Red Meat, Processed Meats, Nitrates and Cancer
It’s grilling season! Among the favorites to grill are heavily processed, red meats such as hotdogs, smoked ham and bacon wrapped burgers. Red and processed meats have routinely been criticized for causing cancer, diabetes and cardiovascular disease. Since there are many aspects of red meats and processed meats that may be to blame for these conditions, let’s put our focus on, nitrates and nitrites.
Nitrates and nitrites are the preservatives often found in cured meats; they’re added to enhance color, provide flavor and prevent deadly bacterial growth (clostridium botulinum)!
Once consumed, nitrates take various forms in the body. First, nitrates are reduced to nitrites, by the bacteria in our mouth. Nitrites may convert to nitric oxide (via the acid in our stomachs), then are absorbed by our small intestine and finally excreted by our kidneys via urine. Some research shows that nitrates that convert to nitric oxide may benefit cardiovascular health. For those of you “gym-goers”, nitric oxide may sound familiar because it’s used as a pre-workout supplement. That’s because it acts on our blood vessels as a vasodilator, which relaxes the blood vessels and makes them more efficient at pumping more blood (and therefore more oxygen) per beat. This has been shown to improve athletic performance, among other benefits. On the other hand, nitrites can take a different path and may form nitrosamines. Nitrosamines are the combination of nitrites and amines (the breakdown product of amino acids – the building blocks of protein). Nitrosamines were shown in some research to cause tumors in lab animals.
Well that’s confusing! On one hand nitrates may cause cancer, but on the other they may benefit cardiovascular health. Furthermore, did you know that more nitrates are found naturally in foods such as turnips, rhubarb, beets and celery, than those chemically added to processed meats (like potassium nitrate)? That’s because nitrates and nitrites are part of the earth’s nitrogen cycle; therefore anything that grows in the ground will contain some level of nitrates. Like so many other divisive nutrition topics, it’s important to consider the context.
Although some research shows nitrites can form cancer causing nitrosamines, this pathway is less likely when antioxidants (in the form of vegetables) are consumed. Since meats do not contain these antioxidants, there is a potential correlation with the meat preservatives, nitrates and nitrites, and an increased risk of stomach and colon cancer.
If it’s the nitrates that are the issue let’s just omit them, right? That’s what some companies are doing, I’m sure you’ve seen the new food claims that state “No nitrates/nitrites added except for those naturally occurring…”? The statement is regulated by the USDA (United States Dept. of Agriculture), but does it really mean anything, and is it better?
For example; a “naturally” cured turkey bacon ingredient list may look like this: [Turkey, Water, Vinegar, Sea Salt, Raw Sugar, Celery Powder]. Although this bacon is indeed preserved without the use of nitrates or nitrites, it is not nitrate- or nitrite-free since there are naturally occurring nitrates in celery. This packaging may lead the consumer to believe it is superior to conventional (chemically preserved) meat. However, the body sees natural nitrates and chemically derived nitrates the same. Unfortunately, labeling meats as uncured is misleading.
To add to the confusion, “processed” meat is multifaceted; cured and processed meat is often red meat of lesser quality and likely fattier cuts; often containing preservatives, sugar, breading and more sodium than likely achieved via home preparation. Additionally, the nutrition of a plant or animal is also dependent on how it is raised, prepared, seasoned and ultimately cooked.
So what is a nutrition conscious person to do? Choose a variety of proteins instead which include seafood, poultry, red meat and vegetable proteins. Limit your use of all processed meats including those that are smoked and cured and consider sodium content; choose products that contain less than 250 or 300 milligrams per serving. While you’re at it, vary your preparation methods as well; roast, slow cook, sauté and grill your meats - just because it’s tasty!