Perspectives in Nutrition 5 th ed. Gordon M.Wardlaw, PhD, RD, LD, CNSD PowerPoint Presentation by Dana Wu Wassmer, MS, RD

Chapter 8: Alcohol

Production of Alcohol Anaerobic condition CO 2 Glucose Pyruvate Acetaldehyde Fermentation of yeast NADH Maltose NAD + Amylase CHO Ethanol

Alcohol Absorption Depends on rate of stomach emptying Intake of certain drugs Type of beverage consumed Moves easily through the cell membranes –Damage the cell membranes –Liver cell damage

Alcohol (Ethanol) Metabolism Depends on gender, race, size, food, physical condition, alcohol content Some ethanol are metabolized by the stomach cells Majority of the ethanol is metabolized by the liver Alcohol cannot be stored and has priority in metabolism

Low Ethanol Intake-ADH Pathway Occurs in the cytosol; yields energy Alcohol dehydrogenase Ethanol Acetaldehyde NAD NADH NAD CoA NADH Acetyl-CoA ATP Citric Acid Cycle

High Ethanol Intake Microsomal ethanol oxidizing system (MEOS) in the cytosol Uses energy Pathway reduces body’s ability to detoxify drugs Liver damage will hamper other metabolic pathways

MEOS Pathway (Fig. 8-1) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

MEOS Pathway Excessive alcohol intake Occurs in the liver ADH cannot keep up with demand Used to metabolize drugs, foreign substances, and alcohol Increase alcohol metabolism, thus, alcohol tolerance Uses ATP in the process (leading to weight loss) Potential for drug overdose

Catalase Found in the liver Minor pathway for alcohol metabolism

Fate of Acetyl-CoA CO2 + H2O Acetyl-CoAFatty Acid Glucose X

Alcohol Abuse Contributes to the leading causes of death Combined with tobacco, increases the risk for esophageal and oral cancer Risk for heart disease, nutritional deficiencies, fetal damage, obesity, cancer

Effects of Alcohol (Fig. 8-2) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Damage to the GI Tract Damage the cells Overabsorption of iron Malabsorption Diarrhea and steatorrhea Inflammation of the pancreas and gall bladder –Decrease enzyme production –Decrease production of bile –Difficulty digesting (and absorbing) nutrients

Effects on Water-Soluble Vitamins Thiamin deficiency –Polyneuropath –Wernicke-Kersakoff syndrome Niacin deficiency –Alcohol uses large amounts of NAD and NADP during its metabolism Vitamin B-6 deficiency –Deficient intake and possibly increase breakdown –Leads to decrease in RBC and anemia

More Water-Soluble Vitamins Vitamin B-12 –Alcohol interferes with absorption –Alcohol decreases output of trypsin Folate deficiency –Inadequate intake –Reduced absorption due to mucosa damage –Much is excreted –Cells, villi decrease in number Vitamin C –Decrease intake and/or altered liver metabolism –Scurvy

Effects on Vitamin A Vitamin A Deficient intake Inability of the liver to produce carrier protein Low stores, regardless of intake Increase degradation of vitamin A Reduce enzymes to digest fat, thus reduces vitamin A absorption Impaired conversion of beta-carotene to retinoids

Effects on Vitamin D Inadequate intake Reduce enzymes to digest fat, thus reduces vitamin D absorption Decrease activation of vitamin D with liver damage May cause bone cell dysfunction, reduces bone formation Compromises calcium and phosphorus metabolism

Other Fat Soluble Vitamins Vitamin K –Decrease absorption –Damage intestinal bacteria Vitamin E –Reduced pancreatic enzymes

Effects on Minerals Magnesium deficiency –Increase magnesium loss via the urine –Tetany—sharp contraction of muscles –Impaired CNS –Hallucinations Zinc deficiency –Decrease absorption and increased excretion –Change in taste and smell, anorexia, trouble seeing at night, impaired wound healing Iron deficiency and toxicity –Injuries in the GI tract; increased uptake

Cirrhosis Fatty infiltration of the liver Response to increased synthesis of fat from accelerated acetyl-CoA production Enlarge fat cells chokes off nutrient and O 2 supply to liver cells Engorged fat cells burst and die Scar tissue 50% chance of death within 4 years

Liver Damage Build-up of acetaldehyde Production of free radicals Alcohol inhibits body’s natural defenses against free radicals Free radicals damage cell membranes and DNA

Fetal Alcohol Syndrome Avoidable Alcohol reaches the fetus Deprive brain of oxygen and nutrients ~4 drinks a day or binge drinking while pregnant Abstinence from alcohol is the best advice

Brain Damage Cognitive dysfunction and motor nerve deficit Shrinks the brain Reduces oxygen and nutrients to the brain Alcohol is a powerful depressant

Cancer Acetaldehyde may promote cancer Damage nucleotides that are incorporated into DNA Acetaldehyde is a carcinogenic Common cancers –Mouth, pharynx. Larynx, esophagus, liver, colon, rectum and breast cancer