

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75
Q

UL

A

difficult to reach through natural foods (unfortified foods) alone

reached by taking supplements and fortified foods

poorly understood for most nutrients

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76
Q

supplements

A

Non-prescription Natural Health Products (NHP):

o vitamin & mineral supplements (single and multi-nutrient)
o amino acids
o essential fatty acids
o probiotics

NPN (natural product number)

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77
Q

benefit supplement?

A

o correcting problems with low nutrient intakes

o providing nutrients to reduce risk of chronic disease

or increase athletic performance

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78
Q

risk supplement?

A

o increased risks of toxicity

o contamination of supplements with other ingredients

o supplements cannot substitute for healthy eating
or living a healthy lifestyle

o “natural” does not mean safe or effective

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79
Q

vitamins functions (co-enzyme)

A
  • co-enzymes – helps enzymes to catalyze reactions in body

E.g. (B vitamins, Vit. C, Vit. K)

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80
Q

vitamins functions (antioxidants)

A

E.g.
(Vit. C, Vit. E)

neutralize free radicals

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81
Q

vitamins functions (hormone precursors)

A

(Vit. A & D)

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82
Q

fat-soluble vitamins

A

Vitamins A, D, E, & K

ADEK

stored in body generally

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83
Q

toxicity problem common with which fat-soluble vitamins

A

Vit A & D

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84
Q

how fat soluble vitamins absorbed?

A
  • Absorbed with lipids in small intestines
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85
Q

Vit K & Colon?

A

o Some Vit. K is produced by bacteria in colon,

can get absorbed there

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86
Q

lipid absorption impaired? FAT SOLUBLE VITAMIN ABSOROPTION WILL BE IMPAIRED.

A

Decrease bile production (liver disease)

Pancreatic disease (decreased enzymes required for fat digestion)

I.e.
PANCREATIC JUICES & BILE – Note also Gallbladder storing bile

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87
Q

how are fat-soluble vitamins transported in blood?

A

in-soluble in blood, like all lipids

transported via LIPOPROTEINS / binding proteins

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88
Q

Vitamin D

A

bone health (calcitriol?)

calcium absorption

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89
Q

vitamin d may reduce risk of

A

CVD, cancer, multiple sclerosis, etc

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90
Q

vitamin d toxicity (UL)

A

100ug/day

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91
Q

vitamin d recommendation

A

RDA 15ug/day (600IU)

maximize bone health

no sun exposure implied

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92
Q

vitamin A

A

regulate epithelium growth

important for vision cells (rods & cones)

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93
Q

vitamin A deficiency

A

night blindness

alopecia

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94
Q

vitamin K

A

activate coagulation factors (2, 7, 9, 10)

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95
Q

vitamin K deficiency?

A

prolonged bleeding time

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96
Q

vitamin E

A

antioxidant

protect membrane lipids from free radicals (“PEROXIDATION”)

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97
Q

vitamin E deficiency

A

peripheral neuropathy

Ataxia

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98
Q

water soluble vitamins

A

vitamin C

B vitamins

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99
Q

B vitamins list

A

B1 - thiamin

B2 - riboflavin

B3 - niacin

B5 - pantothenic acid

B6 - pyridoxine

B7 - biotin

B9 - folate

B12 - cobalamin

TRN
PPB
FC

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100
Q

water soluble vitamins

A

more easily excreted

except Vit B12 stored in liver

less likely cause toxicity

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101
Q

water soluble vitamins and food processing

A

Susceptible to destruction by food processing (heat during cooking, exposure to sunlight, leached into
cooking water, etc…)

heat, sun, boiling (water)

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102
Q

water soluble vitamins where absorb?

A

small intestine

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103
Q

water soluble vitamin how transport in blood?

A

soluble in blood

free in blood

or bound to proteins (some have carrier proteins)

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104
Q

water soluble vitamins coenzyme functions

A

coenzymes for reactions

involved in the breakdown of carbs, fats, and proteins into energy

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105
Q

water soluble vitamins functions in blood cells

A

synthesis of blood cells (folate (B9), B12, B6

Deficiencies = anemia

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106
Q

water soluble vitamins other functions

A

Nerve conduction – some B vitamins

Antioxidant – Vit. C

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107
Q

vitamin C

A

fruit/vegetable

antioxidant

coenzyme – Collagen synthesis

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108
Q

vit c deficiency

A

scurvy – poor wound healing, hemorrhages

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109
Q

vit c toxicity

A

UL 2000mg/day

diarrhea

kidney stones

increased iron absorption

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110
Q

vit c recommendations

A

maximize tissue saturation, minimize urinary excretion:

RDA men – 90mg/day
RDA women – 75mg/day

above “ = excreted in urine

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111
Q

how many servings of fruits/veg per day = ____mg Vit C

A

5 servings = 220-280mg vit C

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112
Q

Vitamin B deficiency (cause & symptoms)

A

see following slides

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113
Q

B1 (thiamin) deficiency

A

causes…
- alcoholism
- over-consuming milled rice

leads to…
- cerebellar symptoms (ataxia,
nystagmus)
- cerebral symptoms
(confabulation, psychosis)

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114
Q

B2 (riboflavin) deficiency

A

many causes for deficiency

leads to…
- scaling of lip borders
- magenta coloured tongue

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115
Q

B3 (niacin) deficiency

A

many causes for deficiency

leads to…
- pellagra
(diarrhea, dementia, dermatitis, &
if untreated, death)

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116
Q

B6 (pyridoxine) deficiency

A

causes…
- alcoholism
- hepatitis
- anti-TB therapy

leads to…
- scaling of lip borders
- convulsions

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117
Q

B12 (cyanocobalmin) deficiency

A

causes…
- aging
- poor nutrition
- removal of terminal ileum

leads to…
- anemia
- peripheral neuropathy

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118
Q

Folic Acid (B9) deficiency

A

causes…
- alcoholism
- pregnancy

leads to…
- anemia
- in early pregnancy can cause
neural tube defects

119
Q

Pantothenic acid (B5)

A

deficiency is rare

leads to…
…

120
Q

trace vs major minerals

A

arbitrary distinction

based on quantity found in the body or how much we need to consume daily

121
Q

minerals functions

A

Cofactors for chemical reactions (Zn, Mg, Fe, Cu, Mn)

Electrolytes – fluid & ion balance – maintain electrical gradients across cell membranes
(Na, Cl, K)

Structural Roles – bone and teeth – maintain protein structure (Ca, P,
Mg, Zn)

part of transport proteins (Fe in hemoglobin)

part of hormones (I in thyroid hormones)

Signal transduction in cells (Ca, P)

122
Q

mineral absorption

A

Mostly small intestine

123
Q

how substances in plants affect mineral absorption

A

Substances in plants can bind to minerals and reduce absorption

(fibre, phytate, oxalate)

124
Q

how does body regulate mineral absorption

A

Mineral status – absorption may be regulated so that it is increased in those with low levels

125
Q

how do minerals compete w/ each other

A

Other minerals – some interfere with each other’s absorption

§ High Ca reduces Fe & Mg absorption

§ High Zn reduces Cu absorption

126
Q

note example of plants and mineral

A

o 1 cup of milk has 300mg Ca - 95mg are absorbed

o 1 cup of spinach has 290mg Ca - 15mg are absorbed

127
Q

minerals and toxicity

A

toxic at levels not far above recommended levels

(low safety margin)

128
Q

Copper (Cu)

A

collagen synthesis

129
Q

Zinc (Zn)

A

cell signaling

adequate immune function

130
Q

Iodine (I)

A

thyroid hormone synthesis

131
Q

Iron (Fe)

A

for hemoglobin (O2 carrying protein of RBC)

sources:
muscle protein

health concern:
deficiency = anemia –> decrease O2 carrying ability

132
Q

Calcium (Ca)

A

maintain adequate bone health

source:
dairy = major source

health concerns:
deficiency = bone weakness –> leg bowing

133
Q

Phosphorus (P)

A

function:
fluid balance
bone formation
enzyme control

sources:
protein foods (meat, milk, cheese, eggs)

RDA:
700mg/day

health concerns:
high phosphorus intake:
muscle spasms/convulsions

134
Q

Chloride (Cl)

A

function:
fluid balance
immune function
part of HCl (stomach)

sources:
o Fresh fruit, vegetables, and whole grains
o Processed foods low in potassium

RDA/AI:
AI = 2.3g Cl/day (2300mg)
Almost all consumed as NaCl

Health concerns:
o High chloride intake
* May lead to hypertension in salt sensitive patients

o Low chloride intake
* Rare, but can occur with eating disorders

135
Q

Potassium (K)

A

function:
fluid/electrolyte balance
part of mm contraction
nerve AP transmission
maintains BP

Sources
o Fresh fruit, vegetables, and whole grains
o Processed foods low in potassium

