Search

BACKGROUND Intensification of organic dairy production leads to the question of whether the implementation of intensive feeding incorporating maize silage and concentrates is altering milk quality. Therefore the fatty acid (FA) and antioxidant (AO) profiles of milk on 24 farms divided into four system groups in three replications (n = 71) during the outdoor period were analyzed. In this system comparison, a differentiation of the system groups and the effects of the main system factors ‘intensification level’ (high-input versus low-input) and ‘origin’ (organic versus conventional) were evaluated in a multivariate statistical approach. RESULTS Consistent differentiation of milk from the system groups due to feeding-related impacts was possible in general and on the basis of 15 markers. The prediction of the main system factors was based on four or five markers. The prediction of ‘intensification level’ was based mainly on CLA c9,t11 and C18:1 t11, whereas that of ‘origin’ was based on n-3 PUFA. CONCLUSION It was possible to demonstrate consistent differences in the FA and AO profiles of organic and standard conventional milk samples. Highest concentrations of nutritionally beneficial compounds were found in the low-input organic system. Adapted grass-based feeding strategies including pasture offer the potential to produce a distinguishable organic milk product quality. © 2014 Society of Chemical Industry

Dietary supplementation with echium oil (EO) containing stearidonic acid (SDA) is a plant-based strategy to improve long-chain (LC) n-3 (ω-3) polyunsaturated fatty acid (PUFA) status in humans. We investigated the effect of EO on LC n-3 PUFA accumulation in blood and biochemical markers with respect to age, sex, and metabolic syndrome. This double-blind, parallel-arm, randomized controlled study started with a 2-wk run-in period, during which participants (n = 80) were administered 17 g/d run-in oil. Normal-weight individuals from 2 age groups (20-35 and 49-69 y) were allotted to EO or fish oil (FO; control) groups. During the 8-wk intervention, participants were administered either 17 g/d EO (2 g SDA; n = 59) or FO [1.9 g eicosapentaenoic acid (EPA); n = 19]. Overweight individuals with metabolic syndrome (n = 19) were recruited for EO treatment only. During the 10-wk study, the participants followed a dietary n-3 PUFA restriction, e.g., no fish. After the 8-wk EO treatment, increases in the LC n-3 metabolites EPA (168% and 79%) and docosapentaenoic acid [DPA (68% and 39%)] were observed, whereas docosahexaenoic acid (DHA) decreased (-5% and -23%) in plasma and peripheral blood mononuclear cells, respectively. Compared with FO, the efficacy of EO to increase EPA and DPA in blood was significantly lower (∼25% and ∼50%, respectively). A higher body mass index (BMI) was associated with lower relative and net increases in EPA and DPA. Compared with baseline, EO significantly reduced serum cholesterol, LDL cholesterol, oxidized LDL, and triglyceride (TG), but also HDL cholesterol, regardless of age and BMI. In the FO group, only TG decreased. Overall, daily intake of 15-20 g EO increased EPA and DPA in blood but had no influence on DHA. EO lowered cardiovascular risk markers, e.g., serum TG, which is particularly relevant for individuals with metabolic syndrome. Natural EO could be a noteworthy source of n-3 PUFA in human nutrition.

Background Alterations in brain structure are among the most robust biological findings in schizophrenia. Also changes in fatty acid profiles including reduced levels of polyunsaturated fatty acids (PUFA) are well replicated in schizophrenia. Being essential for neurodevelopmental processes and structural plasticity and remodeling, alterations of PUFA metabolism might be also associated with the occurrence of brain structural abnormalities. To investigate this assumption in vivo we examined the interrelation of PUFA profiles and brain structure in neuroleptic naïve first-episode psychosis (FEP) patients and healthy controls (HC) matched for age and gender. Methods High-resolution T1-weighted 3T MRI were acquired from 29 FEP patients (age 26.4 ± 5.3y; 13 females/16 males) and 31 HC (age 25.1 ± 4.7y; 14 f/17 m). Fatty acid profiles were analyzed using gas chromatography in the plasma phospholipid (PL) fraction that is rather independent of recent fat consumption, and that potentially indicates PUFA availability in phospholipid structural components essential in the brain. To investigate brain structural abnormalities in FEP and effects of illness on interactions between fatty acid profiles and local grey (GM) or white (WM) matter density, voxel-based morphometry (VBM) with the computational anatomy toolbox (CAT12) was used. Results VBM analyses revealed a reduction of GM in FEP in left frontal operculum, left middle frontal gyrus, left superior frontal gyrus and bilateral temporal gyrus (TFCE, FWE HC. For MCFA interaction analyses revealed effects of illness on associations with GM density in the bilateral superior medial frontal gyrus and left anterior cingulate gyrus with a regression slope HC > FEP patients. Discussion Our results support the notion that the availability of PUFA and MCFA potentially affects brain structural development and remodeling. They also support the notion of PUFA and phospholipids metabolism as a biochemical basis to create early prevention and intervention strategies, e.g. by PUFA supplementation.

