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Flashcards in Diet and Cancer Deck (24)
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1
Q

Origins of hypothesis linking diet with cancer risk

A

Yong-He Yan (960-1279 AD) thought poor diet was cause of oesophageal cancer
Wiseman (1676) thought cancer might be caused by too much meat and salt in diet
Lambe (1815) suggested diet rich in meat might cause cancer
Bennett (1849) recommended diet low in fatty foods to < cancer risk

2
Q

Trends in age-standardised incidence of cancer in men in UK

A

Lung gone down since 1985 (13% incidence in 2015)
Prostate rising since 1970 (26%)
Stomach down slightly since 1970
Colorectal up slightly since 1970 (13%)

3
Q

Trends in age-standardised incidence of cancer in women in UK

A

Breast rising since 1970 (31% incidence 2015)
Colorectal remained same (11%)
Lung rising slowly since 1970 (12%)
Ovary slight rise since 1970

4
Q

Effects of migration on cancer incidence/ mortality

A

European migrants to Australia during 1950-1975 experienced more breast cancer mortality
Asian migrants to USA experienced higher incidence of colorectal cancer than foreign-born Japanese men and 60% higher than US-born white men
Strong evidence of environmental and behavioural influences on aetiology of cancers
Increased risk on duration of residence
One of more exposures or characteristics that differ between migrants and descendents affect development of colorectal cancer

5
Q

Human studies

A

Ecological studies
Case-control studies
Prospective cohort studies
Randomised controlled trials

6
Q

Investigating mechanisms

A
In vitro
Exfoliated cells
Cells in culture
Animal models
Human studies
7
Q

Effects over lifespan

A

Diet, smoking, infection, exercise, medication have an effect towards cancer

8
Q

Food, Nutrition, Physical Activity, and the prevention of Cancer: A Global Perspective 2007

A

5 years, meeting every 6m

>6000 papers considered, 20 SLR groups

9
Q

Body fatness and cancer

A
  • Post menopausal breast
  • Endometrial
  • Colorectal
  • Oesophageal
  • Pancreas
  • Kidney
10
Q

BMI and breast cancer

A

Continuous update panel (CUP)

10 new studies - overall, 13% increased risk/5kg/m^2

11
Q

Obesity and colon cancer

A

CUP: 22 new cohort studies

Overall, 10% increased risk/5kg/m^2

12
Q

Mechanisms linking obesity and endometrial cancer

A

Oestrogens

13
Q

Obesity may be the most important of all nutritional risk factors for cancer

A

Many sites
Men and women
Preventable
Modifiable

14
Q

WCRF recommendations for individuals

A

Be as lean as possible within normal range of body weight
Through childhood and adolescence project toward lower end of normal body weight (BMI 18.5)
Throughout adulthood stay within normal range (BMI<25)
Avoid weight gain and increases in waist circumference

15
Q

Foods and drinks that promote weight
gain: WCRF Recommendations for
in adulthood Individuals

A

Consume energy-dense foods sparingly
Avoid sugary drinks
Consume ‘fast foods’ sparingly, if at all

16
Q

Physical activity and cancer

A

Convincing: colon
Probably: postmenopausal breast cancer, endometrial
CUP - 3% reduced for CRC, 8% reduced risk for colon

17
Q

Physical activity: WCRF Recommendations for Individuals

A

Be moderately physically active, e.g. brisk walking,
For at least 30mins/ day
As fitness improves, aim for 60 mins or more of moderate,
or for 30 mins or more of vigorous physical activity / day
Limit sedentary habits e.g. watching television

18
Q

Plant foods and cancer

A
Probably protective:
Mouth 
Pharynx 
Larynx
Oesophageal
Lung 
Stomach
Pancreatic
Prostate
Colorectal (10% decreased risk/ 10g dietary fibre per day)
19
Q

Plant foods

WCRF recommendation for individuals

A

Eat at least 5 portions or a variety of non-starchy
vegetables and fruits daily
Eat relatively unprocessed cereals and pulses with
every meal
Limit refined starchy foods

20
Q

Animal foods and cancer

A

Convincing: colorectal cancer (red and processed meat)

-17% increased risk/ 100g red meat per week)

21
Q

Animal foods: WCRF

recommendation for individuals

A

Consume <500g red meat per week and very little (if any) processed

22
Q

Alcohol and cancer

A

Convincing increases risk:

  • mouth
  • larynx
  • oesophagus
  • colorectal
  • breast
23
Q

Alcoholic drinks: WCRF

recommendation for individuals

A

Limit consumption to no more than two

drinks per day for men and one drink for women

24
Q

Mechanisms for the role of diet

in carcinogenesis

A

Diet may influence the chance of developing
cancer by:
– Increasing exposure to chemical
carcinogens (Chinese style salted fish)
– Facilitating action of viruses (HPV)
– Influencing effects of hormones (adiposity
and oestrogen, fibre and steroids)
– Minimising oxidant and other damage to DNA
– Influencing DNA repair genes