Marine ω-3 polyunsaturated fatty acid intake and survival after colorectal cancer diagnosis

Objective Experimental evidence supports an antineoplastic activity of marine omega-3 polyunsaturated fatty acids (omega-3 PUFAs; including eicosapentaenoic acid, docosahexaenoic acid and docosapentaenoic acid). However, the influence of omega-3 PUFAs on colorectal cancer (CRC) survival is unknown. Design Within the Nurses' Health Study and Health Professionals Follow-up Study, we prospectively studied CRC-specific and overall mortality in a cohort of 1659 patients with CRC according to intake of marine omega-3 PUFAs and its change after diagnosis. Results Higher intake of marine omega-3 PUFAs after CRC diagnosis was associated with lower risk of CRC-specific mortality (p for trend=0.03). Compared with patients who consumed <0.10 g/day of marine omega-3 PUFAs, those consuming at least 0.30 g/day had an adjusted HR for CRC-specific mortality of 0.59 (95% CI 0.35 to 1.01). Patients who increased their marine omega-3 PUFA intake by at least 0.15 g/day after diagnosis had an HR of 0.30 (95% CI 0.14 to 0.64, p for trend < 0.001) for CRC deaths, compared with those who did not change or changed their intake by < 0.02 g/day. No association was found between postdiagnostic marine omega-3 PUFA intake and all-cause mortality (p for trend= 0.47). Conclusions High marine omega-3 PUFA intake after CRC diagnosis is associated with lower risk of CRC-specific mortality. Increasing consumption of marine omega-3 PUFAs after diagnosis may confer additional benefits to patients with CRC.