Patrizia Risé

Docosahexaenoic acid supplementation decreases liver fat content in children with non-alcoholic fatty liver disease: double-blind randomised controlled clinical trial

Objective To investigate whether dietary supplementation with docosahexaenoic acid (DHA) decreases liver fat content in children with non-alcoholic fatty liver disease (NAFLD). Design, setting and patients We performed a randomised controlled trial of DHA supplementation (250 and 500 mg/day) versus placebo in 60 children with biopsy-proven NAFLD (20 children per group). Main outcome measures The main outcome was the change in liver fat content as detected by ultrasonography after 6 months of treatment. Secondary outcomes were the changes in insulin sensitivity index, alanine transaminase, triglycerides and body mass index after 6 months of treatment. Results Blood DHA increased in children supplemented with DHA (0.65%, 95% CI 0.30% to 1.10% for the DHA 250 mg group and 1.15%, 0.87% to 1.43% for the DHA 500 mg group). The odds of more severe versus less severe liver steatosis after treatment was lower in children treated with DHA 250 mg/day (OR = 0.01, 0.002 to 0.11, p <0.001) and DHA 500 mg/day (OR = 0.04, 0.002 to 0.46, p = 0.01) as compared to placebo but there was no difference between the DHA groups (p = 0.4). Insulin sensitivity index increased and triglycerides decreased to a similar degree in both DHA groups as compared to placebo but there was no effect on alanine transaminase and body mass index. Conclusion DHA supplementation improves liver steatosis and insulin sensitivity in children with NAFLD.

Dietary intake of fish vs. formulations leads to higher plasma concentrations of n−3 fatty acids

The n−3 fatty acids from fish appear to be more efficacious, in terms of cardioprotection, than equivalent amounts provided as capsules. Volunteers were given, for 6 wk, either 100 g/d of salmon, providing 383 mg of EPA and 544 mg of DHA, esterified in glycerol lipids, or 1 or 3 capsules of fish oil/d, providing 150 mg of EPA and 106 mg of DHA or 450 mg of EPA and 318 mg of DHA, as ethyl esters. Further, we reevaluated data from a previous study carried out with the same design, i.e., with 3 and 6 capsules/d of fish oil, providing 1290 and 2580 mg/d EPA and 960 and 1920 mg/d DHA. Marked increments in plasma EPA and DHA concentrations (μg/mg total lipid) and percentages of total fatty acids were recorded at the end of treatment with either n−3 capsules or salmon. Net increments of EPA and DHA in plasma lipids were linearly and significantly correlated with the dose after capsule administration. Further, increments in plasma EPA and DHA concentration after salmon intake were significantly higher than after administration of capsules. The same increments would be obtained with at least two- and ninefold higher doses of EPA and DHA, respectively, if administered with capsules rather than salmon. We provide experimental evidence that n−3 fatty acids from fish are more effectively incorporated into plasma lipids than when administered as capsules and that increments in plasma concentrations of EPA and DHA given as capsules are linearly correlated with their intakes.

Docosahexaenoic acid for the treatment of fatty liver: Randomised controlled trial in children ☆

BACKGROUND AND AIM Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in children. We tested whether dietary supplementation with docosahexaenoic acid (DHA) can decrease liver fat content in children with NAFLD. METHODS AND RESULTS We performed a randomized controlled trial of DHA supplementation (250 mg/day and 500 mg/day) vs. placebo in 60 children with NAFLD (20 children per group). The main outcome was the change in liver fat as detected by ultrasonography after 6, 12, 18 and 24 months of treatment. Secondary outcomes were changes in triglycerides, alanine transaminase (ALT), body mass index (BMI) and homeostasis model assessment of insulin resistance (HOMA). The odds of more severe versus less severe liver steatosis decreased to the same degree at 6 months in children treated with DHA 250 mg/day and DHA 500 mg/day vs. placebo and persisted virtually unmodified for 24 months (OR ≤ 0.02, p ≤ 0.05 for all time points). Triglycerides were lower in the DHA groups than in the placebo group at any time point and ALT was lower in these groups from month 12 onwards. HOMA was lower in the DHA 250 mg group vs. placebo at months 6 and 12. CONCLUSION DHA supplementation improves liver steatosis in children with NAFLD. Doses of 250 mg/day and 500 mg/day of DHA appear to be equally effective in reducing liver fat content.

