Taste Good but Bad? Processed Meats Again Implicated in Cancer; Is It the Nitrites: This Time Pancreatic Cancer
It Looks Like Too Much Bacon, Sausage ,Processed Meats Just Can't Get a Break As Yet Another Study Points the FingerIs eating processed meat that contains nitrite and nitrates bad? Can something that tastes so good be bad? The latest salvo in the battle against "processed meats" came in a metanalysis study (a statistical exam of other studies)in the British Journal of Cancer by Larsson etal. They saw an association between processed meats (using nitrites) to pancreatic cancer. Larsson had previously written of an association with stomach cancer.
A news story about the report said "Eating two rashers (slices) of bacon a day can increase the risk of pancreatic cancer by 19% and the risk goes up if a person eats more, experts have said.Eating 50g of processed meat every day – the equivalent to one sausage or two rashers of bacon – increases the risk by 19%, compared to people who do not eat processed meat at all".
In the article, Red and processed meat consumption and risk of pancreatic cancer: meta-analysis of prospective studies they write "a positive association between processed meat consumption and risk of pancreatic cancer is biologically plausible. Processed meats are usually preserved with nitrite and may also contain N-nitroso compounds. N-nitroso compounds can further be formed endogenously in the stomach from nitrite and ingested amides in foods of animal origin (Sen et al, 2000). N-nitroso compounds reach the pancreas via the bloodstream and are potent carcinogens that have been shown to induce pancreatic cancer in animal models (Risch, 2003). A population-based case–control study observed that intake of dietary nitrite from animal sources was statistically significantly positively associated with risk of pancreatic cancer in both men and women".
What do they mean by "processed". I didn't see the definition in the article but a definition elsewhere:The term processed meat refers to meats preserved by smoking, curing or salting, or by the addition of preservatives. Examples include ham, bacon, pastrami and salami, as well as hot dogs and sausages.
Diet is thought to influence the incidence of several cancers but it's hard to unravel which aspects of diet are important. PLOS Medicine in the past had reported on a study of a link between processed and red meats and cancer. "Nearly half a million US men and women aged 50–71 years old joined the NIH-AARP Diet and Health Study. The participants none of whom had had cancer previously, completed a questionnaire about their dietary habits over the previous year and provided other personal information such as their age, weight, and smoking history". The study used these data and information from state cancer registries to look for associations between the intake of red and processed meat and the incidence of various cancers".
The prospective study( i.e a study in which people are identified and then followed forward in time) provided "strong evidence that people who eat a lot of red and processed meats have greater risk of developing colorectal and lung cancer than do people who eat small quantities". When meat is preserved by smoking, curing or salting, or by the addition of preservatives, cancer-causing substances (carcinogens) can be formed. These substances can damage cells in the body, leading to the development of cancer.
"Red meat intake was calculated from the frequency of consumption and portion size information of all types of beef, pork, and lamb; this included bacon, beef, cold cuts, ham, hamburger, hot dogs, liver, pork, sausage, and steak. The processed meat variable included bacon, red meat sausage, poultry sausage, luncheon meats (red and white meat), cold cuts (red and white meat), ham,regular hot dogs,and low fat hot dogs made from poultry.
"Although the researchers allowed for factors such as smoking history that might have affected cancer incidences, some of the effects they ascribe to meat intake might be caused by other lifestyle factors. Furthermore, because the study's definitions of red meat and processed meat overlapped—bacon and ham, for example, were included in both categories—exactly which type of meat is related to cancer remains unclear".
"Most of the study participants were non-Hispanic white, so these findings may not apply to people with different genetic backgrounds. Nevertheless, they add to the evidence that suggests that decreased consumption of red and processed meats could reduce the incidence of several types of cancer".