European Journal of Nutrition (v.49, #3)

Polyunsaturated fatty acids (PUFAs) can affect various functions of the immune system including inflammatory responses. An oxidative burst of phagocytes accompanied by reactive oxygen species (ROS) and reactive nitrogen species (RNS) formation is one of the phagocyte functions that could be modulated by PUFAs.To investigate the effects of ω-3 (α-linolenic, docosahexaenoic, eicosapentaenoic) and ω-6 (arachidonic, linoleic) PUFAs on lipopolysaccharide (LPS)-stimulated ROS and RNS production by the murine macrophage cell line RAW 264.7.Murine peritoneal macrophages RAW 264.7 were stimulated with LPS (0.1 μg/ml) and treated with 0.1–100 μM ω-3 or ω-6 PUFAs for either 8 (ROS production) or 20 h (RNS production). The cytotoxicity of PUFAs was evaluated by an ATP (adenosine triphosphate) test after both 8 and 20 h of treatment with PUFAs. Changes in ROS production by LPS-treated macrophages subsequently activated with phorbol myristate acetate (PMA) or opsonized zymosan particles (OZP) were determined by luminol-enhanced chemiluminescence, whilst the production of RNS was determined as the concentration of nitrites in cell supernatants (Griess reaction). Changes in inducible nitric oxide synthase (iNOS) expression were evaluated by Western blot analysis. The antioxidant properties of PUFAs were tested by TRAP (total peroxyl radical-trapping antioxidant parameter) assay.All PUFAs in 100 μM concentration except eicosapentaenoic acid decreased ROS production. The effect was most significant when docosahexaenoic acid was used. Arachidonic acid decreased PMA-activated ROS production even in 1 and 10 μM concentrations. On the other hand, 10 and 100 μM eicosapentaenoic acid potentiated ROS production. As concerns RNS production, all the fatty acids that were tested in a concentration of 100 μM decreased iNOS expression and nitrite accumulation. Fatty acids had no significant effect on the viability and proliferation of RAW 264.7 cells. The TRAP assay confirmed that none of the tested PUFAs exerted any significant antioxidant properties.High concentrations of PUFAs of both ω-3 and ω-6 groups can inhibit ROS and RNS formation by stimulated macrophages. The expression of iNOS can also be inhibited. This effect, together with the absence of antioxidant activity and cytotoxic properties, indicates that PUFAs can participate in the regulation of enzymes responsible for reactive species production.
Keywords: Polyunsaturated fatty acids; Reactive oxygen species; Reactive nitrogen species; RAW 264.7 cells; Chemiluminescence

Associations between lactase persistence and the metabolic syndrome in a cross-sectional study in the Canary Islands by Ricardo Almon; Eva E. Álvarez-Leon; Peter Engfeldt; Lluís Serra-Majem; Anders Magnuson; Torbjörn K. Nilsson (141-146).
The single nucleotide polymorphism (SNP) LCT −13910 C>T, associated with genetically determined phenotypes of lactase persistence (LP) or non-persistence (LNP), was studied in relation to the metabolic syndrome (MS).The aim was to determine if milk intake and MS are associated. We applied Mendelian randomization (MR). The SNP, LCT −13910 C>T, with the genotypes LP (TT/CT) and LNP (CC), was taken as a proxy for milk consumption.A representative sample of adults belonging to the Canary Islands Nutrition Survey (ENCA) in Spain aged 18–75 years (n = 551) was genotyped for the LCT −13910 C>T polymorphism. We used the International Diabetes Federation (IDF) criteria to define MS.60% of the population was LP and 40% LNP. One hundred seven LP subjects (35.0%) and 53 LNP subjects (25.6%) showed MS (χ 2 = 5.04, p = 0.025). LP subjects showed a significantly higher odds ratio (OR) for MS than LNP subjects computed for the whole population: both the crude OR (1.56; 95% CI 1.06–2.31) and adjusted OR for sex, age, daily energy intake, physical activity and educational level (1.57; 95% CI 1.02–2.43). Adjusted OR for women with LP was 1.93; 95% CI 1.06–3.52.The T allele of the SNP might constitute a nutrigenetic factor increasing the susceptibility of LP subjects, especially women, to develop MS in the Canary Islands.
Keywords: LCT −13910 C>T polymorphism; Metabolic syndrome; Milk; Mendelian randomization; Nutrigenetics