Very Low Density Lipoprotein–Mediated Signal Transduction and Plasminogen Activator Inhibitor Type 1 in Cultured HepG2 Cells

In normal subjects and in patients with cardiovascular disease, plasma triglycerides are positively correlated with plasminogen activator inhibitor type 1 (PAI-1) levels. Moreover, in vitro studies indicate that VLDLs induce PAI-1 synthesis in cultured cells, ie, endothelial and HepG2 cells. However, the signaling pathways involved in the effect of VLDL on PAI-1 synthesis have not yet been investigated. We report that VLDLs induce a signaling cascade that leads to an enhanced secretion of PAI-1 by HepG2 cells. In myo-[(3)H]inositol-labeled HepG2 cells, VLDL (100 microg/mL) caused a time-dependent increase in [(3)H]inositol phosphates, the temporal sequence being tris>bis>monophosphate. VLDL brought about a time-dependent stimulation of membrane-associated protein kinase C (PKC) activity and arachidonate release. Finally, VLDL stimulated mitogen-activated protein (MAP) kinase, and this effect was reduced by 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H7), which suggests that PKC plays a pivotal role in MAP kinase phosphorylation. VLDL-induced PAI-1 secretion was completely prevented by U73122, a specific inhibitor of phosphatidylinositol-specific phospholipase C, by H7 or by PKC downregulation, and by mepacrine (all P<0.01 versus VLDL-treated cells). 3,4,5-Trimethoxybenzoic acid 8-(diethylamino)-octyl ester, which prevents Ca2+ release from intracellular stores, inhibited VLDL-induced PAI-1 secretion by 60% (P<0.05), and the MAP kinase/extracellular signal-regulated kinase kinase (MEK) inhibitor PD98059 completely suppressed both basal and VLDL-induced PAI-1 secretion. These data demonstrate that VLDL-induced PAI-1 biosynthesis results from a principal signaling pathway involving PKC-mediated MAP kinase activation.

n-3 fatty acid ethyl ester administration to healthy subjects and to hypertriglyceridemic patients reduces tissue factor activity in adherent monocytes.

n-3 Fatty acids are known to influence several functions of monocytes, including adhesion, cytokine synthesis, and superoxide generation. Monocytes express tissue factor, a membrane-bound glycoprotein, that acts as a catalyst in the coagulation cascade. In this study we evaluated the effects of administration of n-3 fatty acid ethyl esters to healthy volunteers and to hypertriglyceridemic patients on tissue factor activity (TF activity) in adherent monocytes. n-3 Fatty acids containing 75% eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (ratio of EPA to DHA, 1.34) were administered (3 g/d) to normal volunteers for 18 weeks. In addition, the effects of this treatment were evaluated in 30 hypertriglyceridemic patients for 24 weeks by using a double-blind, placebo-controlled study. TF activity in adherent monocytes was evaluated with a one-stage clotting assay. Plasma and monocyte fatty acid compositions were determined by gas-liquid chromatography. In healthy volunteers, n-3 fatty acids significantly reduced TF activity in adherent monocytes either in the unstimulated condition or after exposure to endotoxin. The inhibitory effect was observed after 12 weeks of treatment and was more pronounced after 18 weeks (> 70%, P < .001 versus baseline). Concomitantly, levels of EPA and DHA increased in plasma and monocyte lipids. Interestingly, after stopping treatment, monocyte TF activity remained inhibited for at least 14 weeks. Treatment with n-3 fatty acids for 24 weeks also resulted in a significant reduction of TF activity in adherent monocytes from hypertriglyceridemic patients (-31% and -40% in unstimulated and endotoxin-stimulated cells; P < .05 versus baseline).(ABSTRACT TRUNCATED AT 250 WORDS)

Fish consumption, omega 3 fatty acids and cardiovascular disease. The science and the clinical trials.

Fats in fish and marine animals are rich in highly unsaturated fatty acids (FA with 5 or more double bonds) of the Omega 3 series. These FA, present in aquatic animals as an adaptation to the environmental conditions, reached the human diet through the food chain, with a significant impact on nutrition, life style and cultural conditions. Studies in the 70s showed that high fish consumption is associated with better cardiovascular health and this observation was subsequently confirmed in many studies (epidemiological, cohort, case-control). The evidence is stronger for secondary prevention and when the intakes of fish or omega 3 FA are assessed, rather than just estimated. The major effects are reduction of cardiac, especially sudden, death. Underlying mechanisms concern the antiarrhythmic activities, reduction of thrombotic and inflammatory processes and of serum triacylglycerol levels. In conclusion consumption of fish and its components should be promoted on a global scale especially in the case of subjects with cardiovascular problems. Although still some issues need to be faced especially in large scale interventions (Le. the assessment of the omega 3 fatty acid status, correlations between levels and cardiovascular indexes and bioavailability of different forms of administration), these recommendations are highly valuable.

