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 population consumed unleavened bread. the phytates in the bread bind to zinc, decreasing its bioavailability.
the high amount of protein in the diet 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.

Explanation:

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

• Option 1: Vitamin C enhances zinc absorption, so this is incorrect.
• Option 2: Unleavened bread (like flatbreads common in Middle East) contains phytates. Phytates bind to zinc, reducing its bioavailability (the amount the body can absorb), which matches the scenario of high zinc - containing foods but low absorption.
• Option 3: Protein generally does not bind to zinc to decrease its bioavailability; in fact, some proteins can help with zinc absorption.
• Option 4: There's no strong evidence that soil copper levels would bind to zinc in foods to cause this deficiency, and this is not a typical mechanism for zinc deficiency in such populations.

Answer:

B. The population consumed unleavened bread. The phytates in the bread bind to zinc, decreasing its bioavailability.