One reason for this observation unquestionably is oxidative damage to the protein and fat content of meat product during processing. Unlike these factors and the oxidation of fats that you add when you prepare the meat, there's yet another potential reason for the bad effects of processed meats on our health: many of them are only par meat, part additive.
I know that's confusing. So let me explain: As Marco Iammarino, Rosaria Marino and Marzia Albenzio point out in their latest review, "meat products may be compromised by several admitted and not admitted procedures (i.e. addition of food additives and/or foreign proteins)" (Iammarino 2017) - to decide whether it's the meat, as in everything you get from the healthy, naturally reared animal, or the additives which are making you sick is thus impossible and accordingly beyond the scope of this article. What is within its scope, on the other hand, is to provide an overview of what exactly you may be eating on a daily basis and advise on how to reduce your exposure to pseudo-meat, significantly.
|Figure 1: Colorectal cancer risk increase w/ 100g and 25g higher intake of total red meat (incl. processed meat) or all processed meats (incl. white meats), respectively (calculated in a meta-analysis by Sandhu et al. 2001), per day.|
- colors (cochineal, carminic acid, carmines, allura red AG and caramels),
- preservatives (sulfites, acetates),
- acidity regulators (ascorbates, lactates, citrates, and phosphates),
- polyphosphates and nitrates (sulfites, nitrites, nitrates, etc.)
"For these reasons, the topic ‘food additives in meat and meat products’ has become an
emerging issue in food safety" (Iammarino 2017).
Even if we take a look only at the long list of potentially health relevant (ill) health effects of single food additives, we will find all sorts of ailments - from an allergic reaction to cancer.
- Sulphiting agents are used in the sulfuring treatment of fresh meat (but also bottled soft drinks, juice, fruit bars, dried foods, salads and fruit salads, or gelatin and coconut, as well as medications and cosmetics) and meant to avoid bacterial contamination and browning of the foods. Unfortunately, they have been implicated in asthma and other allergies (Vally 2009) and the USDA food safety documents list symptoms including chest tightness, hives, stomach cramps, diarrhea, and breathing problems (USDAa) - according to a 1995 paper by M.R. Lester only < .05% of the population are affected, though (Lester 1995).
Figure 1: There are also naturally sulphated foods, a greater health threat, however, seems to come w/ added sodium or potassium metabisulfite, bisulfite, sodium bisulfite/-sulfite in "meat" products (Lester 1996).
With respect to studies investigating the de facto nitrate + nitrite content of meat products, it is interesting to note that the level of nitrate and nitrite in sausages, salami and co. is at least 2-fold higher in Australian vs. US studies (each done with products from local supermarkets) - with Australian salami reaching the USDA limit and US sausages being 50% below that limit.
As data from Menard et al. (see Table 1) indicates the exact type of meat and, in that, the way it is produced does yet make so much of a difference that it doesn't make sense to compare the Frankfurter's from an Australian study fo breakfast sausages from a US study. Rather than avoiding regional products, it would thus make sense to avoid certain types of processed meat, such as coppa, in which the level of nitrate is ~400 mg/kg and thus higher than the generous USDA limit.
- Food colorings are used to make foods look the way we expect them to look - including meats; and since the latter are usually deep red, food colorings like cochineal, carminic acid, carmines (E120), Ponceau 4R, cochineal red A (E124) and allura red AG (E129) are used and mixed to achieve the same healthy pink to red tint we expect the perfect chicken breast or stake to have.
Minced beef and pork are favorite targets for the abuse of food coloring.
Another coloring from the same family, Ponceau 4R, on the other hand, is suspected to trigger hyperactivity in kids, prohibited in the US and still allowed in the European Union, where it is used to give chorizo sausage/salchichon and sobrasada their characteristic color - and it is difficult to tell exactly how much has been used. After all, "a complete analytical technique able to identify and simultaneously quantify all of the most important red food colorings (banned and not banned) in meat products is" as Immarino et al. point out "still not available" (Iammarino 2016).
- González, Carlos A., et al. "Meat intake and risk of stomach and esophageal adenocarcinoma within the European Prospective Investigation Into Cancer and Nutrition (EPIC)." Journal of the National Cancer Institute 98.5 (2006): 345-354.
- Haschek, Wanda M., Colin G. Rousseaux, and Matthew A. Wallig, eds. Fundamentals of toxicologic pathology. Academic Press, 2009.
- Iammarino, Marco, Rosaria Marino, and Marzia Albenzio. "How meaty? Detection and quantification of adulterants, foreign proteins and food additives in meat products." International Journal of Food Science & Technology 52.4 (2017): 851-863.
- Lester, Mitchell R. "Sulfite sensitivity: significance in human health." Journal of the American College of Nutrition 14.3 (1995): 229-232.
- Menard, Céline, et al. "Assessment of dietary exposure of nitrate and nitrite in France." Food Additives and Contaminants 25.8 (2008): 971-988.
- Sandhu, Manjinder S., Ian R. White, and Klim McPherson. "Systematic review of the prospective cohort studies on meat consumption and colorectal cancer risk." Cancer Epidemiology and Prevention Biomarkers 10.5 (2001): 439-446.
- Vally, Hassan, Neil LA Misso, and V. Madan. "Clinical effects of sulphite additives." Clinical & Experimental Allergy 39.11 (2009): 1643-1651.