Various plant seeds have received little attention in fatty acid research. Seeds from 30 species mainly of Boraginaceae and Primulaceae were analysed in order to identify potential new sources of the n-3 PUFA α-linolenic acid (ALA) and stearidonic acid (SDA) and of the n-6 PUFA γ-linolenic acid (GLA). The fatty acid distribution differed enormously between genera of the same family. Echium species (Boraginaceae) contained the highest amount of total n-3 PUFA (47.1%), predominantly ALA (36.6%) and SDA (10.5%) combined with high GLA (10.2%). Further species of Boraginaceae rich in both SDA and GLA were Omphalodes linifolia (8.4, 17.2%, resp.), Cerinthe minor (7.5, 9.9%, resp.) and Buglossoides purpureocaerulea (6.1, 16.6%, resp.). Alkanna species belonging to Boraginaceae had comparable amounts of ALA (37.3%) and GLA (11.4%) like Echium but lower SDA contents (3.7%). Different genera of Primulaceae (Dodecatheon and Primula) had varying ALA (14.8, 28.8%, resp.) and GLA portions (4.1, 1.5%, resp.), but similar amounts of SDA (4.9, 4.5%, resp.). Cannabis sativa cultivars (Cannabaceae) were rich in linoleic acid (57.1%), but poor in SDA and GLA (0.8, 2.7%, resp.). In conclusion, several of the presented plant seeds contain considerable amounts of n-3 PUFA and GLA, which could be relevant for nutritional purposes due to their biological function as precursors for eicosanoid synthesis. Practical applications N-3 PUFA are important for human health and nutrition. Unfortunately, due to the increasing world population, overfishing of the seas and generally low amounts of n-3 PUFA in major oil crops, there is a demand for new sources of n-3 PUFA. One approach involves searching for potential vegetable sources of n-3 PUFA; especially those rich in ALA and SDA. The conversion of ALA to SDA in humans is dependent on the rate-limiting Δ6-desaturation. Plant-derived SDA is therefore a promising precursor regarding the endogenous synthesis of n-3 long-chain PUFA in humans. The present study shows that, in addition to seed oil of Echium, other species of Boraginaceae (Cerinthe, Omphalodes, Lithospermum, Buglossoides) and Primulaceae (Dodecatheon, Primula), generally high in n-3 PUFA (30–50%), contain considerable amounts of SDA (5–10%). Therefore, these seed oils could be important for nutrition.

To determine trans fatty acid (TFA) distribution of contemporary foods, especially regarding individual trans octadecenoic acids (trans C18:1), 339 German foods of six categories (semi-solid fats, deep-fried potato products, bakery products, confectioneries, instant products and butter) were analysed using two GC methods. Results showed a high variation of TFA content between and within the categories containing between 0 and 40.5% of FAME except in butter, which is a source of natural TFA. The mean TFA values were below 2.0% of FAME, however, bakery products contained 4.5% and butter fat 3.2%, respectively. In addition, the distribution of individual trans C18:1 differed. In samples containing ruminant fat (butter and various confectioneries), vaccenic acid (t11-C18:1, t11) predominated, while in foods containing industrially hydrogenated fats, elaidic acid (trans-9, t9-) and t10-C18:1 were the major trans isomers.. This was reflected by a low t9/t11 index of 0.3 and 0.5 in butter and ruminant fat containing confectioneries, respectively, whilst the highest index was observed in shortenings and deep-fried potato products at 5.2 and 6.8, respectively. In conclusion, the TFA content of foods available on the German market is generally declining, but substantial variations are present. The t9/t11 index could be used as an indicator to determine ruminant fat. Practical applications: A number of studies provide evidence that a high TFA intake, particularly of industrial origin, adversely affects human health. The TFA content of foods could be reduced due to the introduction of several mandatory regulations and modifications regarding the hydrogenation process of oils. The most abundant dietary TFA are the isomers of trans C18:1. Unfortunately, the differentiation of these isomers is not yet very common, though the trans C18:1 profile differs depending on its origin (bacterial hydrogenation in the rumen or industrial hydrogenation). To date, data for TFA content including the trans C18:1 profile of different food categories are limited. The present study confirmed that the TFA contents in German foods are declining. However, TFA are still elevated, especially in bakery products and confectioneries, which are produced using mainly industrial but also ruminant fats. Therefore, the t9/t11 index imparts important information on the source of TFA in processed foods.

