Supplementary selenium influences the response to fatty acid-induced oxidative stress in humans

Abstract

The mutual influences of wheat selenium (Se) and n-3 polyunsaturated fatty acids (n-3 PUFA) on plasma Se and indicators of increased oxidative stress were investigated in a randomized, double-blind study with 31 women (23.5 +/- 3.4 yr). Groups 1 and 2 ingested 5.4 g n-3 PUFA daily (as ethyl esters), whereas groups 3 and 4 received placebo capsules. Groups 2 and 3 received 3 slices of high-Se bread daily, providing 115 micrograms Se, in addition to the 77 +/- 26 micrograms Se in the diet. Groups 1 and 4 received placebo slices. Blood samples were drawn at baseline and at 3 and 6 wk. Serum Se concentrations increased in both groups given Se-enriched bread, but significantly less in subjects given n-3 PUFA (group 2). There were no changes in the plasma ratio alpha-tocopherol:mg cholesterol or plasma ascorbic acid levels. In group 1, plasma-conjugated dienes and thiobarbituric acid-reactive substances (TBARS) rose by 130% (p < 0.005) and 126% (p < 0.005), respectively. Two-way ANOVA showed significant interaction effects of Se and n-3 PUFA on changes in conjugated dienes (p = 0.03) and TBARS (p = 0.015), Se treatment apparently modifying the peroxidative effects of n-3 PUFA. In subjects receiving n-3 PUFA, changes in conjugated dienes and TBARS were negatively correlated with changes in serum Se. In summary, n-3 PUFA modified the effect of Se supplementation, whereas Se seemed to modify the peroxidative effects of n-3 PUFA.

Comparison of the serum selenium content of healthy adults living in the Antwerp region (Belgium) with recent literature data

“…No difference was made in this review between plasma and serum, as done by most authors [14,22,83,[131][132][133][134][135][136][137]. Meltzer et al [83] mentioned serum as well as plasma selenium in the abstract. Only one publication claimed that serum selenium concentrations cannot be equated with plasma values [138].…”

Near infrared spectroscopy—a potentially useful method for rapid determination of fat and protein content in homogenized diets

“…As part of a selenium bioavailability study (Meltzer et al, 1997), 29 female nutrition undergraduate students collected duplicate portions of their regular diet for four consecutive days. The food was gathered in 2 L cartons and frozen consecutively by the end of each day.…”

“…We have previously conducted dietary studies in which mixed diets were carefully sampled and analysed (Meltzer et al, 1990(Meltzer et al, , 1993(Meltzer et al, , 1997 using the so-called duplicate portion method (Borgstro Èm et al, 1975, Cameron & van Staveren, 1988. This implies that the subjects gather a duplicate of all foods they eat and drink for a given number of days.…”

How to use the world's scarce selenium resources efficiently to increase the selenium concentration in food

“…The selenium intake needed for saturating the antioxidant capacity of blood plasma (65,66) and for optimal protection against cardiovascular diseases and cancer, as indicated by epidemiological observations (3,50Á53), is greater than the typical intakes of many people in the world. Two prospective clinical studies have also shown significant protective effects of Se supplementation at a 'supranutritional' level against colorectal cancer, prostate cancer, lung cancer and liver cancer (59,60).…”

“…In the majority of the European countries and other parts of China, classical symptoms associated with severe Se deficiency diseases are not commonly reported, but the daily Se intake is lower than the recommended Se intake (46). In these countries Se Efficient use of selenium resources 213 supplementation of the diet may possibly improve several different measures of health (3,4,12,47,53,56,57), such as reduction in cancer risk (53,58Á60), better immune function (61Á64), reduction of blood lipid oxidation (65,66), anti-ischaemic protection (67Á80), reduction of morbidity and mortality from HIV disease (81Á98), anti-ageing effects (99Á102), improved fertility (3,56,103Á105) and protection against allergic diseases and asthma (106Á111).…”