Are Nitrates/Nitrites Bad For You?

I've always had some vague sense that nitrates are Very Bad Things, and that I should stay away from them... and I've never really given a thought as to why. I imagine this is true of most people who don't know anything about charcuterie, but Ruhlman fights back against the myths:

The fact is, most nitrate we consume comes from vegetables. Nitrate we consume coverts to nitrite in our body, which is a anti-microbial agent in our guts. Sodium nitrite in bacon cures the bacon (more info in my safety concerns for charcutepaloozians) and then converts to nitrous oxide, so, while I’m not chemist, I have heard others suggest that you’re not actually consuming any nitrite by the time the bacon gets to you. Again, almost all the nitrate and nitrite in your body comes from veggies. It’s an anti-oxidant. Studies are coming out now saying it’s good for the heart.

It really does seem to be a relic of 40 year old studies and bacon marketing (No Nitrates Added!!!). An AJCN article from 2009 by Hord et al says the following:

Approximately 80% of dietary nitrates are derived from vegetable consumption; sources of nitrites include vegetables, fruit, and processed meats. Nitrites are produced endogenously through the oxidation of nitric oxide and through a reduction of nitrate by commensal bacteria in the mouth and gastrointestinal tract. As such, the dietary provision of nitrates and nitrites from vegetables and fruit may contribute to the blood pressure–lowering effects of the Dietary Approaches to Stop Hypertension (DASH) diet. We quantified nitrate and nitrite concentrations by HPLC in a convenience sample of foods. Incorporating these values into 2 hypothetical dietary patterns that emphasize high-nitrate or low-nitrate vegetable and fruit choices based on the DASH diet, we found that nitrate concentrations in these 2 patterns vary from 174 to 1222 mg. The hypothetical high-nitrate DASH diet pattern exceeds the World Health Organization's Acceptable Daily Intake for nitrate by 550% for a 60-kg adult.

So either vegetarians have the unhealthiest diet on earth, or maybe nitrates aren't really a big deal? Bacon very well might kill you, but it won't be from the nitrates.