Concerning the relationship of egg consumption to breast cancer risk, 13 separate science studies on this link were analyzed in 2014, and the results published in the journal, Breast Cancer. According to the study analysis authors, these "results showed that egg consumption was associated with increased breast cancer risk for those who consumed 5 eggs or more a week. Egg consumption was associated with increased breast cancer risk among the European, Asian and postmenopausal population and those who consumed 2 to 5 eggs a week."
With egg consumption and colon cancer risk, a series of studies established that link over the years, mostly in science journals outside the United States. In reviewing this body of evidence, scientists writing in a 2009 issue of the Asian Pacific Journal of Cancer Prevention, observed: "Previous studies have suggested that egg consumption may increase the risk of colorectal cancer and some other cancers. To further explore the association between egg intake and cancer risk, we conducted a case-control study of 11 cancer sites in Uruguay between 1996 and 2004, including 3,539 cancer cases and 2,032 hospital controls. With high egg consumption there was a significant increase in the odds of cancers of the colon, breast, and prostate."
Under the general category of poultry, which is dominated by chicken and turkey, there are other bird types whose consumption poses similar cancer risks to human health as the more popular birds do.
Let's not forget duck, which is particularly popular in French cooking. A 2010 study in the journal, Meat Science, compared the formation of heterocyclic aromatic amines from cooking in chicken and duck breast, using the cooking methods of pan-frying, deep-frying, charcoal grilling and roasting.
The authors of the Meat Science study observed: "Results showed that chicken breast cooked by charcoal grilling contained the highest content of total HAAs, as high as 112 ng/g, followed by pan-fried duck breast (53.3 ng/g), pan-fried chicken breast (27.4 ng/g), deep-fried chicken breast (21.3 ng/g), deep-fried duck breast (14 ng/g)."
The most pernicious type of HAA for human health-the PhIPs-formed in both chicken and duck during pan frying at about the same levels, marking each as a meat to be avoided by anyone concerned with cancer and their health.
Still another study on carcinogens formed when cooking duck meat, done in 2012, replicated the earlier study results and added to it. Once again, pan frying followed by charcoal-grilling showed the formation of the most intense and insidious levels of carcinogens, particularly PhIPs, "which formed easily in duck meat," cooked using these grilling methods.
Egg consumption and breast cancer risk: a meta-analysis. Si R. Et al. Breast Cancer. 2014 May; 21(3):251-61.
Egg consumption and the risk of cancer: a multisite case-control study in Uruguay. Aune D. De Stefani E. Ronco AL. Boffetta P. DeneoPellegrini H. Acosta G. Mendilaharsu M. Asian Pac J Cancer Prev. 2009; 10(5):869-76.
"Effect of cooking methods on the formation of heterocyclic aromatic amines in chicken and duck breast." Liao GZ. Et al. Meat Sci. 2010 May.
"Formation of heterocyclic amines during cooking of duck meat." Liao GZ. Et al. Food Addit Contam Part A Chem Analysis Control Expo Risk Assess. 2012.