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Alcohol. “Beer is proof that god loves us and wants us to be happy.” -Benjamin Franklin. History of alcohol. Old religious and medical writings frequently recommended its use Lifts spirits, ease boredom, numb hunger, dull discomfort People value alcohol for its analgesic
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Alcohol “Beer is proof that god loves us and wants us to be happy.” -Benjamin Franklin
History of alcohol • Old religious and medical writings frequently recommended its use • Lifts spirits, ease boredom, numb hunger, dull discomfort • People value alcohol for its analgesic and euphoric qualities
History of Alcohol • 6400 BC: Neolithic people produced berry wines • 4000 BC: Sumerians fermented grains and cereals, producing beer, date wine and other alcoholic beverages • Ancient Egyptians recorded >100 medical prescriptions for alcohol • Babylonians developed >20 different types of beer
Alcohol: definition • Organic compound with one or more –OH groups • The alcohol found in beer, wine or spirits is technically called ethyl alcohol or ethanol • Ethanol is able to cross the blood-brain barrier
Alcohol: definition • Alcohols are lipid solvents – their ability to dissolve lipids out of cell membranes allows alcohol to penetrate rapidly into cells, destroying structures, and killing the cell in the process • Therefore, alcohols are toxic, but they can also be used to kill microbial cells
Alcohol: definition • Ethanol is less toxic than other alcohols • If it is sufficiently diluted, and taken in small enough quantities, it can produce the effect that people seek with a low enough risk to be tolerable • Used in this way, alcohol is a drug • Like all drugs, it offers benefits and hazards
Binge drinking: consumption of 5 or more alcoholic drinks on one occasion
Alcohol consumption • Described as “drinks per day” • Drink: the amount of a beverage that provides .5 fluid oz. of ethanol • Typically, equivalent to: • 1.5 oz. of distilled spirits (80 proof) • 4-5 oz. of wine • 10 oz. of wine cooler • 12 oz. of beer
Alcohol content (by volume) of beer and wine • Non-alcoholic beer 0.5% • “Light” beers 3-4% • Regular beers 5% • Stouts, malt liquors, specialty beers 7% • Wines 7-24%
Proof • The alcohol content of distilled spirits is related directly to its proof. • 100 proof is 50% alcohol • 80 proof is 40% alcohol
Alcohol in the body • Does not require digestion • Absorbed from both the stomach and jejunum • From the mucosal cells, transported by portal vein to the liver • In liver, is metabolized or released into bloodstream • In bloodstream, is rapidly distributed through body’s intra- and extra-cellular spaces
Factors affecting absorption • Amount • Speed • Presence/Absence of food • Carbonation • Gender/Individual differences • Genetic factors/Individual differences
Individual Differences in Alcohol Metabolism Affected by: • Levels of alcohol dehydrogenase • Body size - smaller livers • Body Composition – less water to dilute alcohol • Hormonal fluctuations – heightened response to alcohol during menstruation, or when taking birth control pills
Oxidation of Alcohol begins in the Stomach • Oxidation of alcohol occurs primarily in liver, small amount occurs in stomach through the action of two enzymes: • Alcohol dehydrogenase (ADH) • Aldehyde dehydrogenase (ALDH) For more chronic alcoholics there is a third pathway: (3) Microsomal ethanol oxidizing system
Alcohol in the body: Small Intestine • Alcohol is also rapidly absorbed in the SI • It gets absorbed and metabolized before most nutrients • This priority status helps to ensure a speedy disposal and reflects two facts: 1. Alcohol cannot be stored in the body 2. Alcohol is potentially toxic
Oxidation of Alcohol in Liver • Liver cells are the only other cells in the body that make enough ADH to metabolize alcohol at an appreciable rate • Alcohol dehydrogenase (ADH) catalyzes the conversion of alcohol to acetaldehyde (which is toxic) • Then, aldehyde dehydrogenase (ALDH) quickly converts acetaldehyde to acetate • “Antabuse” deliberately blocks conversion of acetaldehyde to acetate
Alcohol metabolism • Majority of alcohol metabolism occurs in the liver, which contains significant amounts of ADH and ALDH. • The maximum rate of alcohol breakdown is set by the amount of ADH available and its activity level
Alcohol Effects: Brain • 1. Alters reasoning and judgment, depresses inhibitions (A) • 2. Speech and vision (C and D)
Alcohol Effects: Brain • 3. Voluntary muscle control, impairs motor skills (B, C, D, E) • 4. Conscious brain is completely subdued, and the person passes out
Alcohol effects: Brain • Brain cells die with excessive exposure to alcohol. Not all brain cells can regenerate (unlike liver cells) • Some heavy drinkers suffer permanent brain damage
Alcohol effects: Brain • Korsakoff psychosis • Characterized by ongoing memory and learning problems • Wernicke-Korsakoff syndrome • Form of alcoholic encephalopathy • Linked to severe thiamine deficiency • Potentially fatal, occurs with alcohol-related liver failure
Alcohol Effects: Liver • Toxic to liver cells • Alters metabolism of nutrients and drugs • Impairs ability to store nutrients
Alcohol Effects: The Liver • The earliest evidence of liver damage is fat accumulation • Fatty liver can appear after only a few days of heavy drinking, and recedes with abstinence • The liver can increase in weight from ~ 3 pounds, to over 10 pounds • What causes the liver to become fatty?
Alcohol Effects: The Liver • With regular, high intakes of alcohol, the liver becomes chronically inflamed (alcoholic hepatitis) • The hepatitis may be treatable, but it is often fatal • With continued inflammation, the liver becomes fibrous, and scarred: Cirrhosis • About 10-20% of heavy drinkers develop cirrhosis
Alcohol Effects: Upper GI • Carcinogenic to upper GI cells • Increases gastric acid production • Inflames lining of stomach • Increases the likelihood of reflux, gastritis, and esophagitis
Alcohol Effects: Pancreas • Toxic to pancreatic cells • Impairs digestion and absorption • Alters secretion of pancreatic hormones • Increased risk for pancreatitis, which reduces digestive enzyme production
The Hangover • Symptoms can include • pounding headache • Fatigue • muscle aches • Nausea • stomach pain • heightened sensitivity to light and sound • Dizziness • possibly depression, anxiety, and irritability
Causes • Dehydration: dry mouth and headache • Irritation of stomach and intestines: nausea, stomach pain, vomiting • Hypoglycemia: fatigue, light-headedness • Disruption of sleep patterns: fatigue • Congeners
Congeners • Impurities produced during fermentation or metals such as zinc that are added to certain sweet liqueurs in order to enhance flavor. • They contribute to the distinctive smell of the beverage and may increase intoxicating effects and subsequent hangover • Found in: whisky, red wine, brandy
“Curing” A Hangover • The most effective treatment is TIME Others: • Sleep • Drinking hydrating beverages • Eating • Antacids • Aspirin (may improve aches, but could irritate stomach) • Taking vitamin B6 before drinking may reduce the severity of the hangover
Alcohol-induced alterations in nutrient metabolism (1) Interferes with activation of vitamins: • Vitamin D • Thaimine • Riboflavin • Folate • Vitamin B6 • Increases degradation of B-complex vitamins (2) Increases urinary excretion of nutrients: • B-vitamins • Zinc • Magnesium
Alcohol-induced alterations in nutrient metabolism (3) Decreases gluconeogenesis (due to excess NADH) (4) Limits glycogen storage (5) Suppresses fatty acid oxidation (6) Increase in mobilization of stored fatty acids from adipocytes