Chapter 8: Alcohol

Alcohol The character of alcohol Ethanol; the alcohol in beer, wine, spirits Properties No digestion Rapid absorption by simple diffusion Rate high in duodenum No cellular receptors required 5% leaves body in form of sweat, urine, or breath 95% remains in the body until oxidation Metabolized or chemically changed in liver

Is alcohol a nutrient? Provides energy; 7 kcal/gram No other nutritive value Empty calories No vitamins, minerals, fat, or protein Lack nutrient density

Alcohol: Production Malting Fermentation: glucose converted to pyruvate CHO---Maltose---Glucose ----Pyruvate - -Acetaldehyde Ethanol Ethanol processed in a variety of ways to alcohol

Alcohol Absorption

Alcohol Metabolism Small amounts metabolized by Alcohol dehydrogenase (ADH) Liver enzyme

Metabolizing large amounts of alcohol Overwhelm ADH, cannot keep up Uses microsomal ethanol-oxidizing system (MEOS) a back-up system in liver MEOS used by liver to metabolize drugs Increase alcohol metabolism and tolerance Pathway reduces body’s ability to detoxify drugs Increase potential for drug overdose Liver damage will hamper other metabolic pathways Removing alcohol from circulation Liver metabolism limited Blood alcohol level falls slowly

microsomal ethanol-oxidizing

Catalase Found in the liver peroxisomes Minor pathway for alcohol metabolism Catalase H 2 O 2 H 2 O Ethanol Acetaldehyde

Fate of Acetyl-CoA (from alcohol metabolism) More like a fat than a CHO CO2 + H2O Acetyl-CoAFatty Acid Glucose X

Factors affecting Alcohol Metabolism Gender Women: smaller body size, less total body water; less ADH activity in stomach (only 10% metabolized in stomach); more serious effects of chronic alcohol abuse; More alcohol in blood  liver  cirrhosis is high Women are more likely to develop cirrhosis Males High activity of ADH in stomach cells (Metabolize ~30% of alcohol in stomach) Higher amount of body water Age; race; size; food; physical condition; alcohol content

Benefits of Moderate Alcohol Intake (Table 8-3 ) 1 drink a day for men, < 1 drink for women or 1 5oz glass of wine Beer – no benefits Red Wine Phytochemicals called polyphenols from grape skins during processing Lower risk of CVD Lower risk of Ischemic stroke: lack of blood to brain

Effects of Alcohol Alcohol cannot be stored and has priority in metabolism Metabolized by the liver Damages protein in cell membranes as it enters into cells Liver cells-mostly affected May cause Cirrhosis of the liver

Effects of Alcohol: Cirrhosis Fatty infiltration of the liver Increased synthesis of fat from accelerated acetyl-CoA production Enlarged fatty deposits choke off nutrient and O 2 supply to liver cells Engorged liver cells burst and die Scar tissue forms- process called cirrhosis 50% chance of death within 4 years Is the second leading cause for a liver transplant

Alcohol and the Liver Normal Liver Fatty Liver Cirrhotic Liver

Liver Damage Build-up of acetaldehyde can be toxic Free radicals from alcohol metabolism destroy cell membranes & DNA: Alcohol inhibits body’s natural defenses against free radicals Advanced stages of liver damage are not reversible

Alcohol Abuse 3 rd leading cause of death Combined with tobacco, increases the risk of esophageal and oral cancer Risk for CVD Liver cirrhosis, damages cell membranes esp liver cells Fatty liver suicides fetal damage obesity Some forms of cancer osteoporosis, brain damage, impotence, sleep disturbance, etc.

Alcohol & Nutrients Vitamin deficiencies Alcohol interferes with vitamin metabolism Folate, thiamin, vitamin B6, B12, C, vitamin A Magnesium deficiency Increase magnesium loss via the urine Tetany—sharp contraction of muscles, twitches, cramps, seizures Impaired CNS Hallucinations Zinc deficiency Decreased absorption and increased excretion Change in taste and smell, anorexia, trouble seeing at night, impaired wound healing Iron toxicity in liver, hasten cirrhosis, iron deficiency, due to GI bleeding.

Alcohol & Nutrients Polyneuropathy A disease process that involves the peripheral nerves Can culminate in muscle paralysis, loss of sensation in lower extremities if untreated Usually associated with deficiencies in thiamin (vit B) Sideroblastic anemia Anemia characterized by RBC containing an internal ring of iron; due to vitamin B6 deficiency Megaloblastic anemia A form of anemia characterized by large, nucleated, immature red blood cells that result from the inability of precursor cells to divide normally. Due to folate deficiency

Alcohol & Nutrients

Fetal Alcohol Syndrome Alcohol reaches the fetus Deprive brain of oxygen and nutrients ~4 drinks a day or binge drinking while pregnant May cause Mental retardation Short attention span Hyperactivity Social and behavior problems Abnormally small at birth Small head circumference Small, widely spaced eyes Flat mid-face Thin upper lip and jaw underdeveloped

Alcohol Blood Levels and Brain Responses Judgment impaired Emotional control impaired Muscle coordination, reflexes impaired Vision impaired Drunk, lacking control In a stupor Loss of consciousness, death —0.60 Brain ResponseBlood Level

Other Problems of Alcohol Drinking in the workplace Operating motor vehicles and equipment Sexually transmitted diseases Unplanned pregnancy Children of alcoholics are 4x more likely to become alcoholics Warn children of the consequences of alcohol A low threshold to alcohol Depression

Binge Drinking Especially in college students > 4 or more drinks in a row Acute alcohol intoxication Signs of alcohol poisoning semiconsciousness or unconsciousness slow respiration ( 8 seconds between breath) cold, clammy, pale, or bluish skin strong odor of alcohol

2005 Dietary Guidelines Alcoholic Beverages Those who choose to drink alcohol should do so sensibly and in moderation 1 drink/day for women 2 drinks/day for men Alcoholic beverages should not be consumed by Those who cannot restrict intake Women of child bearing age Pregnant & lactating women Children & adolescents Those taking medications Those with specific medical conditions Those driving or operating a machine

Advice on page 273 U.S. Surgeon General’s office, the National Academy of Science, USDA/DHHS do not specifically recommend drinking alcohol “Drink in moderation” Avoid alcohol while pregnant

Diagnosis Physiological dependence Tolerance to the effect of alcohol Evidence of alcohol-associated illnesses Continued drinking in defiance of medical and social advise Depression and blackouts

C.A.G.E. Questionnaire cut C: Have you ever felt you ought to cut down on drinking? annoyed A: Have people annoyed you by criticizing your drinking? guilty G: Have you ever felt bad or guilty about your drinking? eye-opener E: Have you ever had a drink the first thing in the morning to steady your nerves or get rid of a hangover (eye-opener)?