Author: Michael Bernstein, MS, IFNCP
Date: April 2025
This article looked at recent peer-reviewed research regarding different foods and diets on prostate cancer risk. The largest randomized control trial (RCT), the Men’s Eating and Healthy Living (MEAL) trial, which took place between 2011-2015, looked at the increased consumption of fruits and vegetables in subjects following a standard American diet on prostate cancer progression. Subjects had early stage or low-risk prostate cancer and were undergoing active surveillance (AS). The study found no benefits for this increased consumption of fruits and vegetables on prostate cancer progression. The study used PSA (prostate-specific antigen) and PSA doubling time (PSADT) to determine progression of prostate cancer. This study was the largest well-designed RCT study on this topic (Friedrich et al., 2023; Parsons et al., 2018).
RCTs have the highest level of evidence in terms of study designs. They rank higher than cohort studies or case-control studies. A meta-analysis offers increased statistical power by pooling the data from many individual studies and can increase confidence in research findings. Meta-analyses are typically used to guide clinical decision making. In terms of this topic, there was a recent meta-analysis published in 2021 that examined fruit and vegetable consumption in regards to prostate cancer risk. It included 17 cohort studies which took place in several different countries. The findings of this meta-analysis were that neither fruit or vegetable consumption had any effect on prostate cancer risk. There was another meta-analysis published in 2022, which included 25 prospective studies, that examined red and processed meat on prostate cancer risk. For red meat and processed meat, the results were mixed. Some studies showed an increased risk of prostate cancer, while others did not. Processed meat, however, in some studies, was associated with an increased risk of total and advanced prostate cancer (Yan et al., 2022; Nouri-Majd et al., 2022).
The next studies looked at were cohort studies and case-control studies. Cohort studies have a lower level of evidence compared to meta-analyses, however, they have a higher level of evidence compared to case-control studies. A study by Loeb et al. (2021), which was a prospective cohort study that included 47,239 men, found that diets with a high plant-based diet index, which is rich in plant-based foods, was associated with a lower risk of prostate cancer, but only in men less than 65 years of age. A study by Zhang et al. (2020), which was a prospective cohort study that included 36,499 men, looked at mushroom consumption and prostate cancer. They found that frequent mushroom intake, defined as 1-2 times per week or 3 or more times per week, was associated with a lower risk of prostate cancer. A study by Mahmoodi et al. (2024), which was a case-control study that included 125 participants, found that a vegetarian diet was inversely associated with prostate cancer. It also found that a non-healthy diet characterized by high amounts of red meat, processed meat, refined grains, and sweetened beverages was positively associated with prostate cancer. A case-control study by Van Hoang et al. (2018), which involved 244 patients with prostate cancer and 408 controls, looked at foods high in carotenoids and prostate cancer. This study found that a higher consumption of tomatoes and carrots was inversely associated with prostate cancer. In summary, many of the studies indicated that plant-based foods are associated with a lower risk of prostate cancer. Red meat’s relationship to prostate cancer risk may be equivocal, and processed meat may increase the risk of prostate cancer. The meta-analysis regarding fruit and vegetable consumption not being associated with prostate cancer risk conflicted with the results of the other studies. Further research is needed to clarify the relationship between diet and prostate cancer risk.
References:
Friedrich, N. A., Freedland, S. J., & Csizmadi, I. (2023). Plant-based diets to reduce prostate cancer risk and improve prostate cancer outcomes—Ready for prime time? Prostate Cancer and Prostatic Diseases, 26(3), 445–446. https://doi.org/10.1038/s41391-022-00601-x
Parsons, J. K., Pierce, J. P., Mohler, J., Paskett, E., Jung, S. H., Morris, M. J., Small, E., Hahn, O., Humphrey, P., Taylor, J., & Marshall, J. (2018). Men’s Eating and Living (MEAL) study (CALGB 70807 [Alliance]): recruitment feasibility and baseline demographics of a randomized trial of diet in men on active surveillance for prostate cancer. BJU international, 121(4), 534–539. https://doi.org/10.1111/bju.13890
Yan, H., Cui, X., Zhang, P., & Li, R. (2022). Fruit and Vegetable Consumption and the Risk of Prostate Cancer: A Systematic Review and Meta-Analysis. Nutrition and cancer, 74(4), 1235–1242. https://doi.org/10.1080/01635581.2021.1952445
Nouri-Majd, S., Salari-Moghaddam, A., Aminianfar, A., Larijani, B., & Esmaillzadeh, A. (2022). Association Between Red and Processed Meat Consumption and Risk of Prostate Cancer: A Systematic Review and Meta-Analysis. Frontiers in nutrition, 9, 801722. https://doi.org/10.3389/fnut.2022.801722
Loeb, S., Fu, B. C., Bauer, S. R., Pernar, C. H., Chan, J. M., Van Blarigan, E. L., Giovannucci, E. L., Kenfield, S. A., & Mucci, L. A. (2021). Association of plant-based diet index with prostate cancer risk. The American Journal of Clinical Nutrition, 115(3), Article 3. https://doi.org/10.1093/ajcn/nqab365
Zhang, S., Sugawara, Y., Chen, S., Beelman, R. B., Tsuduki, T., Tomata, Y., Matsuyama, S., & Tsuji, I. (2020). Mushroom consumption and incident risk of prostate cancer in Japan: A pooled analysis of the Miyagi Cohort Study and the Ohsaki Cohort Study. International journal of cancer, 146(10), 2712–2720. https://doi.org/10.1002/ijc.32591
Mahmoodi, M., Gabal, B. C., Mohammadi, F., Ibrahim, F. M., Jalilpiran, Y., Nouri, M., & Faghih, S. (2024). The association between healthy and unhealthy dietary indices with prostate cancer risk: a case-control study. Journal of health, population, and nutrition, 43(1), 90. https://doi.org/10.1186/s41043-024-00578-4
Van Hoang, D., Pham, N. M., Lee, A. H., Tran, D. N., & Binns, C. W. (2018). Dietary Carotenoid Intakes and Prostate Cancer Risk: A Case-Control Study from Vietnam. Nutrients, 10(1), Article 1. https://doi.org/10.3390/nu10010070
* The content provided by this article is for informational purposes only. These statements are not intended to diagnose, treat, cure, or prevent any disease. This article is not intended to provide personal medical advice, which should be obtained from a medical professional.
