Nutrition Flashcards
(151 cards)
1
Q
Structure of amino acids
A
central carbon, amino group and acid group
- Side group varies and gives it its properties
2
Q
Acidic group and aromatic group properties
A
Acidic group- important to maintain pH balance in body. They can easily donate hydrogens.
Aromatic group- starting point for our neurotransmitters. Tyrosine, Phenylalanine, Tryptophan
3
Q
2 sulphur based AAs
A
Methionine and Cysteine
4
Q
How many essential and non essential AAs are there?
A
11 non essential and 9 essential
5
Q
What is transamination?
A
how body makes nonessential amino acids - b6 needed
Amino acids transfer amino group to keto acid to synthesise non-essential amino acids in this process
6
Q
which amino acid has an imino group?
A
proline - part of procollagen matrix
7
Q
EQ: What are the BCAAs?
A
isoleucine
leucine
valine
8
Q
What are BCAAs used for and how are they used?
A
Do not have to be metabolised in the liver, utilised directly by muscles
Energy + protein synthesis
Leucine most potent inducer of muscle protein synthesis, and stimulates insulin secretion (maybe leading to hypoglycaemia)
- useful in burns, sepsis and liver disease due to increased protein catabolism and increased needs
9
Q
What are highest sources of BCAAs?
A
Highest sources in meats, isoleucine highest in legumes + meat, low in grains
10
Q
What is maple syrup urine disease?
A
Inability to break down BCAAs
neonates with vomiting, feeding issues
lifelong dietary control of BCAA and protein intake, thiamine useful
11
Q
What is one risk of BCAAs?
A
Can increase plasma ammonia levels - nausea, diarrhoea, vomiting
12
Q
EQ: What is glycine and what is it useful for?
A
Non-essential, an inhibitory neurotransmitter
Precursor to glutathione which is an inhibitory neuromodulator and antioxidant > useful for anxiety; panic disorders; addiction and insomnia.
Useful for muscle spasm
No known toxicity
13
Q
What is proline and what is it used for?
A
Protein and collagen synthesis -> iron and vitamin C required for this process
Supplement as hydrolysed collagen:
- Osteoarthritis: 2-10g/day
- Joint pain for athletes: 5-10g/day
14
Q
What is collagen made of?
A
proline, glycine and lysine
15
Q
What is alanine?
A
Essential - second most abundant after glutamine
Protein synthesis and energy production - gluconeogenesis in the liver in glucose-alanine cycle with glutamine
β-alanine useful for athletes -> removes ammonia from the body and recycles glucose via liver gluconeogenesis, decrease acidosis and muscle fatigue
16
Q
Where is alanine found?
A
Found in poultry, beef, and fish - for vegans, only source is that created in the liver
17
Q
What is a non athletic benefit of alanine?
A
Increase cognition in older adults
18
Q
What is lysine useful for?
A
Inhibits viral replication (herpes) and increases time to resolution
Protein and peptide synthesis, especially for collagen, elastin and hormonal proteins
19
Q
What does lysine compete with and where is it found?
A
Competes with arginine, consume low arginine to maximise absorption of lysine
High in gelatine, legumes, animal protein, low in grains
20
Q
What is arginine and what is it used for?
A
Conditionally essential
Energy Production - precursor for gluconeogenesis
Required for certain viral replication processes - contraindicated with herpes and competes with lysine
Contributes production of NO - lowers BP
Used for pregnancy, hypertension, hyperlipidaemia, erectile dysfunction
21
Q
What is tryptophan a precursor for?
A
makes T-HTP to produce serotonin and melatonin
22
Q
What is tryptophan used for?
A
Energy production, protein synthesis
Mood + sleep, depression, Seasonal Affective Disorder (SAD) and PMS - improves insomnia
Major interactions occur with anti-depressant medications
23
Q
What is phenylalanine a precursor for?
A
Essential
Precursor for L-Tyrosine which is a precursor for dopamine + adrenaline
L-tyrosine also required for T4 production where conversion to T3 requires selenium for activation, and iodine, vitamin c, zn and Fe for synthesis
24
Q
What is phenylalanine used for?
