Increasing fish consumption does not affect genotoxicity markers in the colon in an intervention study.
Observational studies suggest that fish consumption is associated with a decreased colorectal cancer (CRC) risk. A possible mechanism by which fish could reduce CRC risk is by decreasing colonic genotoxicity. However, concerns have also been raised over the levels of toxic compounds found in mainly oil-rich fish, which could increase genotoxicity. Therefore, the objective was to investigate the effects of fish on genotoxicity markers in the colon in a randomized controlled parallel intervention study. For a period of 6 months, subjects were randomly allocated to receive two extra weekly portions of (i) oil-rich fish (salmon), (ii) lean fish (cod) or (iii) just dietary advice (DA). The Comet Assay was used to measure the DNA damage-inducing potential of fecal water (n = 89) and DNA damage in colonocytes (n = 70) collected pre- and post-intervention as markers of genotoxicity. Genotoxicity of fecal water was not markedly changed after fish consumption: 1.0% increase in tail intensity (TI) [95% confidence interval (CI) -5.1; 7.0] in the salmon group and 0.4% increase in TI (95% CI -5.3; 6.1) in the cod group compared with the DA group. DNA damage in colonocytes was also not significantly changed after fish consumption, in either the salmon group (-0.5% TI, 95% CI -6.9; 6.0) or cod group (-3.3% TI, 95% CI -10.8; 4.3) compared with the DA group. Measurements of genotoxicity of fecal water and DNA damage in colonocytes did not correlate (r = 0.06, n = 34). In conclusion, increasing consumption of either oil-rich or lean fish did not affect genotoxicity markers in the colon.
Division of Human Nutrition, Wageningen University, Bomenweg 2, 6703 HD Wageningen, The Netherlands.
Gerda K
GK
Pot
Nina
N
Habermann
Gosia
G
Majsak-Newman
Linda J
LJ
Harvey
Anouk
A
Geelen
Kasia
K
Przybylska-Philips
Fokko M
FM
Nagengast
Ben J M
BJ
Witteman
Paul C
PC
van de Meeberg
Andrew R
AR
Hart
Gertjan
G
Schaafsma
Guido
G
Hooiveld
Michael
M
Glei
Elizabeth K
EK
Lund
Beatrice L
BL
Pool-Zobel
Ellen
E
Kampman
D000818:Animals; D015415:Biomarkers / Q000032:analysis*; D003106:Colon / Q000737:chemistry*; D015179:Colorectal Neoplasms / Q000139:chemically induced / Q000517:prevention & control*; D020552:Comet Assay; D004249:DNA Damage; D004032:Diet; D005399:Fishes; D009153:Mutagens / Q000032:analysis*; D017747:Seafood
D015415:Biomarkers; D009153:Mutagens