Question

while studying egyptian anthropology, lino was surprised to learn that zinc deficiency was common among certain middle eastern populations, even though their diet was high in zinc - containing foods. what caused the zinc deficiency in these populations?
multiple choice
the high amount of vitamin c in rhubarb, which was a popular food in the region, binds to zinc, decreasing its bioavailability
the soil in the region was high in copper. the copper binds to the zinc that is in locally grown foods, decreasing its bioavailability.
the high amount of protein in the diet binds to zinc, decreasing its bioavailability
the population consumed unleavened bread. the phytates in the bread bind to zinc, decreasing its bioavailability.

Explanation:

To determine the cause of zinc deficiency, we analyze each option:

• Vitamin C (in rhubarb) actually enhances zinc absorption, so the first option is incorrect.
• Copper binding to zinc in soil - there's no strong evidence this is a common cause in Middle Eastern diets for zinc deficiency, so the second option is incorrect.
• Protein generally improves zinc bioavailability, so the third option is incorrect.
• Unleavened bread (like flatbreads common in Middle Eastern diets) contains phytates. Phytates bind to zinc, reducing its bioavailability, which matches the scenario of zinc deficiency despite a zinc - rich diet.

Answer:

D. The population consumed unleavened bread. The phytates in the bread bind to zinc, decreasing its bioavailability (Note: Assuming the last option is labeled D; if the original options had different labels, adjust the label accordingly based on the actual numbering, but the content is as above).