The association between high plasma homocysteine levels and lower bone mineral density in Slovak women: the impact of vegetarian diet by Zora Krivošíková; Marica Krajčovičová-Kudláčková; Viera Spustová; Kornélia Štefíková; Martina Valachovičová; Pavel Blažíček; Tatiana Nĕmcová (147-153).
A long-term vegetarian diet is generally poor in vitamin B group. The lack of vitamin B12 together with vitamin B6 and folate deficiency is closely related to homocysteine metabolism. Hyperhomocysteinemia was found to be associated with increased bone turnover markers and increased fracture risk. Thus, hyperhomocysteinemia, vitamin B12 and folate deficiency may be regarded as novel risk factors for micronutrient deficiency-related osteoporosis.To assess the possible impact of a vegetarian diet on bone mineral density in cohort of Slovak vegetarian women.Fasting serum glucose, albumin, calcium, phosphorous and creatinine as well as bone markers, serum vitamin B12, folate and plasma levels of total homocysteine were assessed in two nutritional groups (vegetarians vs. nonvegetarians) of apparently healthy women (age range 20–70 years). Bone mineral density of the femoral neck, trochanter, total femur and lumbar spine was measured in all subjects.Vegetarians had a significantly lower weight (p < 0.05), higher PTH (p < 0.01) and homocysteine (p < 0.001). Vitamin B12 was significantly higher in nonvegetarians (p < 0.001). No differences were observed in folate levels. Univariate analysis showed significant association between homocysteine and B12 (p < 0.01), folate (p < 0.001), creatinine (p < 0.001), total proteins (p < 0.049), age (p < 0.001) and vegetarian food intake (p < 0.001). Vegetarians had a significantly lower TrFBMD (p < 0.05) and ToFBMD (p < 0.05). Age and CTx were significant predictors in all sites of measured BMD and PTH. A strong correlation between homocysteine and FNBMD (r = −0.2009, p < 0.002), TrFBMD (r = −0.1810, p < 0.004) and ToFBMD (r = −0.2225, p < 0.001) was found in all subjects.Homocysteine is one of the predictors of bone mineral density, and hyperhomocysteinemia is associated with lower bone mineral density. In healthy adults, homocysteine levels are dependent on age as well as on nutritional habits. Thus, elderly women on a vegetarian diet seem to be at higher risk of osteoporosis development than nonvegetarian women.
Keywords: Homocysteine; Folate; Vitamin B12 ; Bone mineral density; Vegetarian diet

Soybean whey enhance mineral balance and caecal fermentation in rats by María Dolores Tenorio; Irene Espinosa-Martos; Guadalupe Préstamo; Pilar Rupérez (155-163).
Soybean whey, a by-product of tofu manufacturing, is currently discarded by the food industry. However, it contains valuable compounds such as non-digestible oligosaccharides (NDO), which promote the growth of beneficial lactic acid bacteria in the colon, and are therefore recognized as prebiotics. Acidic fermentation of NDO in the caecum appears to be related with an increase in mineral absorption.To evaluate the effect of consuming soybean whey containing galacto-oligosaccharides (GOS) on mineral absorption and caecal fermentation in rats.An in vivo assay was carried out in rats over a period of 4 weeks; previously, the nutritional composition of soybean whey was determined and NDO were measured by high-performance liquid chromatography (HPLC). Faeces and urine were collected weekly throughout the experiment for mineral balance analyses. Animals were killed under anaesthesia, organs were removed and weighed, and short-chain fatty acids in the caecal contents were determined by gas chromatography.Non-digestible carbohydrates such as GOS stachyose (318 ± 3 mg/100 mL) and traces of inulin were identified by HPLC. When soybean whey was used as a source of GOS in rats, the consumption of diluted soybean whey (75 mL/day per rat) containing GOS (120 mg/day per rat) exhibited a prebiotic effect and led to an improved mineral balance, especially for calcium and magnesium. In view of its composition and potential health-promoting properties, soybean whey could be used as a valuable ingredient in new functional foods.
Keywords: Soybean whey; Galacto-oligosaccharides; Prebiotics; Caecal fermentation; Mineral balance

