Proteins and amino acids Flashcards
What percentage of body weight do proteins account for
17%
Of the 20 amino acids used by the body to code for proteins, how many are essential and what does this mean
9
They cannot be made by the body in sufficient quantities
which amino acid is debated as to whether it is essential or conditionally essential
Histidine - bacteria can produce it, though it is not clear how much is provided by intestinal bacteria.
What is unique about histidine
it is the only aa that does not impair protein synthesis when it is deficient in the diet - thus making it non essential
What might denature a protein
heat, heavy metals, pH, Alcohol
Each protein has a specific function that is determined during protein synthesis. Name 5 such functions
structure of body tissues (eg collagen)
Movement (actin and myosin fibres)
Carrier molecules (haemoglobin)
Storage molecule (Ferritin)
Fluid balance in blood (Albumin)
HOrmones (insulin) and cell membranes
Immune function (antibodies)
Clotting mechanisms
Alternative energy source
PROTEIN FUNCTIONS:
Growth and maintenance
proteins are the building blocks of muscles, blood, skin and body structures
Actin and myosin filaments involved in muscle contraction and are proteins
Collagen: forms bones and provides building materials for ligaments, tendons, blood vessels walls dermis
Proteins are needed for the replacment of cells - eg skin, GIT cells
PROTEIN FUNCTIONS:
Hormones and receptors
Some hormones are derived from cholesterol, others from amino acids. Provide examples
TYROSINE and iodine - thyroid hormones
TYROSINE (and B6) - dopamine, orephinephrine, epinephrine
TRYPTOPHAN - serotonin, melatonin
Insulin (2 polypeptide chains)
Glucagon, PTH, Calcitonin - (1 polypeptide chain)
Cell membrane proteins are receptors for hormones.
PROTEIN FUNCTIONS:
Enzymes - provide example
amylase
PROTEIN FUNCTIONS:
Immunoglobulins (antibodies)
What do they do and name the most abundant
found in blood and bodily fluids
They identify and neutralise foreign materials
IgG most abundant
IgA in body scretions
IgM the first to apprea in response to antigen exposure
IgE allergic reactions
PROTEIN FUNCTIONS:
Transport
Albumin - can bind to Ca, Zn and B6 as well as steroids and fatty acids
Transferrins bind to Fe
Ceruloplasmin binds to Cu
Haemoglobin transports oxygen in the blood
PROTEIN FUNCTIONS:
Buffers - how do they act as buffers and which two amino acids are the best buffers
Some aa have side chains that can easily pick-up or let go of hydrogen ions - helping to regulate the acid-base balance in body fluids
Proteins with lots of these aa are good buffers
Histidine is the best buffer at 7.35-7.45. Cysteine second!
PROTEIN FUNCTIONS:
Fluid balance - what happens if protein levels fall too low
Name two protein related causes of oedema
proteins attract water - the osmotic pressure from fluid is called ONCOTIC PRESSURE
If protein levels fall too low, water leaks out of the blood vessels and accumulates in interstitial spaces - OEDEMA
Protein related causes of oedema include:
- excessive protein losses due to kidney disease
- Inadequate protein synthesis due to liver disease
- inadequate dietary intake of protein (malnutrition) thence distended abdomen in worlds poorest countries
PROTEIN FUNCTIONS:
Glycoproteins (essential component of cell membranes - carb and protein)
- Mucins - mucus and saliva for protective barrier
- ABO blood type antigens
HOrmones - Luteinising Hormone, FSH, TSH - Major histocompatability complex - cell surface receptors involved in adaptive immunity
- Proteoglycans - bound to GAGs and found in extracellular matrix eg chondroitin sulphate found in cartilage - shock absorbs
PROTEIN METABOLISM
What does deamination involve and where does it take place
the removal of the nitrogen containing amino group
the liver
Why must deamination of amino acids take place
to enable them to be used as an energy source or stored as fat - the remaining fragments after the amine has been removed can be used to produce glucose or ketones
When the nitrogen group is removed from the amino acid, what toxic substance is formed
ammonia
PROTEIN SYNTHESIS: What cycle must ammonia go through to make it water-soluble and able to be excreted by the kidneys
the UREA cycle
Ammonia is converted to UREA in hepatocytes
PROTEIN SYNTHESIS: What is deamination and what can the remaining fragments of the amino acids be used to produce
the removal of the amine group from a protein
Glucose or ketones for energy or energy storage
PROTEIN SYNTHESIS: Describe the urea cycle and list the three amino acids involved in the cycle (THIS NEEDS CLARIFICATION)
Ammonia formed from deamination needs to be converted to urea to ensure its safe removal from the body.
