Original Sin.

[cladking]

Fig newtons are heavenly.

There are different types of figs and it's only the egyptian sycamore fig that fixes mefat from dissolved egyptian red sandstone in its fruit. There are likely a few other plants that might work as well and it appears grapes work to a limited extent.

"Mefat" in nature is not extremely rare and anyone eating something and not growing old would probably put two and two together. There probably aren't many plants that work. The mefat "molecule" is quite large.