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					Alcohol
• Only substance that is a nutrient and a drug
  affecting brain function
• There are many alcohols but the one used in
  parties, pubs and bars“alcohol” is used to mean
  ethyl alcohol or ethanol.beer- first drunk by the
  Sumerians and Babylonians around 4000BC
• Wine is mentioned in the old testament
• Brandy and whishey first appeared in the 15th
  century.
    Production of alcoholic beverages
• Produced by alcohol fermentation of glucose
• Specific enzymes are provided by certain yeqast,
  saccharomyces which are unicellular fungi.
• The biological pathway first follows the 10 usual
  steps of anarobic glycolysis to pyruvate as in animal
  metabolism
• Yeast contains the enzyme pyruvate decaboxylase
  not present in animals
• This converts pyruvate to acetaldehyde then alcohol
  dehydrogenase convertys acetaldehyde to ethanol.
            Production of alcohol
• The overall reaction
• C6H1206+Cofactors + ATP→2C2H5OH +2 CO2
• Cofactors-NADH, thiamin, pyrophosphate and
  magnesium.
• Grapes are unusual among fruits in containing a lot
  of sugar nearly all glucose.(16%)
• Alcohol content:
• Beer-5%
• Wine-10%
• Sprits-30%
             Alcohol beverages
Contain
• Variable amount of unfermented sugars and
  dextrins (in beers)
• Small amounts of alcohol other than ethyl
  alcohol(eg propyl alcohol)
• Moderate amounts of potassium, almost no sodium
• Small amounts of riboflavin and niacin but no
  thiamin
• Sometimes some vitamin C
•   Cont
•   A complex array of flavor compounds
•   Colors(eg in red wine)
•   Phenolic compounds
•   A preservative(eg in sodium metabisulphate)
•   Additives.
                 Stage of alcohol intoxication
Blood alcohol          stage                   effects
concentration(g/dl)



Up to 0.05             Feeling of well being   Relaxed, talks a lot


0.05-0.08              Risky stage             Judgement and finer
                                               movements affected

0.08-0.15              Dangerous stage         Slow speech, balance
                                               affected, eyesight blurred,
                                               wants to fall asleep, likely
                                               to vomit, needs help to
                                               walk
0.2-0.4                Drunken stupor          Dead drunk, no bladder
                                               control, heavy breathing,
                                               unconscious(ie. Deep
                                               anesthesia)
0.45-0.6               Death                   Shock and death
           Energy value of alcohol
• 7 kcal/g
• In heavy drinkers 10-30% of energy comes from
  alcohol, but alcohol beverages contain no protein
  and a very few micronutrients.
• This source of nutrients displaces other foods that
  normally provide essential nutrients.
• Appetite may be suppressed in heavy drinkers,
  eithjer by alcoholic gastritis or by associated
  smoking
• Nutrients typically depleted in alcoholics include
  thiamin, folate, niacin and several inorganic
  nutrients.
       Direct consequences of alcohol
1. Acute intoxication
2. Hangovers
3. Chronic alcoholism
4. Delirium treatment or alcohol withdrawal
   syndrome
5. Binge drinkers
       Medical consequence of excess
                consumption
• Alcohol causes 3 types of liver damage
Fatty liver
• This is least severe
• Metabolism of large amounts of ethanol in the
  liver produce an increase ratio of NADH/NAD
   – This depresses the citric acid cycle and
     oxidation of fatty acid and favours triglyceride
     synthesis in the liver cells.
Alcohol hepatitis( inflammation of the liver)
• This is more serious
• This type is not caused by a virus but by prolonged
  excess alcohol intake.
• There is loss of appetite, fevers, tender liver,
  jaundice
• And elevation in the plasma of enzymes produced
  in the livereg aminotransferase (transaminases),
  glutamyl transpeptidase abd alkaline phosphate)
Alcoholic Cirrhosis
• May be associated with chronic alcoholism
• When the liver has to metabolise large amounts of
  alcohol over a long time, membranes inside the cell
  become disordered
• Amount of alcohol to cause liver cirrhosis is difficult
  to establish as most people understate their alcohol
  intake esp heavy drinkers
• It is greater than 40g of ethanol in women and
  50gin men over years, usually much more.
1.   Metabolic effects
2.   Fetal alcohol syndrome
3.   Wernicke-Korsakoff syndrome
4.   Nutritional deficiencies in alcoholic
5.   Predisposition to some types of cancer
6.   Gastrointestinal complications
7.   Hypertension(>3-4 drinks per day)
         Different patterns of alcohol
                 consumption
• The inexperienced drinker(eg an adolescent) who
  misjudges the dose and has an accident.
• The person who does not drink during the week but
  drinks to excess and gets drunk on payday or Saturday
  night.
• The person who enjoys a controlled 1or 2 drinks most
  days.
• The person who has too many drinks each day(most
  after work) but less maintains their(increasing
  inefficient)usual life.
• The person who goes on a binge or bender for weeks
  for heavy drinking.
   Recognition of the problem drinker

• An alcoholic is a group term for any person whose
  drinking is leading to harm(alcohol dependence or
  physical disease or social harm)
• Alcohol can be smelt in the breath and detected in
  the breath, blood or urine within hours of drinking
If a person has not been recently drinking there are
   changes in the blood which are suggestive of long term
   excessive alcohol intake:
 Increases red blood cell volume(mean corpuscular
   volume)
 Increased glutamyl transferace(GGT) activity.
 Increases plasma(fasting) triglyceride(ie. Very low
   density lipoprotein)
 Increased plasma urate.
 Increased plasma transaminases(amino transferases)
 Increased plasma carbohydrate-(deficient transferrin)
 These vary in sensitivity and specificity.
Recommended intakes of alcohol
•   1 standard drink= 10g of pure alcohol
•   Men (biologically safe level)
•   2-3 standard drinks per day (20-30g)
•   i. e. 140-210g alcohol per week
•   Women(biologically safe level)
•   1-2 standard drinks (10-20g) per day
•   Ie. 70-140g alcohol per week
•   Intake should be one standard drink or less in
    pregnancy or in the case of suspected pregnancy
                      Tutorial
1. Explain the metabolism of alcohol in the body.
2. What is a breathalyzer and what level of alcohol
   can be detected be this in Fiji?
3. What are the nutrients present in alcohol?
4. How does alcohol affect the brain?
5. Explain the association of alcohol with liver
   disease.

				
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posted:10/22/2011
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