The urea cycle is the sole endogenous source of the amino acids: arginine, citrulline and ornithine (liver support and detox agent)
PROTEIN SYNTHESIS: What does impairment of the urea cycle lead to
symptoms of hyperammonaemia, including :
chronic fatigue
headache
irritability
nausea and diarrhoea
poor concentration
confusion
intolerance of high protein foods
can lead to LIVER CIRRHOSIS
PROTEIN SYNTHESIS: describe Transamination and state what vitamin the process is dependent on
Important step in the synthesis of some NON ESSENTIAL amino acids. If a particular non essential aa is no available the body can make it from another.
The AMINO group of one aa is transferred onto an ENZYME. The enzyme transfers teh amino group onto a ketoacid, thus forming a NEW AA.
Process is B6 dependent. (sunflowers, green veg, walnuts, bananas, lentils, avo)
PROTEIN SYNTHESIS: what is PROTEIN TURNOVER
the process of proteins constantly being made a broken. e.g enzymes may be recycled in a matter of minutes
Describe the process of protein turnover
When proteins are broken down they free amino acids to join general circulation. These plus diet derived create an AMINO ACID POOL.
They are UTILISED or EXCRETED, but NOT stored.
Why is it important to have a regular supply of protein in the diet
- They are not stored.
- Essential aa have a longer half-life as they are more critical to the body in terms of supply.
- Body will break-down its own tissue to obtain essential aa if can’t obtain from the “pool”
What impact can stress have on protein loss
Stress causes protein loss in areas such as skeletal muscle due to the catabolic actions of stress hormones.
Chronic stress impacts the framework of bones as protein losses can occur in the extracellular matrix (collagen). Think osteoporosis.
PROTEIN METABOLISM: When are proteins used for energy or energy storage
when gucose and fatty acids are limited - eg starvation, disease
But there’s no store so tissue components are broken down
Name endogenous sources of proteins
adults reabsorb 50g protein from shed mucosal cells and 17g from digestive enzymes and gycoproteins
What determines protein quality
digestibility and amino acid composition
What can influence the digestibility of protein
gut function (HCl/digestive enzymes)
Fibre
anti nutrient factors e.g. phytates and lectins
What improves the digestibility of plant protein sources
soaking, sprouting fermenting which can lower anti nutrient factors
The Fibre, prebiotics and phytonutrients can make plants a superior choice.
List ways in which protein digestion can be optimised
Chew thoroughly and don’t drink with meal
support stomach acid levels with Zn and B6 rich foods
Apple cider vinegar before meal
Bitter herbs before meal (watercress, gentian, barberry bark) promote release of pancreatic juice
BETAINE HYDROCHLORIDE SUPPLEMENTS 600mg - one when starting to eat increasing by one up to 5 unti feel warmth then cut back by 1 pill.
Protein quality - how does the microbiome contribute to protein metabolism and with what effects
undigested protein that reach the colon is fermented, creating toxic metabolites that increase inflammatory response and encourages proliferation of opportunistic pathogens
Effects include:
toxicity, nephrotoxicity, carcinogenesis
What is a limiting amino acid and name the 4
to make a protein a cell must have all the required amino acids available simultaneously. If one is missing it will cease making it or dismantle another protein to obtain it.
A limiting aa is one supplied in less than the amount needed for protein synthesis.
LYSINE
THREONINE
METHIONINE
TRYPTOPHAN
What is complete protein and name vegan examples
Food that contains all nine essential aa.
