Continuing through the alphabet (but still stuck in the "C"s).
Very little has been written about chicken & PCa, & I think this might be due to bias. Chicken is not one of the usual dietary suspects. It is a benefiary of Ansel Key's crusade against saturated fat.
And yet, considering how most chickens are raised, it's surprising that the birds are considered to be a healthy alternative. The FDA says that chicken should be cooked to an "internal temperature of 165° F", whereas pork is safe at 145° F. While the risk of trichinosis from pork is now virtually zero in the U.S., there is a systemic tolerance towards salmonella in chicken.
On the other hand, hormones are not used in the U.S. on broilers, as some say or imply, & there is supposed to be a washout period for antibiotics & their metabolites.
Standard feed in the U.S. is mostly corn and soybean meal, but some meat and poultry by-products should be assumed, unless the label says "All-Vegetable Diet". Unfortunately, vegetarian chickens never go outside - because they would eat bugs & cease to be vegetarians.
Pastured chickens get a more natural diet. I went looking for local pastured chickens a few years back. On one highly respected farm, the chickens were in a field that had been pecked clean of every blade of grass & probably every bug. On another, smaller, operation, the farmer told me that the barn door was open & the chickens were free to go outside, but they never do. Their breasts are so heavy, they can barely walk. He said that he had tried rearing old-style chickens that did go outside, but he couldn't sell them, because there wasn't enough breast meat.
Here in NC, we are lucky to have access to Poulet Rouge Fermier [4]. Wouldn't satisfy those who demand more breast meat, but very tasty - the flavor that chicken used to have.
The following info comes from the USDA database.
- "Chicken, broilers or fryers, thigh, meat only, cooked, roasted":
Fats:
- total saturated = 2.311% [1.750% Palmitic acid; 0.477% Stearic acid]
- total monounsaturated = 3.361% [2.815% Oleic acid]
- total polyunsaturated = 1.965% [1.460% Linoleic acid (omega-6)]
These numbers should be viewed in the context of the meat being 67% water, so the one third remaining is roughly 75% protein & 25% fat. {USDA: protein = 24.76%}
For roasted breast meat, the protein goes up to 31.02%, & total fat goes down to 3.020%
STUDIES:
Note that the term "poultry" is confined to chicken & turkey.
[1] (2010 - U.S.)
"We conducted a prospective study in 1294 men with prostate cancer, without recurrence or progression as of 2004–2005, who were participating in the Cancer of the Prostate Strategic Urologic Research Endeavor {CaPSURE} and who were followed for an average of 2 y."
"Intakes of processed and unprocessed ... total poultry, and skinless poultry were not associated with prostate cancer recurrence or progression. Greater consumption of ... poultry with skin was associated with 2-fold increases in risk in a comparison of extreme quantiles {tertile}: ... poultry with skin (HR: 2.26 ...)."
"An interaction was observed between prognostic risk at diagnosis and poultry. Men with high prognostic risk and a high poultry intake had a 4-fold increased risk of recurrence or progression compared with men with low/intermediate prognostic risk and a low poultry intake ..."
"On the basis of previous literature, we hypothesized that meat items high in saturated fat may increase the risk of prostate cancer progression. However, saturated fat from poultry with skin did not explain our observed association between poultry with skin and prostate cancer progression. An alternative mechanism that may explain our observation for poultry with skin is a high intake of heterocyclic amines."
"Heterocyclic amines are mutagens present at much higher concentrations in well-done poultry than in other meats. We had no information on meat-preparation methods, but poultry with skin may be more likely to be broiled or grilled than skinless poultry, which results in higher concentrations of heterocyclic amines."
No mention of KFC!
I'm not sure how this study was conducted. It looks like skin consumption was assumed from skin being present during cooking. One has the option of eating or ditching the skin with certain cooking methods, but perhaps not so much with traditional fried chicken?
"We acknowledge that our study had several limitations, including a short follow-up, a small number of prostate cancer deaths or metastases, and a lack of prediagnostic dietary data."
[2] Erin Richman & June Chan were back - basically, same study; different population : Health Professionals Follow-up Study (HPFS). (2011 - U.S.)
"... we prospectively examined total, unprocessed, and processed ... poultry ... in relation to risk of lethal prostate cancer (e.g., men without cancer at baseline who developed distant organ metastases or died from prostate cancer during follow-up) among 27,607 men followed from 1994 to 2008. We also conducted a case-only survival analysis to examine postdiagnostic consumption of these foods and risk of lethal prostate cancer among the 3,127 men initially diagnosed with nonmetastatic prostate cancer during follow-up."
"In the case-only survival analysis, we observed 123 events during 19,354 person-years."
"... men who consumed more poultry engaged in more vigorous activity, were less likely to be current smokers, and tended to eat less red meat, dairy, and coffee, and more fish compared with men who consumed the least poultry.
"... men who consumed 3.5 or more servings per week of poultry after diagnosis had a 69% increased risk of lethal prostate cancer compared with men who consumed less than 1.5 servings/wk"
"This suggestive association seemed to be driven by sources of poultry other than skinless poultry (e.g., chicken or turkey with skin, chicken or turkey hot dogs, chicken or turkey sandwiches), but we had limited power to examine individual poultry items due to low consumption of these foods in our study population ..."
[3] (2016 - U.S./UK/Australia/Sweden/Finland/Netherlands/Japan)
"a consortium of 15 cohort studies"
"Poultry intake was associated with a statistically significantly higher risk of localized and low grade cancers but was associated with a statistically significantly lower risk of advanced and fatal cancers ..."
"Higher poultry intake was associated with a modestly lower risk of advanced and fatal cancers."
...
I don't know what to make of it. Why do people eat, or not eat, chicken? There are economic arguments for eating chicken, & moral arguments for not. So the choice is not always governed by dietary beliefs.
It's a displacement meat - more chicken = less red meat. A man with cardiovascular issues may switch to white meat, but he might also adopt a number of eating habits that might affect PCa risk. On the other hand, more chicken might mean more fast food.
Finally, there is the cooking method. Seems that some would get the message from the media to stay away from skin, when in fact it is high-heat cooking that is to blame. I will contine to fight with my daughter-in-law for the crispiest bits of skin from the Thanksgiving turkey.
-Patrick
[1] ajcn.nutrition.org/content/...
[2] cancerpreventionresearch.aa...
