In what may be a first, researchers from Johns Hopkins Medicine have found evidence that a healthy diet could reduce the risk of low-grade prostate cancer advancing to a more aggressive form. This study, published in JAMA Oncology, focused on men with low-risk prostate cancer who opted for active surveillance—regular monitoring rather than immediate treatment, which can lead to unwanted side effects.

Dr. Bruce Trock, a study co-senior author and professor at Johns Hopkins, noted that many men with low-grade prostate cancer seek dietary and lifestyle changes to reduce progression risk. The research team collected data on these factors for 20 years, hoping to provide guidance to improve outcomes.

Study Overview

In this study, 886 men (median age 66) with grade group 1 prostate cancer were evaluated. They completed a diet questionnaire upon entering the Johns Hopkins active surveillance program, and their diet quality was assessed using the Healthy Eating Index (HEI), a measure aligned with USDA Dietary Guidelines. Researchers analyzed if high-quality diets correlated with reduced cancer grade progression.

Men with higher HEI scores showed a significant reduction in grade reclassification—meaning their cancer was less likely to progress to a higher, more aggressive grade. Co-senior author Dr. Christian Pavlovich, director of the Prostate Cancer Active Surveillance Program at Johns Hopkins, explained that each 12.5-point increase in HEI was linked to a 15% reduction in reclassification to grade group 2 and a 30% reduction to grade group 3.

Additional Findings and Considerations

The study also assessed the Dietary Inflammatory Index (DII), which measures diet’s inflammatory potential. Though higher DII scores correlated with greater inflammation, no association was found between DII scores and cancer progression. Dr. Trock suggested that while inflammation may influence the initial onset of prostate cancer, other dietary factors might drive progression within existing cancers.

While these findings support healthy diets as a potentially protective factor, the researchers highlighted study limitations, such as reliance on self-reported dietary data and a predominantly white study population. Future studies across diverse groups will be essential for further validation