A
Energy production, protein synthesis
Cognitive performance + memory, sleep deprivation, depression, ADHD, stress, alcohol and drug withdrawal, hypertension, schizophrenia
25
What is phenylketonuria?
rare autosomal, metabolic disorder
missing enzyme to break phenylalanine down - damage to the CNS and seizures
Requires low protein diet
26
EQ: What is tyrosine? What are its cofactors for the production of thyroid hormones?
conditionally-essential amino acid produced from phenylalanine
Precursor to dopamine and adrenaline
Production of thyroxine after it undergoes iodination
Nutrient cofactor for activation of t4 to t3 is selenium
Nutrient cofactor for synthesis of T4 are tyrosine, iodine, vitamin c, Zn, Fe
Required for melanin synthesis in skin, eyes and hair
27
What needs to be supplemented in PKU?
tyrosine because cannot consume phenylalanine
28
What is glutamine used for?
Conditionally essential - Most abundant AA in body and a precursor to nucleotides, found in all protein foods
Cardioprotective, protein synthesis, gut health
Major source of energy for enterocytes and lymphocytes, hepatocytes
GIT protection and repair, endothelium and enterocyte health and proliferation
Cross the BBB and metabolised to glutamate - excitatory neurotransmitter
29
What are the 3 things that make glutathione?
glutamine
cysteine
glycine`
30
What is the pathway to make GABA?
Glutamine -> glutamate -> GABA
requires B6
31
What is glutamate a precursor for?
Excitatory neurotransmitter metabolised to GABA (inhibitory) requiring B6
Antioxidant (precursor to glutathione production with glycine and cysteine)
32
What is glutathione used for?
Cellular anti-oxidant - assists Phase 1 and Phase 2 liver detoxification
DNA synthesis + repair, cellular homeostasis, prostaglandin synthesis
Adjuvant to chemotherapy, assist chronic degenerative diseases, help infertility,
33
Factors increasing glutathione demand
Neurodegenerative + CVD
Diabetes, parkinsons, cancer
Liver and autoimmune diseases
34
Deficiency signs of glutathione
fatigue; pale skin; shortness of breath; light-headedness; haemolytic anaemia.
35
EQ: Factors causing high homocysteine and its effect
low B12, low folate, low b6
low fertility, depression, CVD, genes not regulated properly
36
What is methionine? What is it metabolised to?
essential sulphur-based amino acid
first metabolised by liver into S-adenosyl methionine (SAMe) - body's main methyl donor and starts methylation process
Methylation process important for synthesis of epinephrine, melatonin, myelin sheath maintenance, gene expression, cell membrane phospholipid layer fluidity, metabolism of homocysteine
Important for conversion of homocysteine and back into methionine
37
Food sources of methionine
beef, fish and dairy
38
What is cysteine?
Conditionally essential pre-cursor to glutathione with glutamate and glycine
protein + energy synthesis, mucolytic, detoxification for drugs
Mucolytic - useful for chronic obstructive pulmonary disease (COPD), Cystic fibrosis, Pneumonia, Bronchitis
39
Vitamin C RDI
RDI = 45mg (+35mg smokers)
SDT = 190 - 220mg
40
Vitamin C food sources and functions
found in capsicum, citrus, parsely, broccoli, carrot
- best consumed raw
iron absorption and neurotransmitters - Promotes conversion of:
tryptophan to serotonin
phenylalanine to tyrosine
dopamine to noradrenaline
Vitamin C needs escalate during physical stress - Common cold, immunocompromisation, acute and chronic stress
Collagen synthesis - Cofactor for hydroxylase enzyme involved in metabolism of Glycine, Proline and Hydroxyproline into Collagen
- with iron
41
vitamin c deficiency signs
Fatigue, joint pain, muscle pain, rough skin, anaemia, poor dentition
wound healing problems, poor immunity
Smokers -> have higher need for vitamin C and antioxidants
42
vitamin deficiency if mood problems present
B6 as involved with neurotransmitter production
43
vitamin deficiency inflamed tongue present
B12
44
vitamins for energy
iron and vitamin C, B12 and folate for red cells
45
MC: coenzyme (Active) form for thiamin
TPP - thiamin pyrophosphate
46
Thiamin doses
Need magnesium to convert to active form
Has an RDI (1.1mg) and SDT - alcoholism up to 50mg per day
47
What is thiamin used for?