We analyzed a triacylgylcerol esterified CLA preparation characteristically rich in c9,t11-CLA and free of t10,c12-CLA three times within a period of 2½ years by GC and silver ion-HPLC. For the first time, we present data on the long-term stability of this preparation with regard to the fatty acid profile and the isomeric composition of CLA under certain storage conditions, providing useful information for the planning of long-term trials.

Background Alterations of polyunsaturated fatty acid (PUFA) levels are a well-replicated finding in schizophrenia research. There is however a controversy about the origin of this abnormality and its importance in the pathogenesis of schizophrenic illness. To investigate the influence of nutrition, in this study we investigate different aspects of fatty acid metabolization in a cohort of neuroleptic naïve first-episode schizophrenia patients (FEP) and a group of healthy controls (HC) matched for age and gender. Methods In 33 FEP (25.8 ± 4.8y, male 60.6% 20/33) and 32 HC (24.9 ± 4.6y, male 53.1% 17/32) fatty acid profile was investigated by gas chromatography in blood plasma lipids of the triacylglycerol (TAG) fraction (closely related to fat consumption within recent days, rich in SFA, MUFA (~50%), and LA (C18:2n6)), the cholesterol ester (CE) fraction (dependent on fat consumption within recent days, rich in LA (C18:2n6)(~51%), SFA and PUFA), and the plasma phospholipid (PL) fraction (reflecting fat consumption of the last weeks to month, rich in SFA (~50%), AA (~7%), and LA (C18:2n6). In erythrocyte membranes (sensitive to fat consumption within weeks to month), fatty acid profile was investigated in phospholipids of the phosphoethanolamin (PE) fraction (rich in PUFA (~45%), AA (C20:4n6) and SFA) and of the sphingomyelin (SM) fraction (rich in long chain SFA (>70%) and MUFA (including NA C24:1c15). Psychopathology was assessed using the PANSS, BPRS-E and SCL-90-R ratings. Statistical analysis included multi- and univariate ANOVA, non-parametric tests and correlation analysis. Results In the plasma PL fraction and in the lipid fractions of erythrocyte membranes (PE, SM) that are less influenced by recent nutrition, patients showed generally reduced omega-6 PUFA levels, particularly in terms of AA in the SM fraction. While PUFA of the PL and PE fraction were positively correlated in HC, this was not the case in the FEP group. Discussion Our results support the previous finding of a general omega-6 PUFA deficit in FEP. The decrease points towards an endogenous regulation deficit that is independent of recent nutrition, might affect the metabolism of grey and white matter structural components, and could cause alterations of AA downstream functions. While correlation analysis in HC strongly suggests that nutrition and supplementation have the potential to influence PUFA availability, inner transport and metabolization pathways seem to be disturbed in FEP.

Individual isomers of octadecadienoic acid (C18:2) with conjugated double bonds (conjugated linoleic acids; CLA) exert different biological activities. Their distribution in food and tissues differs. Therefore, the separation of the various positional and geometric isomers is important. The time of analysis using silver ion-high performance liquid chromatography can extend up to 90 min. The aim of this study was to reduce this time. The time of analysis reduced from ca. 90 min onto 45 to 35 min, respectively, by the addition of 0.05% or 0.1% (v/v) 2-propanol to the mobile phase [acetonitrile (0.1%; v/v) and diethyl ether (0.5%; v/v) in n-hexane]. There was no effect on resolution of the 17 individual CLA isomers of the CLA mixture. Regarding the lowest coefficient of variation and an adequate baseline separation the use of 0.05% 2-propanol in the mobile phase is recommended, without any disadvantages and adverse effects on the service life of columns. In conclusion, adding 0.05% or 0.1% 2-propanol to the mobile phase shortens the time of analysis of CLA isomers, saves solvents and reduces costs.

