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Nitrates didn’t earn their bad reputation because of vegetables, but because of how they behave in processed meat. When paired with antioxidants in whole plant foods, nitrates can actually support cardiovascular health and nitric oxide production. Context—not chemistry alone—is what determines whether nitrates help or harm.
Nitrates are mainly known as food additives and tend to be associated with processed meat like sausages and deli cuts. Since the 1960s, nitrate salts of sodium and potassium have been used in the food industry as approved preservatives to reliably extend product shelf life by inhibiting the growth of dangerous bacteria.
In the decades since we have learned that consumption of processed meat increases the chances of colorectal cancer in a dose-dependent manner- the more we eat, the greater the risk. But are nitrates the reason why eating too many salamis and hot dogs can be carcinogenic? Well, yes and no.
Nitrates are broken down and converted into related compounds in the mouth, stomach, intestine, and bladder into nitrites, nitrosamines, and nitric oxide. The nitrosamine family, in particular, has been linked to cancers of the digestive tract; among 300 different subtypes of nitrosamines studied, 90 per cent have been found to have carcinogenic effects in various animals.
These blessed phytochemicals have the effect of encouraging healthy nitrate metabolism. Beets, those crimson stalwart beauties of sports nutrition, are celebrated precisely because their nitrate richness translates into elevated nitric oxide, resulting in improved vascular tone and oxygenation of tissues… not to mention overall strength and endurance.
So, in the end, the common sense intuition to enjoy sausages, charcuterie, and beef jerky in moderation while liberally embracing colourful plant foods to the heart's content is perfectly on point. Nitrates or no nitrates, this is as complicated as it needs to be.
Perhaps the major lesson from the nitrates discussion is the importance of viewing food holistically. While it may be tempting to zero in on an essential ingredient that might be beneficial or harmful, the reality is simultaneously more complex and intuitive: complex because foods contain dozens of different chemicals working intricately in tandem, and intuitive because we don't really need to have a PhD to know that eating broccoli is healthy while living on hot dogs is not.
However, learning about food chemistry can still be invaluable if it enriches our appreciation for life-giving foods we may take for granted. Not only can such knowledge infuse our lives with new richness and depth, but it can motivate us to make positive lifestyle changes and eat in harmony with our biology. What's at stake is not just the prevention of diseases later in life but living more fully today.
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But here is the catch: most dietary nitrates don't come from processed meat, and most aren't food additives. Most of them are naturally occurring and come from vegetables and fruits. To muddy the waters even more, supplemental nitrates are gaining popularity among athletes as performance-enhancing agents. As if it all weren't confusing enough, there is a growing mountain of scientific literature outlining the benefits of dietary nitrates up to and including cancer prevention.
The first key to making sense of it all is that it isn't the nitrates, strictly speaking, that we should be worried about. It is their breakdown products, especially those nasty nitrosamines. When we eat nitrate-rich veggies like spinach, lettuce, beetroot, radish, and fennel, we get them bundled with antioxidants like ascorbic acid (vitamin C) and polyphenols.
When we consume smoked, cured, or canned meats, we are not getting the same smorgasbord of free radical scavengers- not even close. Instead of being naturally parcelled with protective antioxidants, the preserved meat nitrates are packaged without such insurance. If anything, other key players that are present, like polycyclic aromatic hydrocarbons (PAH), have their own cancer-causing potential. The interplay between these components isn't fully understood; still, we do know that eating processed meat results in large quantities of nitrates getting converted into nitrosamines in the body, thereby increasing cancer risk.
In the world of nitrates, this is unique. Dried fruit, red wine, and other sources of nitrates don't lead to large numbers of nitrosamines in the body. Where fresh fruits and vegetables are concerned, nitrate intake has been linked to reductions in systemic inflammation, the inhibition of nitrosamine formation, and protection against cancers of, you guessed it, the whole digestive tract! In other words, nitrates in healthy produce do the exact opposite of nitrates in processed meat.
Nitrates, Nitrites and Nitrosamine. Eating For Energy. (n.d.). https://www.eatingforenergy.com/nitrates-nitrites-and-nitrosamine/#:~:text=Nitrosamines%20are%20potent%20carcinogens%20which,conversion%20known%20as%20N%2Dnitrosation
Omar, S. A., Artime, E., & Webb, A. J. (2012). A comparison of organic and inorganic nitrates/nitrites. Nitric Oxide, 26(4), 229–240. https://doi.org/10.1016/j.niox.2012.03.008
Rojas-Valverde, D., Montoya-Rodríguez, J., Azofeifa-Mora, C., & Sanchez-Urena, B. (2020). Effectiveness of beetroot juice derived nitrates supplementation on fatigue resistance during repeated-sprints: A systematic review. Critical Reviews in Food Science and Nutrition, 61(20), 3395–3406. https://doi.org/10.1080/10408398.2020.1798351
Wikoff, D. S., Thompson, C., Rager, J., Chappell, G., Fitch, S., & Doepker, C. (2018). Benefit-risk analysis for foods (BRAFO): Evaluation of exposure to dietary nitrates. Food and Chemical Toxicology, 120, 709–723. https://doi.org/10.1016/j.fct.2018.08.031
