Relative and combined effects of ethanol and protein deficiency on zinc, iron, copper, and manganese contents in different organs and urinary and fecal excretion.
Level 5 - mechanism / opinion, no new human data
Preclinical animal experiment (rats).
PubMed 9650630 · doi:10.1016/s0741-8329(97)00156-0
What was done
Researchers evaluated the individual and combined effects of ethanol and protein deficiency on trace element metabolism in rats. Four groups of eight rats each were pair-fed for 8 weeks following the Lieber-DeCarli liquid diet model: a nutritionally adequate control diet, a 36% energy ethanol isocaloric diet, a 2% protein isocaloric diet, or a combined 36% ethanol and 2% protein isocaloric diet. An additional control group of five rats was fed ad libitum. Copper, zinc, iron, and manganese concentrations were measured in liver, bone, muscle, blood cells, serum, urine, and feces.
What was found
The abstract reports directional findings without numerical values. Protein malnutrition, but not ethanol intake alone, resulted in liver zinc depletion. Both ethanol intake and protein malnutrition led to muscle zinc depletion and increased urinary excretion of zinc and manganese. Ethanol also independently increased urinary iron excretion and elevated liver manganese content. No differences were detected in copper metabolism across the groups.
Why it matters
Trace element abnormalities in chronic alcohol use often overlap with dietary deficiencies; this study helps differentiate which specific element shifts are driven by ethanol exposure versus co-occurring protein malnutrition.
Limits
The findings derive entirely from an animal model (total n = 37 rats) and cannot be directly translated to human clinical populations. The abstract provides no quantitative data, baseline nutritional values, or effect sizes.
Cited by
- supports Alcohol consumption increases urinary zinc excretion by up to twofold.