If you choose to eat red and processed meats, just how often do you bite into that bologna sandwich or hot dog? What type of pork and beef do you eat? Is it low fat? What brand?
These are the kinds of answers that studies need in order to better understand how processed meat increases the risk of cancer, says Amanda Cross, speaking at our research conference today.
Cross, a scientist at Imperial College London, noted that the research clearly shows even small amounts of processed meat — and high consumption of red meats — increase risk of colorectal cancer. A study by Cross also suggests that processed meat increases risk of lung cancer; while diets high in red meat risk increase risk for esophagus and liver cancers.
Historically, the questionnaires used in studies of dietary intake only asked a couple questions on how much red and/or processed meats people typically ate. Now the science needs more.
When it comes to processed meat, researchers are looking closely at nitrate and nitrite. These chemicals, added to many processed meats, lead to potential carcinogens known as N-nitroso compounds. For burgers and other red meats, grilling and broiling them well-done can form heterocylic amines (HCAs) and polycyclic aromatic hyrdocarbons (PAHs), also potential carcinogens.
If we can figure out how people cook their roast beef and steak, and how many nitrites are in their processed meats, that will go a long way towards understanding why risk increases, says Cross. At the same time, researchers need to know how many nitrites, nitrates, and HCAs are in the meats. That’s happening, says Cross.
Researchers have created a questionnaire with over a dozen questions to get at what type of processed meats people eat and how they cook their meat. They are also developing a database of how many nitrates, nitrites, and HCAs meats contain.
In one study Cross cites, they found those eating meat highest in nitrates had elevated risk of colorectal cancer.
Of course, we also get a lot of nitrates from vegetables, Cross noted. But she went on to explain that when we eat vegetables, we’re getting a lot of other beneficial compounds in the bargain. When we eat nitrates in red and processed meat, however, we get them alongside many other compounds — amines, PAHs, and many others — that are also linked to increased cancer risk. It’s a crucial difference.
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