Alcohol (ethanol) provides 7 calories per gram — making it nearly as calorie-dense as fat but with zero nutritional value. Its effects on nutrition and health are significant.
How alcohol is metabolized:
- Absorbed rapidly in stomach and small intestine
- Metabolized primarily in liver (alcohol dehydrogenase → acetaldehyde → acetate)
- Liver prioritizes alcohol metabolism — delays fat burning
Nutritional effects of excess alcohol:
- Impairs absorption of B vitamins (especially thiamine/B1, B12, folate)
- Depletes magnesium, zinc, potassium
- Damages gut lining, increasing intestinal permeability
- Causes fatty liver (alcoholic steatosis) with chronic heavy use
- Disrupts sleep architecture — reduces REM sleep
Cancer risk: Alcohol is classified as a Group 1 carcinogen. Even moderate drinking increases risk of breast, colon, liver, and esophageal cancer.
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