Block 15 Flashcards
(201 cards)
Bowel cancer is more common where?
The west: Western Europe, America
Oesophageal cancer is most common where?
Eastern Europe/Russia
Levels of what correlate well with colorectal cancer?
Fat consumption
What type of study can be used to explore environmental effects?
Migrant studies
Ex of a migrant study
Looking at Japanese men who migrated to Hawaii. Stepwise increase in lifetime CA risk from 1st to 2nd gen
What is confounding in a Japanese migrant study?
May not just be diet that changed - alcohol, smoking etc.
What % of cancer is caused by the diet?
30%
In the UK, what are the top 4 causes of cancer? in order
Smoking
Diet
Obesity
Alcohol
What type of study are best for looking at affect of diet?
Observational studies
Some problems with case control studies in diet and cancer:
Recall bias
Hard to measure diet
Early CA may influence diet
Problems with cohort studies in diet and cancer:
Measuring diet difficult
Takes a long time
General problems with observational studies:
Bias
Confounding
Ex of confounding in diet and cancer
Beta carotene. Thought to be protective for lung cancer, but seems to cause it. Confounders weren’t controlled properly (i.e. those who take in more beta carotene tend to smoke less/drink less)
Measures of diet:
Food disapperance data Household surveys 24 hr recall Food frequency questionnaires Diet diary
Pros of food frequency questionnaires:
- Easy to code and complete
- Captures usual diet
Cons of food frequency questionnaires:
- Doesn’t actually capture what people eat
- No portion size/energy intake
- People overestimate fruits/veg
Pros of diet diary
- Captures actually what people eat
- Portion size/energy intake
- More flexible, can track a lot of food
Cons of diet diary:
- Expensive and difficult to code
- Take effort to do
- Misrepresentation
- People may change diet when completing diary to make it easier
Aflatoxin is a what found it what
Fungal toxin found in cereals and peanuts
Aflatoxin is linked to what cancer?
Hepatic
Colorectal cancer is caused by
red meat
processed mat
overweight
alcohol
beta carotene is causative of what and protective of what
causative = lung cancer protective = oesophageal
Why is it 5 a day?
Evidence shoes 400g/day of fruit and veg is protective of cancer. Average portion is 80g
Evidence shows less that what fruit and veg is associated with increased cancer?
<200g/day