There seems to be a buzz lately on what we should do when it comes to consuming red and processed meat. There also maybe a little confusion on what actually is considered red and processed meat. Some maybe under the impression that red meat is just beef and some may be under the impression that process meats are hot dogs and deli meats… There is more to it and we will get into more of the details below.
There was a recent set of analyses published on September 30th of 2019, in the Annals of Internal Medicine challenges the widespread recommendations to cut back on red and processed meats.
The prominent medical journal has also published a new recommendation from a panel of scientists, many of whom are not nutrition experts: “The panel suggests adults continue current processed meat consumption,” according to the guideline paper.
This panel was quickly discredited by professionals in nutrition in science. When you have the American Heart Association and The American Cancer Society, contradicting the guideline, it’s tough for AIM to have much credibility.
What does the industry consider as red meat? This is what the World Health Organization says:
-Red meat refers to all mammalian muscle meat, including, beef, veal, pork, lamb, mutton, horse, and goat.
What does the industry consider as processed meat? This is what the World Health Organization says:
-Processed meat refers to meat that has been transformed through salting, curing, fermentation, smoking or other processes to enhance flavor or improve preservation. Most processed meats contain pork or beef, but processed meats may also contain other red meats, poultry, offal, or meat by-products such as blood.
-Examples of processed meat include hot dogs (frankfurters), ham, sausages, corned beef, and biltong or beef jerky as well as canned meat and meat-based preparations and sauces.
Ok, so now you know what red meat and processed meats are. So why should we be cautious?
According to a study in 2015 by IARC the International Agency for Research on Cancer (IARC) is a part of the World Health Organization.
- IARC compiles several databases on carcinogenic risk to humans, epidemiology and cancer control.
In this particular study in 2015, red meat was classified as Group 2A, probably carcinogenic to humans. What does this mean exactly?
In the case of red meat, the classification is based on limited evidence from epidemiological studies showing positive associations between eating red meat and developing colorectal cancer and there is also evidence of links with pancreatic cancer and prostate cancers as well as strong mechanistic evidence.
Limited evidence means that a positive association has been observed between exposure to the agent and cancer but that other explanations for the observations (technically termed chance, bias, or confounding) could not be ruled out.
The cancer risk related to the consumption of red meat is more difficult to estimate because the evidence that red meat causes cancer is not as strong. However, if the association of red meat and colorectal cancer were proven to be causal, data from the same studies suggest that the risk of colorectal cancer could increase by 17% for every 100 gram portion of red meat eaten daily.
Also in this study, processed meat was classified as Group 1, carcinogenic to humans. What does this mean?
This category is used when there is sufficient evidence of carcinogenicity in humans. In other words, there is convincing evidence that the agent causes cancer. The evaluation is usually based on epidemiological studies showing the development of cancer in exposed humans.
In the case of processed meat, this classification is based on sufficient evidence from epidemiological studies that eating processed meat causes colorectal cancer.
The consumption of processed meat was associated with small increases in the risk of cancer in the studies reviewed. In those studies, the risk generally increased with the amount of meat consumed. An analysis of data from 10 studies estimated that every 50 gram portion of processed meat eaten daily increases the risk of colorectal cancer by about 18%.
- For this study, the cancer risks associated with consumption of poultry and fish were not evaluated.
- Tobacco smoking and asbestos are also both classified as carcinogenic to humans (Group 1). Does it mean that consumption of processed meat is as carcinogenic as tobacco smoking and asbestos?
- Group 1: The agent (mixture) is carcinogenicto humans. The exposure circumstance entails exposures that are carcinogenic to humans.
- Group 2: The agent (mixture) is probably carcinogenic to humans.
- Colin Campbell, co-author of the landmark China Study and arguably the foremost epidemiological researcher alive today, believes that animal proteins are a prime carcinogen. He points out that “human studies also support this carcinogenic effect of animal protein, even at usual levels of consumption. … [N]o chemical carcinogen is nearly so important in causing human cancer as animal protein.”
In general, the American Cancer Society does not determine if something causes cancer (that is, if it is a carcinogen). Instead, we rely on the determinations of other respected agencies, such as the International Agency for Research on Cancer (IARC) and the US National Toxicology Program (NTP).
The IARC is highlighted in this article.
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