Gene-by-diet interactions play an important role in the prevention of several diseases. Conjugated linoleic acids (CLA) are ligands of gene regulators [e.g. peroxisome proliferator-activated receptors (PPAR)] and have anti-inflammatory properties. The aim of the study was to investigate the changes in gene expression in monocytes during the intervention with two trans fatty acids (trans-11 18:1 and trans-12 18:1) and endogenous CLA from trans-11 18:1 as precursor in humans. Monocytes were isolated at baseline and after a 6-week intervention period. The female and male test groups received S6.0 g trans-11 and trans-12 18:1/ day (1 : 1). The control group received control oil. The expression of candidate genes was determined by quantitative RT-PCR. Gender- and treatment-related gene expression was found. Due to trans fatty acid intake in both gender subgroups, the relative PPARg expression was up-regulated. In the female test group, the expression of FAT, SCD, COX2 and BCL2 were induced, while in the male test group E-FABP, CYP, GLUT4 and PBE were induced. In the male test group compared to controls, a clear increase in gene expression of PPARg and GLUT4 was shown. The results reveal a gender- and treatment-related gene expression. There is no clear indication as to what extent the supplemented trans fatty acids and the synthesized cis-9,trans-11 CLA were involved.

Trans-fatty acid intake is associated with an increased risk of CHD and diabetes. The effects of singletrans-fatty acid isomers are largely unexplored. The present study examined the effects of a 6-week supplementation with twotrans-18 : 1 isomers (trans-11 andtrans-12) in human subjects on immune cells, several inflammatory and immunological biomarkers (for example, IL, TNFα, C-reactive protein, adiponectin, intercellular adhesion molecule-1, prostacyclin, phagocytic process). Following a 2-week adaptation period without supplements, the test group (n12) received vaccenic acid (trans-11-18:1) andtrans-12-18 : 1 in equal amounts (6·0 g/d) for 6 weeks. The control group (n12) consumed an oil withouttrans-fatty acids and conjugated linoleic acids (CLA). Samples were collected at the end of both periods.Trans-11- andtrans-12-18 : 1 were significantly increased in cellular lipids. The endogenous synthesis ofcis-9,trans-11-CLA fromtrans-11-18 : 1 was demonstratedviaincreased CLA in cellular lipids of the test group. Generally,trans-isomer supplementation did not affect either inflammatory biomarkers (for example, IL-6, IL-8, TNFα) or immune function (for example, phagocytosis) during the present study. The dietary supplementation oftrans-11- andtrans-12-18 : 1 (6 g/d) and their accumulation in leucocytes had no effects on biomarkers of inflammation and immune function. However, because of the limited data on the safety oftrans-fatty acid intake and effects of individualtransisomers on human health (for example,trans-9-18 : 1,trans-10-18 : 1) at present, it is prudent to reducetrans-fat intake in general.

A plant-based strategy to improve long-chain (LC) omega (n)-3 PUFA supply in humans involves dietary supplementation with oils containing α-linolenic acid (ALA) alone or in combination with stearidonic acid (SDA). The study aimed to compare the effects of echium oil (EO) and linseed oil (LO) on LC n-3 PUFA accumulation in blood and on clinical markers. In two double-blind, parallel-arm, randomized controlled studies, all volunteers started with 17 g/d run-in oil (2 weeks). Thereafter, subjects received diets enriched in study 1 with EO (5 g ALA + 2 g SDA; n = 59) or in study 2 with LO (5 g ALA; n = 59) daily for 8 weeks. The smaller control groups received fish oil (FO; n = 19) or olive oil (OO; n = 18). Participants were instructed to restrict their dietary n-3 PUFA intake throughout the studies (e.g., no fish). To investigate the influence of age and BMI on the conversion of ALA and SDA as well as clinical markers, the subjects recruited for EO and LO treatment were divided into three subgroups (two age groups 20–35 y; 49–69 y with BMI 18–25 kg/m2 and one group with older, overweight subjects (age 49–69 y; BMI >25 kg/m2). In plasma, red blood cells (RBC), and peripheral blood mononuclear cells (PBMC), EPA and docosapentaenoic acid (DPA) were ~25 % higher following EO compared to LO. Comparing all treatments, the effectiveness of increasing EPA and DPA in plasma, RBC, and PBMC was on average 100:25:10:0 and 100:50:25:0 for FO:EO:LO:OO, respectively. EO led to a lower arachidonic acid/EPA-ratio compared to LO in plasma, RBC, and PBMC. Following EO, final DHA was not greater compared to LO. Higher BMI correlated negatively with increases in plasma EPA and DPA after EO supplementation, but not after LO supplementation. Decreasing effect on plasma LDL-C and serum insulin was greater with EO than with LO. Daily intake of SDA-containing EO is a better supplement than LO for increasing EPA and DPA in blood. However, neither EO nor LO maintained blood DHA status in the absence of fish/seafood consumption. ClinicalTrials.gov Reg No. NCT01856179 ; ClinicalTrials.gov Reg No. NCT01317290 .

