Call me clueless, but what's the difference between the Nitrates and Nitrites found in vegetables that this article says are good for you and the Nitrates and Nitrites found in processed meats which are known carcinogens.

Does anybody know?

I have always wondered about nitrates in plants.  This article actually enforces my concerns.  Both nitrates and nitrites are potentially dangerous.

Nitrates are associated with increased risk of lymphomas.  Nitrites are supposedly converted to deadly (carcinogenic) nitrosamines in the presence of proteins during digestion.  It would be interesing to see a study comparing lymphoma rates with amounts of nitrate absorbing veggies eaten.  Also, nitrates can be toxic by binding to hemoglobin forming methemoglobin, which cannot release oxygen.  This is why it is dangerous to serve very young children high nitrate veggies or additives.  People have died from nitrate toxicity, usually from accidental overdose from cooking additives.