The second answer means the food may or may not be harmful.
If proof that a food is harmless is needed before anyone eats it, we will never have any new foods. The answer is to use judgement and common sense - the qualities that would have told us that feeding animal parts to herbivores was asking for trouble.
If we take this approach, we will accept foods altered to make them taste better, but will reject foods made lethal to insects on the grounds that it is highly likely that some people will, at the very least, be allergic to them, and that they will upset the ecological balance.
Similarly, plants altered to enable them to survive heavy doses of herbicide are liable to have some harmful herbicide residues, and to have serious ecological effects, and should not, in my judgement, be grown or eaten in Britain. However, no one has a monopoly of intuition on these matters.
Dr ERNEST RUDD