Quinoa, buckwheat, pumpkin seeds, chia seeds, hemp, tempeh
Meal, poultry, fish, eggs, dairy (not butter)
What is an incomplete protein
food that is low in one or more essential amino acids
Plant foods often have an incomplete amino acid profile, how can this be overcome
Plant foods can be combined to ensure the essential aa’s are combined. Eg
Legumes + nuts/seeds
Whole grains + legumes
Vegetables + grains
Do vegans/vegetarians need to combine all the amino acids in one meal
No - the amino acid pool is stable so they can eat a range of plants throughout the day
What are the drawbacks of animal protein
High in METHIONINE :
immune stimulating effect on T cells, leading to autoimmunity/chronic inflammation.
Excess methionine can lead to increased homocysteine = atherosclerosis
Name disease states associated with high long term animal protein intake
osteoporosis
kidney disease
increased cancer risk
liver disorder
atherosclerosis
increased muscle soreness post exercise
What % of calorie intake is a high level of protein considered to be
20%
Why should we promote plants as a good source of protein
because they buffer the acidic load of animal protein
EXCESS PROTEIN DISEASE STATES: name 4 and explain why
CANCER:
moderate and high intake of animal protein increase cancer risk.
Red meat is possible cause of cancer (WHO)
Processed is carcinogenic
SKELETAL DISEASE:
Acidic burden draws calcium out of bones - osteoporosis. Protein deficiency can also impact bone health due to collagen structure of bone
KIDNEY DISEASE:
extra acidity needs buffering by kidneys
CVD:
oxidation and inflammation in the endothelium
What compounds are produced during the high temps of cooking meat
Polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HCAs) - CARCINOGENIC
What are the benefits of plant based protein
Less methionine and branch chain aa (predominant in meat) is beneficial to health
Protective against cancer, CVD, DM, autoimmunity due to phytonutrients, fibre and prebiotics
Protective against ageing as lower levels of LEUCINE, which can increase teh expression of TOR, an enzyme that regulates cell growth
What is TOR
Target of Rapamycin - enzyme that regulates cell growth
Protein requirements: what is the debate
Infants get their protein from breast milk where protein is low.
Determining requirements is difficult as no deficiency symptoms until severe
Deficiency would start at .4-.5g/kg body weight
Whole foods set a natural balance for protein intake as NO WHOLEFOOD IS PURELY PROTEIN
Why do athletes require more protein and what are the recommendations
increased catabolism of aa during exercise
Usual recommentation is .75g/kg weight
minimal exercise: 1
moderate: 1.3
intense: 1.6g
Should be met as a proportion of increased calorie intake
How do protein recommendations differ for pregnancy and lactation and vegans
pregnancy: add 6g day
lactating: 11g 0-6 months and 8g 6+months
Vegans: multiply by 1 to accommodate the lower protein bioavailability
Who is most likely to be affected by protein deficiency
Children and teens with western diet
older people due to immobility, dentition, digestive health
anorexia nervosa
recovering patients
Homeless and disadvantaged
drug and alcohol addicts
Chronic digestive conditions and use of PPIs
Chronic or active infections
In addition to being crucial for protein synthesis, AMINO ACIDS also
contribute to synthesis of hormones and neurotransmitters
act as neurotransmitters (glycine)
act as methyl donors (methionine)
build bile acids for digestion (glycine and taurine)
precursors for NO production (arginine)
help detoxify chemicals (phase II)
Precursors for the manufacture of endogenous antioxidants
How are amino acid levels in the body measured and in what circumstances is this useful
plasma and urine
useful in chronic fatigue syndrome due to mitochondrial ineffeciency or long term PPI use due to reduced aa absorption
Helpful in clinic as high levels of branched chain aa (leucine, valine, isoleucine) and homocysteine are linked to heart disease
EXPLAIN WHAT A COMPLETE PROTEIN IS AND PROVIDE THREE EXAMPLES OF FOODS THAT FIT THIS CATEGORY
contains all 9 essential amino acids
animal sources, quinoa, buckwheat, pumpkin seeds, chia seeds, hemp seeds, tempeh
Tyrosine is required for the formation of certain hormones, name 2
with iodine: thyroid hormones
dopamine, norepinephrine, epinephrine
WHY CAN OEDEMA OCCUR WHEN PROTEIN LEVELS FALL TOO LOW
PROTEINS ATTRACT WATER - THE PRESSURE FROM PROTEINS (E.G. ALBUMIN) IS CALLED ONCOTIC PRESSURE
IF PROTEINS FALL TOO LOW, WATER LEAKS OUT OF THE BLOOD VESSELS AND ACCUMULATES IN INTERSTITIAL SPACES = OEDEMA
WHAT IS THE IMPORTANCE OF TRANSAMINATION and what enzyme is it dependent on
Important step in synthesis of NON ESSENTIAL amino acids. If a particular one isn’t available, the body can make it from another.
