Lipids Flashcards
What are fat cells called?
Adipocytes
What is BAT & WAT?
Brown and white adipose tissue
What did Ancel Keys declare in the 1950’s?
High saturated fat would increase serum cholesterol.
What is WAT?
A complex metabolically- active endocrine tissue.
Name 4 forms of lipids in the body?
Triglycerides
Phospholipids
Cholesterol
fat soluble vitamins
What are 4 functions of lipids?
Energy production (ATP)
Storage of energy reserves
Cell membrane structure
Steroid hormones
What are short & medium chain fatty acids used for in the body?
Used in the liver to create energy or ketones.
What are long chain fatty acids used to build?
Cell membranes.
Name 3 SCFA?
Acetate
Propionate
Butyrate
Why is butyrate important?
It supports the intestinal tight junctions.
What is the process of hydrogenation?
Unsaturated fats become saturated with the addition of hydrogen e.g. oils made into solid spreads.
Explain saturated fats and give example?
All carbons are completely saturated with hydrogen bonds, solid at room temperature
E.g. margarine
Explain unsaturated fatty acids and give 1 example.
The contain 1 or more double bonds and are liquid at room temperature
E.g Olive oil
Explain monounsaturated fatty acids and give 1 example.
The have 1 double bond in the chain
E.g sunflowers oil
Explain polyunsaturated fatty acids and give 1 example.
The have several double bonds
E.g vegetable oil
How are trans fats produced?
By hydrogenation and high temperatures.
Where are trans fats found?
In margarine, processed foods and refined vegetable oils.
What are the negative effects of trans fats?
The stiffen cell membranes which makes them prone to oxidation and impedes normal cell function.
The alter blood triglyceride and cholesterol profiles increasing the risk of cardio vascular disease, insulin resistance and cancer.
What are cis fats?
They are natural fats with H atoms on the same side
What are triglycerides?
Triglycerides are the major form of dietary fat, they circulate in the blood when released for energy.
What are triglycerides made up of?
1 unit of glycerol and 3 fatty acids
What are high blood triglyceride levels related to?
Atherosclerosis
What is the process of converting dietary energy to triglycerides?
Lipogenesis
Where does lipogenesis take place?
In adipose tissue and the liver
Why does lipogenesis take place?
When there is an excess of carbohydrates
Acetyl-CoA is converted to triglycerides for storage in fat
What is lipolysis?
Fatty acids from triglycerides are mobilised when dietary energy is limited.
What stimulates lipolysis?
Adrenalin, noradrenalin
Adrenocorticotrophic hormone (ACTH)
Glucagon and growth hormone
Thyroid stimulating hormone (TSH) and thyroxine
How does carnitine assist energy production?
Carnitine facilitates the transport of fatty acids across the mitochondrial membrane.
What is ketosis?
Ketosis is the process by which fat becomes the primary fuel for energy production
Ketones are made when glucose is in short supply
When does ketosis take place?
When carbohydrates are restricted to 40g daily
What are the health benefits of ketosis?
Weight loss
Management of epilepsy
Parkinson’s
Alzheimer’s Disease
Which 2 enzymes assist lipid digestion?
Gastric lipase- stomach
Pancreatic lipase- duodenum
What is the purpose of bile?
It emulsifies the fat.
The remaining 2 fatty acids and monoglyceride are packaged into chylomicrons and transported in the lymph to the blood stream.
Identify 4 ways to optimise lipid digestion.
Increase bile production by optimising stomach acid with zinc and B6 rich foods.
Add choleretics like dandelion, artichoke and turmeric to increase bile flow.
Ensure good hydration to support bile flow.
Increase glycine and taurine with legumes, sea veg, spinach and eggs.
List 3 foods, rich in Vit E to support fat-soluble antioxidants.
Sunflower seeds
Almonds
Wheatgerm
List 4 benefits of a diet high in healthy fats.
Greater satiety value
Source of Essential fatty acids
Source of choline
Source of fat soluble vitamins
List 4 food sources of healthy dietary fats.
Avocado
Chia seeds
Oily fish
Walnuts
What are MCT’s and what oil might you find them in?
Medium chain triglycerides
In coconut oil
Why might you cook with coconut oil and ghee?
Due to their high smoke point and tolerance of heat.
Why would you choose to consume polyunsaturated oils in their raw, cold pressed form?
Because they oxidise when heated producing free radicals.
They should be stored in dark coloured bottles in cool areas as they can become rancid.
What are the dangers of rancid oil?
Rancid oil becomes oxidised and produces malondialdehyde which is a potential mutagen.
What makes fats more prone to oxidation?
If they are high in polyunsaturated fat
If they are exposed to prolonged heat
If they are naturally low in antioxidants
If they are refined or heavily processed
Which fats are considered more stable?
Saturated fatty acids e.g. coconut oil due to their lack of double bonds.
What are the two essential fatty acids?