Energy production: cofactor for enzymes involved in TCA/citric acid cycle
Fat, sterol and nucleic acid production
Exercise and growth: support muscle growth, reduces muscle fatigue and soreness
Low energy (inadequate dietary intakes): supports conversion of macronutrients into energy (ATP)
Nerve + brain function -> Supports thalamus, hypothalamus, cerebellum, brainstem and mammillary bodies function. Substrate for neurotransmitters that support mood and relaxation (via methylation cycle) - stress
48
Factors increasing thiamin demand and signs of deficiency
Alcoholism - 4/5 are deficient
Pregnancy
Malnutrition
Chronic illness
Medications
Loss of appetite, nausea, weakness, faitufe, sleep disturbance and irritation
Late signs - Beri beri
49
Dry vs wet beri beri
Dry beri beri - nerve damage, muscle weakness and wasting, no oedema
Wet beri beri - cardiovascular and respiratory problems, congested heart failure, oedema
Wernicke-Korsokoff syndrome - Cerebral beri beri and typically alcohol-induced:
- Includes brain damage
- Ataxia, nystagmus (eye-rolling)
- Confusion, vertigo
50
Sources of thiamin
yeast, cereal grains, breads, nuts and meat
Half is in skeletal muscle, rest in brain, liver, heart and kidneys
51
Riboflavin (b2) pathway
glutathione peroxidase pathway
Forms a part of of FAD that acts as a co-factor for glutathione reductase, which reduces oxidised glutathione back to its active form.
Detoxification: Glutathione supports a pathway in the liver to metabolise and excrete toxins
52
Riboflavin effects in the body
may also be synthesised by colonic bacteria.
- Energy production - Coenzymes involved in TCA/citric acid cycle
- Cofactor for synthesis of the active form of B6
- DNA synthesis and cell growth - Promotes iron absorption and use
- Fatigue: May up circulating haemoglobin levels and up RBCs
53
Factors increasing demand of Riboflavin and deficiency signs
Alcohol, pregnancy, chronic diseases, medications, physiological stress increase demand
inflammation of the mouth, skin, eyes and GI tract
54
Pantothenic acid (B5) sources, function
avocado, wholegrains, legumes, broccoli, yoghurt, eggs
coenzyme A and synthesis of Ach neurotransmitter
Supports tissue healing and cell structure
- Rare deficency bc in most food
55
B6 - Pyroxidine function and deficiency signs
Neurotransmitter production
- Phenylalanine to dopamine and adrenaline
- Tryptophan to serotonin and melatonin
- Tryptophan to Niacin (B3)
Synthesis of haem and DNA/RNA
Coenzyme for transamination of making non-essential amino acids
Low mood, depression, fatigue, neural implication, anaemia
56
Vitamin B7 - biotin sources, function
Peanuts, leafy greens, liver, raw egg
Stable to heat, destroyed by light, acid
- Function -> carboxylase enzymes that add carbon in TCA cycle and gluconeogenesis, lipogenesis and amino acid synthesis
Consuming 24 raw egg whites would cause a deficiency
57
Choline food sources and function
Egg yolk, liver, kidneys, meal, full fat milk, leafy greens, peanut butter
- Component of Ach
- Deficency rare
58
Inositol (B8) function and sources
High in rockmelon and fruit, whole grains, seeds and nuts
Glucose transport in form of myoinositol
- Deficiency rare
59
Vitamin B9 - Folate - Sources, function, what does it activate?
Plants - foliage, legumes, mushrooms. No animal sources (apart from liver)
Destroyed by heat and UV
Methylation cycle and DNA/rna synthesis
Activates vitamin B12
60
What happens in a vitamin B12 or folate deficiency?