The amino group of an aa is transferred onto an enzyme which transfers it onto a ketoacid, thus forming a new aa.
B6 (wholegrains, sunflower seeds, walnuts, bananas)
WHAT HAPPENS IN THE UREA CYCLE
ammonia formed by deamination (removal of the nitrogen containing amino group needs to be converted to urea for safe removal from teh body. Takes place in hepatocytes.
OUTLINED TWO WAYS TO OPTIMISE DIGESTION OF PROTEINS
CHEW thoroughly
support stomach acid levels - B6 and zinc rich foods/bitter fooods before meals
THE PROTEIN IN PLANT FOOD IS OFTEN DESCRIBED AS INCOMPLETE. WHY AND HOW CAN DIFFERENT FOODS BE COMBINED TO OVERCOME IT
plants do not contain complete proteins, they are deficient in one or more aa.
Nuts can be combined with legumes
Wholegrains, with legumes
Vegetables with grains
WHAT ARE THREE ADVERSE EFFECTS ASSOCIATED WITH LONG TERM HIGH INTAKE OF ANIMAL PROTEIN
Red meat is associated with certain cancers
Skeletal diseases eg osteoporosis due to calcium leached from bones to buffer the acid
Kidney disease - buffer acid and filter the increased urea that’s generated
CVD - oxidation and inflammation
GLUTAMINE
What is the most abundant amino acid in the body
Glutamine - 60% of total pool of amino acids
What is the role of glutamine and the intestinal barrier and what diseases can cause intestinal permeability
Primary amino acid source for intestinal cells and helps regulate tight junction integrity and enterocyte proliferation. Depletion = intestinal permeability.
INTESTINAL PERMEABILITY: what diseases can cause intestinal permeability
What can leak into the blood
Intestinal permeability linked with coeliac, IBD, candidiasis, food allergies, chemo
LPS - lipopolysaccharides (released from the cell walls when they die) which can lead to chronic disease/autoimmunity
What is the preferred amino acid for rapidly dividing cells such as enterocytes (gut) and lymphocytes and macrophages (immunity)
glutamine
When is glutamine synthesis imparied
acute stress (injury/infections), therefore CONDITIONALLY ESSENTIAL.
List out ways in which we can naturally support the intestinal permeability
remove the cause and supply nutrients that support enterocyte junctions:
Glutamine supplementation (10g/day)
Glutamine rich foods (cabbage juice, spirulina, broccoli, cod, salmon)
Zinc (rapid cell division and tight junction support)
Antioxidants (C E beta-carotene)
Herbs (marshmallow, slippery elm, goldenseal
Bone broth (collagen, glucosamine, chondroitin, glycine)
Quercitin
N acetyl glucosamine
Name a key role of glutamine in the body
acts as a buffer, receiving excess ammonia (nitrogen) and releasing it when needed to form other amino acids and nucleic acids
What type of cells is glutamine the preferred source for
rapidly dividing cells such as enterocytes (gut) and lymphocytes and macrophages.
List four functions and therapeutic uses of glutamine
Immunity: SUpport lymphocyte and macrophage proliferation.
Therapeutic Use: recurrent infections/compromised immunity
Hypoglycaemia: substrate for gluconeogenesis
Therapeutic use:
2tsp in water between meals in place of snacks while adapting to healthier eating
Muscle recovery: promotes faster recover and reduces muscle breakdown
Therapeutic use: exercise recovery/sports nutrition
Neurotransmitter: its converted to glutamate (excitatory) then GABA (inhibitory). Requires B6, taurine and Zn.
Therapeutic use: if conversion is working, supplementation can help anxiety and sleep.
HIV support due to intestinal, muscle and immune support functions.
What are the guidelines for glutamine supplementation inculding:
dose
drug interactions
toxicity
caution
Start low and gradually increase.
10-30g/day ideally AM.