RDA/AI:
o AI = 3.4g/day (3400mg)

136
Q

potassium health concerns

A

o Hyperkalemia
* High blood potassium
* Can alter normal heart rhythm resulting in heart attack
* Can occur in patients with kidney disease

o Hypokalemia
* Low blood potassium
* Can result from kidney disease, diabetic acidosis, or from some diuretic
medications

137
Q

sodium (Na)

A

major electrolyte

fluid balance

pH regulation

muscle contraction

nerve AP

138
Q

sodium (Na) sources

A

o Small amounts naturally present in most foods

o Added as salt (NaCl) to foods (~10% of salt eaten)

o During food manufacturing (processed foods account for ~75% of salt eaten)

139
Q

Na where absorbed

A

Absorption

o 95-99% of salt eaten gets absorbed in small intestine & colon (not regulated)

o Na levels are regulated in the blood by strict control of urinary Na excretion

140
Q

Na AI/UL

A

AI = 1.5 g/day (3.8g of NaCl)

o More if you sweat a lot

o UL = 2.3 g Na/day

o To minimize adverse effects of Na in blood pressure

o Typical North American intake = 2.3-5g Na/day

141
Q

Na deficiency

A

occurs with excessive fluid loss (vomiting, diarrhea, sweating = dehydration)

Symptoms
* Muscle cramps
* Dizziness & Nausea
* Leads to seizure, coma, death

cause changes in nervous system function, which can alter proper muscle function (e.g. cardiac muscle)

142
Q

Na health concerns

A

o Hypertension
high salt intake, high BP

o disagreements on effects of high sodium diets
= Some people more sensitive

143
Q

increase Na sensitivity in…

A

Increased sodium sensitivity also seen with

o Hypertension
o Diabetes
o Kidney disease
o Old age

high Na –> higher BP –> higher CVD

high BP –> CVD has strong evidence

high Na –> higher BP is debated

144
Q

how to reduce Na intake

A

whole foods

reduce sauce intake

read labels for sodium

reduced processed/outdoor foods

use other spices (e.g. pepper)

145
Q

monosaccharide

A

simple sugar

one sugar unit

E.g.
fructose (fruits/honey)

glucose

galactose

146
Q

fructose

A

most sweet

fruits, honey

sweetener (high fructose corn syrup)

147
Q

glucose

A

second most sweet

used most in body

present in small amounts in fruits/vegetables

148
Q

galactose

A

least sweet

in milk products

see lactose

149
Q

disaccharides

A

two sugar units

2 monosaccharides linked

maltose
sucrose
lactose

150
Q

maltose

A

glucose + glucose

note starch digestion

not generally found in foods (but part of breakdown)

151
Q

sucrose

A

glucose + fructose

table sugar

in fruits, some vegetables, & grains

152
Q

lactose

A

glucose + galactose

milk sugar

153
Q

disaccharide to monosaccharide enzymes

A

maltose uses maltase

sucrose uses sucrase

lactose uses lactase

154
Q

disaccharides must be

A

must be converted to monosaccharides before the body can use them

only one enzyme for each disaccharide

enzymes via Intestinal brush border

155
Q

lactose intolerance

A

people lack digestive enzyme lactase

lactase normally decrease as a person ages

infants have high levels

during lactose intolerance——->
whole disaccharide remains intact in the intestines —> = GI discomfort

156
Q

polysaccharide

A

many sugar units

w/ proper enzymes –> broken down into simple sugars

157
Q

starch (polysaccharide)

A

glucose chains

plants

grains, legumes, tubers (potato)

158
Q

fibre (polysaccharide)

A

chains of sugars

plant stems/leaves

does not get broken down to simple sugars

helps bowel movement health / GI health

cows have enzymes to break down fibre to monosaccharides

159
Q

glycogen (polysaccharide)

A

chains of glucose

produced in body to store glucose

store glycogen in skeletal muscles & liver

not really via food

160
Q

carbohydrate digestion (polysaccharide)

A

polysaccharide

up to 4 hours get to blood

161
Q

in mouth

A

salivary amylase in mouth

– breaks long polysaccharide chains into DEXTRIN chains

– DEXTRIN also a polysaccharide

162
Q

in small intestine

A

DEXTRIN broken to disaccharide

via PANCREATIC JUICES (ENZYMES)

THEN…
Brush Border Enzymes break down disaccharides

– BB enzymes = maltase, lactase, sucrase

Monosaccharides taken to liver & other cells

163
Q

monosaccharides digestion

A

sugar can be in blood in 20 mins after eating

taken to liver & other cells via blood after reaching small intestine

164
Q

Glucose metabolism

A

liver converts monosaccharides to GLUCOSE

165
Q

where glucose go?

