No red or processed meat link to prostate cancer: Meta-analysis

The review, published in Nutrition Journal​, looked at data from 15 large scale prospective studies on red meat and 11 studies investigating processed meats and cancer risk – finding that consumption of red or processed meats overall have no association with prostate cancer.

“The results of this meta-analysis are not supportive of an independent positive association between red or processed meat intake and prostate cancer,” ​stated the researchers, led by Dr Dominik Alexander of Exponent Health Sciences Practice.

The study received partial funding support from the National Cattlemen’s Beef Association (NCBA), however the researchers stated that NCBA did not contribute to the writing, analysis, or interpretation of research findings.

Diet link​

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. “As a result, diet has been the focus of numerous epidemiologic studies of prostate cancer, although findings have not been consistent,”​ stated the authors.

It has been suggested that red meat or processed meat may be responsible for increasing the risk of prostate cancer.

Over the last decade, several large cohort studies of meat intake and prostate cancer have been published. In a recent systematic review of dietary factors, it was suggested 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 the authors note that findings across the collective body of prospective cohort studies have not produced results to suggest a positive association

In their 2007 report on diet and cancer, the World Cancer Research Fund/American Institute for Cancer Research concluded that there was “limited evidence from sparse and inconsistent studies suggesting that processed meat is a cause of prostate cancer,” ​however the current authors noted that the assessment was based on only four cohort studies.

“We conducted a meta-analysis of prospective studies to clarify any potential relations between red meat or processed meat and prostate cancer,”​ stated the researchers.

No association​

Dr Alexander and colleagues reported no association between consumption (of high versus low intake) of red meat and total prostate cancer in the meta-analysis of 15 prospective studies.

Similar to the high versus low intake analysis, the researchers found no association per 100 gram increment of red meat for prostate cancer in a dose-response regression meta-analysis

The authors also observed no association with red meat was for advanced prostate cancer, however a weakly elevated summary association between processed meat and total prostate cancer was found from the 11 studies on processed meats.

Not significant​

“The results of this meta-analysis of prospective studies do not support an independent positive association between intake of red meat or processed meat and prostate cancer,”​ concluded the researchers.

“Summary results for processed meat were weakly elevated; however, the association across the more recently published studies that adjusted for key factors was attenuated and not statistically significant. Furthermore, there was evidence of publication bias across the cohort studies of processed meat,”​ they added.

The authors stated that additional studies are needed to fully evaluate any potential associations between consumption preferences, dietary mutagens, and prostate cancer.

Source: Nutrition Journal​
Volume 9, Issue 50, doi: 10.1186/1475-2891-9-50
“A review and meta-analysis of prospective studies of red and processed meat intake and prostate cancer”​
Authors: D.D. Alexander, P.J. Mink, C.A. Cushing, B. Sceurman