The Mediterranean diet is well known for its role in helping to prevent heart disease, diabetes and several forms of cancer. But for some men with prostate cancer, this healthy and delicious way of eating may also slow existing disease.

In a new study, men with low-risk prostate cancer who are on active surveillance have a better chance of reducing their risk of disease progression if they adhere to a Mediterranean diet rich in vegetables, fish, beans, grains, fruit, olive oil and other healthy foods. The findings were published in the journal Cancer by researchers at the University of Texas MD Anderson Cancer Center. 

Researchers at the university followed 410 men with low-grade prostate cancer on active surveillance. Participants underwent a biopsy at the study’s start and were evaluated every six months using clinical exams and lab studies of prostate-specific antigen (PSA) and testosterone.

The men were required to complete a 170-item baseline food frequency questionnaire. Researchers calculated their Mediterranean diet score across nine energy-adjusted good groups and then split them into three groups (high, medium and low) based on their adherence to diet. 

Participants were majority white (83%), followed by other or unknown race (9%) and Black (8%) with a median age of 64.

After adjusting for several factors known to increase the risk of cancer progression, including age, PSA and tumor volume, findings showed that men with a higher baseline diet score were more likely to have a lower risk of cancer grade progression. Every one-point increase in their Mediterranean diet score was associated with a 10% reduced risk of progression.

The effects of a Mediterranean diet were more pronounced in Black men and participants who identified as nonwhite. For African-American men, these findings are crucial, as a prostate cancer diagnosis, higher risk of death from prostate cancer and disease progression are much higher among this group.

Overall, 76 of the 411 men followed saw their prostate cancer progress.

“Our findings suggest that consistently following a diet rich in plant foods, fish and a healthy balance of monounsaturated fats may be beneficial for men diagnosed with early-stage prostate cancer,” said Justin Gregg, MD, assistant professor of urology at the University of Texas MD Anderson Cancer Center and the study’s lead author.

Gregg is hopeful these results will encourage men who want to slow the advance of their disease and improve their quality of life to make healthy lifestyle choices.

For related coverage, read “How the Dietary Guidelines Report Supports a Cancer-Protective Diet” and “Are We Doing Diet and Nutrition Research Wrong?”