Starting to spend more and more time in the library preparing for exams, in a weird way I actually enjoy final exams; despite the head ache of reading 100s of pages of notes and textbook material, I know I’m going to miss it when I’m done school. Planning on doing some major Christmas decorating as soon as my last class is over (this Wednesday!!); I am so excited for Christmas festivities and to make my way back home. I think I have a problem with how much I love Christmas, on Saturday I forced my co-worker to listen to Christmas music through our shift together- I’m sure she’s looking forward to getting more shifts with me as Christmas approaches: p.
Here’s a picture of me climbing at my favorite place (Kentucky) earlier this year!
Anywaysss, this post will be on the implications of cooked or preserved meat consumption towards cancer. Hope you enjoy!
Many cancers including colorectal, esophageal, larynx, gastric, bladder, prostate and breast cancer have been shown to have increased risks for development in association with cooked or preserved meat consumption, increasing with the level of ‘doneness’. Maternal exposure to preserved meats has also been linked with childhood brain tumors. These associations are obviously very controversial in terms of research findings and recognition.
The major dietary carcinogens present today are all secondary carcinogens that are very stable and usually formed during processing and cooking. The main categories are polycyclic aromatic hydrocarbons (PAHs), heterocyclic amines (HCAs) and nitrosamines (NAs). PAH results from smoking and requires cooking temperatures of 250 degrees Celsius or higher; fatty meats have the greatest concentrations. HCA is from cooking between 100-250 degrees Celsius and requires amino acids, creatine and sugar- therefore it is primarily from meat consumption (amino acid and creatine). HCA production is enhanced by dry environments and is seen at high concentrations in jerky, dried meat, gravy, etc. Nitrosamines occur from nitrate and amine combinations- nitrate as a preservative and amines from the meat. Nitrate preservation is a method used to decrease the risk for botulism. It can be formed from cultured celery or beet extract as well as many other methods. All of these secondary carcinogens help produce many tasty flavors we enjoy today.
So how do secondary carcinogens actually promote cancer? Bear with me for the science of it all… Secondary carcinogens have to be metabolized to avoid accumulation in fatty tissue or in the brain. This metabolism is done predominantly by an enzyme called cytochrome P450 (phase 1 metabolism of toxins) which essentially makes an ultimate, water-soluble carcinogen that can then be detoxified by phase 2 reactions. While the phase 1 of toxin metabolism is essential in preventing the accumulation of secondary carcinogens, it does not need to be so quick since we typically aren’t exposed to high doses of carcinogens. When the activity of phase 1 is faster (by exposure to secondary carcinogens); more ultimate carcinogens will be formed that the phase 2 enzymes won’t be able to handle, resulting in an increased risk for cancer. The balance between both phase 1 and 2 enzymes are essential for the reduction in cancer risk, you want enough phase 2 enzymes to keep up with phase 1 (as well as the reduction of phase 1 activity). Diet and lifestyle have a big impact on the effects of secondary carcinogens through the regulation of P450 enzymes, and phase 2 enzymes.
Consumers remain poorly informed on the risks from meat preservation and cooking as well as the implications towards cancer. Current diets have a tendency towards an increased cancer risk due to meat processing and cooking as well as the reduction of phytochemical (via vegetables and fruit) intake, which is seen to both decrease phase 1 toxin metabolism and increase phase 2. A lot of the most common cancers are responsive to both diet and lifestyle; an estimated 60% of cancers are thought to be avoidable with a good diet and lifestyle.
So some concluding thoughts; be conscious of how you cook your meat (if you actually eat it) – although keep in mind, one over cooked steak is not going to give you cancer. Risks come from continuously eating these sources for secondary carcinogens. If you do eat over done meat; maybe pair it up with a plate of vegetables. And finally, the best way to reduce your risks would be to increase plant products and decrease cooked or preserved meats in your diet.
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