Promotive effects of resistant maltodextrin on apparent absorption of calcium, magnesium, iron and zinc in rats by Shoko Miyazato; Chie Nakagawa; Yuka Kishimoto; Hiroyuki Tagami; Hiroshi Hara (165-171).
It has been reported that low-viscous and fermentable dietary fiber and nondigestible oligosaccharides enhance mineral absorption. Resistant maltodextrin, nonviscous, fermentable and soluble source of dietary fiber, has several physiological functions. However, influence of resistant maltodextrin on mineral absorption is unclear.We conducted balance studies in rats to investigate effects of resistant maltodextrin and hydrogenated resistant maltodextrin on apparent mineral absorption.In experiment 1 (Exp. 1), 40 rats were fed test diets based on AIN-93G with or without resistant maltodextrin or hydrogenated resistant maltodextrin for 2 weeks. In experiment 2 (Exp. 2), 32 rats were cecectomized (CX) or sham-operated (Sham) and fed diets with or without hydrogenated resistant maltodextrin for 1 week.In Exp. 1, ingestion of resistant maltodextrin and hydrogenated resistant maltodextrin dose-dependently enhanced apparent absorption rates of Ca, Mg, Fe and Zn, and increased cecal fermentation with cecal expansion. In Exp. 2, the absorption rates of Ca and Mg were significantly enhanced by ingestion of hydrogenated resistant maltodextrin in Sham group but not in CX group. The promotion of Fe and Zn absorption was not affected by cecectomy.Ingestion of resistant maltodextrin and hydrogenated resistant maltodextrin increased apparent Ca and Mg absorptions dependent on cecal fermentation, while other mechanisms may also be involved in promotion of apparent Fe and Zn absorption by resistant maltodextrin.
Keywords: Resistant maltodextrin; Hydrogenated resistant maltodextrin; Apparent mineral absorption; Cecal fermentation; Short-chain fatty acid

Effect of probiotic supplementation on immunoglobulins, isoagglutinins and antibody response in children of low socio-economic status by Néstor Pérez; Juan C. Iannicelli; Cecilia Girard-Bosch; Silvia González; Ana Varea; Liliana Disalvo; María Apezteguia; Juan Pernas; Dimas Vicentin; Ricardo Cravero (173-179).
Antigen exposure is one of the major exogenous factors modulating human immunocompetence acquisition. Decline in family size and improvements in public health and hygiene in developed countries, may deprive the immune system of appropriate antigen input by diminishing infectious stimuli. Probiotics are a large group of microorganisms defined by their beneficial effects on human health and with stimulating effects on different functions of the immune system.We conducted a double-blind, placebo-controlled trial to determine if probiotics maintain their immune-stimulating effects in a population of 162 children with a high index of natural exposure to microorganisms. Children were to ingest for at least 4 months one of two products, low-fat milk fermented by Streptococcus thermophilus (control product) or low-fat milk fermented by S. thermophilus and Lactobacillus casei, with Lactobacillus acidophilus, oligofructose and inulin added after the fermentation process (test product). According to their age, children were vaccinated with DTP-Hib vaccine or a 23-valent anti-pneumococcal vaccine.Final analysis of results was done in 70 children in each group, showing that the rate of immunoglobulin and isoagglutinin acquisition was similar in both groups. There was no difference between groups in antibody levels neither before nor after vaccination. Days of fever and number of episodes of infection were not statistically different in either group.Supplementation of standard fermented milk with additional probiotics was not of benefit. The high natural rate of early microbial exposure in infants and children from a population of low socio-economic status living in a “less hygienic environment” may account for the absence of an additional immune-stimulating effect by supplementary probiotics.
Keywords: Probiotics; Immune system stimulation; Antibody response; Hygiene hypothesis