A

energy for cells

most tissue prefers glucose – But fats also used

Brain & RBC can ONLY USE GLUCOSE (not fat)

166
Q

what happens if not enough carbs?

A

GLUCONEOGENESIS

make glucose from proteins/fats etc.

or KETONE BODIES as alternate energy for brain
—> Can cause problems (?)

167
Q

how else is glucose used?

A

for other important molecules

RIBOSE for RNA/DNA synthesis

Note also glucose & Kreb’s cycle intermediates (???)

168
Q

blood glucose regulation

A

eating = increase blood Glucose = increase INSULIN from pancreas = DECREASE BLOOD SUGAR

(glucose uptake by cells via Insulin)

169
Q

blood glucose regulation when not eating

A

decrease blood sugar

–> increase GLUCAGON from pancrease

–> increase blood sugar

(GLUCOSE RELEASE FROM GLYCOGEN INTO BLOODSTREAM)

I.e.
glucose via glycogen
+
glucose via gluconeogenesis

170
Q

tight regulation of blood glucose

A

fasting blood glucose
= 4-6mM (millimole) (per Litre?)

less than 3mM (per litre?) = Life-threatening (?)

greater than 6mM (per litre?) = dehydration / tissue damage

171
Q

health conditions & glucose

A

type 1 diabetes

type 2 diabetes

complications of type 1/2 diabetes

dental caries (cavities)

172
Q

type 1 diabetes

A

Insulin Dependent Diabetes Mellitus (IDDM)

10% of diabetics

Autoimmune disease

immune system attacks pancreas cells that produce insulin

–> I.e. lack of insulin

Usually before 20y/o

FATAL IF INSULIN NOT TAKEN

173
Q

type 2 diabetes

A

Non-Insulin Dependent Diabetes Mellitus (NIDDM)

90% diabetics

usually after 40 y/o

becoming more common in younger people & children

174
Q

type 2 diabetes cause

A

family history

lack of exercise & physical activity

obesity

diet

environmental factors (?)

175
Q

type 2 diabetes mechanism

A

a) insulin released in decreased quantities

and/or
b) insulin released, but tissue becomes resistant to insulin

I.e.
less uptake of glucose

176
Q

recommendation to decrease risk of type 2 diabetes

A

healthy diet

healthy body weight (body fat)

regular physical activity

177
Q

complications of type 1/2 diabetes

A

via hyperglycemia

– dehydration (excess glucose released in urine

– excess urine production

– GLYCOSYLATION of proteins
(glucose attaches to proteins in blood)
I.e.
reduced circulation in some areas (Esp. EXTREMITIES)

ALSO
–> damage of endothelial cells of BV
–> INCREASED RISK OF ATHEROSCLEROSIS

kidney & eye disease

178
Q

note GLYCOSYLATION of proteins in blood

A

= decreased circulation in some areas (ESP. extremities)

= damage to endothelial cells of BV

= increased risk of atherosclerosis

Note that sugar in blood can potentially be worse than saturated bad for atherosclerosis

179
Q

note diabetes & eye disease

A

= damage to blood vessels around eyes

180
Q

dental caries & carbohydrates/sugars

A

Bacteria digest carbohydrates around teeth

–> acids are biproduct of bacteria metabolism

–> erosion of enamel

–> cavities

181
Q

dietary carbs recommendations

A

Carb requirement ~ 50-100g/day to prevent build up of ketone bodies (~10-20% of kcal)

RDA = 130g/d
o based on average amount of glucose used by brain (~25% kcal for a 2000kcal/d diet)

AMDR = 45-65% of total kcal as carbohydrates

o <45% makes it difficult to get enough nutrients that come from carb rich foods (fibre, vit. C, folate, etc…)

o >65% makes it difficult to eat enough protein & EFAs

182
Q

carbohydrate recommendation for people who are physically active

A

“Recommendations for Athletes”
* 55-65% of kcal as carbs

  • carbs are usually major fuel for muscle (from stored glycogen & blood glucose)
  • glycogen stores are maximized by a high carb diet
183
Q

fibre types

A

soluble

insoluble

184
Q

soluble fibre

A

in water they swell up

form gel

185
Q

where soluble fibre?