Differences in Fatty Acid Composition between Aquatic and Terrestrial Insects Used as Food in Human Nutrition

Edible insects may be a source of long-chain polyunsaturated fatty acids (LC-PUFA). The aim of this article is to test for differences in aquatic and terrestrial insects used in human nutrition. We implemented linear models and discovered that differences in the proportion of LC-PUFA between aquatic and terrestrial insects do exist, with terrestrial insects being significantly richer in particular omega-6 fatty acids. In conclusion, any kind of insect may provide valuable sources of LC-PUFA. Because terrestrial insects are more abundant and easier to collect, they can be considered a better source of LC-PUFA than aquatic ones.

Maternal smoking habits are associated with differences in infants’ long-chain polyunsaturated fatty acids in whole blood: a case-control study

Objective: To study the effects of maternal smoking on the status of long-chain polyunsaturated fatty acids (LCPUFA) in infants’ whole-blood lipids. Design: A case-control matched study planned on the basis of preliminary observations. Setting: Maternity ward. Patients: A total of 159 healthy, term, breastfed infants with weight appropriate for gestational age, subdivided (53 per group) into those born to non-smokers (reference), smokers (⩾5 cigarettes per day) who either stopped within the first trimester of pregnancy (early smokers) or who continued througout pregnancy (late smokers). Interventions: The fatty acid profile of 4-day-old infants was determined on whole blood. Results: Higher levels of linoleic (LA) and alpha-linolenic acid (ALA) and lower levels of the metabolic products di-homo-gammalinolenic (DHGLA) and arachidonic (AA), of the n-6 series, and docosahexaenoic acid (DHA), of the n-3 series, were found in infants born to late smokers compared with the reference group. The DHGLA/LA and AA/DHGLA ratios in the n-6 series and DHA/ALA in the n-3 series, which are indices of the metabolic processes in LCPUFA synthesis, were lower in infants born to smokers compared with those born to non-smokers. Infants born to early smokers showed n-6 PUFA levels and ratios similar to references and n-3 parameters closer to those born to late smokers. No dietary differences were found among the three groups of mothers. All the independent associations with smoking persisted after adjustment for maternal covariates. Pre-pregnancy body weight, which is lower in late smokers compared with non-smokers, independently correlated with LCPUFA levels in both series. Conclusions: Maternal smoking is associated with a reduction in LCPUFA pools in infants, which might have structural and functional consequences.

n-6 and n-3 fatty acid accumulation in thp-1 cell phospholipids.

The human monocytic leukemia cell line THP-1 is depleted of the long-chain n-6, AA, when compared to human monocytes. This reflects the low availability of this FA in the growth medium generally used for cultured cells. The effects of AA, as well as EPA, supplementation of THP-1 cells on the incorporation of these FA in cell PL, especially in PC and PE, was investigated. In addition the incorporation of labeled AA in PL from THP-1 cells was compared to that in human monocytes. Measurements were done through HPLC separation of PL, detected by UV absorption and radioactivity, FA analysis by GC and characterization of PC subclasses by FAB-MS. Marked differences were observed in the incorporation of the two FA in cell PL, particularly two PC subclasses, and in the accumulation in individual PL after supplementation of THP-1 cells. Accumulation of AA and EPA in THP-1 cells appeared to be mutually independent. The incorporation of AA was also quite different in THP-1 from that in monocytes. Thus, characterization of the FA content in lipids of cultured cells is an essential requirement for optimal utilization of these cells.

Whole blood fatty acid composition at birth: From the maternal compartment to the infant

BACKGROUND & AIMS The biological role of fatty acids (FA) in the perinatal period is under active investigation. We here describe the application of a simplified microanalytical procedure to compare the FA profile of maternal, umbilical cord and infant whole blood, inclusive of all circulating lipid fractions and cells. METHODS The FA composition has been analyzed with a micromethod in 16 triplets, including maternal blood, cord blood at delivery and infant blood at day 4, respectively. RESULTS As expected, the FA composition of blood samples withdrawn from the umbilical cord is more similar to the FA composition of blood from 4-day old infants than the FA pattern of maternal blood at delivery. Nevertheless, infant blood FA profile differed from cord for lower long-chain polyunsaturated FA and higher monounsaturated FA. CONCLUSIONS Our explorative data using whole blood microanalysis confirm the progressive increase of long-chain polyunsaturated FA levels from the mothers towards cord and then infant blood.