Influence of dietary fish oil supplementation on DNA damage in peripheral blood lymphocytes of nine healthy dogs

Abstract

Background Fish oil (FO) supplementation as a source of omega 3 fatty acids is associated with beneficial effects on health. However, high unsaturated fatty acid content in the diet could result in increased lipid peroxidation and damage to proteins, lipids and DNA. We evaluated the effect of dietary FO supplementation on DNA damage in peripheral blood lymphocytes of dogs. Additionally, we determined the effect of FO supplementation on lipid peroxidation and lipid profile of these dogs. Methods Healthy male dogs ( n = 9) were randomly assigned to one of two diets during 90 days: control (CG, n = 4), based on a commercial food, and FO (FOG, n = 5), the same food supplemented with 1000 mg FO. Blood samples were collected on days −1, 30, 60 and 90. DNA damage was assessed with the comet assay, and the damage index was obtained. Malondialdehyde (MDA) levels were determined as an indicator of lipid peroxidation. Lipid profile determination included serum triglyceride, cholesterol, low‐density lipoprotein and high‐density lipoprotein levels (HDL). Results Damage index values (arbitrary units) were lower in FOG on day 30 (CG, 13.7 ± 2.5; FOG, 6.5 ± 2.5), 60 (CG, 14.7 ± 2.5; FOG, 3.5 ± 2.5) and 90 (CG, 15.5 ± 2.5; FOG, 3.0 ± 2.5) compared with CG (treatment × time interaction, p < 0.01). Serum MDA and HDL concentrations were lower in FOG compared with CG on day 60 and 90 (treatment × time interaction, p < 0.05). Conclusion These findings suggest that dietary FO supplementation did not induce DNA damage in peripheral blood lymphocytes of healthy dogs, but rather reduced it.

Genotoxicity evaluation of a fish oil concentrate containing Very Long Chain Fatty Acids

“…Our results are also in keeping with findings that fish oil supplementation did not result in genotoxic effects and can actually provide protection from genotoxic effects in in vivo models of rats, dogs and humans [15] , [18] , [20] .…”

A Review on Genotoxic and Genoprotective Effects of Biologically Active Compounds of Animal Origin

“…Supplementation of a dog’s diet with fish oil rich in omega-3 fatty acids (1 g per day, 90 days) reduced DNA damage as assayed by alkaline single-cell electrophoresis in peripheral blood lymphocytes from five dogs receiving fish oil compared with four dogs receiving a standard diet. The DNA damage index was reduced already at day 30 and became more pronounced at day 90 [ 81 ]. Bioactive oligopeptides (FWKVV and FMPLH) from the protein hydrolysate of the miiuy croaker ( Acanthuriformes , Miichthys miiuy ) muscle protected human umbilical vein endothelial cells (HUVECs) against damage produced by hydrogen peroxide.…”

Feeding of fish oil and medium-chain triglycerides to canines impacts circulating structural and energetic lipids, endocannabinoids, and non-lipid metabolite profiles

“…The levels of total FO (or EPA + DHA) offered to dogs as well as the DHA-to-EPA ratio were lower in all of those trials than in the current trial. In the three trials that showed no effect of FO on triglycerides, one tested FO as a supplement in client-owned, mixed-breed dogs with an intake of 0.03–0.04 g FO/kg BW ( 88 ), while the other two studies used FO in food form at 0.11 g EPA+DHA/kg BW in Belgian Shepherd working dogs ( 89 ) and 0.06 g FO/kg BW in beagles ( 36 ). In the two trials that showed a reduction in triglycerides with FO, one tested FO as a supplement in miniature Schnauzers with primary hyperlipidemia (intake of 0.10 g EPA+DHA/kg BW, though it is unclear how this amount was present in one FO capsule) ( 84 ) and the other tested a food form of FO (0.10 g EPA+DHA/kg BW) in beagles ( 66 ).…”