Nutrition and Cancer 2020 Flashcards
differences between photo-oncogenes and oncogenes
Proto-oncogenes may be changed into oncogenes which will promote cell-growth and division. Note that proto-oncogenes are responsible for the promotion of cell-growth and proliferation of ALL genes where oncogenes particularly target cancer cells.
clinical cancer
when an actual mass is detected
anti-initiation strategies
serve to limit genetic and epigenetic alterations
- alter carcinogen metabolism
- enhance carcinogen detoxification
- scavenge ROS
- enhance DNA repair
anti-promotion/progression strategies
- scavenge ROS
- decrease inflam
- suppress inflam
- enhance apoptosis
- enhance immunity
- discourage angiogenesis
gene expression
-genotype to phenotype ( affected by penetrance and epigenetic
can gene mutation be inherited?
yes, example: BRCA1 gene which increases the risk of breast cancer- it also has high penetrance so phenotype will likely show
polymorphism vs mutations
SNP much more common but much less penetrance
epigenetic example specific to cancer development
DNA methylation (turns off gene) of tumour suppressor
how can diet play a role in the development of cancer
bioactive food compartments could affect DNA but mostly affects epigenetic ( the expression o mRNA and the post translational modifications)
- example: oxidative damage to DNA from carcinogens in food
oxidative damage to DNA may be caused by what?
increased carcinogen sound in food, PUFS (when oxidized), free iron, glycophosphate from pesticides, decreased AN or cofactors for AN enzymes (selenium and copper)
which dietary factors are important determinants of human cancer?
- excess weight (and factors that related: elevated insulin and IGF-1) - could account for 1/3 of CA known to be influenced by diet (excess weight= CA of colon, kidney, pan, eco, endometrium, liver, gall)
energy restriction does what to cancer development?
reduces dev - we should take away that eating more will cause an increased rate of cancer
obesity and breast cancer
greater risk only after menopause
fat intake and cancer risk
no association
- one study: animal fat and premenopausal breast CA, but low-fat diets do not support belief that they prevent breast CA (even found higher risk in one!)
dietary fat and colon cancer
red meat and processed meat associated with colorectal CA
red meat vs processed meat and cancer risk
processed is higher evident but red meat is slightly less evident
mechanisms behind meat and cancer
- preservatives: nitrites alone are not carcinogens but when linked with aa nitrosamines which occur in the stomach- cause cancer
- heme molecule may promotes formation of nitrosamine compounds
- high heat- polycyclic aromatic hydrocarbons and heterocyclic amines (carcinogenic) - however no number attached to this?
dairy products and cancer
high milk and dairy (>4 servings/day)associated with decreased risk of colon CA, some say increased risk of prostate (advanced and fatal type- could be to do with ca) but no association with regular prostate CA
fruit and veg and cancer
> 250 studies say decreased risk of cancer ( but recently level of evidence may be less than originally thought- due to limitations of descriptive and case-control studies - French fry example)
fiber
dilute carcinogens (simular to Ca in dairy products), serve as substrate for microbiota- butyrate= anti-proliferative
alcohol
very well know cause of CA (oral, larynx, eco, liver) espessical in combo with smoking
mechanism for alcohol and Ca risk
anti-folate
- take folate supp reduce risk of breast in alcoholics
Calcium and CA
reduce risk of colon- bind toxic substances
- get to RDA, sup if not met
