riddle with no answer ... do you know it?

[Trina]

Doreen wrote:

Does anyone have a clue to the answer? It is said that 80% of 
> small school children answered it and only 17% of all college 
> children. (It also said that if I sent it to 10 people the answer 
> would appear, but I know better than to believe that nonsense)
> 
> Help!!
> 
> Here is the riddle:
> 
> What is greater than God, More evil than the devil, The poor have 
it,  the rich need it, And if you eat it, you'll die?

My mom gave me the riddle last year sometime, but without the "More 
evil than the devil" line...

Trina, who knows the answer