It is difficult to pinpoint a specific diet to its benefits or detriments, largely because so many other factors often go along with diet. For example, it can be tedious to document one’s diet, particularly as one’s consumption may change on a daily, weekly, or monthly basis. Isolating the impact of diet can also be challenging because people who eat healthier often tend to exercise more, which in itself is typically beneficial. However, due to anecdotal evidence that diet has significant impacts on cancer and other disease, scientists from the Mayo Clinic in Rochester, MN, recently conducted an extensive literature review to look closer at the links between prostate cancer and diet. Their research was published in The Journal of the American Osteopathic Association.
The National Cancer Institute estimates that approximately 11.6% of men in the US will receive a prostate cancer diagnosis at some point during their lifetime. That’s equivalent to roughly 174,650 new cases of prostate cancer in the United States in 2019. While it has been a challenge to establish a connection between diet and risk of prostate cancer, the researchers’ findings conclude that there may be an association between plant-based diets and a decreased risk of prostate cancer, as well as between dairy consumption and increased risk.
In their review, the researchers looked at all relevant studies from between the years 2006 and 2017 – 47 in total, encompassing over one million participants. They write: “Most studies showed that plant-based foods are associated with either decreased or unchanged risk of [prostate cancer], whereas animal-based foods, particularly dairy products, are associated with either increased or unchanged risk of [prostate cancer]." They didn’t find any changes in prostate cancer risk in studies that assessed red meat, white meat, processed meat, or fish intake.
"Our review highlighted a cause for concern with high consumption of dairy products. The findings also support a growing body of evidence on the potential benefits of plant-based diets," stated lead author Dr. John Shin. Nevertheless, the authors are quick to say that their findings are associations at best, and do not show causation.
The authors say that while their findings merit more investigation, the study also highlights that one of the "biggest obstacles in the field of dietary research is the lack of standardized methods for capturing and reporting diet and lifestyle data." For example, when individuals are required to document their diets, human error levels are extremely high. The fact that prostate cancer usually appears in older men also makes it difficult to know how diet has an impact on long-term health. Nevertheless, they hope that this subject will continue to receive a spotlight in the medical field, especially as we continue to strive to comprehend the effects of diet on general health.