Linoleic acid (omega 6 fatty acid) Alpha-linolenic acid (omega 3 fatty acid)
What does the enzyme Delta-6 desaturase do?
It creates the chemical reaction to create other fatty acids from LA and ALA
Does the typical western diet tend to be more abundant in Omega 3 or 6?
Omega 6.
We tend to eat more plant oils, grain fed meat and dairy than flax seeds, pumpkin seeds and oily fish.
What are conditionally essential nutrients?
The are nutrients which they body can make but is unable to convert so they become essential.
They are EPA & DHA and can be consumed in oily fish.
What are the functions of fatty acids?
To maintain membrane fluidity
To transport substances into and out of the cell
For cell to cell communication
For foetal and child brain development
Precursors of prostaglandin (local hormones)
What are the clinical indicators of an EFA requirement on the skin?
Dry, flaky lips and eyes
Delayed wound healing
Dry brittle nails
What are the clinical indicators of an EFA deficiency in the endocrine system?
Weight imbalances
PMS/menstrual cramps
What are the indicators of an EFA requirement in the reproductive system?
Infertility
Impotence
Repeated miscarriage
What are the clinical indicators of an EFA requirement in the circulatory system?
Frequent nose bleeds
Bleeding gums
Easy bruising
What are the clinical indicators of an EFA requirement in the musculoskeletal system?
Chronic joint pain
Delayed recovery
What are the indicators of an EFA requirement in the Immune system?
Susceptibility to infections
What are the indicators of an EFA requirement in the neurological system?
Dementia
Parkinson’s
Tingling arms and legs
What are the food sources of ALA?
Flaxseeds
Hempseeds
Walnuts
What are the therapeutic uses of ALA?
Reduces C-reactive protein
Anti hypertensive
Decreases risk of atherosclerosis and myocardial infarction
Increases Brain derived neurotrophic factor
Supports inflammatory bowel disease
What drug interactions can ALA have?
Statins
What food sources revise EPA and DHA?
Oily fish
Human breast milk
Marine algae
What are the therapeutic uses of EPA & DHA?
Reduce blood triglycerides Lower BP Anti inflammatory effects Support learning and behavioural problems Support foetal brain development
Can a vegan diet meet the EPA?DHA needs?
Yes, using Flaxseed, hempseed.
Supporting conversion with sins, magnesium and B6
Avoid processed foods
Consider algae supplements
What factors determine Omega fish oil quality?
Sustainability practices
Independently tested oil
EPA/DHA content listed on the label
What factors determine the quality of vegan omega oil?
Water extraction methods
Contains stearidonic acid
Free from carrageenan
Cold pressed organic
What possible drug interactions could EPA/DHA have with medications?
Anticoagulants- may increase bleeding time
Aspirin- could risk bleeding
Diabetes medications- may lower blood glucose and strengthen diabetes drugs
Blood pressure medication- may lower blood pressure
What Omega family does Linoleic acid belong to?
Omega 6
What are the food sources for Linoleic acid?
Safflower, sunflower, soybean and corn oils. Nuts & seeds.
Name the Omega 6 EFA
Linoleic acid
Gamma- linoleic acid
Arachidonic acid
DPA
List some food sources of GLA
Evening primrose oil
Blackcurrant seed oil
Hemp
What are the therapeutic uses of Gamma-linoleic acid (GLA)?
Rheumatoid arthritis
ADHD
Eczema
What are the benefits for female health in using evening primrose oil?
PMS
Breast pain
Female fertility
What possible drug interactions exist with GLA?
Chemotherapy - may increase treatment effects
Cyclosporine- may increase immunosuppressive effects
NSAIDS- may cancel out affect of GLA
Where is arachidonic found?
Meat
Eggs
Dairy
What can too much arachidonic acid lead to?
Inflammation
What are Eicosanoids?
Locally acting hormones made by oxidation of omega 3 & fats.
They are involved in: Inflammation Blood vessel permeability and constriction Blood coagulation Immune cell behaviour
How are eicosanoids created?
Fatty acids a re released from the phospholipids by phospholipids A2
Cox & LOX converts these to eicosanoids
Eicosanoids can be be from AA, EPA & DGLA
They can have both pro & anti-inflammatory effects.
What are prostaglandins?
They are found within eicosanoids.
They are PG1, PG2 & PG3
Which prostaglandins are Pro-inflammatory?
PG2
What can too much Omega 3 in the diet create?
Immune suppression because of too much EPA & DHA at the expense of AA
What can too much Omega 6 in the diet lead to?
Inflammation due to too much AA
What co factors are required for activation of Delta-desaturase?
Vit C B3 B6 Magnesium Zinc
What factors inhibit EFA metabolism?
Mag, B6, zinc deficiency Insulin resistance Viruses Alcohol Stress hormones
What is Genova?
Essential and metabolic fatty acids blood test
What is cholesterol beneficial for?
Synthesis or action of Vit D Cortisol Sex hormones Membrane integrity
What stimulates cholesterol synthesis?
