Supplementary table 1. Characteristics of included prospective studies investigating the association of n-3 PUFAs and risk of colorectal cancer.

Study / Country / Years of follow-up / Case / Participant / N-3 PUFAs / Statistical adjustment
Type / Levels / RR (95%CI)
Bostick, 1994 / USA / 4.8 / 212 CC / 35215 women / Total / ＞0.18 vs.＜0.03 g/d / 0.70 (0.45-1.09) / Age, height, parity, a total vitamin E by age interaction term, intakes of total energy, total vitamin E and vitamin A supplement intake.
Pietinen, 1999 / Finland / 8 / 185 CRC / 27111 men / Total / 0.7 vs. 0.2 g/d / 1.2 (0.8-1.9) / Age, BMI, smoking, alcohol, education, physical activity at work, calcium intake, and supplement group.
Terry, 2001 / Sweden / 9.6 / 460 CRC / 61463 women / ALA
EPA
DHA / 0.70 vs. 0.45 g/d
0.9 vs. 0.3 g/d
0.18 vs. 0.08 g/d / 0.99 (0.75-1.32)
0.96 (0.72-1.28)
0.90 (0.67-1.20) / Age, BMI, education, and intakes of red meat and alcohol, energy, dietary fiber, calcium, vitamin C, folic acid, vitamin D, Saturated fat and monounsaturated fat.
Lin, 2004 / USA / 8.7 / 202 CRC / 29876 women / Marine (EPA+DHA) / 0.21 vs. 0.03
% total energy / 1.11 (0.73-1.69) / Age, random treatment assignment, BMI, family history of CRC, history of colorectal polyps, physical activity, smoking, postmenopausal hormone therapy, and intakes of energy and total energy.
Oba, 2006 / Japan / 7 / 213 CC / 30221 men and women / Marine (EPA+DHA) / Men:
1405 vs. 462 mg/d
Women:
1092 vs. 378 mg/d / Men:
1.24 (0.80-1.95)
Women:
0.89 (0.56-1.44) / Age, height, BMI, smoking, alcohol intake, and physical activity.
Hall, 2008 / USA / 17.6 / 500 CRC / 21406 men / Total / N.R. / 0.76 (0.59-0.98) / Age, smoking, BMI, multivitamin use, history of diabetes, random assignment to aspirin or placebo, vigorous exercise, and intakes of alcohol and red meat.
Bulter, 2009 / Singapore / 9.8 / 961 CRC / 61321 men and women / Total / 0.67 vs. 0.36
g/1000 kcal / Localized:
0.97 (0.71-1.32)
Advanced:
1.07 (0.84-1.36) / Age, sex, dialect group, interview year, diabetes status, smoking, BMI, education, physical activity, first degree relative diagnosed with CRC, and intakes of alcohol and total daily energy.
Murff, 2009 / China / 7.4 / 396 CRC / 73242 women / Total / 1.61 vs. 0.64 g/d / 1.41 (0.77-2.57) / Age, energy intake, BMI, current smoker, alcohol use, physical activity, intakes of n-6 PUFA, intakes of energy and red meat, menopausal status, and uses of hormone multivitamin and aspirin.
Daniel, 2009 / USA / 6 / 869 CRC / 99080 men and women / Total / Men:
≥1.47 vs.＜0.99 g/d
women:
≥1.38 vs.＜0.93g/d / Men:
0.86 (0.66-1.13)
Women:
1.38 (1.02-1.85) / Age, BMI, energy, HRT (in women only), physical activity, NSAID use, colorectal screening, and intakes of energy, red and processed meat, low-fat dairy, fruit, and vegetable.
Key, 2011 / UK / 3.0-8.4 / 565 CRC / 2516 men and women
(nested case-control) / Total / 2.08 vs. 1.02 g/d / 0.82 (0.59-1.13) / Age, sex, date of diary, height, weight, smoking, education, social class, physical activity, and intakes of energy, alcohol and dietary fiber.
Sasazuki, 2011 / Japan / 9.3 / 1268 CRC / 98466 men and women / Total / Men:
4.48 vs. 1.76 g/d
Women:
4.48 vs. 2.13 g/d / Men:
0.76 (0.48-1.18)
Women:
0.68 (0.41-1.12) / Age, area, BMI, smoking, alcohol drinking, history of diabetes, physical activity, screening for CRC, and intakes of total energy, alcohol , calcium, vitamin D, fiber and red meat.
Kantor, 2013 / USA / 6.7 / 488 / 68109 men and women / Marine
(EPA+DHA) / ≥0.29 vs. ＜0.08 g/d / 0.88 (0.65-1.20) / Age, sex, race, education, BMI, physical activity, smoking, and intakes of energy, n-6 fatty acids, alcohol, multivitamin, calcium, dietary fiber, fruit/vegetable and red/processed meat, uses of aspirin and nonaspirin NSAID, family history of CRC, history of sigmoidoscopy/ colonoscopy/polyps, HRT, CVD, memory loss, and cholesterol-lowering drugs use.
Song, 2014
(NHS) / USA / 20 / 1469 / 76386 women / ALA
Marine / ≥1.20 vs. ＜0.90 g/d
≥0.30 vs. ＜0.15 g/d / 1.05 (0.86-1.29)
1.03 (0.89-1.20) / Age, calendar year, family history of CRC, prior lower gastrointestinal endoscopy, smoking, BMI, physical activity, multivitamin use, postmenopausal status and hormone use, regular aspirin or NSAID use, and intakes of energy, red/process meat, alcohol , folate, calcium, vitamin D and total fiber.
Song, 2014
(HPFS) / USA / 22 / 987 / 47143 men / ALA
Marine / ≥1.30vs. ＜0.90 g/d
≥0.41 vs. ＜0.16 g/d / 0.89 (0.70-1.13)
1.05 (0.85-1.30) / Age, calendar year, family history of CRC, prior lower gastrointestinal endoscopy, smoking, BMI, physical activity, current multivitamin use, regular aspirin or NSAID use, and intakes of energy, red/process meat, alcohol, folate, calcium, vitamin D and total fiber.