High adherence to Western dietary pattern and prostate cancer risk: findings from the EPIC-Spain cohort.

ABSTRACT

OBJECTIVE: To explore the association between three previously identified dietary patterns (Western, Prudent and Mediterranean) and prostate cancer (PCa) risk by tumour aggressiveness. SUBJECTS AND METHODS: The Spanish cohort of the European Prospective Investigation into Cancer and Nutrition study provided dietary and epidemiological information from 15 296 men recruited during the period 1992-1996. The associations between the adherence to the three dietary patterns and PCa risk (global, for Gleason grade groups 6 and >6, and for International Society of Urological Pathology [ISUP] grade 1 + 2 and ISUP grade 3 + 4 + 5) was explored with multivariable Cox proportional hazards regression models stratified by centre and age. RESULTS: While no effect on PCa risk was detected for the Prudent and Mediterranean dietary patterns, a suggestion of a detrimental effect of the Western dietary pattern was found (hazard ratio [HR]Q4vsQ1 1.29 [95% confidence interval {CI} 0.96;1.72]). This effect was only observed for Gleason grade group >6 (HRQ3vsQ1 1.61 [95% CI 1.00; 2.59] and HRQ4vsQ1 1.60 [95% CI 0.96; 2.67]) and in particular ISUP grade 3 + 4 + 5 tumours (HRQ2vsQ1 1.97 [95% CI 0.98; 3.93]; HRQ3vsQ1 2.72 (95% CI 1.35; 5.51); HRQ4vsQ1 2.29 [95% CI 1.07; 4.92]). CONCLUSIONS: Our results suggest that a high adherence to a healthy diet such as that represented by the Prudent and Mediterranean dietary patterns is not enough to prevent prostate cancer. Additionally, reducing adherence to a Western-type diet seems to be necessary.