Chapter 2 Flashcards
What percentage of cancers could be prevented?
~40%
What are the 2 most important lifestyle factors for cancer prevention?
- Avoiding tobacco
- Maintaining a healthy body weight throughout life
What is Leptin?
A hormone that helps your body maintain its weight long term. It’s produced by fat cells. Leptin resistance causes you to feel hungry and eat more even though your body has enough fat stores.
All forms of physical activity (including recreational and occupational) protect against these 3 forms of cancer.
Colon, post menopausal breast, endometrium
Vigorous physical activity prevents against this 1 type of cancer
Pre-menopausal breast
What are the physical activity guidelines in depth
75 mins vigorous/week or 150 minutes moderate. Once achieved, increase to 30 mins vigorous daily or 45-60 mins moderate daily. Children, 60 mins/day of moderate-vigrous . This provides greater protection/
Nonstarchy vegetables & fruit PROBABLY protect against these 4 cancers
Mouth, larynx, pharynx, esophagus
Limited evidence suggests that nonstarchy vegetables & fruit may reduce the risk of cancer in these 3 cancers
Lung (current/former smokers), breast (ER-), bladder
Limited evidence links a low intake of non-starchy vegetables & fruit with these 2 cancers
Colorectal & stomach
*high fiber foods, specifically whole grains, protects against colorectal
Caroteinoids, vitamin c, and isoflavone may reduce the risk of these 3 cancers
Lung, breast, colorectal
Most nutrients & phytochemicals show an ability to inhibit ________________ & promote activity of ________________
phase 1 carcinogen-activating enzymes (i.e. cytochrome p-450)
phase II carcinogen-detoxifying enzymes (i.e. glutathione s-transferase)
Nutrients/plant foods may reduce risk of cancer through these 4 mechianisms
- Epigenetics (impacting gene expression, such as tumor suppressor genes)
- Hormones like insulin (fiber sloes glucose absorption which reduces insulin secretion)
- Antioxidants (direct protection or stimulating antioxidant pathways)
- Microbiota acting on fermentable fiber/resistant starch to produce butyrate
Whats the most common Stilbene?
Resveratrol from grapes & berries
What are processed meats
Meats (often red but not always) preserved by smoking, curing, fermenting, salting, or with chemical preservatives
What are 4 possible mechanisms for the link between red meat & colorectal cancer
- Heme iron in red meat forms free radicals. It also promotes the formation of of N-nitroso compounds in the gut
- NOCs form when nitrites combine with amines from amino acids (both during the curing process and in the gut)
- Cooking meat at high temps causes production of heterocyclic amines & polycyclin aromatic hydrocarbons, both carcinogens
- Possibly gut microbiota convert protein residue and fat-stimulated bile acids from high meat diets to carcinogenic and/or proinflammatory substances
What are NOCs
N-Nitroso compounds are carcinogens that are linked to heme iron & nitrites, either during the meat curing process or in the gut
A high glycemic load is linked to this type of cancer
Endometrial
What are recommendations on fruit juice?
Limit to 2 1 serving/day, likely contributes to weight gain the same as sugary beverages (high energy, low satiety)
What are recommendations on artificial sweeteners?
Research is too mixed, make recommendations on an individual basis
What is a standard drink?
14 g ethanol = 5 oz. wine, 12 oz. beer, 1.5 oz liquor
What 2 carcinogens are found in alcohol?
- Ethanol
- Acetaldehyde (metabolite)
What 5 mechanisms link alcohol to cancer?
- Ethanol & acetaldehyde (metabolite of alcohol) are both carcinogens
- Alcohol is a solvent, which enhances dietary carcinogens into cells
- Alcohol metabolism generates ROS (reactive oxygen species, type of free radical) that can damage DNA
- Works synergistically with tobacco d/t solvent properties, increasing risk of H&N cancers
- May in crease circulating levels of estrogen, a risk for breast cancer
Alcohol increases risk for which 8 cancers?
- Mouth
- Pharynx
- Larynx
- Liver
- Colorectum
- Breast (pre & post menopause)
- Esophagus (squamous cell)
- Stomach
Calcium supplements protects against __________ cancer but increases risk for _________ cancers (limited evidence)
Colorectal (>200 mg/d)
Prostate