Alcohol

AlcoholThe character of alcohol

EthanolThe alcohol in beer, wine,

spiritsMethanol

Wood alcohol—poisonousIs alcohol a nutrient?

Provides energy7 kcal/g

No other nutritive value

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Alcohol and Its Sources

FermentationYeast cells metabolize

sugar to make alcoholAlcoholic beverages

Beer: 5–6% alcoholWine: 8–14% alcoholLiquor: 35–45% alcohol

“Proof” is twice the alcohol percentage

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What Is a Drink?

Alcohol Absorption

No digestion requiredAbsorbed from mouth,

esophagus, stomach,and small intestine

Absorption slowed by food

Alcohol Metabolism

Small amounts of alcoholAlcohol dehydrogenase

Alcohol acetaldehyde

Aldehyde dehydrogenaseAcetaldehyde

acetateAcetaldehyde, acetate

converted to acetyl CoAAcetyl CoA molecules

built into fatty acids

Alcohol Metabolism

Large amount of alcoholOverwhelms alcohol

dehydrogenase systemUses microsomal ethanol-

oxidizing system (MEOS)

Alcohol MetabolismRemoving alcohol from

circulationLiver metabolism limitedBlood alcohol level falls

slowlyIndividual differences

in rate of alcohol metabolismGenderRace/ethnicityAge

Graph source: National Institute on Alcohol Abuse and Alcoholism

Alcohol Metabolism: Gender Differences

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When Alcohol Becomes a ProblemAlcohol in the brain and nervous system

Depressant; affects all parts of brainAlcohol’s effect on GI system

Esophagitis and gastritis

When Alcohol Becomes a Problem

Alcohol and the liverFatty liverFibrosisCirrhosis

Fetal alcohol syndromePhysical abnormalitiesMental retardationLow birth weight and poor growth

Alcoholics and MalnutritionPoor diet

Alcohol provides energy but no nutrients

Economic factorsLack of interest in food;

GI problemsVitamin deficiencies

Alcohol interferes with vitamin metabolism

Folate, thiamin, andvitamin A

Alcoholics and MalnutritionMineral deficiencies

Inadequate diet; fluid lossesCalcium, magnesium, iron, and zincSome mineral levels are elevated

MacronutrientsAlcohol interferes with amino acid absorptionAlcohol raises blood levels of fats

Body weightInconsistent effect of alcohol calories on weight

Does Alcohol Have Benefits?Moderate drinking has been associated

with reduced mortalityHeart disease

French paradox: red wine

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Harmful Effects

Alcohol

People who should not consume alcoholThose 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

Energy DrinksBackgroundHealth risksTo ban or not to ban?