Dietary nitrates may sound familiar – they are found in abundance in plants, which account for 80% of your nitrate consumption. They have notable health benefits relating to cardiac function, vasodilatation and blood pressure. Nitrates form Nitric Oxide (NO2) when ingested. They have even been shown to markedly increase exercise endurance from this effect.
However, the safety of nitrates/nitrites applied to foods as preservatives is questionable.
This isn’t a case of black or white; rather a grey area in need of some clarification.
You may have heard (who hasn’t?) that processed meat consumption carries with it a risk of cancer. Gastrointestinal cancer mostly. If this is true, then it would be fair to say that processed meats might not be the best for digestive health in general.
Anecdotally speaking, IBS is exacerbated by many processed and preserved foods already. It isn’t wild to assume that a potential carcinogen could make matters worse for an already irritable bowel.
Nitrates and Nitrites are everywhere, whats the beef?
Unlike red meat, to which a safe consumption amount exists (18Oz/week), no clear levels are known for processed meats. A review even implicated the consumption of any processed meat in upping gastrointestinal cancer risk.
A key differentiation between fresh and processed meats are the preservatives. Particularly concerning is the formation of gastrointestinal cancers related to the consumption of nitrates/nitrites.
Wait a second……how can these health promoting components of plants now be associated with cancer?
The answers might be in the fine print – the form in which nitrates are consumed.
Nitrates are found in abundance in plants, with addition to very small amounts of Nitrites. Upon consumption of Nitrates, the bacteria in your mouth and GI tract actually reduce them to Nitrites.
So, you are exposed to both nitrates and nitrites, even through plants. But what accounts for the difference in toxicity between plants and meats? What makes nitrites toxic?
It may be that we are not well equipped to deal with ingested Nitrites when isolated from their plant bodies. Lets take a look:
Isolated vs plant packaged Nitrates and Nitrites
Nitrates and Nitrites are used to preserve meats (duh). The Sodium Nitrate actually converts to Sodium Nitrite when it comes into contact with the meat. So for starters, you are straight up ingesting Nitrite.
An association between ingested Nitrites and gastrointestinal cancers has been noted. Nitrites when ingested are thought to poorly interact with other compounds, producing Carcinogenic N-nitroso compounds (NOS), or nitrosamines.
Interestingly, Vitamin C has been used to prevent the formation of NOS, when eaten in the presence of meats.
A study used vitamin C to regulate the formation of NOS. Interestingly, the presence of fat (found a plenty in processed meats) promoted the production of NOS. Whereas without fat, NOS production was inhibited.
Therefore the presence of other compounds alongside Nitrites in food, such as antioxidants found in plants could strongly influence the way Nitrites are processed in the body. This could explain the health differences seen in the consumption of Nitrate/Nitrites from plants and those from processed meats.
If this is the case, it highlights the intricate nuances of food preservation, food treatment and manufacture. It even highlights the complexity of isolating supposedly healthy, naturally occurring compounds and applying them to other foods. It could be that the interaction between the preservative and the food it is applied to might explain some of the negative outcomes.
Making sense of it all
Bottom line is that Nitrates come from plants, yet still form some Nitrites in the body. But, they come with an abundance of antioxidants, like Vitamin C, which helps them form Nitric oxide (NO2). Nitric oxide is beneficial for blood pressure, cardiac health and exercise performance.
However, when Nitrites are applied to meats directly, they lack the antioxidant wrapping that help them form Nitric oxide. Without the presence of Vitamin C, and in the presence of fat, Nitrites form Nitrosamines. Nitrosamines are the carcinogenic compounds implicated in gastrointestinal cancers.
If you decide to go nitrate free or not, its still a good idea to eat a lot of plants with meats regardless. Even if processed meats don’t produce any immediate symptoms, they may be working undercover over the longer term.
Maybe a little free range, minimally processed bacon or sausages are ok now and again. Its your body, you know it best. But its safe to say that spam and heavily processed deli meats aren’t ideal, for anyone.
Currently the recommendations for Nitrates are set at 0–3.7mg nitrate ion/kg bodyweight
Nitrites – 0–0.07mg nitrite ion/kg bodyweight
The best way to gauge these markers, because lets face it, its a chore to always check labels, is to watch your consumption of cured/processed meats.