Fish consumption and markers of colorectal cancer risk: a multicenter randomized controlled trial.
BACKGROUND
Diet is a major factor in the etiology of colorectal cancer, with high fish consumption possibly decreasing colorectal cancer risk, as was shown in several observational studies. To date, no intervention trials have examined the possible beneficial effects of fish intake on colorectal cancer risk.


OBJECTIVE
The objective was to investigate the effects of a 6-mo intervention with oil-rich or lean fish on apoptosis and mitosis within the colonic crypt.


METHODS
In a multicenter, randomized, controlled intervention trial, patients with colorectal polyps, inactive ulcerative colitis, or no macroscopic signs of disease were recruited (n = 242) and randomly allocated to receive dietary advice plus either 300 g oil-rich fish (salmon) per week (n = 82), 300 g lean fish (cod) per week (n = 78), or only dietary advice (DA) (n = 82). Apoptosis and mitosis were measured in colonic biopsy samples collected before and after intervention (n = 213).


RESULTS
The total number of apoptotic cells per crypt did not increase in the salmon or cod group: -0.10 (95% CI: -0.36, 0.16) and -0.06 (95% CI: -0.32, 0.20), respectively, compared with the DA group. The total number of mitotic cells per crypt decreased nonsignificantly in the salmon group (-0.87; 95% CI: -2.41, 0.68) and in the cod group (-1.04; 95% CI: -2.62, 0.53) compared with the DA group. Furthermore, the distribution of mitosis within the crypt did not significantly change in either group.


CONCLUSIONS
An increase in the consumption of either oil-rich or lean fish to 2 portions weekly over 6 mo does not markedly change apoptotic and mitotic rates in the colonic mucosa. This trial was registered at www.clinicaltrials.gov as NCT00145015.
Pot
Gerda K
GK
Division of Human Nutrition, Wageningen University, Netherlands.
Majsak-Newman
Gosia
G
Geelen
Anouk
A
Harvey
Linda J
LJ
Nagengast
Fokko M
FM
Witteman
Ben J M
BJ
van de Meeberg
Paul C
PC
Timmer
Robin
R
Tan
Adriaan
A
Wahab
Peter J
PJ
Hart
Andrew R
AR
Williams
Matthew P
MP
Przybylska-Phillips
Kasia
K
Dainty
Jack R
JR
Schaafsma
Gertjan
G
Kampman
Ellen
E
Lund
Elizabeth K
EK
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D014408:Biomarkers, Tumor; D003106:Colon / Q000166:cytology / Q000473:pathology; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D004032:Diet; D005260:Female; D005395:Fish Oils / Q000494:pharmacology*; D048388:Gadiformes; D006801:Humans; D007413:Intestinal Mucosa / Q000166:cytology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D008938:Mitosis / Q000187:drug effects*; D012307:Risk Factors; D012474:Salmon; D017747:Seafood; D055815:Young Adult
D014408:Biomarkers, Tumor; D005395:Fish Oils