There is increasing evidence indicating that the dietary intake of food with high antioxidant capacity may protect mitochondria from damage and exert positive effects on different pathogenic processes.The present study was designed to evaluate the possible protective effect of alcohol-free beer intake on chain components dysfunction of liver and heart mitochondria, and to compare with the effect of alcohol beer intake.The study was carried out in rat heart and liver mitochondria by inducing with Adriamycin the dysfunction of the respiratory chain. Heart and liver mitochondria were isolated from rats and subjected to oxidative stress with two doses of Adriamycin (5 mg/Kg) 7 days from the beginning of consumption of both alcohol-free and alcohol beer during 31 days. Complexes I and IV and the levels of coenzymes Q9 and Q10 were evaluated and compared with a control group.Liver and heart mitochondria isolated from rats treated with Adryamicin showed a decrease in levels of complex I and complex IV enzymatic activity and in levels of coenzymes Q9 and Q10. Beer intake for itself does not affect any of the studied parameters. Therefore, the consumption of both alcohol and alcohol-free beer by rats treated with Adriamycin prevents the inhibition of enzymatic activities of complexes I and IV and the oxidation of coenzymes Q9 and Q10 in rat heart and liver mitochondria.These results indicate that alcohol-free beer prevents adriamycin-induced damage to mitochondrial chain components and, therefore, helps to prevent mitochondrial dysfunction.
Keywords: Alcohol-free beer; Adriamycin; Mitochondrial enzymes; Coenzymes Q

Dietary intake and plasma concentrations of PUFA and LC-PUFA in breastfed and formula fed infants under real-life conditions by Jana Schwartz; Claudia Drossard; Katharina Dube; Frank Kannenberg; Clemens Kunz; Hermann Kalhoff; Mathilde Kersting (189-195).
The breastfed infant is usually used as standard for formula feeding, also regarding long-chain polyunsaturated fatty acids (LC-PUFA). Here, plasma fatty acid concentrations in formula fed infants and the effects of LC-PUFA supplementation were investigated under real-life conditions.Term healthy infants being fully milk fed until the age of 4 months were categorized as breast milk “BM” (n = 73) if consuming >95% of energy from breast milk or formula (F) if consuming >95% of energy from formula subdivided into formula without (F−) (n = 15) and with LC-PUFA supplementation (F+) (n = 15). Formula as marketed was chosen by the parents. Dietary fatty acids (FA) intake was calculated from continuous dietary records from 2 months of age onwards. Total plasma FA were analyzed at the age of 4 months with docosahexaenoic acid (DHA) as primary outcome.Dietary ratios of the polyunsaturated fatty acids (PUFA; linoleic acid/alpha-linolenic acid) were smaller in both F groups than in the BM group. Plasma DHA as % of total FA was similar in BM and F(+) but higher in BM in absolute amounts (mg/L). Plasma DHA as % of total FA in F(−) was higher than what might be supposed on the basis of dietary intake.Infants consuming present-day LC-PUFA-supplemented formula achieved plasma LC-PUFA concentrations similar to breastfed infants. In infants consuming non-LC-PUFA-supplemented formula, the favorable PUFA pattern of the formula may have supported n-3 LC-PUFA biosynthesis.
Keywords: LC-PUFA; PUFA; Biomarkers; Breast milk; Formula