Breaks down rapidly so consume asap.
Drug interactions: anti seizure meds
Toxicity: no adverse in short term dosing up to 50-60mg/day
CAUTION: cancer cells use glutamine to fuel growth and metabolism
avoid in cancer, epilepsy, liver and kidney disease
CYSTEINE:
what amino acids is cysteine formed from, where made and what co factors
methionine and serine
the liver
B6 B9 B12
Name food sources of cysteine
Legumes, sunflower seeds, eggs, chicken
What amino acids are components of glutathione and which is the rate limiting a.a
CYSTEINE, glutamic acid, glycine
Name three compounds that cysteine is a component of
glutathione
co-enzyme A
taurine
why is cysteine important for detoxification and antioxidant support
it is the rate limiting a.a. in the synthesis of glutathione
It is the source of sulphate, used in phase II liver detoxification pathway sulfation 9used for many drugs, steroid hormones), increasing water solubility for their excretion.
N-ACETYL CYSTEINE (NAC): what is it
a derivative of L-cysteine. Used in supplementation as easier to absorb
list four functions and therapeutic uses of N-acetyl Cysteine (NAC)
- liver detox/antioxidant. Building block of glutathione; role in building antiox defences. Crucial in drug metabolism in the liver (drugs deplete glutathione, cysteine depletes it)
Therapeutic use: liver support/heavy metal detox. Healthy aging. Ulcerative colitis - Reproductive health: increase sperm concentration, benefits serum testosterone
Therapeutic use: infertility - respiratory health: Expectorant properties (breaks-up mucus for easier elimination from respiratory tract.
Therapeutic use: respiratory infections, cystic fibrosis, asthma - Insulin resistance: increases insulin sensitivity:
Therapeutic use: DM. PCOS
HIV support (increased glutathione); Neurodegenerative diseases Parkinsons, alzheimers
N-Acetyl Cysteine
Application in hospital setting
dosage
drug interactions
caution
antidote to paracetamol toxicity from OD
Dose: 600mg-1.5g/day
Drug interactions: Nitro-glycerine and insulin
Caution: can cause adverse GI effects
METHIONINE - what type of a.a. is it
sulphur containing ESSENTIAL
name food sources of methionine
high in animal foods - eggs, beef, chicken.
brazil nuts, sunflower seeds, beans, whole grains
what is the main function of methionine
a major METHYL donor in teh body for methylation reactions eg the homocysteine cycle and phase 2 liver detox.
What is the effect on the body of raised homocysteine
damages the vascular endothelium, increases risk of atherosclerosis and miscarriage
what vitamins support methylation whilst restricting dietary methionine (animal) to lower homocysteine
B6 folate B12
What caution must be exercised around methionine levels in the body
excess methionine also increases acidity in the body
CARNITINE:
what amino acids can it be synthesised from
methionine and lysine. Can also be obtained from diet.
What vitamins and minerals is carnitine production dependent upon
iron, C B3 B6
How common is deficiency of carnitine
rare as body can make it - results from errors of metabolism
When would carnitine become conditionally essential
in a mutation of the SLC22A5 gene
Name food sources of carnitine
nuts, seeds, avocado, asparagus, spinach, red meat, diary
List ONE function of carnitine and therapeutic uses
Assists ATP synthesis from fatty acids: facilitates transport of long chain fatty acids across the mitochondrial cell membrane so they can be oxidised to create ATP.
Acts as antioxidant and removes potentially toxic metabolites out of mitochondria.
THERAPEUTIC USES: hyperthyroidism as acts as thyroid hormone antagonist.
weight loss
heart failure
infertility - improves sperm count and motility
Fatigue and concentration
Athletic performance
ADHD
CARNITINE supplementation:
dose
drug interactions
caution
1-2g twice day
drug interactions: with warfarin will increase blood thinning effects.
contraindicated with hypothyroidism (thyroid hormone antagonist)
Caution: at HIGH doses: nausea, vomiting, abdominal cramps, heartburn, gastritis
Urine, sweat, breath - fishy odour
CREATINE: name the three amino acids its made of and where formed
arginine, glycine, methionine. Formed in liver, kidneys and pancreas
Where is creatine found and what is one of its key functions
95% in muscles (some in brain)
Creatine phosphate is a fast source of ATP
List the main function of creatine and therapeutic uses
storage form of ATP: enables explosive power in the muscles for 8-12 seconds.