A

in fruits & legumes, oats & barley

“gums, mucillages, pectins, & some hemicelluloses”

186
Q

effect of soluble fibre

A

slow gastric emptying & time through stomach and small intestine

§ feel full for longer
§ slows glucose absorption

187
Q

soluble fibre & blood cholesterol

A

o decrease blood cholesterol by decreasing reabsorption of bile acids, and therefor increasing
bile acid synthesis from cholesterol in liver

188
Q

does soluble fibre have laxative effect

A

no

189
Q

insoluble fibre

A

in all plants

“esp high in bran, legumes, root vegetables & whole grain foods”

“cellulose, some hemicelluloses, & lignan”

190
Q

insoluble fibre effect

A

o increases fecal bulk by not breaking down – attracting water

§ increases speed of movement through colon

o can have a laxative effect
§ decreases constipation & associated disorders

191
Q

health benefits of fibre

A

the benefits of fibre alongside other components of a high fibre diet

o diets low in cholesterol & total and saturated fats

o high in phytochemicals & antioxidant vitamins

192
Q

dietary fibre recommendations

A

= ~25g/d for women (Cnd avg 15-17g/d)
= ~38g/d for men (Cnd avg 19-22g/d)

193
Q

too much fibre

A
  • too much fibre is not good (~60g/d or more)

o GI discomfort

o Can bind to minerals and decrease their absorption

o Can displace nutrient/energy dense foods

194
Q

3 groups of lipids

A

triglycerides

phospholipids

sterols

195
Q

trigglycerides

A

major fat in diets

glycerol backbone (3 carbon alcohol)

+ 3 fatty acids (long chains of Carbon surrounded by Hydrogen)

196
Q

function of triglycerides

A

energy storage

insulation

cushioning organs

197
Q

phospholipids

A

glycerol backbone

+ 2 fatty acids
+ phosphate group (head)

amphipathic
–> head hydrophilic
–> tails hydrophobic

198
Q

function of phospolipids

A

part of cell membranes

component of bile

assist with lipid transport

precursor of EICOSANOIDS (hormone-like substances)

199
Q

sterols

A

E.g. cholesterol

& other compounds made from cholesterol (animals)

& plant sterols

200
Q

function of sterols

A

part of cell membrane (structure when heat, fluidity when cold)

precursor to bile acids & STEROID hormones

201
Q

fatty acids

A

chains of carbon atoms

bound to other compounds

not found free in foods, or body

Triglycerides and phospholipids contain fatty acids

202
Q

types of fatty acids

A

saturated & unsaturated fatty acids

cis vs trans fatty acids

203
Q

saturated fatty acids

A

no double bonds

i.e.
fully saturated with hydrogen
(single covalent bonds (?))

204
Q

saturated fats @ room temp

A

tend to be solid

e.g. bacon fat

205
Q

saturated fats where?

A

foods from animals

(dairy, meat)

206
Q

saturated fats & oxidation?

A

not susceptible to oxidation

207
Q

saturated fats & blood cholesterolal

A

increase blood cholesterol

increase risk of CVD

208
Q

unsaturated fatty acids

A

one or more double bonds

include Monounsaturated fatty acids (one double bond)

& polyunsaturated fatty acids (more than 1 double bond)

209
Q

unsaturated fatty acids facts

A

liquid at room temp

foods from plants

do not raise blood cholesterol (?)

210
Q

MUFA & PUFA (unsaturated fats)

A

see following slides

211
Q

PUFA (polyunsaturated fatty acids) –> rancidity

A

susceptible to OXIDATION

(chemical damage to molecules)

(causes rancidity in foods)

damage to cell membrane, DNA, & other molecules

damage increases risk of cancer & CVD

212
Q

cis vs trans fatty acids

A

Hydrogen atoms around double bonds on SAME side

most Unsaturated fatty acids are CIS

213
Q

trans fatty acids

A

produced by microorganisms

small amount found in dairy

made also by hydrogenation of plant oils

changes shape of fatty acid (HYDROGEN around double bond on OPPOSITE SIDE)

214
Q

trans fatty acid behaves like…

A

saturated fats

solid @ room temp

increase blood cholesterol

215
Q

some notes about naming fatty acids

A

location of first double bond (E.g. omega 3 / 6)

also via length of carbon chain

also via total number of double bonds

E.g.
alpha linolenic acid (type of OMEGA 3 fa)

–> first double bond @ carbon 3 (b/w 3 & 4) (“counting from omega end”)

other name: C18:3
I.e.
18 carbons in whole chain
3 double bonds in total

216
Q

essential fatty acids

A

2

omega 3 & 6 (different types for each)

cannot be made in body

must obtain from food

217
Q

why essential?

