How Plant-Based Foods May Help Prostate Cancer Patients

Following a plant-based diet, which is rich in fruits, vegetables, legumes, and whole grains, has long been associated with numerous health benefits, including a reduced risk of type 2 diabetes and premature death. Now, a new study suggests that this eating plan may also slow the progression of prostate cancer.

Published in the journal JAMA Network Open, the research found a significant link between a plant-based diet and a reduced risk of localized prostate cancer worsening over time. According to the study, people with prostate cancer who consumed the most plant-based foods had the lowest odds of their cancer progressing.

The Study and Its Findings

Study author Stacey A. Kenfield, ScD, a professor of urology at the University of California, San Francisco, stated that “consuming a primarily plant-based diet—and less animal-based food—after a prostate cancer diagnosis may be associated with better prostate cancer-specific outcomes.” While this cohort study shows a strong association, it does not establish causation.

The research is a follow-up to earlier work by Kenfield and her colleagues that linked a plant-based diet to a reduced risk of developing fatal prostate cancer, especially in men under 65. In this study, the team gathered data on 2,062 men with non-metastatic prostate cancer enrolled in the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE) study. These men, with a median age of 65, were treated at 43 different urology practices across the U.S. from 1999 to 2018.

Participants completed a diet and lifestyle questionnaire about 31 months after their diagnosis, and researchers followed up with them for approximately 6.5 years. During this period, 190 participants experienced cancer progression, and 61 died from it. The study found that men who ate the most plant-based foods had a 47% lower risk of prostate cancer progression. Among men with at least medium-grade cancer, those who consumed the most plant-based foods had a 55% reduced chance of their cancer worsening.

Diet and Prostate Cancer Progression

Samuel Haywood, MD, a urological oncologist at Cleveland Clinic, noted that the slower cancer progression seen in those who follow plant-based diets could be due to other healthy lifestyle choices. Nonetheless, the data supports the potential benefits of plant-based diets for prostate cancer patients. Haywood emphasized that dietary and exercise interventions are common queries from his patients and that a plant-based diet could be a worthwhile recommendation for those motivated to make dietary changes.

Possible Mechanisms Behind the Diet’s Benefits

While the exact mechanisms remain unclear, several factors could explain the beneficial effects of a plant-based diet on prostate cancer progression. Many plant-based foods contain antioxidants and anti-inflammatory compounds that may have cancer-fighting properties. Such diets might also cause beneficial changes in the microbiome, which can influence cancer progression. Additionally, plant-based diets are often lower in fats and processed foods, potentially contributing to better health outcomes.

High fiber content in plant-based diets may regulate glucose levels and promote satiety, aiding in weight management and reducing chronic inflammation. Kenfield highlighted the association between insulin resistance, chronic inflammation, and cancer, suggesting that managing or losing weight can improve insulin sensitivity and reduce chronic inflammation.

Foods That Show Promise

Kenfield pointed to several plant-based foods associated with better outcomes for prostate cancer patients, including nuts, avocado, olive oil, fish, cooked tomatoes, and cruciferous vegetables like broccoli and cauliflower. However, Haywood cautioned that while many foods are suggested to be beneficial, the evidence for each individual component is not particularly strong, making it difficult to recommend any specific food item definitively.

Future Research Directions

Kenfield acknowledged the need for future studies to examine the role of plant-based diets in more racially and ethnically diverse populations and to focus on men with metastatic prostate cancer. A randomized controlled trial, the gold standard in epidemiological research, is necessary to determine whether plant-based diets cause better outcomes for cancer patients. In the meantime, Kenfield hopes that ongoing observational studies will confirm these findings and contribute to the limited data on this topic.

By adopting a plant-based diet, prostate cancer patients may potentially reduce their risk of cancer progression and improve their overall health outcomes. This research underscores the importance of dietary choices in managing prostate cancer and highlights the need for further investigation into the benefits of plant-based diets.