Atherosclerosis : Nutritional Aspects of Cardiovascular Disease Flashcards
What is the number 1 mortality cause in Western countries?
cardiovascular disease
What is the main cause of cardiovascular disease?
atherosclerosis
What happens in coronary heart disease?
- plaque builds up in coronary arteries- these arteries are vital for supplying the heart with oxygen
What are 3 types of main coronary heart disease?
- stable/ unstable angina 2. acuta myocardial infarction (MI; heart attack)3. sudden death with or without history of chest pain and/or previous infarction
Define stroke.
-sudden localised loss of brain function due to ischaemia OR haemorrhage and lasting longer than 24 hours
What are MOST stroke causes due to in UK?
Due to ischaemia; which is due to thrombosis (85%); blood clot in vessel and and emboli; travelling blood clot
What are haemorrhagic strokes due to?
consequence of rupture of arterial wall due to aneurysm or wall disease
What are 2 types of strokes?
- Ischaemic (due to thrombus or embolus) 2. Haemorrhagic (bleeding)
What other disease often co-exists with cardiovascular disease?
paripheral vascular disease
What vessels does peripheral vascular disease affect? (3)
disease of the…1. aorta 2. iliac arteries 3. leg arteries(essentially restricted blood supply to leg muscles)
What are 6 main “groups” of cardiovascular disease?
- coronary heart disease (CHD) 2. stroke 3. peripheral vascular disease 4. rheumatic heart disease 5. congenital heart disease6. deep vein thrombosis and pulmonary embolism
What does rheumatic heart disease cause?
damage to the heart muscle and heart valves from rheumatic fever caused by streptococcal bacteria
What are congenital heart disease?
malformations of heart structure existing at birth
With developing atherogenesis, what 3 diseases become increasingly more common particularly?
- ischaemic heart disease 2. stroke 3. peripheral vascular disease
Describe the steps in formation of an atherosclerotic plaque. (4)
- normal 2. fatty streak (with foam cells) 3. fibrous cap and lipid core formed (lipid-rich plaque) 4. thrombus formed
List the steps of the development of an atheroscletotic lesion. (7)
- endothelial cell dysfunction (decrease in NO production and LDL production) 2. endothelial cell activation (VCAM1 and ICAM1 produced with collagen proteins)3. infammation (monocyte, t cell and foam cell recruitment) 4. proteolysis and apoptosis 5. lipid core and fibrous cap formation 6. angiogenesis (thrombus attaches to atheroma formed_ 7. thrombosis (formation of established blood clot in blood vessel wall)
What 2 processes occur in the tunica intima which induce cytokine and macrophage production that create proliferation and foam cell production in atheromas?
- monocyte adhesion2. diapedesis
What is diapedesis?
passage of blood cells through the intact walls of capillaries, typically accompanying inflammation
What are foam cells?
- indication of plaque build up and atherosclerosis - formed when macrophages sent to fatty deposits on blood vessel walls -macrophages surround fatty tissue to destroy it but become filled with lipids - lipids surrounded by macrophages gives it the “foamy” appearance
What are main risks of cardiovascular disease? (9)
- diet (if excess energy intake)2. obesity 3. hypertension 4. insulin resistances, diabetes 5. physical activity 6. smoking 7.alcohol 8. foetal and infant growth 9. genetic
What substances are pro-atherogenic? (5)
- cholesterol 2. saturated fatty acids3. trans fatty acids 4. sodium 5. alcohol
What substances are anti-atherogenic?
- polyunsaturated fatty acid (PUFA) 2. carbohydrate rich diet 3. non-starch polysaccharides 4. monounsaturated fatty acids (MUFA) 5. antioxidants
What are 2 miscellaneous factors (different elements) that decrease risk of CV disease?
- homocysteine 2. B12 and folate
What type of cholesterol has a strong link with coronary heart disease?
LDL cholesterol in plasma
What is plasma concentration of LDL influenced by? (2)
- fat content 2. quality in diet
How does reduction in plasma cholesterol affect risk of coronary heart disease?
1% reduction in plasma cholesterol translates to 2-3% lower risk of coronary heart disease
What can hypercholesterolaemia be caused by?
- poor lifestyle 2. genetic
What is HDL cholesterol associated with?
associated with LOWER risk of coronary heart disease but only when LDL cholesterol is high
When is dietary cholesterol a problem to health?
when there is a presence of hypercholesterolaemia
What feature of saturated fatty acids affects its effect on modulating cholesterol level.
the chain length of saturated FA (shorter chained length do NOT modulate cholesterol level)
Describe the action of saturated fatty acids for modulating cholesterol.
- act on LDL receptors (inhibition and suppression) 2. have aggregatory effect (combines molecules)
Replacing 1% of energy from saturated fats with unsaturated fats, reduces coronary heart disease risk by how much?
by 2-3%
What is the current recommendation for daily saturated fatty acid intake for men and women?
men: no more than 30g/day women: no more than 20/day
What percent of UK population exceed the maximum recommended fat intake?
over 80% of UK population
What should the fat intake from food energy be?
recommended 11%
What effect do trans fatty acids have on: LDL cholesterol, plasma TAG and HDL?
- raise LDL cholesterol - raise plasma TAG - lower HDL cholesterol
By replacing 1% of energy from trans fats with unsaturated fats, by how much is coronary heart disease risk reduced?
by 2-3%
What is the daily recommendation for trans fatty acids for an adult?
