Evidence of an association between dietary fiber intake and risk of advanced and aggressive forms of prostate cancer (PC) and PC mortality is limited.
To examine associations between intakes of dietary fiber overall and by food source and risk of advanced and aggressive forms of PC.
Pooled analysis of the primary data in 15 cohorts in three continents. Baseline dietary fiber intake was assessed using a validated food frequency questionnaire or diet history in each study.
842,149 men were followed for up to 9-22 years between 1985-2009 across studies.
The primary outcome measures were advanced (stage T4, N1, or M1 or PC mortality), advanced restricted (excluded men with missing stage and those with localized PC who died of PC), high grade (Gleason score ≥8 or poorly differentiated/undifferentiated) PC, and PC mortality.
Study-specific multivariable hazard ratios (MVHR) were calculated using Cox proportional hazards regression and pooled using random effects models.
Intake of dietary fiber overall, from fruits, and from vegetables was not associated with risk of advanced (n=4,863), advanced restricted (n=2,978), or high-grade PC (n=9,673) or PC mortality (n=3,097). Dietary fiber intake from grains was inversely associated with advanced PC (MVHR comparing the highest vs. lowest quintile=0.84, 95% confidence interval [CI] 0.76-0.93), advanced restricted PC (MVHR=0.85, 95%CI 0.74-0.97), and PC mortality (MVHR=0.78, 95%CI 0.68-0.89); statistically significant trends were noted for each of these associations (p≤0.03), while a null association was observed for high grade PC for the same comparison (MVHR=1.00, 95%CI 0.93-1.07). The comparable results were 1.06 (95%CI 1.01-1.10, p-value, test for trend=0.002) for localized (n=35,199) and 1.05 (95%CI 0.99-1.11, , p-value, test for trend=0.04) for low/intermediate grade (n=34,366) PC.
Weak nonsignificant associations were observed between total dietary fiber intake and risk of advanced forms of PC, high grade PC, and PC mortality. High dietary fiber intake from grains was associated with a modestly lower risk of advanced forms of PC and PC mortality.
Journal of the Academy of Nutrition and Dietetics. 2024 Apr 15 [Epub ahead of print]
Elkhansa Sidahmed, Stephen J Freedland, Molin Wang, Kana Wu, Demetrius Albanes, Matt Barnett, Piet A van den Brandt, Michael B Cook, Graham G Giles, Edward Giovannucci, Christopher A Haiman, Susanna C Larsson, Timothy J Key, Erikka Loftfield, Satu Männistö, Marjorie L McCullough, Roger L Milne, Marian L Neuhouser, Elizabeth A Platz, Aurora Perez-Cornago, Norie Sawada, Jeannette M Schenk, Rashmi Sinha, Shoichiro Tsugane, Kala Visvanathan, Ying Wang, Kami K White, Walter C Willett, Alicja Wolk, Regina G Ziegler, Jeanine M Genkinger, Stephanie A Smith-Warner
Research Fellow, Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, Research Fellow, Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts., Professor, Department of Urology, Cedars-Sinai Medical Center, Los Angeles, California, Staff Physician, Urology Section, Durham VA Medical Center, Durham, North Carolina., Associate Professor, Departments of Epidemiology and Biostatistics, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, Associate Professor of Medicine, Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts., Department Associate, Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, Massachusetts (at time work completed)., Senior Investigator, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, Bethesda, Maryland., Analytic Section Manager, Division of Public Health Sciences, Fred Hutchinson Cancer Center, Seattle, Washington., Professor of Epidemiology, Department of Epidemiology, GROW-School for Oncology and Developmental Biology, Maastricht University, Maastricht, the Netherlands., Senior Investigator, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, Bethesda, Maryland (at time work completed), Honorary Senior Visiting Fellow, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom (current)., Head of Research, Cancer Epidemiology Division, Cancer Council Victoria, Melbourne, Victoria, Australia, Honorary Professor, Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia, Honorary Professor, Precision Medicine, School of Clinical Sciences at Monash Health, Monash University, Clayton, Victoria, Australia., Professor, Departments of Nutrition and Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts., Professor, Department of Preventive Medicine, Keck School of Medicine and Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California., Principal Researcher, Unit of Cardiovascular and Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden, Associate Professor, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden., Professor of Epidemiology, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom., Investigator, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, Bethesda, Maryland., Research Manager, Department of Public Health and Welfare, Finnish Institute for, National Institute for Health and Welfare, Helsinki, Finland., Senior Scientific Director, Epidemiology Research, Department of Population Science, American Cancer Society, Kennesaw, Georgia., Head, Cancer Epidemiology Division, Cancer Council Victoria, Melbourne, Victoria, Australia, Honorary Professor, Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia, Professor, Precision Medicine, School of Clinical Sciences at Monash Health, Monash University, Clayton, Victoria, Australia., Professor, Cancer Prevention Program, Division of Public Health Sciences Fred Hutchinson Cancer Center., Professor, Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland., Associate Professor, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom., Chief, Division of Cohort Research, National Cancer Center Institute for Cancer Control, Tokyo, Japan., Senior Staff Scientist, Division of Public Health Sciences, Fred Hutchinson Cancer Center, Seattle, Washington., Visiting Scientist, Division of Cohort Research, National Cancer Center Institute for Cancer Control, Tokyo, Japan., Senior Principal Scientist, Department of Population Science, American Cancer Society, Atlanta, Georgia., Research Biostatistics Manager, Epidemiology Program, University of Hawaii Cancer Center, Honolulu, Hawaii., Professor, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden, Professor, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden., Associate Professor, Department of Epidemiology, Mailman School of Public Health and Herbert Irving Comprehensive Cancer Center, Columbia University, New York, New York., Senior Lecturer, Departments of Nutrition and Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts. Electronic address: .