CANCER AND THE DIET

Question 1

what about the epidemiology of cancer suggests that the incidence is influenced by the environment?

Answer 1

the fact that different GI tract cancers are prevalent in different populations
e.g. gastric cancer is most present in Russia and colon cancer in the Western world

Question 2

what about the diet seems to colerate with colorectal cancer levels?

Answer 2

dietary fat levels

Question 3

what was the evidence for the five a day campaign?

Answer 3

the evidence showed that having an average fruit/veg intake of less than 200g is associated with increased risk of cancer
an average portion of fruit is 80g so the 5 a day was introduced

Question 4

what percentage of cancers are preventable?

Answer 4

50%

Question 5

what are the top risk factors for cancer?

Answer 5

smoking
alcohol/poor diet/physical inactivity/excess body weight
UV radiation

Question 6

what are the bradford hill criteria for?

Answer 6

a group of nine principles that can be useful in establishing epidemiologic evidence of a causal relationship between a presumed cause and an observed effect

Question 7

what are the 9 bradford hill criteria?

Answer 7

temporal association
specific
consistent
strong association
dose-response/biological gradient 
Experiment
analogy
plausible
coherent

Question 8

what is temporality in the bradford hill association?

Answer 8

the effect has to occur after the cause

Question 9

what is strength on the bradford hill criteria?

Answer 9

the larger the association, the more likely it is causal

Question 10

what is consistency in the bradford hill criteria?

Answer 10

consistent findings in other studies strengthens the likelihood of an effect i.e. its reproducible

Question 11

what does specificity mean in the bradford hill criteria?

Answer 11

the more specific an association between a factor and effect, the bigger the probability of a causal relationship

Question 12

what is dose-response in bradford hill criteria?

Answer 12

greater exposure should lead to greater incidence of effect

Question 13

what is plausibility in bradford hill criteria?

Answer 13

a plausible mechanism between cause and effect/ there must be some idea of the mechanism

Question 14

what is coherence in bradford hill criteria?

Answer 14

causality needs to be coherent with science as we know it

Question 15

what is experiment in bradford hill criteria?

Answer 15

the evidence should be based on a robust study design

Question 16

what is analogy in bradford hill criteria?

Answer 16

is there a similar causal relationship with another exposure/disease

Question 17

what are the 2 main issues with establishing causality?

Answer 17

confounding

reverse causality

Question 18

what is confounding?

Answer 18

when risk 1 is associated with risk 2 which is associated with an outcome, but inclinical settings risk 1 is incorrectlt associated with the outcome

Question 19

what is reverse causality?

Answer 19

a risk factor is associated with an outcome which leads to the development of another risk factor which is incorrectly associated with the outcome

Question 20

what are the pros of case control studies?

Answer 20

fast
cheap
good for rare diseases

Question 21

what are the cons of case control studies?

Answer 21

recall bias
diffiuclities measuring risk
impact of diseases on risk

Question 22

whst are the pros of a cohort study?

Answer 22

near definitive data

you can measure multiple risks and associated outcomes

Question 23

what are the cons of cohort studies?

Answer 23

expensive
long time to read out
difficulties in measuring risk
risk of bias
risk of confounding

Question 24

what are pros of RCTs?

Answer 24

identifies a causal relationship

randomsation reduces confounding and bias

Question 25

what are the cons of RCTs?

Answer 25

expensive
takes a long time to read out
issues with generalisability i.e. is the study population representative of the population at large/

Question 26

whats the cons with meta analysis?

Answer 26

needs periodic revision as new information is published
takes a long time
publication bias

Question 27

what diet risk factors is oesophageal cancer linked to?

Answer 27

low fruit/ve

Question 28

what diet risk factors is bowel cancer associated with?

Answer 28

red meat

low fibre

Question 29

what is the broken plate 2021?

Answer 29

An annual report showing the state of our current food system and the huge challenges we face in ensuring that everyone in the UK can afford and access a healthy and sustainable diet.

Question 30

what did the broke plate 2021 find?

Answer 30

access to healthy food is diffiuclt - eating healthier is more expensive
1/4 places seeling food are fast food outlets and these are over represented in poorer places

Question 31

what are some ways a patient can measure their diet?

Answer 31

food frequency questionnaires

food diary