diet and chd

Question 1

what is atherosclerosis?

Answer 1

Focal chronic inflammatory disease of large and medium arteries. Induced by lipid products

Question 2

what is atherosclerosis characterised by?

Answer 2

thickening of the intima + lipid deposition

Question 3

what are major modifiable risk factors for athersclerosis?

Answer 3

• Hyperlipoproteinaemia – hypercholesterolaemia
• Hypertension
• Smoking
• Diabetes

Question 4

what is LDL?

Answer 4

bad cholesterol

Question 5

what is HDL?

Answer 5

good cholesterol

Question 6

what are other modifiable risk factors?

Answer 6

• Obesity –
• Dietary pattern
• Physical inactivity
• Alcohol intake
• Psychosocial

Question 7

how do you measure obesity?

Answer 7

measure by waist/hip ratio or BMI

Question 8

what are non-modifiable risk factors for atherosclerosis?

Answer 8

• Increasing age
• Male gender (females before menopause are protected)
• Family history/genetics
• Ethnicity

Question 9

which ethnicity has an increased risk of atherosclerosis?

Answer 9

South Asians have an increased risk

Question 10

what conditions does obesity predispose you to?

Answer 10

T2D, MI and hypertension

Question 11

what is metabolic syndrome?

Answer 11

• A syndrome including an increased risk of CVD consisting of;
o Insulin resistance/T2D
o Abdominal obesity
o Dyslipidaemia (particularly hypertriglyceridaemia)
o Hypertension

Question 12

what is metabolic syndrome a consequence of?

Answer 12

excess food intake of poor quality

Question 13

what induces insulin resistance?

Answer 13

• Hypertriglyceridaemia/increased intracellular fatty acids

Question 14

explain the mechanism of insulin resistance?

Answer 14

• Hypertriglyceridaemia/increased intracellular fatty acids induce insulin resistance/T2D
• In a typical muscle cell, fatty acid transporter CD36 transports excess fatty acids from blood lipids
• Normally, fatty acids are metabolised in the mitochondria
• Excess fatty acid accumulates that isn’t burnt in the mitochondria
• Saturated fatty acids are metabolised to toxic products e.g. ceramide
• Toxic products cause signalling from the insulin receptor to become blocked
• Insulin on the receptor normally activates GLUT4, but GLUT4 becomes blocked so cells can’t take up glucose
• Insulin resistance occurs

Question 15

what foods raise blood cholesterol?

Answer 15

saturated fat and dietary cholesterol

Question 16

what type of carbohydrate is good and which is bad?

Answer 16

o BUT polysaccharide carbohydrate (starch) as whole grains is beneficial rather than harmful as with refined sugar

Question 17

what are saturated fatty acids? give examples

Answer 17

no double bonds between the carbon atoms in the chain e.g. stearic acid, palmitic acid etc. Aren’t v reactive

Question 18

what are monounsaturated fatty acids? give examples?

Answer 18

single carbon-carbon double bone.

E.g. oleic acid, palmitoleic acid, erucic

Question 19

what are polyunsaturated fatty acids?

Answer 19

first double bond exists as the third carbon-carbon double bond from the terminal methyl end of the carbon chain

Question 20

what type of double bonds are made artificially?

Answer 20

trans double bonds

Question 21

what is arachidonic acid?

Answer 21

omega 6 fatty acid

Question 22

what fatty acids can and cant be metabolised into arachidonic acid?

Answer 22

Linoleic acid can be metabolised to arachidonic acid, omega 3s cannot

Question 23

what happens to omega 6 and omega 3 fatty acids on inflammation?

Answer 23

• On inflammation, omega 6 arachidonic acid is released from membrane phospholipids by phospholipase A2 enzyme
• Initially inflammatory mediators, eicosanoids e.g. prostaglandins and leukotrienes are synthesised from it
• Omega3 FAs are metabolised to anti-inflammatory eicosanoids

Question 24

what effects do omega 3 FAs have on inflammation and atherosclerosis?

Answer 24

anti-inflammatory and anti-atherogenic

Question 25

what is trans a common name for?

Answer 25

common name for unsaturated fat with trans-isomer fatty acids

Question 26

what effect do trans-unsaturated fatty acids have on LDL and HDL?

Answer 26

Increase LDL (bad) and reduce HDL (good)

Question 27

what are flavonoids? what are they found in?

Answer 27

pigmented polyphenol plant compounds involved in photosynthesis Found in fruit, veg, tea, chocolate, wine, olive oil

Question 28

why are nitrates important in the diet?

Answer 28

nitric oxide production

Question 29

what is the mediterranean diet?

Answer 29

fish, pasta, salads with olive oils, pulses, fresh fruit, nuts etc

Question 30

which diet has major effects on preventing CVD?

Answer 30

mediterranean

Question 31

what effect does exercise have on CVD and how?

Answer 31

* Exercise stimulates blood flow through the arteries  increases NO production  dilation and anti-atherosclerotic * Reduces hypertension through dilation and reduction of peripheral resistance

Question 32

explain the main stages of atherosclerosis?

Answer 32

- macrophages appear from monocytes - endothelial lining cells have become inflamed - sticky adhesion molecules allow monocytes to bind and enter tissue to become macrophages - macrophages take up oxidised LDL - recognised by scavenger receptors to become foam cells - Macrophages die and eventually release cholesterol •LDL carries cholesterol into the wall and HDL takes it out

Question 33

what factors are pro-atherosclerosis?

Answer 33

* Hyperlipidaemia and LDL * Smoking * Hyperglycaemia * Diabetes

Question 34

what factors are anti-inflammatory/anti-atherosclerosis?

Answer 34

* HDL * Increased blood flow from exercise * Nitrites from nitrates * Flavonoids in fruit, veg and wine * Statins

Question 35

how do statins protect against atherosclerosis?

Answer 35

inhibit cholesterol formation in the liver bc they’re HMG-CoA reductase inhibitors

Question 36

what complications does low birth weight lead to?

Answer 36

increased CHD, T2D, stoke and hypertension risk increased LDL and fibrinogen levels and increased blood pressure

Question 37

what dietary and lifestyle factors have an effect on hypertension?

Answer 37

* Obesity * Excess sodium – raises BP bc of genetic disposition. Mild effect on CVD * High alcohol intake increases BP * Potassium (high in fruit/ vegetables), magnesium, calcium and dietary fibre may be protective factors. * Exercise lowers BP * Smoking >15/day elevates BP, less smoking tends to decrease it

Question 38

what are the nhs dietary recommendations for hypertension?

Answer 38

* 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)