A diet rich in triglycerides.
It is excreted in bile products and is increase by fibre absorption.
What are the carriers of cholesterol called and explain them?
LDL (low density)- takes cholesterol from liver to cells
VLDL (very low density)- takes triglycerides to cells
HDL (high density)- collects cholesterol from cells to bring back to liver
I what condition would we find LDL?
Atherosclerosis- inflammatory disease
Injury to endothelium cause cholesterol to deposit
What is a better measure of cholesterol?
LDL particle size- small & dense particles = risk of coronary heart disease
HDL particle size- larger particles = more effective at removing cholesterol from the blood (anti-inflammatory)
Name 3 cardiovascular markers?
C-reactive protein- inflammatory marker
Lipoprotein (a)- blood clotting agent= higher levels greater risk
Lip-PLA2- enzyme in endothelial inflammation & atherosclerosis
What are phospholipids and name 3?
Structural basis of cell membranes
Phosphatides - signalling for cells
Phosphatidylcholine- predominant in the body
Lecithin- improves cognitive function
What is the fat composition of a healthy man?
16%
What is the lipid content of a severely obese man?
70%
What type of tissue is white adipose tissue and list 4 functions?
Metabolically active endocrine tissue
Secretion of hormones
Reproduction ( oestrogen held in fat)
Glucose and lipid metabolism
Protection of organs
List 4 functions of lipids
Steroid hormones- oestrogen. And progesterone
Growth and development- brain rich in AA and DHA
Absorption of fat soluble vitamins
Eicosanoids - signalling molecules involved in inflammation
How many C’s in SFA?
6 or less
How many C’s in MCFA?
6-12
How many C’s in LCFA?
14-22
Name 3 SCFA?
BAP- Butyrate, acetate, propionate
Why is butyrate important for gastro health?
Primary energy source for enterocytes, supports tight junctions and has an anti inflammatory effect on the colon.
What are trans fats and why are they damaging to health?
Unnatural trans fats are when hydrogen has been added to an unsaturated fat to make it saturated. The H atoms are on separate sides of the double bond. They are unsaturated but act like saturated as they do not have a kink.
Trans fats stiffen cell membranes, making them prone to oxidation, they alter blood triglyceride and cholesterol levels, linked to an increase in CVD, insulin resistance and cancer.
Where does lipogenesis occur?
Adipose and liver
Describe the process of lipogenesis
Fatty acid synthesis when excess carbs. Acetyl CoA (created by glycolysis) - 2 carbon atoms added to palmitic acid. Three fatty acids bound to glycerol and stored as triglycerides.
Describe the process of lipolysis
Energy limited- fatty acids released
Triglycerides hydrolysed by lipase
Stimulated by hormones: adrenaline/noradrenalin, glucagon and growth hormone, thyroid stimulating hormone.
What is insulin’s affect on lipolysis?
Insulin antagonises the lipolytic effect of these hormones- insulin resistance=central adiposity
What is carnitine’s impact on fatty acids?
Facilitates transport of fatty acid across mitochondrial membrane. FA undergo oxidation to produce Acetyl CoA which is oxidised via the krebs cycle and energy is generated in the electron transport chain.
When would an adult drop into ketosis?
When carb intake is reduced below 40%
How would you optimise a clients digestion of fats?
Optimise bile production:
Optimise stomach acid: zinc, B6 and stress management
Bitter foods- chicory and rocket
Increase choleretics e.g. dandelion
Glycine and taurine: components of bile-legumes, eggs, spinach
Olive oil
Why is coconut oil a good cooking option?
Has a high smile point- lowers oxidation and rancidity
Source of Sat. Fat?
Coconut oil
Source of Monounsaturated Omega 7 & 9
Omega 7- Seabuck thorn
Omega 9- Avocado
Source of Omega 3
Flaxseed, Blackcurrant, Oily fish
Source of Omega 6
Sunflower, chia, pumpkin seed. Evening primrose oil
Why not cook with veg oils?
Poly unsaturated fats oxidise when heated and produce free radicals that damage cells. Store in dark bottles in the fridge.
What are essential co factors in EFA conversion?
B3, B6, Zinc, Vit C
Why would you supplement an alcoholic with DHA & EPA?
What inhibits Delta 6 and Delta 5 Desaturase?
Alcohol Refined sugars Zinc, Vit B Insulin resistance
Functions of EFA’s?
Maintain fluidity of cell membrane. Key component of organelle membrane Cell to cell communication Child brain development Precursors of eicosanoids
Key signs of EFA deficiency
Skin- dry and flaky
Nails- brittle
Hair- dry, alopecia
Endocrine- weight imbalance, PMS
Reproductive system- Infertility, impotence
Circulatory- Easy bruising, delayed recovery
Musculoskeletal skeletal- Chronic joint pain, arthritis
Immune- Susceptible to infection
Which 2 AA are required for bile production?
Glycine and taurine
