Diet and CHD Flashcards
What is atherosclerosis
- A focal disease of large and medium sized arteries characterised by fatty deposition and intimal thickening
What is bad and good cholesterol
HDL is a good cholesterol – high density lipoprotein
LDL – low density lipoprotein – bad cholesterol
triglyceride is not as bad as…
LDL
what are the modifiable major risk factors of cardiovascular disease
Hyperlipoproteinaemia - LDL, HDL, triglycerides
hypertension
smoking
diabetes
what are some more modifiable risk factors for cardiovascular disease
Obesity dietary pattern physical inactivity ethanol intake psychosocial
How much does modifiable factors account for MI risk
90% risk factors of MI
What are the non modifiable risk factors for developing cardiovascular disease
Increasing age (development of atherosclerosis is a life-long process) Male gender (females before menopause protected – female sex hromoens stops the cholesterol and lipoproteins getting into the wall ) Family history/ genetic – heritability 0.57 / 0.38 ♂/♀. Ethnic:- increased in South Asians 1.7 million genetic loci identified [polygenic +++!] – total makes only a modest contribution to total risk, roughly = any one standard risk factor
as blood pressure and cholesterol increases…
- As blood pressure increases death rate increases
- As cholesterol increases death increases
what is the NHS cholesterol range normally
- cholesterol ranges normally below 5mm/L
what does obesity predispose you to
- type 2 diabetes
- hypertension
- And MI
women have a …
- Women have a 90 times risk of getting type 2 diabetes if they are obese
What is metabolic syndrome
- A syndrome including an increased risk of cardiovascular disease consisting of:-
- Insulin resistance/ Type II diabetes
- Abdominal obesity
- Dyslipidaemia (particularly hypertriglyceridaemia)
- Hypertension
How does the metabolic syndrome work
- cells take up fatty aids
- lipoproteins takes the fatty acids of blood lipids
- CD36 then carries the fatty acids into the cells
- these fatty acids are normally metabolised in the mitochondria
- but if there are too much fatty acid production this can make toxic byproducts such as ceramide
- the toxic by products block signalling from the insulin receptor
- this means that the cells cannot take up glucose from the GLUT4 transporter as it cannot go to the surface
any source of calories can be metabolised too…
cholestrol and therefore lead to CVD so instead of reducing intake of saturated fat and cholesterol we should control the total amount of calories that we intake
what can be cardioprotective
- polysaccharide carbohydrate (starch) as whole grain
- dietary fibre
what are the classes of fatty acids
saturated
monounsaturated
polyunsaturated
describe saturated fatty acids
- No double bond
- come with a different number of carbons
what is a monounsaturated fatty acid
- single double bonds
- less harmful forms of fat
- has a Cis double bond
describe polyunsaturated fatty acids and some examples
- Contain multiple double bonds
- 2 categories omega 3 (alpha-linolenic acid) and omega 6 (alpha Linoleic acid)
where are trans double bonds made
- they are only made in industry these are very harmful so there is a reduction in the number we have produced (only 0.7% intake in the uK)
- they are atherogenic so damage blood vessels
what are the difference names for omega 3 and omega 6
omega 3 (alpha-linolenic acid) omega 6 (alpha Linoleic acid)
what type of omega acid is arachidonic acid
Omega 6 fatty acids (Linoleic acid)
what is the proper name for arachidonic acid
eicosa tetra enoic acid
describe the structure of arachidonic acid
- Has 4 double bonds
describe what arachidonic acid is used for
- Found in membranes phospholipid
- It is released from the membrane by phospholipase A2
- Metabolised to leukotrienes and prostaglandins - therefore gives rise to pro-inflammatory mediators
what is a difference between omega 6 and omega 3
Omega 3 - gives rise to anti-inflammatory mediators which inhibit inflammation therefore better in the diet than omega 6, (e/g. resolvins, protectins & maresins)
omega 6 - sometimes gives pro inflammatory mediators
omega 3 fatty acids are…
are relatively anti-inflammatory and anti-atherogenic
what do aspirins and statin do in regards to omega 3 and omega 6
enhance anti-inflammatory mediators from 3 & 6 FAs
What effect does egg have on cardiovascular disease
Choelstorl
• Egg consumption 1/day (major source of cholesterol -200mg/egg) shows no correlation with CVD, except possibly in diabetes patients
• Currently reported that egg consumption reduces stroke incidence
what is most cholesterol synthesised from and why is this important
- More cholesterol is synthesised in the body from saturated fatty acids each day (about 1g), than is ingested (about 0.3g).