A

for cell membrane

for growth/development

precursor for other PUFAs –> to eicosanoids

–> i.e. regulation of clotting & inflammation

218
Q

omega 6 fatty acids types

A

linoleic acid

arachidonic acid

219
Q

linoleic acid

A

animal and plant fats

vegetable oils

growth & skin cell function

deficiency = growth problem, skin problem

LINOLEIC ACID IS PRECURSOR OF ARACHIDONIC ACID (other omega6 fa)

–> Used to make eicosanoids
–> inflammation response & blood clotting
(immune response)

220
Q

types of omega 3 fatty acids

A

alpha linolenic acid

eicosapentaenoic acid (EPA)

docosahexaenoic acid (DHA)

221
Q

alpha linolenic acid

A

high in canola oil, soy, flaxseed oil

small amount in animal fats

precursor for other omega 3 fa (eicosapentaenoic acid)
(docosahexaenoic acid)

222
Q

EPA & DHA

A

o eicosapentaenoic acid [EPA]
§ precursor for eicosanoids that decrease inflammation and blood clotting

o docosahexanoic acid [DHA])
§ important component of cell membranes – found in high levels in the brain

223
Q

are EPA & DHA made in plants?

A

EPA & DHA are not made in plants

o small amounts found in fatty fish oil, some shellfish, very small amounts in meat and
eggs

o deficiency is not well understood
§ Impaired visual and neural function

224
Q

digestion of lipids

A

Lipids in our diet:

  • 95% triglycerides
  • some phospholipids and sterols (sterols are mostly cholesterol)
  • fat soluble vitamins get absorbed with other lipids
225
Q

where most digestion

A

small intestine

226
Q

what essential for lipid dig

A

Bile is essential for lipids to be digested in this water environment

227
Q

what bile do

A

o Bile helps pancreatic enzymes to be able to reach the fat molecules to cleave the fatty acids off
triglycerides, phospholipids and cholesterol

228
Q

bile mechanism

A

§ Fats form droplets in intestine that make it hard for enzymes to penetrate to molecules inside

§ Bile contains bile acids and phospholipids that can interact with water and lipid

§ Fat droplets are broken into smaller droplets (emulsification)

§ Allows enzymes to access more lipid molecules

§ = digestion
efficiency

229
Q

what bile also do

A

o Bile also interacts with the products (forms micelles) of digestion to bring them close enough to the intestinal cells to be absorbed into the cells

§ = digestion efficiency

230
Q

triglycerides and phospholipids in intestinal cells

A

Once inside the intestinal cell
o Triglycerides and phospholipids reform

231
Q

chylomicrons

A

o Reformed fat molecules combine with
a) proteins, b) cholesterol, and c) fat soluble vitamins

–> to form particles called chylomicrons

232
Q

how chylomicrons go to blood?

A

o Chylomicrons enter lymphatic vessels & lymph transports chylomicrons to the blood

233
Q

Bile acid recycling

A

o Bile acids do not get absorbed with products of lipid digestion (chylomicrons?)

bile?
o Absorbed later in the small intestine and returned to liver via blood (hepatic portal vein)

o Usually 90% recirculated back to liver (pretty efficient)

234
Q

how fibre reduce cholesterol

A

o soluble fibre in small intestine

= binding of bile acids to soluble fibre

= excretion of bile acids in feces

= liver production of new bile acids from cholesterol

= lower blood cholesterol levels

235
Q

how transport lipids?

A

lipids are not soluble in water/blood,

so transporting them in blood requires bind to other molec

(lipoproteins)

236
Q

lipoproteins

A
  1. Chylomicrons
  2. VLDL (very low density …
  3. LDL (low density …
  4. HDL (high density …
237
Q

Chylomicrons

A

Chylomicrons

o transports triglycerides and other lipids from intestines

o to adipose tissue for storage

o to the liver

238
Q

where chylomicrons go?

A

o to adipose tissue for storage

o to the liver

239
Q

VLDL

A

VLDL (very low density lipoprotein)

o transports triglycerides from the liver to other tissues

240
Q

where vldl go?

A

from the liver to other tissues

241
Q

ldl

A

LDL (low density lipoprotein)

o transports cholesterol from liver to other tissues

o known as “bad” cholesterol – can get trapped in arterial walls if inflammation is present

242
Q

where what ldl go take?

