Chapter 2: Nutrition and Cancer Prevention

Question 1

A cancer survivor is someone who:

Answer 1

Has ever been diagnosed with cancer. At the time of diagnosis, they are considered a survivor. They don’t have have to wait until after they are “recovered”

Question 2

T of F: Body fatness probably protects against premenopausal breast CA but increases the risk of postmenopausal breast CA

Answer 2

True

Question 3

What are the AICR/WCRF Recommendations?

Answer 3

• Be as lean as possible within normal range of body weight
• Be physically active as part of everyday life
• Limit consumption of energy-dense foods; avoid sugary drinks
• Eat mostly foods of plant origin
• Limit intake of red meat and avoid processed meats
• Limit alcoholic drinks
• Limit consumption of salt; avoid moldy cereals or pulses
• Aim to meet nutritional needs through diet alone
• Mothers to breastfeed; children to be breastfed
• Survivors follow the same recommendations above

Question 4

The AICR/WCRF recommendations were developed by an expert panel that reviewed and synthesized the large body of relevant peer-reviewed literature on ______, _______, and ________, aimed at the prevention of cancer as a whole.

Answer 4

Diet, physical activity and cancer

Question 5

What is a protective hormone that decreases insulin resistance and inflammation and promotes apoptosis?

Answer 5

Adiponectin

Question 6

AICR/WCRF recommend that those who consume red meat limit intake to what amount per week?

Answer 6

less than 500 g (18 oz) per week

Question 7

How is breastfeeding beneficial in regards to cancer?

Answer 7

Mother’s risk for both pre and post-menopausal breast CA is reduced

Babies are less likely to become overweight/obese, reducing their risk of cancers that are associated with lifestyle/obesity

Question 8

AICR/WCRF recommendations regarding alcohol consumption include:

Answer 8

Alcohol works synergistically with tobacco, multiplying the risk of mouth and throat CAs.

A modest increase in breast CA risk occurs even at intake of the recommended max daily intakes (max amounts are one/day for women, two/day for men)

Question 9

True or False: High dose of Vitamin E has been shown to reduce the risk of colon cancer

Answer 9

False

Question 10

What are two supplements/nutrients that may promote the risk of prostate cancer?

Answer 10

Vitamin E and Calcium - both shown to increase risk

Question 11

A plant-based diet helps reduce the risk of cancer by what mechanisms?

Answer 11

Epigenetic effect (changes in gene expression)

Reducing levels of circulating hormones that promote cell proliferation

Provide fermentable fiber to the intestional microbiota, promoting normal colon cell development and possible reducing inflammation

Question 12

True or False: Beta-carotene and Vitamin E are two examples of high-dose supplements that increase the risk of cancer

Answer 12

True

Question 13

Body Fatness is related to influencing cancer risk by:

Answer 13

Decreased levels of adipose hormone adiponectin, which decreases insulin resistance and inflammation

Question 14

What two nutrients may be beneficial as a supplement if blood levels are low, but aren’t beneficial once levels are optimal?

Answer 14

Vitamin D and Selenium

Question 15

Both the AICR/WCRF and the ACS recommend exercise to prevent cancer. What are their recommendations?

Answer 15

AICR/WCRF:
30 minutes every day and as fitness improves, aim for 60 minutes of moderate or 30 minutes of more vigorous activity daily
Also limit sedentary habits such as watching TV

ACS:
adults get 150 minutes of moderate activity of 75 minutes of vigorous activity each week
children/adolescents be physically active for a min of 60 minutes every day, including at least 3 days/week of vigorous activity

Question 16

Foods containing selenium and foods containing lycopene have been shown to protect against what type of cancer?

Answer 16

Prostate

Question 17

The risk of colorectal cancer increases by an estimated ____ percent for every ____ grams of processed meat consumed daily.

Answer 17

18%

50 grams

Question 18

T or F: Soy foods have been proven to increase cancer risk in both animals and humans

Answer 18

False - only in rat models, not in humans

Question 19

What is the American Cancer Society’s recommendation on sodium intake and cancer prevention?

Answer 19

There is no recommendation from ACS

Question 20

T or F: Increased years of amenorrhea can reduce Breast CA risk

Answer 20

True

Question 21

Adipose tissue is the primary site of what hormone in post-menopausal women?

Answer 21

Estrogen

Question 22

The AICR recommends a waist circumference of ___ in men and ___ in women?

Answer 22

Men - 37”

Women - 31.5”

Question 23

Body fatness has been linked to several types of cancer. What are these cancers and what percentage of these cases can be attributed to overweight/obesity?

Answer 23

esophageal, pancreatic, colorectal and endometrial, kidney, and breast. (possibly gallbladder)

20%

Question 24

A predominantly plant based diet is associated with decreased cancer risk. List categories of animal foods and comment on their relationship to cancer risk.

Answer 24

red meat (beef, lamb, pork):

• increases colorectal cancer risk
• limit consumption to >18 ounces per week

processed meat (meats preserved by smoking, curing, salting, or by the addition of chemical preservatives, i.e. ham, bacon, hot dogs, salami, etc):

• increased colorectal cancer risk
• limit consumption to very little, if any

There is a lack of evidence associated with increase or decrease in cancer risk with regards to consumption of poultry, fish, and eggs. The research with dairy is conflicted.

Question 25

List mechanisms through which physical activity can influence cancer risk.

Answer 25

reduced weight gain and easier maintenance of a healthy level of body fat

improved insulin sensitivity and reduced insulin levels

decreased levels of bioavailable sex steroid hormones

more rapid gut transit time reducing exposure of colon cells to carcinogens

improved immune function

Question 26

Dietary Supplement information - Calcium

Answer 26

Probably protect against colorectal CA, but above 1,500 mg daily increases prostate CA risk

Question 27

Dietary Supplement information - Beta-carotene

Answer 27

Initially showed to lower risk of lung CA, but now shows that in smokers that took high-dose supplements developed cancer at higher rates than the placebo

Question 28

Dietary Supplement information - Vitamin E

Answer 28

High dose vitamin E supplements may promote modest increase in the risk of prostate CA

Question 29

Dietary Supplement information - Selenium

Answer 29

Food/supplements may reduce prostate CA growth in its aggressive form, but not overall risk. Suggested may be beneficial to supplement in people how already have low selenium levels due to dietary intake, but to not supplement those with adequate serum levels already

Question 30

Dietary Supplement information - Vitamin D

Answer 30

May reduce cancer risk throughout the cancer process, but still being studied. Current study results are inconsistent when trying to target a specific level

Question 31

Emerging Topic - Omega-3 Fatty Acids

Answer 31

May protect against cancer by decreasing inflammation, cell proliferation, and angiogenesis while increasing apoptosis. However, exact amounts of EPA, DHA, ALA and such is difficult in studies

Question 32

Emerging Topic - Soy Foods

Answer 32

Isoflavones in soy are studied as possible cancer risk due to initial research in rats that showed increased growth in ER+ breast CA. However, we now know that human metabolize them differently than rats.

Studies that show moderate soy consumption (1-2 standard servings) saw no increased Breast CA risk, possible decreased risk.

Question 33

Emerging Topic - Flaxseed

Answer 33

Highly studied in Breast CA. Primarily focused on its conversion to plant lignans and ALA, it may reduce risk of breast and other CAs. Too limited for a recommendation at this time.

Question 34

Emerging Topic - Green Tea

Answer 34

Primarily studied for epigallocatenchin gallate (EGCG). Results are limited, but may help with antioxidant capacity.