Adherence to a Mediterranean-style diet by men on active surveillance for localized prostate cancer (PCa) decreased their risk for disease progression, according to a recent study.
The diet is characterized by an emphasis on fruits, vegetables, grains, and fish and limited intake of meat and dairy food items, moderate intake of alcohol, and a healthy balance of monounsaturated fats relative to saturated fat.
In a prospective study of 410 men on active surveillance for newly diagnosed Gleason grade group (GG) 1 or 2 PCa, Justin G. Gregg, MD, of the University of Texas MD Anderson Cancer Center in Houston, Texas, and colleagues found that greater adherence to a Mediterranean diet was associated with a lower risk for GG progression.
In adjusted analyses, each 1-unit increase in Mediterranean diet score was associated with a 12% decreased risk for GG progression overall and a 36% and 18% decreased risk among non-White men and men without diabetes, respectively, the investigators reported online in Cancer.
“Our findings suggest that consistently following a diet rich in plant foods, fish, and a health balance of monounsaturated fats may be beneficial for men diagnosed with early-stage prostate cancer,” Dr Gregg, assistant professor of urology, said in a press release from MD Anderson Cancer Center.
A number of mechanisms support a potential protective effect of the Mediterranean diet in localized PCa, according to the authors. For example, they noted that the antioxidant and anti-inflammatory properties of the Mediterranean diet via a variety of plant foods and a healthy balance of fats “may collectively support a systemic and tumor environment that inhibits progression.”
At baseline, the 410 participants filled out a 170-item food frequency questionnaire. Investigators calculated a Mediterranean diet score (0 to 9) for each patient across 9 energy-adjusted food groups. They assigned a value of 1 for each beneficial dietary component (vegetables, fruits, whole grains, legumes, and fish) whose consumption was at or above the median and 1 for each detrimental component (meat and dairy products) at or below the median. A fat intake ratio (monounsaturated to saturated fatty acids) at or above the median had a value of 1. Moderate alcohol consumption (up to 13 drinks per week) was assigned a score of 1, whereas no alcohol consumption or consumption greater than 13 drinks per week were assigned a score of 0.
Of the 410 men, 358 (87.3%) had GG1 and 52 (12.7%) had GG2 disease based on their diagnostic prostate biopsy. Over a median follow-up of 36 months, 76 patients (18.5%) experienced GG progression.
Gregg JR, Zhng X, Chapin BF, et al. Adherence to the Mediterranean diet and grade group progression in localized prostate cancer: an active surveillance cohort. Published online January 7, 2021. Cancer. doi:10.1002/cncr.33182
Mediterranean diet may decrease risk of prostate cancer progression for men on active surveillance [press release]. MD Anderson Cancer Center press release. January 7, 2021.