Nutrition and Cancer Flashcards
1
Q
What are tumors?
A
Are abnormal growths of body tissue. Can be new (neoplasms) and those present at birth (congenital).
2
Q
What are the two classes of tumors?
A
Benign and malignant
3
Q
Explain benign tumors
A
Not cancer. Tumor cells grow only locally and cannot spread by invasion or metastasis.
4
Q
Explain malignant tumors
A
Cancer. Cells invade neighboring tissues enter blood vessels and metastasize to different sites.
5
Q
What is the clinical definition of cancer?
A
A set of diseases characterised by uncontrolled/unregulated cell growth leading to the invasion of surrounding tissues and spread (metastasis) to other parts of the body
6
Q
How does cancer develop?
A
From mutations in genes regulating cell division. The development of cancer, called carcinogenesis, often proceeds slowly and continues for several decades
7
Q
Explain adenomas
A
Cancer that arises from glandular tissues
8
Q
Explain carcinomas
A
Cancer that arises from epithelial tissues (lung, breast, colon, prostate)
9
Q
Explain gliomas
A
Cancer that arises from glial cells of the CNS
10
Q
Explain neuromas
A
Cancer that arises from neural tissue
11
Q
Explain leukemias
A
Cancer that arises from the white blood cell precursors (blood, blood-forming organs)
12
Q
Explain lymphomas
A
Cancer that arises from lymphoid tissues (NHL white blood cells, lymphocytes)
13
Q
Explain melanomas
A
Cancer that arises from pigmented skin cells
14
Q
Explain myelomas
A
Cancer that arises from plasma cells in the bone marrow
15
Q
Explain sarcomas
A
Cancer that arises from connective tissues, such as muscular bone
16
Q
What are the four main types of cancer?
A
Lung, breast, prostate and colorectal. Account for >50% of all CA cases
17
Q
What increases the risk of breast CA?
A
- Age
- Early puberty or late menopause
- Late first pregnancy
- Overweight
- Family history
- Excessive alcohol intake
18
Q
What decreases the risk of breast CA?
A
- More pregnancies
- Having babies at a young age
- Breastfeeding, especially prolonged
19
Q
What is the group age that can be affected by colorectal cancer?
A
55-70
20
Q
How can you decrease the risk of colorectal cancer?
A
by regular exercise
21
Q
Which diseases increase the risk of colorectal cancer?
A
inflammatory bowel disease, ulcerative colitis or Crohn’s disease
22
Q
What are the symptoms of colorectal cancer?
A
- blood or mucus in stools
- unusual bowel habits, e.g. diarrhoea or constipation
- unexplained weight loss
- extreme tiredness or iron deficiency
- lump in the abdomen
23
Q
What is the ‘at risk’ age for Breast CA?
A
50-64
24
Q
Explain some possible causes of cancer
A
- Genetic factors: inherited, genetic defect that alters DNA. Certain metabolic processes and chronic inflammation (increase the rate of cell division).
- Interaction between a person’s genes and environmental factors: exposure to cancer-causing substances or carcinogens.
25
Name some cancer-causing substances:
- Arsenic, cadmium, chromium and nickel.
- Iodine - deficiencies or excess - thyroid carcinomas.
- PCB
- Agricultural residues DDT
- Mycotoxins
- Polycyclic aromatic hydrocarbons
- Nitrate
26
What is the recommended daily limit of meat consumption?
70g
27
Explain sodium nitrites and nitrosamines
They are added to processed meats, hot dogs, bacon, and any other meat that needs a reddish colour to look "fresh".
Also found in food items that are pickled, fried, or smoked; in things such as beer, cheese, fish byproducts, and tobacco smoke.
Nitrosamines are extremely carcinogenic.
28
How can nitrates and nitrites be harmful when added to meat?
Nitrite + Haem = nitrosylated-haem.
nitrosylated-haem + protein fragments = NOCs
29
How does obesity increase cancer risk?
