Positive association between plasma antioxidant capacity and n−3 PUFA in red blood cells from women

Abstract

PUFA are susceptible to oxidation. However, the chain-reaction of lipid peroxidation can be interrupted by antioxidants. Whether an increased concentration of PUFA in the body leads to decreased antioxidant capacity and/or increased consumption of antioxidants is not known. To elucidate the relationship between plasma total antioxidant capacity (TAC), the concentration of antioxidant vitamins, and the proportion of PUFA in red blood cells (RBC), plasma TAC was measured by a Trolox equivalent antioxidant capacity assay in blood samples from 99 Icelandic women. Concentrations of tocopherols and carotenoids in the plasma were determined by HPLC, and the FA composition of RBC total lipids was analyzed by GC. Plasma TAC and the plasma concentration of alpha-tocopherol correlated positively with the proportion of total n-3 PUFA, 20:5n-3, and 22:6n-3 in RBC, whereas the plasma lycopene concentration correlated negatively with the proportion of total n-3 PUFA and 20:5n-3. On the other hand, plasma TAC correlated negatively with the proportion of n-6 PUFA in RBC. Plasma TAC also correlated positively with the plasma concentration of alpha-tocopherol, alcohol consumption, and age. Both the plasma concentration of alpha-tocopherol and age correlated positively with the proportion of n-3 PUFA in RBC; however, n-3 PUFA contributed independently to the correlation with plasma TAC. Because the proportion of n-3 PUFA in RBC reflects the consumption of n-3 PUFA, these results suggest that dietary n-3 PUFA do not have adverse effects on plasma TAC or the plasma concentration of most antioxidant vitamins.

Effect of consumption of tomato juice enriched with n-3 polyunsaturated fatty acids on the lipid profile, antioxidant biomarker status, and cardiovascular disease risk in healthy women

“…However, increased intake of EPA/ DHA has been reported to reduce in vivo lipid peroxidation and oxidative stress in humans [1,36]. A positive association between the n-3 PUFA content of red blood cells, which reflects the consumption of n-3 PUFAs, and plasma antioxidant capacity, has been also described [45]. In the present study, the consumption of n-3 PUFA-enriched juice did not produce any increase in lipid peroxidation, since MDA levels remained unchanged during the intervention period.…”

Effect of lycopene on biomarkers of oxidative stress in rats supplemented with ω−3 polyunsaturated fatty acids

“…Saito and Kubo (2003) reported that a-tocopherol in serum became lower with increasing degree of unsaturation of dietary polyunsaturated fatty acid. On the other hand, Thorlaksdottir et al (2006), using a human model, concluded that xÀ3 polyunsaturated fatty acids did not present adverse effect on plasma TBARS or plasma level of most antioxidant vitamins. No changes in plasma a-tocopherol concentration were observed among the groups and no lycopene was detected in plasma of animals supplemented with both doses.…”

“…Compared with all other constituents of LDL, polyunsaturated fatty acids show the highest sensitivity to oxidation by molecular oxygen in function of the number of double bounds (Frankel, 2005;. Actually, whether a diet rich in EPA and DHA fatty acids, containing five and six double bonds respectively, leads to a decrease in antioxidant capacity and/or an increased consumption of antioxidants is not yet known (Kris-Etherton, Harris, & Appel, 2002;Thorlaksdottir et al, 2006;. Studies on the oxidation rate after ingestion of dietary EPA and DHA in both animal or human models have shown conflicting results (Luostarinen, Laasonen, & Calder, 2001).…”

“…According to Buettner et al (2006), high-fat fish oil-fed rats showed enhanced expression of genes for lipid oxidation. Some authors have found an increase in the levels of oxidation biomarkers in both plasma LDL and tissue homogenates after EPA and DHA supplementation (Higdon et al, 2000;Leigh-Firbank et al, 2002;Puiggró s, Chacó n, Armadans, Clapés, & Planas, 2002) while others have shown opposite results, even including antioxidant properties associated with these two fatty acids (Barbosa et al, 2003;Erdogan et al, 2004;Frankel et al, 1994;Frenoux et al, 2001;Gordoa et al, 2002;Higgins et al, 2001;Hsu, Lee, & Chen, 2001;Thorlaksdottir et al, 2006).…”

Conceitos atuais e perspectivas na prevenção da degeneração macular relacionada à idade

“…Entre os principais mecanismos estudados, está o efeito protetor contra arritmias (115)(116) , efeitos no perfil lipídico (117)(118) , principalmente redução dos níveis séricos de triglicerídeos (119)(120)(121) , efeito antioxidante (122)(123)(124)(125) e antiinflamatório (126)(127) . Em 2001, dois estudos demonstraram evidênci-as sobre o efeito favorável dos ácidos graxos ômega-3 na redução do risco de DMRI.…”