trans. question (comparative)

Hi, I am having problems with what appears to be a double negative in comparison (this is from Chapter 9 of Chase and Phillips):

ouk esth hugieias kreitton ouden en bio.

How would this be translated?

All I can think of is “Nothing in life is not stronger than health.” Yet this sounds strange. I would have thought, “Nothing in life is stronger than health.” Thanks for your help.

~Eric

Smyth’s grammar sections 2760-2762 deal with this.
I think that in the case of your sentence, section 2761 applies.
In short, the second negative simply confirms the first.

In colloquial English we have that in a sentence like; I haven’t done nothing wrong.