Obesity alters levels of hormones that influence cell growth (sex hormones, insulin sensitivity, and growth factors)
30
What are the cancer sites for obese people?
Esophagus, colon, rectum, pancreas, gallbladder, kidneys, and breast (postmenopausal). In the case of breast CA, the hormone estrogen is likely involved (obese women have higher estrogen levels)
31
How food prep can increase the risk of cancer?
- cooking at high temperatures causes carcinogens to form, and smoke adheres to food during grilling - present in the charred surfaces of grilled foods (heterocyclic aromatic amines HAA)
- red meat, processed meats (colon, rectum)
- salted and salt-preserved foods (stomach)
- beta-carotene supplements (lung cancer ??)
- high calcium diets (over 1500mg/day) prostate
32
What are the three common cancer-causing substances in foods?
- acrylamides
- omega 6 - vegetable oils
- sodium nitrite
33
Explain 'Acrylamide'
These are formed from sugars and an amino acid (asparagine) during certain types of high-temperature cooking, mainly in foods made from plants (potato, grain, coffee).
It is more likely to accumulate when cooking is carried out for longer periods or at higher temperatures
34
Explain omega-6 FA
one of the two groups of essential fatty acids (EFAs)
- Omega-6 FA include linoleic acids and its derivates
- Excessive levels of certain n-6 FA, relative to certain n-3 (omega-3 FA), shift the physiologic state of tissues to prothrombotic, proinflammatory and pro constrictive states.
35
What is the optimal ratio for omegas?
(n-6 FA: n-3 FA) 4:1 or lower 1:1
36
What is associated with the excessive consumption of Omega-6 PUFAs?
Chronic excessive production of n-6 eicosanoids is associated with heart attacks, thrombotic stroke, arrhythmia, arthritis, osteoporosis, inflammation, mood disorders, obesity and cancer
37
What is the structure and dietary sources of Omega-3 ALA?
C18:3 - Oils: flaxseed, olive, canola
38
What is the structure and dietary sources of Omega-3 EPA?
C20:5 - Fish oil, marine algae
39
What is the structure and dietary sources of Omega-3 DHA?
C22:6 - Fish oil, marine algae
40
What is the structure and dietary sources of Omega-6 LA?
Linoleic acid C18:2 - oils: corn, soybean, sunflower, peanut
41
What is the structure and dietary sources of Omega-6 AA?
Arachidonic acid C20:4 - small amount in meat, dairy products and eggs
42
Which oil has the most balanced fatty acid composition?
Canola oil. Good omega-6 and omega-3 ratio, and a high percentage of monounsaturated fat
43
What substance in olive oil has anti-cancer effects?
Squalene
44
What does the excess of arachidonic acid in the body increases?
The production of 5-LOX facilitates cancer cells' propagation, infiltration, and metastasis.
45
What is the recommended intake of n-3? (cold seawater oily fish)
1.6gm/day for man and 1.1gm/day for women
46
What contributes to lower breast and colorectal cancer risk?
An increase in the consumption of fish and fish n-3. Consumption is associated with protection against the later promotional stages of colorectal carcinogenesis.
47
Which vitamin plays a role in DNA synthesis and repair?
B9 Folate
48
Why does consuming plenty of fruits and vegetables help decrease cancer risks?
Because of the antioxidant-active nutrients and phytochemicals, fibre-rich diets help with colon cancer.
49
Name the top cancer-fighting foods
1. Green tea
2. Curcumin
3. Cruciferous vegetables
4. Folate-rich foods
5. Tomatoes
6. Ginger
7. Vitamin D (2,000 IU/day)
50
Which is the polyphenol compound found in green tea?
Epigallocatechin gallate (EGCG)
51
What are the benefits of Green Tea?
- Chemopreventive effect against prostate cancer, induce apoptosis.
- decreased BCA tumor size in mice
- inhibits VEGF growth and cell proliferation and migration.