~5g a day (no more than 2% of total energy per day)
Is sodium atherogenic?
No, but influences thrombosis by its effect on blood pressure
What should happen to Na and K intake to decrease BP?
- Na intake decreased - K intake increased
What is the current average salt intake and what is the current recommendation?
- current salt intake on average: 7.2g/day - current recommendation: don’t exceed 6g NaCl (2.3g Na)
How many units of alcohol per week can raise BP significantly?
30 units weekly (habitual heavy as well as acute consumption increases risk of stroke)
What effect does polyunsaturated fatty acid have on LDL and HDL cholesterol?
- lowers LDL - lowers HDL Generally has anti-atherogenic properties
What is the main monounsaturated fatty acid that can be used to substitute saturated fatty acids with?
oleic acid
What are 2 types of polyunsaturated fatty acids (PUFA)?
- n-6 PUFA 2. n-3 PUFA (marine origin, not plant origin)
What effect does MUFA oleic acid have on plasma properties?
-reduces total cholesterol in plasma -reduces LDL cholesterol in plasma
What effect does n-3 PUFA (polyunsaturated fatty acid) have TAG, LDL and HDL levels (plasma properties)?
- reduces TAG levels -minimal effect on LDL and HDL effect
What extra properties does n-3 PUFA have?
- anti-infammatory - anti-thrombotic Effects due to long chain one (EPA and DHA) but not α18:3.
What percentage of total energy intake should carbohydrates make up?
50% (biggest part out of all food groups)
Why do carbohydrates reduce risk of coronary heart disease?
by consuming carbohydrates, it decreases fat intake ultimately
What should the daily intake of free sugars be?
~5% daily ( they don’t have anti-atherogenic properties)
What are the benefits of Non-Starch Polysaccharides (NSP)? (4)a
- decrease risk of coronary heart disease - reduce cholesterol levels but no effect on VLDL and TAG levels - benefit insulin secretion - beneficial effects on gut health
What is the job of antioxidants?
- essential components of the cellular defence against activated oxygen species (protects body from free radicals)- Free radicals are unstable molecules generated by sun exposure, stress and as part of the natural aging process. - They damage cells, DNA and collagen.
What are some examples of antioxidants?
They include Se, Zn, Mn, vit C and E, as well as carotenoids (βcarotene, luthein and lycopene) and flavonoids
What vitamins are associated with lowering risk of cardiovascular disease?
vitamins C and E (found in fruit and vegetables)
What 2 less common factors have anti-atherogenic properties?
- Green tea due to catechin (natural oxidant)2. Garlic due to allicin
What benefits does allicin in garlic have?
- reduces platelet aggregation - increases fibrinolysis -decreases plasma fibrinogen (effects on cholesterol still debatable)
What type of fatty acids have shown to be very effective in reducing sudden death and non-fatal MI (when there are not enough lipid lowering mechanisms)?
n-3 PUFA (polyunsaturated fatty acid)
What effect does omega 3 in reducing cardiac death?
90% reduction risk
What effect does N3 LCPUFA (long chain polyunsaturated fatty acids) have on lipoprotein metabolism? (1)
fasting and post-prandial triglycerides
What effect does N3 LCPUFA (long chain polyunsaturated fatty acids) have on smooth muscle cells? (1)
growth factors
What effect does N3 LCPUFA (long chain polyunsaturated fatty acids) have on immune cells? (3)
- chemo-attractants2. pro-inflamamtory cytokines 3. pro-inflammatory eicosanoids
What effect does N3 LCPUFA (long chain polyunsaturated fatty acids) have on vascular endothelium? (6)
- growth factors 2. chemoattractants 3. pro-inflammatory cytokines4. pro-inflammatory eicosanoids 5. blood pressure 6. adhesion molecule expression
What effect does N3 LCPUFA (long chain polyunsaturated fatty acids) have on platelets?(1)
thrombosis
What effect does N3 LCPUFA (long chain polyunsaturated fatty acids) have on heart? (1)
arrhythmias
Which food tend to have high levels of n-3 LCPUFA? (4)
- mackerel - trout- salmon -cod (roast lamb, beef and chicken have smaller quantities)
What effect do whole grain foods generally have on the heart?
generally protective (cardio-protective)
What effect does Beta-glucan have in metabolism? (2)
- decreases cholesterol/bile acid absorption - increases cholesterol mobilisation
Increased levels of what organic compound is linked to increased risk of cardiovascular disease?
TMA; trimethylamine (oxidised to trimethylamine oxide; TMAO)
Which products lead to production of TMA which can increase risk of CV disease? (3)
- meat2. eggs3. cheese ( phosphatidylcholine changes to choline which produced TMA)
What is the current recommendation in UK for wholegrain intake?
- not very specific - choosing wholegrain varieties of starchy food whenever people can
What are 3 other components which are very important in good cardiovascular health?
- vitamin D2. carotenoids 3. phytochemicals
What polymorphism causes homozygous individuals to be more susceptible to dietary salt (NaCl) than those without?
A-6G polymorphism in the angiotensinogen gene
How can dietary componenets alter body process which can lead to complications in the CV system?
- alter DNA structure -alter gene expression and metabolism - affects disease development and progression - gene variation affects how nutrients are assimilated, metabolised, stored and excreted