A

o transports cholesterol

from liver to other tissues

243
Q

HDL

A

HDL (high density lipoprotein)

o transports cholesterol from tissues to liver

o known as “good” cholesterol – can transport cholesterol from walls of arteries back to liver

244
Q

hdl where what?

A

o transports cholesterol

from tissues to liver

245
Q

why hdl good?

A

can transport cholesterol from walls of arteries back to liver

246
Q

Lipids and Cardiovascular Disease (CVD)

A

Atherosclerosis

Blood LDL levels

w-3 Fatty Acids & CVD

247
Q

Atherosclerosis

A

CVD – lipid deposits on arterial walls

248
Q

atherosclerosis increased risk =

A

§ high blood cholesterol (as LDL)

§ high blood triglycerides (mainly as VLDL)

249
Q

atherosclerosis protective measure?

A

o protective blood marker
§ high HDL levels

250
Q

blood LDL levels & CVD

A

see following slides

251
Q

why blood LDL increase?

A

o increase due to increased dietary cholesterol, saturated & trans fats

252
Q

how decrease blood LDL? Decrease dietary cholesterol?

A
  • but usually only results in small LDL decrease because liver often increases
    cholesterol synthesis in response to decreased dietary cholesterol
  • although some people respond with greater LDL decrease
253
Q

decrease blood LDL – decrease saturated fat?

A
  • usually more effective than decreasing cholesterol
254
Q

decrease blood LDL – decrease trans fat?

A
  • effect similar to decreased saturated fat
  • but, this will also support healthy HDL levels as high trans fats also decrease HDL levels
255
Q

decrease LDL – increase dietary fibre?

A
  • reduces LDL by reducing body’s cholesterol levels

why?
b/c decrease recirculation of bile acids

I.e.
cholesterol used to make bile

256
Q

w-3 Fatty Acids & CVD

A
  • reduce risk of death due to heart disease largely by reducing tendency of blood to clot
257
Q

dietary lipid recommendations (AMDR)

A

Total Fats
AMDR = 20-35% of total kcal as lipids

o < 20% make it difficult to obtain sufficient EFAs

o > 35% make it hard to stay below upper limit for saturated fat & cholesterol intake

258
Q

AMDR of lipids for “athletes”

A

AMDR for “athletes”

= 20-25% of total kcal as lipids

o To allow for high carb intake without reducing proteins

259
Q

saturated fat AMDR

A

Saturated Fat
AMDR = < 10% of total kcal

260
Q

trans fat AMDR

A

Trans Fat
AMDR = < 1% of total kcal

261
Q

Essential Fatty Acids AMDR

A

Linoleic Acid (w-6) AMDR

= 5-10% of total kcal
a-Linolenic Acid (w-3) AMDR
= 0.6-1.2% of total kcal

262
Q

why need protein?

A

o maintaining our amino acid pool to make peptide hormones, neurotransmitters, etc…

o producing strength & structure to tissue – connective tissue, epithelial tissue, tendons, ligaments,
bones, cartilage

o contractile proteins – muscle

o making proteins that carry nutrients and hormones through the blood

o producing all our body’s enzymes

o making membrane proteins

o hormones

o energy production

o maintaining the immunoglobulin pool (immune system)

o buffering various body fluids

o producing & maintaining DNA & RNA

263
Q

what are proteins?

A
  • chains of amino acids held together with peptide bonds

o amino group of one amino acid joins the carboxyl group of the next amino acid

264
Q

how peptide bonds broken down?

A

o peptide bonds are broken by hydrolysis

§ this breaks proteins into amino acids and short chains of amino acids

265
Q

how similar to lipid & carbohydrate?

A
  • contain C, H, & O (like carbs and lipids), but also contain N
  • the “R” group (side chain/amino group) is different for each amino acid
266
Q

shape/form of protein vs function?

A
  • the shape of the protein is key for its function

o although they can be chemically reproduced, it is difficult to reproduce the intricate shapes

267
Q

types of proteins

A
  • dipeptide – chain of 2 amino acids
  • tripeptide – chain of 3 amino acids
  • oligopeptide – chain of 3-10 amino acids
  • polypeptide – chain of many amino acids
  • protein – chain of > 50 to many 100s of amino acids
268
Q

essential amino acids

A

20 (or 22) amino acids

body can produce 11 (non-essential via TRANSAMINATION (transferring amino groups)

CANNOT PRODUCE NINE (9)

9 = essential

some are conditionally essential (E.g. during infancy)
(during pathology?)