52
Explain the benefits of curcumin
- interfere with cell-signalling pathways, suppressing cancerous cells' transformation, proliferation and invasion.
Induces apoptosis (programmed cell death)
53
What are the sources of cruciferous vegetables?
Arugula, broccoli, Brussels, sprouts, bok choy, cabbage, canola, cauliflower, collard greens, daikon, mustard, radish, kale, and watercress.
54
What is the cancer-fighting compound found in cruciferous vegetables?
Indole-3-carbinol (I-3C)
55
What is the recommendation for cruciferous vegetables to reduce the risk of breast cancer?
1 serving per day
56
What are food sources of Folate?
Wheat bread, pasta, breakfast cereals.
57
What is the recommended intake of folate to cut the risk of developing pancreatic cancer?
400 mcg
58
What are the potential health benefits of lycopene?
Higher levels of lycopene in the blood and tissue are associated with a lower risk of certain cancers, such as breast and prostate (30mg per day)
59
What is Lycopene?
A red-coloured pigment and antioxidant found in fruits and vegetables like tomatoes, watermelon and pink grapefruit
60
What are the benefits of ginger?
Ability to kill cancer cells in two ways:
1. In apoptosis
2. In autophagy
61
Explain "wasting" associated with cancer-1
- anorexia - cancer cachexia, affects 80% of people with terminal cancer
62
Explain the consequences of Cancer-2
Cytokines released by both tumor cells and immune cells induce a catabolic state; poor appetite accelerated and abnorlmal metabolism and the diversion of nutrients to support tumor growth result in a lower supply of energy and nutrients.
63
Explain the consequences of Cancer-3
Metabolic alterations:
- increase protein turnover
- reduced muscle protein synthesis
- triglyceride breakdown - elevates blood lipid levels
- insulin resistance
64
Explain the consequences of Cancer-4
Cancer patients exhibit an increased protein turnover rate but reduce muscle protein synthesis.
Triglyceride breakdown increases, elevating serum lipids.
Many patients develop insulin resistance.
65
Explain the consequences of Cancer-5
Anorexia and reduced food intake
GI obstructions
66
What are the primary medical treatments for cancer?
Chemotherapy, surgery, radiation therapy or any combination of the three - aims to remove cancer cells, prevent further tumor growth and alleviate symptoms.
67
What is B-glucan?
Derived from black yeast. Polysaccharide composed of D-glucose.
In addition to yeast, it is also found in oats, barley, and mushrooms. Can boost/activate the immune system. Beta-glucans are antagonists to both benign and malignant tumors.
68
B-glucans act as immune stimulators by activating macrophages and
creating a positive immune action on:
- B lymphocytes
- natural killer cells
- Suppressor T-cell
69
What are the objectives of medical nutrition therapy for cancer patients?
- to minimise loss of weight and muscle tissues
- to correct nutrient deficiencies
to provide a diet that patients can tolerate and enjoy, despite the complications of illness
70
What is the recommended protein intake in MNT for Cancer?
1.0 - 1.5 g.kg.bw for maintenance
1.5 - 2.5 g.kg.bw for stores repletion
71
What are the UK recommendations?
1)Be a healthy weight [be as lean as possible without becoming underweight]
2) Be physically active [for at least 30mins/day].
3) Eat a diet rich in whole grains, vegetables, fruit and beans.
4) Limit consumption of ‘fast-foods’ and other processed foods high in fat, starches or sugars.
5) Limit consumption of red and processed meat and salty foods.
6) Limit consumption of sugar-sweetened drinks [i.e. Energy-dense foods].
7) Limit alcohol consumption [If at all, limit alcoholic drinks to 2/day (M) & 1/day (F)].
8) Do not use supplements for cancer prevention.
9) For mothers: breastfeed your baby, if you can [best to breastfeed exclusively up to 6m of
age].
10) Do not smoke or chew tobacco.
