Red meat and cancer have been linked in many studies. Out of the different types, colon cancer and bladder cancer show a clear link whilst the evidence for breast cancer is still unclear.
Foods that are associated with an INCREASED risk of bladder cancer include pork, barbecued meats, fat, soy, and excessive coffee consumption1.
Conversely, foods associated with a DECREASED risk of bladder cancer include carrots, selenium (found in brazil nuts and macadamia nuts), any vegetables belonging to the cabbage family, and fruits1.
Most of us readily accept that fruit and vegetables will improve health - and I hope you noted that the favored vegetable family for cancer protection is the cabbage which contains Lactobacillus plantarum.
But, if you need convincing on the benefit of eating a handful of brazil or macadamia nuts each day, read this great article on the connection between cancer and selenium.
A 2012 study showed that eating processed meat was positively associated with bladder cancer with the strongest link being to processed red meat7.
This same study showed that vitamin B12 intake was associated with a lesser risk of developing bladder cancer7.
The jury is still out on whether there is a clear connection between eating red meat and breast cancer. High processed meat consumption has been associated with a small INCREASE in breast cancer risk2 but the conclusion from this study was: "We have not consistently identified intakes of meat, eggs, or dairy products as risk factors for breast cancer. Future studies should investigate the possible role of high-temperature cooking in the relation of red meat intake with breast cancer risk."
Another study shows that many of the foods eaten in Italy such as plenty of vegetables and fruit DECREASE your chance of developing cancer. In particular, micronutrients such as flavones, flavonols and resveratrol, all found in fruit and veg, reduce the risk of breast cancer. Olive oil, which is another typical component of the Mediterranean diet, also lessens the risk of breast cancer3.
A 2014 study published in the British Medical Journal found that a higher red meat intake in early adulthood may be a risk factor for breast cancer, and that by substituting one serving per day of red meat with a combination of legumes, poultry, nuts and fish was associated with a 14% lower risk of breast cancer6.
It is believed that fecal water toxicity is linked with colon cancer and red meat, saturated fats, bile acids, and fatty acids are associated with an INCREASE in fecal water toxicity4.
Eating red and processed meat INCREASES the risk of large bowel cancer and it has been demonstrated that haem in red meat stimulates the production of nitreous compounds within the gastrointestinal tract5.
Fecal water toxicity is DECREASED by calcium, probiotics, and prebiotics4.
These key points are from Effect of Processed and Red Meat on Endogenous Nitrosation and DNA Damage by Annemiek M.C.P. Joosen, Gunter G.C. Kuhnle, Sue M. Aspinall, Timothy M. Barrow, Emmanuelle Lecommandeur, Amaya Azqueta, Andrew R. Collins, and Sheila A. Bingham. You can read the full article here.
Red and nitrite-preserved processed red meat increase the risk of colorectal cancer with the processed meat showing higher risk estimates per gram of intake than red meat.
Known carcinogens are formed during cooking of meat at high temperatures.
A red meat diet shows a dose-response relation with the formation of nitroso compounds (NOC). Many of these are known carcinogens and specifically for colon cancer. There is no such relation for white meat.
Cells in the colon have been shown to be particularly susceptible to NOC-induced damage. Clearly there is strong relationship between red meat and cancer.
1. Silberstein JL, Kellogg Parsons J. Evidence-based Principles of Bladder Cancer and Diet. Urology. 2009 Oct 10. [Epub ahead of print]
2. Pala V, Krogh V, Berrino F, Sieri S. Meat, eggs, dairy products, and risk of breast cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Am J Clin Nutr. 2009 Sep;90(3):455-6.
3. La Vecchia C, Bosetti C. Diet and cancer risk in Mediterranean countries: open issues. Public Health Nutr. 2006 Dec;9(8A):1077-82.
4. Pearson JR, Gill CI, Rowland IR. Diet, fecal water, and colon cancer--development of a biomarker. Nutr Rev. 2009 Sep;67(9):509-26.
5. Lunn JC, Kuhnle G, Mai V, Frankenfeld C, Shuker DE, Glen RC, Goodman JM, Pollock JR, Bingham SA. The effect of haem in red and processed meat on the endogenous formation of N-nitroso compounds in the upper gastrointestinal tract. Carcinogenesis. 2007 Mar;28(3):685-90. Epub 2006 Oct 19.
6. Farvid MS, Cho E, Chen WY, Eliassen AH, Willett WC. Dietary protein sources in early adulthood and breast cancer incidence: prospective cohort study. BMJ. 2014 Jun 10;348:g3437. doi: 10.1136/bmj.g3437.
7. Wu JW, Cross AJ, Baris D, Ward MH, Karagas MR, Johnson A, Schwenn M, Cherala S, Colt JS, Cantor KP, Rothman N, Silverman DT, Sinha R. Dietary intake of meat, fruits, vegetables, and selective micronutrients and risk of bladder cancer in the New England region of the United States. Br J Cancer. 2012 May 22;106(11):1891-8. doi: 10.1038/bjc.2012.187. Epub 2012 May 8.