“Numerous scientific panels have evaluated sodium nitrite safety and the conclusions have essentially been the same: nitrite is not only safe, it is an essential public health tools because it has a proven track record in preventing botulism”. Maple Leaf Foods
As a member of Dietitians of Canada I receive many brochures, coupons and the like from food manufacturers – sometime it’s to publicize a new product, sometimes it’s to try to convince me that certain processed foods aren’t that bad. While most get no more than a cursory glance before a toss in the recycling bin (sorry Canadian Sugar Institute!), the new “What your should know about nitrate, nitrite and a healthy balanced diet” pamphlet from Maple Leaf Foods was downright insulting (and I’m not the only one who thought so)! Did they really think they could convince me that the nitrates in bacon are good for cardiovascular health?
Maple Leaf does a good job of owning up to celery extract as a source of sodium nitrite and explains the food safety benefits of nitrates and nitrites too. But that is where the flattery ends. For all the defending they do and emphasizing the importance of nitrites in preventing foodborne illness, need I remind them that nitrites do nothing to prevent listeria outbreaks, as was readily apparent in 2008?
Yes – nitrates and nitrites do naturally occur in some nutritious foods like spinach, broccoli and tomatoes. True – breast milk colostrum is full of nitrites. Are they really trying to compare deli ham with beets and breast milk though? Nitrates and nitrites do have very real functions in the body – they are converted to the potent vasodilator nitric oxide (NO), which is important for cardiovascular function and blood flow (aside: increased NO production is what makes Viagra work!).
The fact remains that the nitrates/nitrates in lettuce, radishes and spinach have never been linked to an increased risk of cancer; those added to cured meats HAVE been linked to cancer, though the results have been somewhat equivocal (some show an increased risk, others do not) (1). While Maple Leaf suggests that the evidence supporting an increased risk is old and outdated, the EPIC study (a large, prospective study of cancer risk) recently found that N-nitroso compounds, particularly N-nitrosodimethylamine (NDMA) which is found in smoked, pickled and cured foods (not veggies!), was associated with an increased risk of GI cancers, especially rectal cancer (2). The WCRF/AICR’s Second Expert Report, Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective still recommends limited processed meats as they are “convincing or probable causes of some cancers” (3).
No Baloney’s advice? As for the “all-natural” and “preservative-free” products containing celery extract, they may actually contain more nitrates than conventional versions. These natural preservatives *could* hypothetically be safer than their synthetically produced counterparts, but we are reserving judgment until there is some actual research to substantiate claims (4).
Keep in mind that these added nitrates and nitrates, natural or synthetic, are used as preservatives in processed foods, which are typically energy-dense and nutrient-poor. While we agree that the evidence regarding nitrates/nitrates and cancer is by no means rock solid, whether it’s the nitrates, saturated fat or excessive salt in hot dogs and bacon to blame for negative health outcomes seems irrelevant – these are foods that we shouldn’t be eating a lot of any way. If you want to boost NO production in your body, best bets would be beets, spinach or other veggies… not bologna (4).
Safe (re: not toxic) may not be synonymous with good for you – watch The Nature of Things “Programmed to be Fat” episode for examples of this very concept. While we do agree that cured meats can be a part of a healthy diet (we like bacon as much as the next gal!), it’s a matter of how much and how often. There are no clear guidelines for how often you can consume these products without risk of adverse outcomes, but we would suggest keeping it to less than weekly and watch the portion size (i.e., a Saturday morning “bacon bender” won’t cut it). If added-synthetic nitrite foods are a part of your current diet, evidence suggests that adequate vitamin C intake (preferably via veggies and fruit, not additives or supplements!) may provide some protective benefit against cancer risk (2).
- Milkowski A, Garg HK, Coughlin JR, Bryan NS. Nutritional epidemiology in the context of nitric oxide biology: a risk-benefit evaluation for dietary nitrite and nitrate. Nitric Oxide 2010; 22:110-9.
- Loh YH, Jakszyn P, Luben RN, Mulligan AA, Mitrou PN, Khaw KT. N-Nitroso compounds and cancer incidence: the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk Study. Am J Clin Nutr 2011; 93:1053-61.
- World Cancer Research Fund / American Institute for Cancer Research. Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective. Washington, DC: AICR, 2007.
- Hord NG, Tang Y, Bryan NS. Food sources of nitrates and nitrites: the physiologic context for potential health benefits. Am J Clin Nutr. 2009; 90:1-10.