It's very mildly toxic. Acidic foods react with it and metal leaks into the food. It's why canned food says you should transfer it to another container after opening. I assume greater temperatures accelerate this process, as heat makes molecules move, though I'm no expert on crystalline structures in metals.

Searching for "aluminium toxicity" will bring up many results.

Titanium, on the other hand, is so safe to our bodies that it's used in surgical implants.

>Titanium, on the other hand, is so safe to our bodies that it's used in surgical implants.

So is Teflon used surgically and considered safe but only at biological temperatures and slightly above. Maybe titanium doesn't have such dark secrets as Teflon.