Long chain polyunsaturate supplementation does not induce excess lipid peroxidation of piglet tissues

Summary.

Background:

Addition of highly polyunsaturated fatty acids to infant formulas raises the possibility of increased lipid peroxidation.

Aim of the study:

We determined the effects of increasing levels of dietary docosahexaenoic acid (DHA) and arachidonic acid (AA) on lipid peroxidation and peroxidative potential in piglet tissues.

Methods:

Four groups of piglets (n = 6) were bottle-fed a formula containing one of four treatments: no long chain fatty acid (Diet 0) and three different levels of DHA/AA at 1-fold (0.3 %/0.6% FA; Diet 1) 2-fold (0.6 %/1.2% FA; Diet 2) and 5-fold (1.5%/3% FA; Diet 5) concentration used in some human infant formulas, and all with equal amount of vitamin E (5.7 IU/ 100 kcal formula) for four weeks.

Results:

There were no significant differences between the groups in conjugated diene and glutathione (GSH) levels in the liver, and thiobarbituric acid-reactive substance (TBARS) in plasma. TBARS levels of the erythrocyte membranes increased in a dose-dependent manner when in vitro oxidation was induced with 10 mM hydrogen peroxide (H₂O₂) for 30 minutes. The TBARS levels of the liver homogenates of the Diet 5 and Diet 2 groups were significantly different than those of the membranes of the Diet 0 group when the in vitro oxidation was induced with H₂O₂.

Conclusion:

The results show that dietary vitamin E effectively prevented lipid peroxidation at the LCP concentrations investigated and suggest that levels presently in infant formulas are sufficient.