Hi guys,
I'm not an expert in jungle survival, but have expert my time in the southern Venezuelan Amazon, and can tell you with out a doubt that I would never drink any milky substance coming out of a tree. It is not that I'm picky, just that I have never seen such a thing neither form people that have tons of experience in the terrain or the Yanomami or Pemon tribes.
Just my 2 cents.
Saludos
PS: I have eaten the mangos that fall from the trees with out any problems, but may be I?m used to the parasites and bacteria from this side of the globe <img src="/images/graemlins/wink.gif" alt="" />