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

To explore the association between three previously identified dietary patterns (Western, Prudent and Mediterranean) and prostate cancer (PCa) risk by tumour aggressiveness.

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.

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 (HR_Q3vsQ1 1.61 [95% CI 1.00; 2.59] and HR_Q4vsQ1 1.60 [95% CI 0.96; 2.67]) and in particular ISUP grade 3 + 4 + 5 tumours (HR_Q2vsQ1 1.97 [95% CI 0.98; 3.93]; HR_Q3vsQ1 2.72 (95% CI 1.35; 5.51); HR_Q4vsQ1 2.29 [95% CI 1.07; 4.92]).

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.