The association between processed meat and different types of cancer has more and more scientific evidence. The World Health Organization already includes processed meat as evidence group 1 carcinogens: They are known to cause cancer because there is strong evidence of it. Is red meat the same as processed meat? What types of cancer are the ones with the highest risk of appearing? Let’s see it.
It is not the same to talk about meat, red meat or processed meat
Imagine that a friend arrives and tells you that he has seen Juan or María. You may know a lot of Juanes and Marías, so that will give you little information. You need the last name, a nickname or some extra reference. The same thing happens with meat and cancer: We cannot say that meat increases the risk of cancer if we do not specify the “surname or nickname” of that meat and that cancer.
That’s what happened a few years ago when news about red meat and processed meat and the increased risk of cancer went viral. The World Health Organization (WHO) included processed meat in the group of foods proven to have a strong association with different types of cancer.
Many of the headlines confused the population I didn’t know very well what kind of meat and what kind of cancer they talked, ending up with a half-truth: meat causes cancer. Any meat? Any cancer?
Processed meat, cancer and scientific evidence
The most used meat classification is the one that differentiates white meat, red meat and processed meat. It is not the objective of this article to talk about each one of them, but we must know that the effect on cancer is not the same for all three.
The International Agency for Research on Cancer (IARC) is the specialized cancer agency of the World Health Organization. This association produced a monograph of more than 500 pages that focuses on the relationship of red meat and processed meat with different types of cancer.
19 of those 500 pages are for scientific references (more than 800 references), which demonstrates its high level of depth in the subject. said report It will be the scientific basis for the elaboration of this article, since they specify the association between this type of food and 12 types of cancer.
White meat is left out of the equation as it is not associated with increased cancer risk on its own. Red meat belongs to evidence group 2A: the consumption of red meat is probably carcinogenic to humans. It is a lower step than that of processed meat because the evidence to date exists, but it is limited.
Processed meat is in evidence group 1: consuming processed meat is carcinogenic to humans. There is no doubt in this case, we should avoid processed meat because its consumption is not healthy. In that same group of evidence 1 is tobacco smoke, alcohol, plutonium or polluted air, among other unhealthy substances.
What is processed meat?
All the meats that have been processed with salt, cured, fermented or smoked. Sausages of all kinds, industrial hamburgers and cured meats (ham, bacon, salami…) are processed meats, which can be better or worse depending on their processing.
Any and all conclusions about the increased risk of cancer from consuming processed meat is limited to this type of meat, not red meat or white meat. The guidelines are clear and unequivocal: eliminate the consumption of processed meat from your diet.
Relationship between processed meat intake and different types of cancer
Below we copy and paste a few lines from one of the latest systematic reviews and meta-analyses that investigated the Association between processed meat and cancer incidence. It was published last year in the prestigious magazine European Journal of Epidemiology.
Our findings provide strong evidence that high consumption of processed meat increases cancer risk breast cancer, endometrial cancer, colon cancer, rectal cancer, squamous cell carcinoma of the esophagus, lung cancer, renal cell cancer, and hepatocellular cancer, as well as colorectal cancer and pancreatic cancer.
To get an idea of the complex mechanisms that make processed meat increase the risk of cancer, we use as an example some of them in the following sections.
Processed meat and bowel cancer
Current research shows that there are certain chemicals in processed meats that make these foods carcinogenic. these substances are broken down in the intestine forming reactions that damage cells that cover this organ.
Examples of these substances are nitrite and nitrate preservatives used to preserve processed meat. These substances may be familiar to you because of the “possible ban” that was studied a few years ago for their use in meat foods such as kebabs. However, they continued to be accepted by the European Union.
Red meat itself, before being processed, already has heme (the iron in red meat) that gives it that reddish color for which it gets its name: red meat. breaking down heme in the intestine forms compounds that damage cells, as we just discussed.
when the meat it is cooked at high temperatures, such as on the grill or on a barbecue, heterocyclic amines (HCA) and polycyclic amines (PCA) are created which are highly carcinogenic. This form of cooking further increases the risk of damage to our intestines.
Processed meat and colon cancer
Daily consumption of 50 grams of processed meat increases the risk of colorectal cancer by 18%. This does not mean that by eating 50 grams of sausages tomorrow we will have that increase, but rather that doing it continuously over time could produce itbeing greater the more quantity we consume habitually.
A meta-analysis reported a statistically significant association between consumption of processed meat and adenomas (benign tumor adhered to the mucosa of the colon or rectum that can become malignant over time).
As with the increased risk of bowel cancer, the scientific evidence is clear with the Association between colon cancer and consumption of processed meat.
Processed meat and breast cancer
Processed meat consumption may increase the risk of breast cancer due to its high iron content, estrogen administration to cattle, and mutagens created during cooking. This is the conclusion drawn from the UK Biobank where they evaluated 262,195 women.
The explanation is similar to what we have already discussed in the two previous types of cancer: the substances contained in the meat itself and what it generates once it is cooked and consumed.
Processed meat and prostate cancer
The debate about the possible carcinogenic effects of consuming processed meat is still open, despite the fact that the entire trend points in one direction. Proof of this is that review studies continue to be published.
Just a few months ago the magazine Frontiers in Nutrition published a systematic review with meta-analysis (the highest degree of scientific evidence) that indicated that a higher consumption of processed meat could be associated with an increased risk of prostate cancer.
The list goes on: avoid high consumption of processed meat on a frequent basis
Scientific evidence supports dietary guidelines that promote avoid, or at least limit as much as possible, the consumption of processed meat to reduce the risk of various types of cancer.
Of course cannot be determined as the only risk factor affecting cancer. That is why some research shows a greater or lesser association, since the effect of processed meat on a sedentary middle-aged person will never be the same as on a teenage athlete.
What we can say with all the information gathered in this article is that processed meat (without going into the red meat) is a important risk factor to avoid to reduce the risk of cancer. Having a hamburger or a hotdog from time to time will not cause any inconvenience, but consuming sausage every day in large quantities for a long time could.
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