The study is the latest research to investigate the linked between meat consumption and cancer risk, after several previous research papers offered mixed results on such links.
The new study – published in the journal Carcinogenesis – assessed the association between red meat and poultry intake and localized and advanced prostate cancer in more than 1500 cancer suffered.
Led by Dr Mariana Stern from the University of Southern California (USC) and Cancer Prevention Institute of California (CPIC), USA, the researchers found that men who ate more than two servings of red meat cooked at high temperatures per week increased risk by 40%.
"We found that men who ate more than 1.5 servings of pan-fried red meat per week increased their risk of advanced prostate cancer by 30 percent," Stern said. "In addition, men who ate more than 2.5 servings of red meat cooked at high temperatures were 40 percent more likely to have advanced prostate cancer."
“Our results support a role for carcinogens that accumulate in meats cooked at high temperatures as potential PCA risk factors, and may support a role for heterocyclic amines in prostate cancer etiology,” said the researchers, who added that their findings provide important new evidence on how red meat and its cooking practices may increase the risk for prostate cancer.
Diet and cancer
Prostate cancer is the second most common cancer among men, with only lung cancer accounting for more cancer diagnoses annually.
Studies of populations migrating to Westernized countries suggest that adopting certain dietary and lifestyle characteristics, may contribute to increasing the risk of malignancy.
Over the last decade, several large cohort studies of meat intake and prostate cancer have been published, with a recent review of dietary factors suggesting that high meat consumption may increase the risk of prostate cancer (Journal of Human Nutrition and Dietetics, doi: 10.1111/j.1365-277X.2009.00946.x).
However, overall findings have been mixed – with a recent systematic review of 26 large scale trials finding no link between meat consumption and prostate cancer (reported here).
Stern and her team examined pooled data from nearly 2,000 men who participated in the California Collaborative Prostate Cancer Study. Participants completed a comprehensive questionnaire that evaluated amount and type of meat intake, including poultry and processed red meat. Information regarding cooking practices (e.g., pan-frying, oven-broiling and grilling) was also obtained using color photographs that displayed the level of doneness.
The team noted that more than of the participants with cancer in the study, more than 1,000 were diagnosed with advanced prostate cancer.
They reported that cooking red meats at high temperatures, especially pan-fried red meats, may increase the risk of advanced prostate cancer by as much as 40%.
When considering specific types of red meats, hamburgers—but not steak—were linked to an increased risk of prostate cancer, especially among Hispanic men, they said.
"We speculate that these findings are a result of different levels of carcinogen accumulation found in hamburgers, given that they can attain higher internal and external temperatures faster than steak," Stern explained.
The team also found that men with diets high in baked poultry had a lower risk of advanced prostate cancer, while consumption of pan-fried poultry was associated with increased risk.
Stern said that pan-frying, regardless of meat type, consistently led to an increased risk of prostate cancer. She added that while the team cannot offer a full reason for why pan-frying poses a higher risk for prostate cancer, they suspect it is due to the formation of the DNA-damaging carcinogens—heterocyclic amines (HCAs)—during the cooking of red meat and poultry.
Published online ahead of print, doi: 10.1093/carcin/bgs242
“Red meat and poultry, cooking practices, genetic susceptibility and risk of prostate cancer: results from the California Collaborative Prostate Cancer Study”
Authors: Joshi AD, Corral R, Catsburg C, Lewinger JP, Koo J, John EM, Ingles S, Stern MC.