[divegeek]

I doubt it. We're very flexible omnivores, and have acquired the capability to create supplements for whatever specific nutrients we lack.

The impact would be to the variety and tastiness of the food we have available, but I doubt it would significantly impact our ability to feed the population, or the health of that population. Oh, I'm sure that good access to fruits and nuts does make us healthier than we'd be without it, but it's a matter of small degrees, not life or death.