Enhances skeletal and cardiac muscle
THERAPEUTIC USE: enhance muscular performance (esp HIT)
Heart failure and coronary artery disease
Why should creatine supplementation be reduced over time
Skeletal muscle has a saturation point, therefore if a weight trainer supplements for 5 days of .3g/kg body weight for 5 days, they would reduce it down to .03. (front loading - half before work out and half after)
Name the drug interactions and cautions around creatine supplementation
Caffeine, ephedra and creatine may lead to ischaemic stroke.
High doses may affect renal function.
NSAIDS and antibiotics may have harmful effect on kidney function
CAUTION: can cause abdominal pain, nausea, diarrhoea, palpitations, cramping.
Creatine draws water from the rest of your body - therefore HYDRATE
GLYCINE: name food sources
legumes, seaweed, spinach, kale, cauliflower, cabbage, banana, pumpkin, bone broth, meat, fish, eggs
What compounds is glycine required for the synthesis of
haem, DNA, RNA, bile acids, gultatione, creatine, skin, connective tissue.
What vitamin and aa is required to make gycine
B6 and serine
Glycine is conditionally essential in the case of certain metabolic stresses, provide examples of these
Increased haem synthesis for blood formation
Collagen formation for growth and repair
Glycine conjugation in detoxification
Name three functions and the therapeutic uses of GLYCINE
- COLLAGEN SYNTHESIS - collagen is the most abundant protein in the body - 1/3 glycine. Crucial for bones, dermis, GIT, tendons, ligaments
THERAPEUTIC USES: GIT repair (IBD, leaky gut) Skin - LIVER DETOX - required to conjugate toxins in phase 2 liver detox.
Component of glutathione and bile acids
THERAPEUTIC USE: liver support, digestion - NEUROTRANSMITTERS: it’s inhibitory in the CNS and reversibly converted to serine and used to form acetylcholine.
THERAPEUTIC USE: insomnia; cognition, memory and learning
TAURINE: What vitamin and aa are needed for it synthesis
B6 and cysteine
Under what circumstances might taurine synthesis be inhibited
extreme stress and illness
Name food sources of taurine
ONLY animal, esp chicken and turkey thighs and fish and breast milk
Why is supplementation of taurine necessary in non-breastfed infants
because their ability to synthesise taurine is underdeveloped
List 5 functions of TAURINE and therapeutic uses
- Muscle health: Highly concentrated in muscles - imp role in contraction. Also heart health as anti inflammatory and BP lowering properties
THERAPEUTIC USE: heart failure, hypertension, Duchenne, Sarcopenia - Antioxidant. Protects mitochondria from ROS. Taurine is high in neutrophils and it provides anit-inflamm and antiox effects
THERAPEUTIC USE: atherosclerosis; infertility (sperm health) - Neurological: inhibitory neurotransmitter (agonist of GABA receptors in the CNS). Supports development of the cerebellum
THERAPEUTIC USE: Parkinsons, epilepsy, insomnia - Bile: bile acid conjugation
THERAPEUTIC USE: supports liver detox. Digestive support (fats) - Insulin: improves insulin resistance
THERAPEUTIC USE: DM
TAURINE dose, drug interactions, contraindicated, toxicity, caution
Dose: 500mg 3x dat
Drug interactions: Lithium and blood pressure meds
Contraindicated: bipolar disorder
Caution: added to energy drinks but its NOT a good source due to all the additives
THEANINE (calming/sleep)
non essential
Why is it beneficial in green tea
it counteracts the bitterness of green and black tea, and reduces the negative effects of caffeine by. having opposing effects (relax not stimulate)
What amino acid is uniquely found in green tea?