DNA damage destroys rbc causing macrocytic or megaloblastic anaemia - cannot carry oxygen - fatigue and lethargy
Folate deficiency can mask B12 deficiency
Folate deficiency -> Anaemia, weakness, glossitis, hyperhomocysteinaemia
61
VItamin B12 sources and functions
Primarily from animals foods - dairy and eggs and product of bacterial fermentation - vegans at risk
Folate metabolism, TCA cycle and myelin sheath maintanence, RBC synthesis, DNA synthesis, energy production
Binds to intrinsic factor to be absorbed in SI - inflammation in SI impacts absorption
Need adequate HCl to activate pepsinogen to pepsin and B12 can then be released from proteins
B12 required for homocysteine metabolism
62
B12 Deficiency signs and doses
Anaemia megaloblatic anaemia, weakness, glossitis, depression, degeneration of peripheral nerves, Yellow pallor, premature greying, red burning sore tongue with beefy appearance
Increased demand in pernicious anaemia -> autoimmune condition that damages the parietal cells of the stomach, where intrinsic factor is produced
Has an RDI
SDT -> 500-2000mcg
63
Vitamin A Functions and increased demand
Eye function, bone tissue, immune function, skin health
retinal makes rhodopsin
Retinol needed for spermatogenesis
Increased demand - fat malabsorption (inflammatory conditions), growth periods in kids, pregnancy - need bile for fat breakdown
64
Vitamin A animal and plant sources
Animal sources - retinoids or preformed vitamin A. lamb liver, chicken liver, dairy, fish, ghee and butter. Unstable
Plant sources - carotenoids or provitamin A (precursor to retinoid). More stable, food processing increases bioavailability
65
VItamin A deficiency and toxicity signs
deficiency -> night blindness, dry cornea, hyperkeratosis
Toxicity - liver dysfunction, poor bone density, birth defects
66
EQ: Outline steps of vitamin D activation
1. expose skin to UVB
2. 7-dehydrocholesterol converted to previtamin D3
3. heat from body converts to D3 (cholecalciferol) over 2-3 days
4. Goes to blood then in the liver hydroxylated to calcidiol (25-hydroxyvitamin D3)
5. Then in the kidneys hydroxylated to calcitriol (1,25-hydroxyvitamin D3) that is biologically active
OR from the diet -> D2 (ergocalciferol) from plants and D3 (cholecalciferol) from animals does direct to liver (skip step 1-3 above)
67
Effects of vitamin D
Vitamin D causes increased Ca by reducing excretion of ca and P from kidneys and increase absorption from enterocytes, increasing release from bones via osteoclasts
Rising calcium stimulates calcitonin release from thyroid
-> Activation of vitamin D inhibited -> calcium stays in bone and also excreted
68
Defieincy and toxicity of vitamin D
Deficiency -> rickets in children, osteomalacia in adults
Toxicity - high serum Ca and calcification of soft tissue
69
Roles of vitamin D
Bone development, cell differentiation, immune function, brain function (depression)
Maintenance of ca and phos homeostasis
70
Vitamin E function and food sources, signs of deficiency
Antioxidant
Tahini, nuts and seeds, leafy greens, eggs, olive oil and almonds - Destroyed by heat
Signs and symptoms of deficiency very broad
- breakage of blood cells, nerve damage
71
Factors increasing vitamin E demand, doses
Low fat diets, digetive disorders like gallbladder issues, crohns, pancreatitis
RDI and upper limit of 300mg/d
72
What vitamin can act as an anticoagulant?
Vitamin E at high doses - careful with warfarin use
73
Vitamin K animal and plant source forms, function
K1 phylloquinone - plants
K2 menaquinones - animal
blood clotting and bone mineralisation
- bacterial synthesis provides 80% requirements
works with enzymes to ensure bone mineralisation occurs
facilitates calcium binding and sulphur metabolism to prevent kidney stones
Deficiency -> haemorrhage, newborns need to be given
Long antibiotic use can reduce - due to bacterial synthesis
74
Minerals important for structural function
Calcium, Magnesium and Phosphorus
provide structure to tissues in collagen mineral matrix - bones, cartilage and teeth
75
Minerals important for fluid and electrolyte balance
Sodium, Potassium and Chloride
76
Calcium function and food sources
What inhibits absorption?
Most abundant mineral in the body - provides structure and forms hydroxyappatite
neurotransmitter release, muscle contraction, acidity balance, blood clotting, cell signalling
green leaf, dairy, seeds, tofu, animal bones - Absorption reduced by high iron and phosphorus intake, excess fats and fibre (phytates)
77
Calcium regulation
Blood calcium drops -> parathyroid hormone released to activate vitamin D and increase ca level in blood -> increase intesitnal absorption, reduce excretion and release ca from bones
Homeostasis highly regulated by vitamin D, pth and calcitonin
Low serum calcium levels stimulate PTH secretion
Rising serum calcium levels stimulate the thyroid to secrete calcitonin,
78
Deficiency of calcium signs, doses
hypocalcaemia, seizures, osteoporosis, tetany
Factors increasing demand: High tannin intake can inhibit absorption, alcohol causes malabsorption and low levels of vitamin D, high sodium
Suggested therapeutic range - 500-2000mg/d
Upper limit 2500mg/d
Excess fibre may inhibit absorption
79
