Nutrition-Cancer Flashcards
Factor associated with exposure of interest, outcome of interest and is not in the causal pathway; thus it may distort the association between the study and the exposure.
Confounder
What type of regulatory gene is p53, which is a common target for mutation in many different cancer?
Tumor suppressor gene.
4 steps in risk assessment
1) Hazard identification 2) Dose response 3) Exposure assessment 4) Risk characterization
Bias that happens when the accuracy of info collected on subjects is not equal between cases/controls or exposed/unexposed groups.
Measurement (information) bias
A mutation in genes that results in a mutator phenotype
DNA repair genes
Study design that is the only ethical design for potentially hazardous exposures
Observational studies
7 changes that determine malignant phenotypes
1) Defects in DNA repair 2) Evasion of apoptosis 3) Sustained angiogenesis 4) Limitless reproductive potential 5) Tissue invasion/metastasis 6) Insensitivity to anti-growth signals 7) Self sufficiency growth signals
Charring of meats produces what class of carcinogens
Heterocyclic amines. Charring food produces polycyclic aromatic hydrocarbons
Most of known carcinogens are metabolized by what family of enzymes?
P450-dependent mono-oxygenases
2 classes of anticancer properties of plant-based food
1) Direct inhibitor actions (reduces DNA damage and pro-apoptotic effects for damaged cells) 2) Microenvironment (anti-angiogenesis and anti-inflammatory
Bradford Hill criteria used in assessing causality
Temporality, Strength of association, Dose-response, Reversibility, Consistency, Biologic plausibility, Specificity, Analogy
Indirect acting carcinogens must undergo what process?
Metabolic conversion (also called biotransfromation and bioactivation)
Overweight and obesity are though to impact cancer risk through effects on what 4 areas?
Immune function/inflammation, hormone levels/metabolism, growth factors, proteins that make hormones more or less available.
Eating fruits and vegetables is associated with level I evidence of decrease in cancer risk of what organs?
GI tract (mouth, pharynx, esophagus, stomach, colon, rectum) and lung.
What proportion of cancers may be due to diet?
35.00%
Nitrates and nitrites are converted to what substance that is a mutagen/carcinogen in animals? How can you inhibit this?
Nitrosamines. Vitamin C is supposed to be an antioxidant that limits the radicals.
Class of chemicals that provide the chemopreventive properties of plant-based food thought to aid in blocking the progression of latent micro tumors?
Phytochemicals
2 overarching concepts of dietary guidelines for Americans
1) Maintain calorie balance to achieve a healthy weight 2) Consume nutrient dense food and beverages
Reversible, heritable changes in gene expression without mutation, involving post-translational modification of histones and DNA methylation, which may directly contribute to tumor development.
Epigenetics
Group of fatty acids that are pro-inflammatory
Omega 6
Group of fatty acids that are anti-inflammatory
Omega 3
4 classes of regulatory genes that are the primary targets of genetic damage in carcinogenesis
1) Proto-oncogenes 2) Tumor suppressor genes 3) Apoptosis genes 4) DNA repair genes
Fallacy that may occur in interpreting results from a study when the exposure is only known for groups but not for individuals within the groups
Ecologic
2 mechanisms possibly associated with increased prostate cancer risk with increased dairy consumption
Increased insulin growth factor 1 (IGF1) levels and impaired vitamin D metabolism
10 recommendations for cancer prevention form WCRF/AICR
1) Be lean 2) Be active 3) Avoid soda 4) Eat whole foods, plants and veggies 5) Limit red meat, avoid processed meat 6) Limit alcohol 7) Limit salt 8) Don’t use supplements 9) Breast feed at least 6 months 10) Follow these steps after cancer treatment
What study designs have the greatest strength of evidence?
1) Meta-Analysis 2) Systematic review 3) Randomized controlled trial 4) Cohort 5) Case control 6) Case series/report 7) Animal research
4 things shown to increase breast cancer survival
1) Decreased body fat 2) Decreased dietary fat 3) Increased fruits/veggies/exercise 4) Soy 2 servings/day
3 stages of carcinogenesis
1) Initiation (mutation gets locked in) 2) Promotion (mutation drives proliferation) 3) Progression (things go bad)
Product produced by mold on grains and nuts that causes cancer
Aflatoxin B1
Father of toxicology that basically said too little of a substance and too much of a substance is bad
Paracelsus
3 most important modifiable risk factors for cancer in Americans
1) Diet 2) Weight control 3) Physical activity
In addition to excess estrogen in excess fat, a high fat, low fiber diet may increase estrogen levels by what mechanism?
Enterohepatic circulation recirculates estrogen
30% risk of cancer with the “meat-sweet” diet
Breast cancer
