Y khoa, dược - Spotlight on alcohol

Spotlight on AlcoholThe Character of AlcoholEthanolThe alcohol in beer, wine, spiritsMethanolWood alcohol—poisonousAlcohol: Is it a Nutrient?Provides energy7 kcal/gNo other nutritive valueAlcohol and Its SourcesFermentationYeast cells metabolize sugar to make alcoholAlcoholic beveragesBeer: 5–6% alcoholWine: 8–14% alcoholLiquor: 35–45% alcohol“Proof” is twice the alcohol percentageAlcohol AbsorptionNo digestion requiredAbsorbed from mouth, esophagus, stomach,and small intestineAbsorption slowed by food80–95% of alcohol is absorbed unchangedAlcohol in the BodyMetabolizing small amounts of alcoholAlcohol dehydrogenaseAlcohol  acetaldehydeAldehyde dehydrogenaseAcetaldehyde  acetateAcetaldehyde, acetate converted to acetyl CoAAcetyl CoA molecules built into fatty acidsAlcohol in the BodyMetabolizing large amounts of alcoholOverwhelms alcohol dehydrogenase systemUses microsomal ethanol-oxidizing system (MEOS)Alcohol in the BodyRemoving alcohol from circulationLiver metabolism limitedBlood alcohol level falls slowlyAlcohol in the BodyIndividual differences in rate of alcohol metabolismGenderRace/ethnicityAgeWhen Alcohol Becomes a ProblemAlcohol in the brain and nervous systemDepressant; affects all parts of brainAlcohol’s effect on GI systemEsophagitis and gastritisWhen Alcohol Becomes a ProblemAlcohol and the liverFatty liverFibrosisCirrhosisFetal alcohol syndromePhysical abnormalitiesMental retardationLow birth weight and poor growthFetal Alcohol SyndromeCan have a devastating impact when consumed during pregnancyVariety of congenital defects:Mental retardationCoordination programsHeart, eye, and genitourinary malformationsSlowed growth ratesAlcoholics and MalnutritionPoor dietAlcohol provides energy but no nutrientsEconomic factorsLack of interest in food; GI problemsAlcoholics and MalnutritionVitamin deficienciesAlcohol interferes with vitamin metabolismFolate, thiamin, andvitamin AMineral deficienciesInadequate diet; fluid lossesCalcium, magnesium, iron, and zincSome mineral levels are elevatedAlcoholics and MalnutritionMacronutrientsAlcohol interferes with amino acid absorptionAlcohol raises blood levels of fatsBody weightInconsistent effect of alcohol calories on weightDoes Alcohol Have Benefits?Moderate drinking has been associated with reduced mortalityHeart diseaseFrench paradox: red wineDoes Alcohol Have Benefits?People who should not consume alcohol:Those who cannot moderate their intakeChildren and adolescentsThose taking certain medicationsThose with illnesses worsened by alcoholThose who drive or operate machineryPregnant or breastfeeding womenThose with a strong family history of alcoholism