- Conclusion: Dietary cholesterol has little importance in regulating serum cholesterol or risk of CVD
What are flavonoids
Pigmented polyphenol (flavone-like) plant compounds involved in photosynthesis and protection from UV light.
Where are flavonoids found
Found in fruit, vegetables, tea, chocolate/ cocoa, wine, olive oil.
What do flavonoids have beneficial effects on and why
Have beneficial effects on MI & stroke in epidemiological studies, particularly flavone & flavonol groups.
- Are inhibitors of inflammatory enzymes, including NADPH oxidase that generates damaging reactive oxygen intermediates.
Name some examples of flavonoids
quercetin (flavonol) - apples, onions, citrus fruits
epicatechin (flavon-3-ol) - tea, chocolate
what is the best diet to act as secondary protection for an MI
Mediterranean diet
What does the Mediterranean diet consist of
Fish, pasta, salads laced with olive oil, vegetables++, cereals, pulses, fresh fruit, nuts, red wine
how are nitrates protective
Nitrates: from beetroot & green leafy vegetables nitric oxide production
How are sulforaphane protected
Sulforaphane: protective organosulfur molecule in brassica vegetables e.g. Cabbages
why can wine be cardioprotective
- Protective effects of alcohol through improving blood lipid profile and inhibiting thrombosis
- Wine contains multiple flavonoids and flavonoid like compound resveratrol with anti-CVD and possible life prolonging effects
how can a deficiency in B12 and folate cause cardiovascular risk to increase
- causes low level of methionine and high blood homocysteine level
- homocysteine spontaneously converts to thiolactone which can damage to the endothelial cells
how does exercise reduce cardiovascular risk
- Exercise stimulates blood flow through arteries which increases production of nitric oxide which can cause dilatation and is anti-atherosclerotic
- This reduces hypertension through the dilatation and reduction of peripheral resistance in the blood vessels
What should blood cholesterol be lower than if you are normal and if you are at high risk of CVD
- Total cholesterol should be less than 5 mmol/L in healthy
- If you are high risk of CVD then below 4 mmol/L
- The lower cholesterol can be kept the better
what are the things that regulate atherosclerosis forming
endothelial dysfunction
- pro-infllammtory
- pro-atherosclerosis
normal
- anti-inflammatory
- init atherosclerosis
what factors are endothelial dysfunction, pro inflammatory and pro atherosclerosis
- hyperlipideamiea and LDL
- smoking
- hyperglycaemia (diabetes)
- homocysteinaemia
- oxidised LDL and atherosclerosis itself as it creates a positive feedback loop
what factors are anti-inflammatory and anti-atherosclerosis
- HDL
- increased blood flow due to exercise
- nitrites from nitrates
- nitric oxide
- flavonoids in fruit, veg and wine
- anti inflammatory mediators from omega 3 fatty acids
- statins
why things during birth and pregnancy can predispose the feotus to cardiovascular disease
- Low birth weight increases risk
- this is because eating during pregnancy - starved fetus reprogrammed neuro-homronal pathways for lipid metabolism and therefore increases cardiovascular risk later in life
Wha happens if you increase your fat intake and total saturated fat intake
- Obesity
- Increase hepatic cholesterol synthesis – increases hypercholestrolaemia
- Increase LDL
what happens if you increase refined carbohydrate
- Obesity
- Metabolic syndrome
- Type 2 diabetes
- Hypertriglyceridaemia
what happens if you increase salt intake
- Hypertension
what happens if you decrease folate/B6/B12
- Homocysteinaemia
what happens if you decrease physical activity
- Decrease HDL
- Decrease nitrix oxide in arterial wall
What does the NHS recommend for diet
- Eat a balanced diet, not to excess.
- Plenty of potatoes, bread, rice, pasta or other starchy foods (polysaccharides with a low glycaemic index)
- Plenty of fruit & vegetables:- 5 portions (of 80g) a day
- Moderate amounts of low fat milk and dairy foods
- Moderate amounts of meat, fish, eggs & beans (sources of protein)
- Restrict food & drink with a high fat, sugar or salt content (e.g.chips, fizzy drinks, crisps)