EQ: Dietary approaches to stop hypertension
High calcium
High magnesium
High potassium
Low sodium
Regualates hypertension by influencing vasodilation
80
Phosphorus function
Part of hydroxyappetite in bones and teeth
Carbohydrate metabolism and energy storage (ATP, creatine phosphate) cell structure
Part of phospholipids - cell membranes, micelles, transportaion of lipids, bile
May inhibit absorption of other minerals by binding with phytate containing cereals and seeds
Phytate-containing foods and other minerals can impair intestinal absorption
81
Magnesium functions, dose, sources and deficiency signs
inhibitory and calming neurotransmitters - reduce SNS activation
Upper level 350mg/d, therapeutic dose 600-1500mg
Involved in energy production (ATP to ADP), nerve and muscle function, bone formation, insulin production and release, platelet activity
legumes, nuts and seeds, green leaf, cocoa
Hypertension, cramps, twitching, heart disease, stroke, diabetes, lethargy
82
Phosphorus sources, dose and deficiency signs
dairy, legumes, sunflower seeds, egg and meat
therapeutic dose <1500mg of elemental phosphate
Rickets in children, bone pain and muscular weakness
Severe deficiency -> respiratory failure, reduced cardiac output, ataxia
Absorption with calcium regulated by vitamin D
83
Intracellular and extracellular electrolytes
Intracellular - K+ princple cation, phosphate important anion
Extracellular - Na and Cl principle cation and anion
84
Factors increasing phosphorus demand
Alcoholics - malabsorption
Contraceptives that increase bone resorption
Lack of vitamin D imparing active absorption
High dose calcium supplementation -> 1.5g calcium can bind 500mg phosphorus
85
Sodium intake and function
1 teaspoon - 2300mg max intake
High blood pressure - SDT 2000mg
Water and electrolyte balance
Maintenance of blood pressure; homeostasis of cellular hydration via the sodium-potassium pump
Nerve and muscle: together with potassium and calcium, sodium assists with nerve impulse generation for the stimulation of muscle contraction.
Bone and minerals: as a constituent of bone, Na+ may be released in times of need
86
Conditions increasing sodium demand
Diebetes mellitus - high glucose cuasing sodium excretion
Cystic fibrosis - losses in sweat
Physical activity, reduced kidney function in elderly, diarrhoea, medications like diuretics
87
Hyponatraemia symptoms
- Headaches
- Nausea and vomiting
- Dehydration
- Depression
- Delusions, hallucinations and confusion
Severe -> brain oedema, coma, seizure, single dilated pupil
88
Potassium intake
therpaeutic dosage range 3000-8000mg/d
Adequate intake
89
Potassium functions
Heart contractility, nerve function, gastric acid secretion
vasodilating effects
Fruit, veg, potato, banana, squash
sodium potassium pump, component of gastric acid secretion, supports cell integrity, synthesising protein and metabolising carbs
90
Factors increasing potasssium demand
Food processing/cooking in water
Vomiting/diarrhoea
High caffiene intake
Diuertics, laxatives, blood thinners
91
Potassium deficiency sings
- Salt sensitivity
- High blood pressure; stroke
- Kidney stones
- Osteoporosis / osteopenia
- Hypokalaemia
Severe nerve and muscle dysfunction - cramping, paralysis, low BP, altered heart rate
92
Chloride function and regulation
- fluid balance, protein digestion (HCl), maintains osmotic pressure, component of HCl
Chloride shift -> a process that assists carbon dioxide transport from cells, via blood, back to the lungs.
immune function in mucus secretions
No NRV due to high availability in diet - has an AI
Chloride is always balanced with bicarbonate and an increase in one results in a decrease in the other.
93
Chloride deficiency signs
- Weakness, lethargy, convulsions, muscle twitches and spasm
- Low blood pressure, slowed breathing and tachycardia
-Digestive discomfort
- Anorexia
- Irritability, restlessness, confusion and aggressive behaviour
94
What are microminerals?
Required in quantities of less than 100mg/day.
Most relevant - iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), iodine (I), selenium (Se), and chromium (Cr).
**Other microminerals and trace minerals include:**
- flouride, molybdenum, silica, boron, and vanadium
95
Iron - digestion and absorption
Ingested iron freed from other food constituents by gastric HCl
absorbed in SI via ferroportin and transferrin protein carries it in blood
Absorption controlled by hepcidin -> regulates amount absorbed
stored as ferritin in the liver - Over 65% of body iron found as haemoglobin and rest myoglobin or part of enzymes, in storage
96
Heme vs non heme iron
Heme iron - animal food, higher absorption rate. For absorption, the heme portion must be hydrolysed from the globin portion by enzymes in the stomach and SI
Nonheme iron - plant food, less absorption. stomach acids and digestive enzymes help release the nonheme iron from compounds bound to it
97
What is haemochromotosis?
too much iron is absorbed, not enough hepcidin made by liver
genetic
iron becomes pro-oxidant
joint pain and GIT pain
98
Compounds inhibiting iron absorption
polyphenols, oxalates, phytates, calcium
99
Stable forms of iron
Ferric 3+ and ferrous 2+ are only stable forms in the body
100
EQ: What is microcytic anaemia?
