Eicosapentaenoic acid (EPA) efficacy for colorectal aberrant crypt foci (ACF): a double-blind randomized controlled trial by Higurashi, T, Hosono, K, Endo, H, Takahashi, H, Iida, H, Uchiyama, T, Ezuka, A, Uchiyama, S, Yamada, E, Ohkubo, H, Sakai, E, Maeda, S, Morita, S, Natsumeda, Y, Nagase, H, Nakajima, A