Cancer in British vegetarians: updated analyses

Y aquí otro estudio que puede explicar en parte por qué los fish eaters tienen menos riesgo de cáncer colon que los vegetarianos y veganos, dicho de otra forma: los vegetarianos y veganos, según el estudio anterior, tiene un riesgo similar de cáncer de colo-rectal que los omnívoros.

In our extended analysis we found evidence that colorectal

cancer risk differed between diet groups: whereas we observed
34% lower risk in fish eaters than in meat eaters, colorectalcancer risk did not differ between vegetarians or vegans and meat

eaters, and the risk in meat eaters with moderate and low intakes

did not differ from that in meat eaters with high intakes of meat

Y el estudio:

http://www.ncbi.nlm.nih.gov/pubmed/24053119

Long-chain omega-3 polyunsaturated fatty acid intake and risk of colorectal cancer.

A total of 68,109 Washington residents aged 50-76 completed a questionnaire between 2000-2002 and were followed for CRC through 2008 (n = 488). Persons using fish oil supplements on 4+ days/wk for 3+ yr experienced 49% lower CRC risk than nonusers (hazard ratio = 0.51, 95% CI = 0.26-1.00; P trend = 0.06). The association between fish oil use and decreased CRC risk was primarily observed for men (P interaction = 0.02; P trend men = 0.02; P trend women = 0.88) and for colon cancer (P difference = 0.05; P trend colon = 0.03; P trend rectum = 0.87