Alcohol III Flashcards
What is the link between ethanol and cancers?
chronic consumption leads to alot of upper GI cancers, liver, colorectum and female breast tissue
how many percent of all cancers are linked to ethanol?
3.6%
in men its as high as 10%
how many % of all cancers (both sexes) are linked to alcohol consumption?
50% of all cancers in both sexes are linked to alcohol consumption
what are the main culprits of cancer causing in ethanol? and what is the safe the safe threshold of ethanol consumption for it to cause cancer?
main culprits are ROS and acetalaldehyde and there is no safe threshold for some cancers
what are the two types of upper GI cancers that are the most common and increase highly as the intake of alcohol goes higher in one day?
esophagus cancer and oral cavity and pharynx cancer
if you drink 10g or even less than that in one setting per day, u increase (increase in relative risk)
how does acetaldehyde cause cancer?
acetaldehyde binds to DNA and changes its shape and structure. The problem arises when the DNA has to replicate itself with the new structure and can cause mutation in replicating itself the wrong way… which can lead to cancer.
also when the DNA tries to repair itself on the new structure produced, it can make mistakes which can lead to cancers
a structure called ethyldenndoxyguanosine is made from acetylaldehydes modification of DNA
if you add ADH then you see less DNA alterning because ADH metabolizes acetylaldehyde into acetate
why are some reasons for cancer being in the upper digestive tract that have to do with ethanol?
ethanol is metabolized to acetaldhyde by microbes in the saliva that can be 10-100 times higher in concentration than in the blood
poor dental hygiene increases the concentraiton of this because theres more microbes on the tongue
smoking shifts the microbes towards the types that produce higher (50%) acetaldehyde levels
aka u need to brush ur teeth often if ur drinking alot
How does liver cancer occur in chronic alcoholics?
chronic alocholics often have higher CYP2E1 enzymes and catalase enzymes.
CYP2E1 causes more acetaldehyde and increase ROS
CYP2E1 also metabolizes retinoic acid (RA) aka vitamine A which is thought to act as a negative regulator of maliganant/cancer cells and prevent cancer cells from proliferating
low RA levels as a result of high CYP2E1 can result in lower RA receptors, and changes the levels of proteins involved in gene regulation and proteins involved in liver cell proliferation which causes an increase risk of cancer
what causes brain damage in chronic alcoholics (5)?
- ROS and acetaldehyde
- nutiritional deficiency… as a result of inflammated gut
- repeated head trauma
- hyperactivity of glutametergic systems leading to excitotoxicity
- alcohol induced neuroinflammation… BBB is compromised when immune cells enter the brain and cause same problems as they do in the liver
what are 3 main differences in the MRI scans of individuals who are chronic drinkers and individuals who are not?
- larger ventricles
- less space between cerebellum and skull
- larger gap between skull and cortex
overall just a total loss of neurons
What is Wernicke’s disease? what does it result from?
Wernicke’s disease is a result of B1 (thiamine) deficiency and can be partially reversible by IV of B1
deficiency is due to the fact that B1 isnt absorbed well in the gut of chronic alcoholics due to inflammation
- thiamine is involved in myelin formation, glucose utilization and amino acid production
- this is why in B1 deficiency you see ataxia (motor movement problems), confusion, abnormal eye movement, shaky eyes and paralysis of eye muscles due to myelin damage
what is korsakoff’s psychosis? what does it result from?
korsakoff’s psychosis results from wernicke’s disease going untreated.
it involves short and long term memory loss, inability to learn new information
it is NON-reversable and associated with neuronal loss
What did the study from Center for ADdictions Reseach tells us in 2016 about the studies done in the past about alcohol increasing lifespan?
tells us that the abstainer group (the control group) used in those experiments were actually made up of previous drinkers who stopped rinking because they were so unhealthy… this made the drinking group look healthy
when they corrected those experiments, they found that the risk of mortality in even casual drinking is higher than previously imagined
this makes more sense and is in par with the cancer data from ethanol
what are some potential cardioprotective effects of ethanol? (4)
AT LOW ETHANOL DOSES
- it increases density of the good lipoprotein (transports fats from blood to liver for metabolism)
- decreases platelet aggregation and caogulation
- decreased inflammation in blood vessels
- improved endothelial function, balance between blood vessel constriction and dialation
what are some cardiotoxic effects of ethanol?
high doses of ethanol causes caridomyopathy (diseas of heart muscle)
- alcohol is a direct myocardial depressant… slows down the heart
acetaldehyde inhibits myocyte function by altering calcium homeostasis and myocardial protein synthesis … the heart muscles need calcium to contract
calcium release from the sarcoplasmic reticulum is inhibited, which has a neg. effect on calcium sensitive contractility protiens
- ethanol metabolites result in mitochondrial dysfunction and poor energy use… (low energy for the heart)
alcohol slows down the heart by preventing muscle cells from contracting…