The association between protein intake and prostate cancer risk remains unclear.
To prospectively investigate the associations of dietary intakes of total protein, protein from different dietary sources, and amino acids with prostate cancer risk and mortality.
In 131,425 men from the European Prospective Investigation into Cancer and Nutrition, protein and amino acid intakes were estimated using validated dietary questionnaires. Multivariable-adjusted Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).
During a mean follow-up of 14.2 years, 6939 men were diagnosed with prostate cancer and 914 died of the disease. Dairy protein was positively associated with overall prostate cancer risk in the three highest fifths compared to the lowest (HRQ3 =1.14 (95% CI 1.05-1.23); HRQ 4=1.09 (1.01-1.18); HRQ5 =1.10 (1.02-1.19)); similar results were observed for yogurt protein (HRQ3 =1.14 (1.05-1.24); HRQ4 =1.09 (1.01-1.18); HRQ5 =1.12 (1.04-1.21)). For egg protein intake and prostate cancer mortality, no association was observed by fifths, but there was suggestive evidence of a positive association in the analysis per standard deviation increment. There was no strong evidence of associations with different tumour subtypes.
Considering the weak associations and many tests, the results must be interpreted with caution.
This study does not provide strong evidence for an association of intakes of total protein, protein from different dietary sources or amino acids with prostate cancer risk or mortality. However, our results may suggest some weak positive associations, which need to be confirmed in large-scale, pooled analyses of prospective data.
Cancer medicine. 2022 Sep 23 [Epub ahead of print]
Julie A Schmidt, Inge Huybrechts, Kim Overvad, Anne Kirstine Eriksen, Anne Tjønneland, Rudolf Kaaks, Verena Katzke, Matthias B Schulze, Valeria Pala, Carlotta Sacerdote, Rosario Tumino, Bas Bueno-de-Mesquita, Maria-Jose Sánchez, José M Huerta, Aurelio Barricarte, Pilar Amiano, Antonio Agudo, Anders Bjartell, Tanja Stocks, Elin Thysell, Maria Wennberg, Elisabete Weiderpass, Ruth C Travis, Timothy J Key, Aurora Perez-Cornago
Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK., International Agency for Research on Cancer, Lyon, France., Department of Public Health, Aarhus University, Aarhus, Denmark., Danish Cancer Society Research Center, Copenhagen, Denmark., Division of Cancer Epidemiology, German Cancer Research Center (DKFZ), Heidelberg, Germany., Department of Molecular Epidemiology, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany., Epidemiology and Prevention Unit, Fondazione IRCCS Istituto Nazionale dei Tumori di Milano, Milan, Italy., Unit of Cancer Epidemiology, Città della Salute e della Scienza University-Hospital, Turin, Italy., Hyblean Association for Epidemiological Research, AIRE ONLUS, Ragusa, Italy., Former senior scientist, Centre for Nutrition, Prevention and Health Services, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands., Escuela Andaluza de Salud Pública (EASP), Granada, Spain., Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain., Instituto de Salud Pública de Navarra, Pamplona, Spain., Unit of Nutrition and Cancer, Catalan Institute of Oncology - ICO, L'Hospitalet de Llobregat, Spain., Department of Translational Medicine, Medical Faculty, Lund University, Malmö, Sweden., Department of Clinical Sciences Lund, Lund University, Lund, Sweden., Department of Medical Biosciences, Pathology, Umeå University, Umeå, Sweden., Department of Public Health and Clinical Medicine, Section of Sustainable Health, Umeå University, Umeå, Sweden., International Agency for Research on Cancer, World Health Organization, Lyon, France.