NUTR1030 Exam 2 Alcohol

ethyl alcohol (ethanol) nutritional contribution, digestion, absorption

- 7kcal/g

- contributes 10% of total energy intake in moderate consumers, 50% in AUD

- digestion: not required

- absorption: through GI tract, in stomach

oxidation of ethanol pathway

post absorption, etoh travels through blood to liver, where oxidized

ethanol --> acetylaldehyde --> acetate

acetate enters circulation --> acetyl coA --> TCA cycle for energy or FA synthesis

oxidation of alcohol systems and enzymes involved

1. alcohol dehydrogenase --> uses alcohol dehydrogenase to form acetylaldehyde

2. microsomal ethanol oxidizing system --> uses cytochrome P450 enzyme CYP2E1 to form acetylaldehyde

3. catalase system --> uses catalase to form acetylaldehyde

oxidation of alcohol systems , when to use each

1. ADH: oxidizes majority of ethanol

2. MEOS: more important at high etoh concentrations, inc CYP2E1 prod can lead to metabolic tolerance --> can consume more alcohol before showing signs of intoxication

3. catalase: minor pathway, relevant in peroxisomes and uses H2O2

biochemical and metabolic alterations associated with excessive alcohol intake; health consequences and causes

1. acetylaldehyde toxicity

- can bind to enzymes, impair activity

- interfere with microtubule formation in liver cells. can lead to cirrhosis

- contribute to cancer development

- cause cellular damage

2. increased NADH:NAD+ ratio

- inc triglyceride accumulation in the liver: fatty liver

- impaired gluconeogenesis: hypoglycemia without food

- lactic acidemia

3. malnutrition

- poor dieterary intake and diet

- GI problems

- reduced nutrient absorption

- alcohol related disorders

4. micronutrient deficiencies

- thiamin

-folate

-magnesium

-vitamins C, B6, B12

5. other disorders

- alcohol use disorder

- alcoholic liver disease

- chronic pancreatitis

- increased risk of injury

definition of moderate alcohol consumption

men: less than 2 drinks/day

women: less than 1 drink/day

one standard drink:

- 12 oz beer

- 5 oz wine

- 1.5 oz of 80 proof spirits