theanine
Name one function of theanine and its therapeutic uses
NEUROLOGICAL CALMING it crosses the blood brain barrier and blocks GLUTAMATE receptors whilst increasing GABA activity (which is calming); increases alpha brain waves, producing mood enhancing effect without drowsiness. INcrease dopamine and serotonin levels
THERAPEUTIC USE: increased concentration; anxiety, stress, insomnia, low mood, hypertension
Good for nerudiverse/ADHD
What is a therapeutic dose of THEANINE; drug interactions and adverse effects
50mg-200mg (green tea not practical source, just 20mg in average Japanese drinker day)
Drug interactions: lower BP therefore don’t use with anyi-hypertensives
Adverse effects: headache/sleepiness
TYROSINE: conditionally essential. What aa is it derived from
(great for focus and mood)
Phenylalanine
Name food sources of TYROSINE
nuts, seeds, legumes, whole grains, fish, meat, poultry
List one function and therapeutic uses of TYROSINE
ENdocrine health: precursor to THYROID hormones, dopamine, epinephrine, noradrenaline. Precursor to melanin.
THERAPEUTIC USE: Adrenal fatigue, hypothyroidism, ADHD, depression, anxiety, cognition
Tyrosine supplementation
Dosage
Drug interactions
Contraindicated
Caution
Dose: 400-6000mg/day. High dose safe up to 3 months
Drug interactions: MAOI antidepressants (MAO deactivates dopamine) levidopa, thyroxine
Contraindicated: overactive thyroid, might increase thyroxine levels worsening hyperthyroidism.
Melanoma.
Caution: high dose GIT upset
TRYPTOPHAN essential or not?
Name food sources
Essential
Brown rice, turkey, pumpkin seeds, oats, bananas, quinoa, fish, eggs
Name 2 functions and therapeutic uses of tryptophan
- ENDOCRINE HEALTH: used for serotonin and melatonin synthesis. INSULIN assists it across the BBB. If supplementing consume with carbs.
THERAPEUTIC USE: depression, insomnia, stress, anxiety , PMS, weight control, smoking addiction - ATP synthesis: needed to make B3 which is needed for 2 coenzymes NAD NADP in ATP production.
THERAPEUTIC USE: fatigue, fibromyalgia, Alzheimer’s.
Why is tryptophan of interest for athlete and anti aging studies
Enhances release of growth hormones.
Tryptophan supplementation
Dose
Drug interactions
Adverse effects
Dose: 100-600mg/day. 5HTP is usually preferred as it cannot be used for anything other than serotonin and melatonin production.
Drug interactions: antidepressants, sedatives
Adverse effects l-tryptophan can cause some GIT disturbances.
PHENYLALANINE
essential?
Food sources?
Essential.
Avocado, brown rice, lentils, eggs, fish, meat, soy.
Name two functions of phenylaline
1 endocrine health : can be converted to TYROSINE which is used to make thyroid hormones, dopamine etc
Therapeutic use: depression, cognition., Parkinson.
2 skin pigmentation : melanin production (via tyrosine pathway)
Therapeutic use: vitiligo (50mg/kg to 100 mg/kg 6-18 months)
Phenylalanine
Dose
Drug interactions
Caution
Contraindication
Dose: 150-7000mg/day
Drug interactions : antipsychotics , neuroleptics
Caution: can worsen schizophrenia symptoms
Contraindications: phenylketouria
Lysine
Essential?
Food sources
Essential
Quinoa, legumes, tempeh, chicken eggs dairy fish red meat
What is the sister amino acid to lysine
Arginine. They compete for absorption
Name dietary sources of Arginine
Nuts seeds seaweed meat
What is the key therapeutic use of lysine
herpes simplex virus - prevents and fights outbreaks.
What amino acid can be used for the prevention of cold sores and what vitmin can enhance its action
Lysine
vitamin C
What amino acid does the herpes simplex use to replicate
arginine. therefore as lysine competes with lysine for absorption, increasing lysine can limit viral replication
List three functions and therapeutic uses of lysine
- STRUCTURE: forms part of collagen - therefore plays role in tissue repair and bodily structure. Builds muscular tissue
THERAPEUTIC USE: recovery from muscle injury, osteoporosis - ABSORPTION: aids intestinal absorption of Ca, Fe and Zn
THERAPEUTIC USE: osteoporosis, hair loss , anaemia - GLUCOSE LOWERING EFFECT
THERAPEUTIC USE: hyperglycaemia and DM
Name the function and therapeutic uses of arginine
Precursor to NITRIC OXIDE - vasodilator and lowers BP.
