Transcript: Are Nitrates Pollutants or Nutrients?
We know cured meat increases cancer risk—childhood leukemia, for example—yet, higher intake of vegetables is associated with a reduced risk. How can nitrites be bad in meat, but good when they originate in our own mouth from all the nitrates we get from green leafy vegetables?
Well, one possibility could be that nitrates are not good. And such a case has been made—blaming the rise of Alzheimer’s, diabetes, Parkinson’s, and the kitchen sink, on not only the rise in fast food and processed meat, but also the use of nitrate-containing fertilizers on our crops. Now, this was dismissed as an unsupportable conclusion—but by the vice president of the Fertilizer Institute, so how do we know it’s not just a load of bull? And speaking of manure, organic producers, in fact, brag that their vegetables are significantly lower in nitrates.
So, nitrates in plants; is it just a matter of too much of a good thing? Are nitrates in foods harmful, or healthy?
Before our heads explode, let’s go back to the basics: the facts of the case. The nitrosamines are the carcinogens, not the nitrites themselves. The nitrosamines are what cause the cancers. The only reason we’re concerned about nitrites is that, under certain circumstances, they can turn into nitrosamines, and other N-nitroso compounds.
And the only reason we’re worried about the nitrates is that they form nitrites, which, again, under certain circumstances, can form nitrosamines. The nitrites themselves are fine—in fact, amazing. That’s what all the new beets and blood pressure evidence I showed points to. And the nitrates turn into nitrites, which turn into nitric oxide, which helps our arteries and athletic performance. So as long as nitrites turn into NO [nitric oxide], we’re good. It’s only when they turn into nitrosamines that they cause trouble.
So, the answer to the riddle—finally—lies in the circumstances in which nitrites form nitrosamines. And that circumstance is in the absence of plants. Phytonutrients—like caffeic acid, found in all plants, blocks nitrosamine formation. Ferulic acid, ascorbic acid (vitamin C), and others. So, nitrates plus plant foods; no problem.
But is there any vitamin C in meat? No. So, you add nitrites to meat, and nitrosamines preform in the meat before it even makes it into our mouths. It’s not so much that we’re eating the nitrites added to the meat, but eating the nitrosamines that form in the meat when they add nitrites to it. Nitrites, in the absence of plants, turn into carcinogenic nitrosamines.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Dianne Moore.
Please consider volunteering to help out on the site.