Does that mean I should stop ingesting C60 Buckminsterfullerene despite the superstrength?

I assume you're joking, but yes. The issue is surface area and cross section, as these very small molecules tend to disrupt/block catalytic processes inside the cell. In the early hype days of nanotechnology they were thought to be extremely bio-compatible because they are basically chemically inert from a biological perspective, but it turns out they can act very well as a wrench in the gears of cellular machinery in ways that we are just now beginning to understand.

I don't want that to be considered anti-nanotech in any way, as that is my field and hope for the future. But that vision of carbon nanobots swimming our bloodstream is probably not accurate foretelling of the future. We'll probably be using protein components instead for easier bio-biodegradability.