Red cells smaller than usual due to inadequate haemoglobin due to insufficient iron to make heme hindering oxygen transport to organs and tissues
Can also occur due to low copper, B6
Signs - skin pallor, pale conjunctiva, brittle nails, glossitis
Symptoms - fatigue, breathlessness, tachycardia, cold hands and feet
101
Iron toxixcity is called
Haemochromatosis
102
Copper - MC question - function and something that competes with absorption. 2 diseases that result from abnormal copper utilisation
Copper is a cofactor in the formation of haemoglobin.
Allows iron to be transported and involved in iron absorption
Blood clotting, energy production in the electron transport chain
cofactor for several enzymes in mitochondrial electron transport chain and oxidative phosphorylation
Too much zinc can compete with copper absorption
Menkes’ disease and Wilson’s disease result from abnormal utilisation of copper
103
EQ: Zinc - signs and symptoms of deficiency and role in the body
trace mineral, competes with copper for absorption
AI, EAR, RDI, UL
Signs -> frequent infections, poor appetite, skin rash, loss of taste, poor wound healing
Functions -> spermatogenesis, insulin synthesis, pancreatic enzyme and stomach acid synthesis, enhances smell and taste, immunity, displaces copper during absorption and metabolism, neurogenesis, production of HCl, absorption of folic acid
Wound healing, synthesis of superoxide dismutase (SOD)
A component of an antioxidant called metalloenzyme
Deficiency associated with -> vegan diet, eating disorder, old age, chronic diarrhoea or crohns disease
reduction in absorption -> phytates, processed food, low stomach acid prevents release from proteins
104
Iodine - Sources and something that reduces uptake
- Essential trace mineral
RDI, UL is 1100ug/d, STD
Production of T3 and T4, metabolic rate
Richest source is seafood and seaweed, amount in veg depends on soil
goitrogens reduce iodine uptake to thyroid -> can be inactivated via cooking and fermentation
Soy, peanuts, almonds all contain goitrogens
105
What causes cretinism?
iodine deficiency during pregnancy
106
Nutrient cofactors required for the synthesis and activation of thyroid hormones
nutrient cofactors required for synthesis -> tyrosine, iodine, vitamin C, Zn, Fe
- nutrient cofactors required for activation -> Selenium (high in prawns and shellfish, brazil nuts)
what does thyroid gland produce - thyroxine
107
what is a condition that relates to iodine deficiency or thyroxine deficiency
hypothyroidism, goitre
108
Selenium function and deficiency signs
Antioxidant - part of the enzyme glutathione peroxidase.
Functions similar to vitamin E
Immune function, hormone synthesis, cell replication and maintains sperm mitochondria
RDI, UL
Glutathione is an antioxidant (3 amino acid complex). - flavonols like EGCG in green tea and anthocyanins found in berries increase glutathione activity
Deficiency -> poor growth decrease T3. muscle pain, depigmentation of hair, skin, reproductive failure, depression
prawns and shellfish, brazil nuts
109
What may be effectively detoxified by selenium?
Mercury
110
Mangenese - sources, potential for toxicity
Trace mineral
Antioxidant
Bones, liver, kidneys, pancreas
Therapeutic dose and UL 11mg/d
Deficiencies are rare but toxicity may result from inhalation of dust contaminated with manganese
111
Copper - digestion and absorption
bound to proteins in blood
Gastric secretions, hydrochloric acid (HCl) and pepsin all function to digest copper. Copper is reduced from Cu2+ to Cu+ by reductase enzymes (which require vitamin C) before absorption.
Absoprtion - duodenum. Active transport, carrier-mediated in low concentrations, or passive transport, diffusion in high concentrations
112
Copper deficiency signs
1. Hypochromic, microcytic anemia that does not respond to supplemental iron.
2. Leukopenia (specifically neutropenia, a lower-than-normal number of neutrophils
113
Factors increasing zinc demand
Vegetarian or vegan diets (high intake of inhibitors like phytates).
Chronic alcohol consumption (zinc is required for alcohol dehydrogenase activity)
Digestive disorders
Interactions with vitamin A, folate, iron, calcium, copper - divalent cations compete for binding and transporters.