THERAPEUTIC USE: hypertension, CVD, sports performance (increase blood flow to muscle), erectile dysfunction
Dose and drug interactions of arginine
What does arginine compete with for absorption
6-12 g day
Competes with lysine and histidine - so don’t supplement with food.
Drug interaction: GTN spray (angina); anti hypertensives
General guidelines for protein supplementation :
when should it not be advised to supplement
what might inhibit absorption and how can you enchance absorption
avoid in pregnancy and breastfeeding
Proteins compete with each other at the cell surface for absorption - use just one aa at a time
Long term can lead to imbalance
Name functions in the body that can be restored by providing amino acids
Neurotransmitter and hormone synthesis
physical and immunologic barriers in the gut can be restored
Blood glucose can be stabilised through better gluconeogenesis (glutamine)
improved mitochondrial performance and therefore utilisaiton of fatty acids for energy
Hepatic and gastrointestinal detoxification reactions improved - amino acids required for conjugation reactions are available
Oxidative damage is reduced when sulphur amino acid supply is adequate to maintain glutathione (eg cysteine, glycine, glutamine)
What amino acids are required for glutathione production
cyteine, glycine, glutamine
What amino acid is needed for transport of fatty acids across mitochondrial cell membrane
carnitine
what amino acids are needed for detoxification / conjugation reactions
glycine - needed for glutathione (liver detox), bile acids, and to conjugate toxins in phase II
glutamine
taurine
Cysteine (the rate limiting aa for glutathione synthesis)
Methionine (major methyl donor important for phase II liver detox)
What amino acids can be used to stabilise blood sugars
glutamine,
cysteine (increase insulin sensitivity),
taurine (reduce insulin resistance)
Lysine - glucose lowering effect
What amino acids can restore the gut
Glutamine (primary amino acid source for intestinal cells/regulate tight junction integrity)
What amino acids can be used for hyperthyroidism or hypothryoidism
carnitine - acts as a peripheral thyroid hormone antagonist, therefore used for hyperthyroidism
Tyrosine - precursor to thyroid hormones - hypothyroidism
Phenylalanine - can be converted to tyrosine … thyroid hormones
What amino acids are used for athletes/sports performance
Creatine: found in muscles and functions as fast source of ATP (creatine phosphate)
Taurine - muscle contraction
What amino acid is neurologically calming
Theanine - crosses the BBB and blocks glutamate receptors and increases GABA activity
what amino acid supports vitiligo
phenylalanine
What is a major reason for impaired UTILISATION of amino acids
lack of micronutrients needed for interconversions eg zinc, B6 B12. Therefore always address the diet first
What are free-form amino acid formulas
their free (non-peptide linked) form are efficiently absorbed, even in absence of stomach acid pancreatic secretions.
They provide balance of amino acids needed in pre digested form.
Add to juice for flavour.
Suggest an amino acid and dosage for: 30 year old woman with low mood, poor sleep and carbohydrate cravings and PMS
Tryptophan.
100-600mg
What amino acid is used for serotonin and melatonin synthesis
Tryptophan
Why does low serotonin cause carbohydrate cravings
serotonin is synthesised from tryptophan which needs insulin to cross the BBB
Suggest an amino acid and dosage for: a 65 kg woman with vitiligo
Phenylaline.
50mg/kg =
Suggest an amino acid and dosage for: 25 year old man with recurrent cold sore outbreaks
Lysine, inhibits viral replication
300-3000mg
Suggest an amino acid and dosage for: 18 year old student stressed about exams
Theanine, calms the nervous system without causing drowsiness
Suggest an amino acid and dosage for: middle aged man with fatigue and lack of motivation due to stressful job
Tyrosine - increases production of dopamine which is associated with lack of motivation. Supports the adrenals
Suggest an amino acid and dosage for: 40 year old woman with hyperthyroidism
Carnitine - thyroid hormone antagonist (blocks)
Suggest an amino acid and dosage for: 55 year old overweight man with hypertension.
Arginine - precursor to nitric oxide therefore vasodilator therefore lowers BP. Good for sports performance, erectile dysfunction CVD, hypertension
6-12g
or
Taurine, lowers BP
1500mg day in 3 divided doses
Carnitine for weight loss but must be combined with physical activity
