Recently, there has been an announcement from the International Agency for Research on Cancer that red meat is a definitive cause of cancer. This claim carries significant weight as the IARC's purpose is to evaluate how likely any phenomena is to cause cancer, and over 800 reports regarding red meat and its link to cancer were evaluated. In order to understand how and the magnitude to which red meat causes cancer, the chemistry has been studied. The problems from red meat arise from the large presence of the chemical heme and the compounds produced when meat is cooked at high temperatures.
Heme is a chemical that is part of hemoglobin, the protein-iron complex that is responsible for the red color of blood. Although there is no blood in meat from the market, there are still high levels of heme in red meat. When these molecules are broken down in the digestive tract, they produce compounds called N-nitrosos. These chemicals damage the cells of the bowel, which requires the bowel cells to replicate in order to replaced damaged cells and a high rate of replication increases the chance that mistakes in replicating DNA can order, which can lead to cancerous cell formation.
Additionally, heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) are problematic compounds that can form from cooking meet at high temperatures. They are noted to be mutagenic, meaning they cause changes in DNA that may increase the risk of cancer. HCAs are formed when amino acids, which are the building blocks of proteins, sugars, and creatine (a chemical present in muscles) react at high temperatures. PAHs are formed from the fat dripping from meat on a grill falls into the fire, and the process of cooking makes them adhere to the meat surface.
Heme is a chemical that is part of hemoglobin, the protein-iron complex that is responsible for the red color of blood. Although there is no blood in meat from the market, there are still high levels of heme in red meat. When these molecules are broken down in the digestive tract, they produce compounds called N-nitrosos. These chemicals damage the cells of the bowel, which requires the bowel cells to replicate in order to replaced damaged cells and a high rate of replication increases the chance that mistakes in replicating DNA can order, which can lead to cancerous cell formation.
Additionally, heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) are problematic compounds that can form from cooking meet at high temperatures. They are noted to be mutagenic, meaning they cause changes in DNA that may increase the risk of cancer. HCAs are formed when amino acids, which are the building blocks of proteins, sugars, and creatine (a chemical present in muscles) react at high temperatures. PAHs are formed from the fat dripping from meat on a grill falls into the fire, and the process of cooking makes them adhere to the meat surface.
From research of HCAs and PAHs, these compounds are known to become carcinogenic only after a certain enzyme in the body metabolizes them. The amounts of this enzyme present can vary between organisms in a species, making some more at risk than others. The evidence for the development of cancer as a result of exposure to HCAs and PAHs comes from rats who were exposed to dose levels thousands of times higher than a person with a normal diet. To date, no
population studies have established a definitive link between HCA and PAH exposure from cooked meats and cancer in humans, as levels are difficult to quantify and exposure of PAHs can also occur from other sources, such as cigarette smoke.
Overall, it is important to remember that these findings only indicate whether red meat causes cancer, and not how much cancer it causes. It is worth noting that some types of meat are presumed worse than others, for example processed meats have a higher confidence of causing cancer than red meat. These findings suggest that a high meat diet is not ideal, but do not imply that the occasional burger will kill you, which if you are like me, is something I cannot live without.
References:
http://www.independent.co.uk/life-style/health-and-families/health-news/cancer-definitely-caused-by-processed-meat-what-you-need-to-know-a6709266.html
http://www.cancer.gov/about-cancer/causes-prevention/risk/diet/cooked-meats-fact-sheet
population studies have established a definitive link between HCA and PAH exposure from cooked meats and cancer in humans, as levels are difficult to quantify and exposure of PAHs can also occur from other sources, such as cigarette smoke.
Overall, it is important to remember that these findings only indicate whether red meat causes cancer, and not how much cancer it causes. It is worth noting that some types of meat are presumed worse than others, for example processed meats have a higher confidence of causing cancer than red meat. These findings suggest that a high meat diet is not ideal, but do not imply that the occasional burger will kill you, which if you are like me, is something I cannot live without.
References:
http://www.independent.co.uk/life-style/health-and-families/health-news/cancer-definitely-caused-by-processed-meat-what-you-need-to-know-a6709266.html
http://www.cancer.gov/about-cancer/causes-prevention/risk/diet/cooked-meats-fact-sheet
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