269
Q

vegetable/plant proteins?

A

not contain all 9

eat variety of plant proteins to get 9

or eat meat/animal protein

270
Q

protein digestion

A

in stomach:

o HCl acid denatures proteins to expose whole molecule to enzymes

o PEPSIN (enzyme secreted in stomach)
breaks protein into shorter polypeptides

271
Q

proteins in small intestine

A

proteases & peptidases FROM PANCREAS

–> break proteins and large polypeptides into small
polypeptides, tripeptides, dipeptides, and amino acids

272
Q

in small intestine after pancreatic enzymes/juices

A

o enzymes on brush border break small polypeptides to

tripeptides, dipeptides, and amino acids

273
Q

what can be absorbed into intestinal lining?

A

o only tripeptides, dipeptides, and single amino acids can be absorbed into intestinal cells

274
Q

what happens @ intestinal cells?

A

o Tri & dipeptides broken into amino acids before entering blood

275
Q

what happens to amino acids?

A

uptake by tissues E.g. liver

put together to make proteins

or gluconeogenesis (glucose)

or broken down for energy directly (?)

or made via fats (AAs?)

276
Q

what happens when AA gets used for energy/energy/fats?

A

results in a toxic ammonia molecule
(NH3)

o liver converts ammonia to urea
o kidney excretes urea from body

277
Q

Protein Synthesis

A

amino acids needed

non-essential via body or food

essential via food

278
Q

how is structure of protein determined?

A

via DNA of a gene

279
Q

how protein made?

A

o transcription – genetic information in DNA is used to make a messenger RNA (mRNA)
copy

o translation – converting genetic information on mRNA into a chain of amino acids to form a
protein

280
Q

dietary protein – quality of protein

A
  • Complete Protein (aka: high quality protein)

o dietary protein containing all of the essential amino acids in relatively the same amount the
human beings require

o animal protein, soy, quinoa

281
Q
  • Incomplete Protein (aka: lower quality protein)
A

o low in one or more essential amino acids

o most plant proteins, especially grains

§ plant proteins tend to be highly associated with fibre, which also decreases their
“digestibility”

282
Q

note fibre & protein digestion

A

§ plant proteins tend to be highly associated with fibre, which also decreases their
“digestibility”

283
Q
  • Complementary Proteins
A

o two different proteins whose amino acid profiles complement each other, so that the
essential amino acids missing from one, are supplied by the other

o ie: eating rice and beans together

284
Q

quantity of protein

A

o animal proteins generally more nutrient dense than plants

o higher nutrient density for proteins = meat, seafood, dairy, legumes

285
Q

nitrogen balance

A

nitrogen balance is when:

o nitrogen incorporated into the body each day = nitrogen excreted each day

o negative nitrogen balance = excreted > added

o positive nitrogen balance = excreted < added

286
Q

negative nitrogen balance

A

o protein malnutrition
o dietary deficiency of even 1 essential aa
o starvation
o uncontrolled diabetes
o infection

287
Q

positive nitrogen balance

A

o growth
o pregnancy
o recovery from a condition associated with negative nitrogen balance

288
Q

protein RDA

A

RDA = 0.8g protein/day/kg body weight
o should be high quality mixed protein diet for both vegetarians and omnivores

AMDR = 10-35% of kcal

o < 10% = risk of not meeting protein requirement

o > 35% = risk of inadequate carb & fat intake

289
Q

inappropriate protein nutrition –> effects on health (low protein intake)

A

o most widespread form of malnutrition worldwide

o Marasmus

o Kwashiorkor

o also a risk in North America

290
Q

low protein intake affects who?

A

o most widespread form of malnutrition worldwide

o affects mostly children

o many die due to impaired immune system function

291
Q

o Marasmus

A

o severely inadequate intakes of protein, energy, and other nutrients

§ severe wasting of muscle tissue
§ stunted physical growth
§ stunted brain development
§ anemia
§ fluid & electrolyte imbalances

292
Q

o Kwashiorkor

A

o Extremely low protein intake in early weaning, complicated by infections

§ some weight loss and muscle wasting
§ edema resulting in abdominal distention
§ delayed growth & development
§ skin sores & brittle hair

293
Q

who in north america?

A

o alcohol/drug users
o homeless
o low income elderly

o those with illnesses that interfere with eating
§ anorexia nervosa
§ AIDS
§ cancer
§ tuberculosis

294
Q
A

Semester 2 (14 decks)

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