114
Signs of zinc deficiency
Anorexia, diarrhoea, lethargy, depression,
- Skin rash/lesions/dermatitis
- Hypogeusia (blunting of sense of taste)
- Alopecia (some hair loss, and remaining hair may take on a reddish hue)
- Vision problems, and impaired immune function
- Protein synthesis, and wound healing
115
Defieincy of iodine signs
Hypothyroidism - lethargy, constipation, cold intolerance
Reproductive issues - anovulation, gestational hypertension
Neurologic deficits
Goitre - damage occurs in the brain
116
Therapeutic actions of selenium
Hypothyroid or hashimotos
A component of iodothyronine deiodinase a selenoenzyme family which converts T4 to active T3
117
What is Kashin-beck syndrome?
childhood osteoarthritis and is common in China as the soil is deficient in selenium.
118
Manganese functions and signs of deficiency
Enzyme functions
Bone formation - manufacturing cartilage
Energy metabolism - metabolism of amino acids, carbs and cholesterol
- Skin rashes
- Bone and joint abnormalities
- Decreased clotting proteins
- Impaired carbohydrate and lipid metabolism
- The decreased growth of hair and nails
- Loss of pigmentation of the hair
- Low serum cholesterol
119
Flouride - sources, intake, functions
maintains fluorapatite - hard enamel layer on teeth, strength to bones
Sources - water, tea, grapes, fish, wine
Tea and fish contain more in parts per million than water
Deficiency - teeth decay
Toxicity - dental fluorosis, discoloured enamel
120
Chromium functions, sources
- blood sugar regulation, - glucose metabolism, insulin binding - enhances insulin activity
Chromium is a component of glucose tolerance factor
Black pepper is a good source of chromium and vanadium
found in unrefined food
found in blood sugar supplements - could be benefit in having extra rather than deficiency
121
Molybdenum functions and sources
pllants
- Legumes are an excellent source of Molybdenum
cofactor for enzymes processes
Wilson's Disease Treated with Molybdenum as tetrathiomolybdate - It can bind as a complex with **copper** so that copper leaves the body through the urine
- deficiency and toxicity unknown
122
What two processes does the detoxification of metals require?
Chelation and Excretion
123
What is chelation?
Chelation involves agents which act like claws or calipers that fasten to the metal ion and form a ring structure
Chelating agents in the body include:
- Thiol groups in: GSH, Methionine, Cysteine, SAMe, Taurine, alpha-lipoic acid
- Disulfide bonds in: Metallothioneines
124
Nutritional methods of chelation, detoxification and excretion include:
- Antioxidants and micronutrient cofactors - zinc, selenium, vitamin C and E, quercetin
- Chelation with glutathione, taurine, N-acetylcysteine - NAC -, α-lipoic acid, and methionine
- Foods containing chelation compounds and phytonutrients include garlic, gotu kola, coriander, green tea, and turmeric. Coriander is a powerful agent.
125
What is a major chelating agent?
Glutathione
Promoted by:
- Moderate exercise
- Consumption of cruciferous vegetables
- Nutritional supplementation options: NAC, resveratrol, selenium, whey protein and lipoic acid
126
What does lead do in the body?
- Displaces Ca and Fe - shared the ferroportin transporter to blood
- interferes with zinc
- Accumulates in bone and causes cognitive problems
Lead binds to thiol (SH) and amide (NH2) groups in enzymes. In particular, it competes with metallic cations (Ca2+, Fe2+).
127
Who is high risk for lead exposure? What are the effects?
Occupational exposure and some hobbies are high risk - miners, painters, restoring cars
- Chronic toxicity can lead to neurological effects and immune dysregulation - due to disruption of Ca+ metabolism and nerve firing.
- Pregnant women exposed to lead may need to take calcium to keep the lead from mobilising - lead can cross the placental barrier
128
Treatment of lead toxicity
acute -> chelation
Chronic -> remove exposure, NAC to increase metallotionein and GSH, Cu, Zn supplements to increase superoxide dismutase
129
Arsenic - function, sources and effects
possible benefits for methylation - increasing SAMe
Accumulates in connective tissue and CNS
Arsenic inhibits enzymes like pyruvate dehydrogenase and others involved in gluconeogenesis and beta-oxidation
inhibits uptake and metabolism of selenium and iodine in the thyroid
soil and water, pesticides, alloys
Inorganic forms are most toxic
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Nickel sources, function and effects
membrane attack complex
Nickel may substitute for zinc, copper and iron, thereby reducing their activity.
