Can a modified Mediterranean diet reduce inflammation in men with prostate cancer?

Abstract

Background Prostate cancer is the most commonly diagnosed malignancy and the third leading cause of mortality in New Zealand men. Global distribution patterns of prostate cancer suggest that development and progression may be linked to diet and lifestyle. Objectives The goal of this study was to determine the effect of following a Mediterranean-style diet on inflammation in men with prostate cancer. Methods Men with low-grade PCa, (n=20), aged 52-74, followed a modified Mediterranean diet for three months. Health related information, 4-day diet records and blood samples were collected at baseline. Participants received dietary counselling, a recipe book, dietary guidelines and samples of key foodstuffs. At study end, blood samples and dietary information were gathered, and dietary adherence assessed. Analysis of prostatespecific antigen, C-reactive protein, whole-blood fatty acids, and DNA damage were performed. Evaluation of interactions of the diet with these biomarkers was undertaken. Results There were no changes in C-reactive protein or prostate-specific antigen levels. Mean dietary adherence scores increased from 6.3 to 13.6 out of 20 (p<0.0001). Dietary adherence was inversely correlated with DNA damage (p=0.013), as was whole blood monounsaturated fatty acids (p=0.009) and dietary intake of legumes (p=0.004), green tea (p=0.002), dietary folate (p=0.023) and vitamin C (p=0.007). DNA damage was positively correlated with intake of dairy products (p=0.008), red meat (p=0.007), whole blood n6FA (p=0.015) and with the n6:n3 ratio (p=0.023). Conclusion We have shown, for the first time (to the best of our knowledge), that a high polyphenol diet, modelled on Mediterranean traditions, results in significant reduction in DNA damage in New Zealand men with low-grade prostate cancer. To validate these findings, a larger and longer study is warranted.