Sources -> inhalation or swallowed
nuts, legumes, grains, choc, wine - food manufactured in stainless steel
Chelation for acute, NAC and Zn for chronic
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Mercury toxicity occurs by:
primarily via inhaling vapour from dental amalgams or from batteries, light bulbs, cosmetics
Flake, swordfish and marlin are high - 1 serve a week of these
Or 2-3 serves of other fish a week
Mercury binds to thiol and selenohydryl groups, destroying tertiary and quarternary protein structure, damaging cell membranes, and inactivating enzymes.
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Alumunium main sources
one of most abundant in earths crust - not quite as toxic as the rest as low bioavailability
Binds to transferrin when absorbed, affecting the transport of iron
main sources - processed foods in anti caking and flowing agent, antacids, vaccines, antipersperants, displaces Mg
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Cadmium effects, testing and sources
competes with zinc leading to poor immune function and prostate disease
Displaces Zn and increase risk for BPH
Sources - cigarettes, batteries, paint, cosmetics, galvanised pipes, superphosphates (root vegetables contain soil levels)
Concentrates in kidneys (urine or hair used to test)
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Silica - effects and where it is concentrated
Concentrated in connective tissues – bones, tendons & skin and appears to be involved with growth, formation and development of bone tissue
second-most abundant element in the earth’s crust
Sources - whole grains, beer, anti-caking agents, tea, cofee, juice, wine
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Boron - concentration in body
Most in bones, with some in hair, nails and teeth
no specific biochemical function has yet been identified.
Boron deficiency may impair calcium metabolism, brain and energy function
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What toxicity may silica help?
Aluminium - complexing with it and hindering absorption
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Vanadium - action
May mimic insulin activity in pharmacologic doses
No intake recommendations
Ingested or inhaled
Mild GIT upset at high doses or green tongue, fatigue
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Cobalt - concentration in body and function (what is it a component of)
Most in bones, with some in hair, nails and teeth
Organic form is essential for the human body as a component of vitamin B12 in the central corrin ring system
The inorganic form present in ions can be toxic
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Cobalt functions
Same as B12
Synthesis of erythropoietin, Formation of amino acids and proteins, Creation of myelin sheath and neurotransmitter synthesis
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What are phytonutrients?
atural compounds produced by plants to protect against damage from UV radiation, fungal and bacterial attack, and injury by insects and other predators
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What are polyphenols?
Role in the prevention of chronic degenerative diseases like dementia, cardiovascular disease, and cancer
Phenolic acids, stillbenes, lignins, flavonoids, gingerol, oleuropein, coumestans, capsaicins, Glucosinolates, Carotenoids, Sterols, Stanols
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What is resveratrol?
A stilbene found in grape skins; anticarcinogenic
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What is Epigallocatechin gallate ?
A flavanol found in green tea; antioxidant
Increases blood glutathione and inhibit accumulation of amyloid plaques
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What is cinnamic acid?
A phenolic acid with antidiabetic properties
Antioxidant, anticancer, anti-diabetic, everything
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What are anthocyanins?
A blue-coloured polyphenol flavonoid found in berries
Potent anti-oxidant, protective against CVD and glycaemic control
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What is quercetin?
An anti-inflammatory flavonoid found in onion
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What is the mediterranean diet?
characterised by olive oil, small oily fish and shellfish, legumes, small amounts of fermented dairy (generally goat and sheep), small amounts of meat (generally chicken, duck, rabbit), herbs, nuts and very minimal sweets.
Red wine is consumed daily.
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Benefits of meditteranean diet components - olives, resveratrol, oily fish
Olives/EVOO/oleocanthal/oleuropein – protects against CVD, dementia, T2DM, cancer
- Resveratrol/red wine/grapes – protects against cancer, ageing, neurodegeneration
- Oily fish/LCn3 – anti-inflammatory, protects against heart disease, arthritis, depression, IBD
- Med Diet has been shown to protect against CVD, T2DM, cancer, dementia and depression
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What is DASH diet?
Dietary Approaches to Stop Hypertension
high calcium, magnesium, potassium and low sodium to regulate hypertension and decrease CVD risk
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What does the FODMAP diet eliminate?
eliminates Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols (sugar alcohols) which may exacerbate IBS.
After symptoms are gone (6-8 weeks) these are slowly reintroduced to induce tolerance or identify a single cause.
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Where are FODMAP foods found?
Oligosaccharides: wheat, rye, onions, garlic and legumes/pulses
Disaccharides: milk, soft cheeses and yoghurts
Monosaccharides: honey, apples, high fructose corn syrups
Polyols: some fruit and vegetables, artificial sweeteners