The definition and evaluation of trans fatty acids (TFA) with regard to foodstuffs and health hazard are not consistent. Based on the current situation, the term should be restricted only to TFA with isolated double bonds in trans-configuration. Conjugated linoleic acids (CLA) should be separately assessed. Ideally, the origin of the consumed fat should be declared, i.e., ruminant TFA (R-TFA) and industrial TFA (non-ruminant; I-TFA). In ruminant fat, more than 50% of R-TFA consists of vaccenic acid (C18:1 t11). In addition, natural CLA, i.e., c9,t11 CLA is also present. Both are elevated in products from organic farming. In contrast to elaidic acid (t9) and t10, which occur mainly in partially hydrogenated industrial fat, t11 is partially metabolized into c9,t11 CLA via Δ9-desaturation. This is the major metabolic criterion used to differentiate between t11 and other trans C18:1. t11 indicates health beneficial effects in several studies. Moreover, CLA in milk fat is associated with the prevention of allergy and asthma. An analysis of the few studies relating to R-TFA alone makes clear that no convincing adverse physiological effect can be attributed to R-TFA. Only extremely high R-TFA intakes cause negative change in blood lipids. In conclusion, in most European countries, the intake of R-TFA is assessed as being low to moderate. Restriction of R-TFA would unjustifiably represent a disadvantage for organic farming of milk.

Background: High consumption of trans fat has been associated with high oxidative stress in humans, which could increase the risk of the development or acceleration of several diseases, such as atherosclerosis, cancer, and type 2 diabetes. Objective: Several urinary and blood biomarkers of oxidative stress [8-iso-prostaglandin-F2(alpha) (PGF(2 alpha)), 15-keto-dihydro-PGF(2 alpha), and 7,8-dihydro-8-oxo-2'-deoxy-guanosine in urine and alpha-, beta, gamma-, delta-tocopherol, and retinol in plasma] were monitored to evaluate the oxidative stress induced by dietary supplementation of 11trans- and 12trans-18:1 isomers in humans during a 6-wk intervention. Design: After a 14-d adaptation period free of trans fatty acid supplementation (baseline), the test group (n = 12) received 3.0 g 11trans-18:1/d and 3.0 g 12trans-18:1/d (Sigma 6.0 g/d), and the control group (n = 12) consumed a control oil free of trans fatty acids and conjugated linoleic acids for 6 wk. Results: The postintervention concentration of urinary 8-iso-PGF(2 alpha) (free radical-induced lipid peroxidation) in the test group was significantly higher than baseline and significantly higher than that observed in the control group. The concentrations of 15-ketodihydro-PGF(2 alpha) (cyclooxygenase-mediated inflammatory response indicator) and 7,8-dihydro-8-oxo-2'-deoxy-guanosine (oxidative DNA damage) were not affected by the 11trans- and 12trans-18:1 supplementation. Conclusions: Although an increase in urinary 8-iso-PGF(2 alpha) was observed and the effects of prolonged high (ie, > 5.0 g/d) consumption of trans fat could be relevant to the development of disease, the mean intakes of 11trans- and 12trans-18:1 in Europeans are estimated to be significantly below the amounts administered in this study (ie, 6.0 g/d); such low intakes could minimize the possible risk of detrimental effects on human health.

The fatty acids contained in marine oils or products are traditionally analyzed by gas chromatography using capillary columns coated with polyethylene glycol phases. Recent reports indicate that 100 % cyanopropyl siloxane phases should also be used when the analyzed samples contain trans fatty acids. We investigated the separation of the fatty acid methyl esters prepared from menhaden oil using the more polar SLB-IL111 (200 m × 0.25 mm) ionic liquid capillary column and the chromatographic conditions previously optimized for the separation of the complex mixture of fatty acid methyl esters prepared from milk fat. Identifications of fatty acids were achieved by applying Ag(+)-HPLC fractionation and GC-TOF/MS analysis in CI(+) mode with isobutane as the ionization reagent. Calculation of equivalent chain lengths confirmed the assignment of double bond positions. This methodology allowed the identification of 125 fatty acids in menhaden oil, including isoprenoid and furanoid fatty acids, and the novel 7-methyl-6-hexadecenoic and 7-methyl-6-octadecenoic fatty acids. The chromatographic conditions applied in this study showed the potential of separating in a single 90-min analysis, among others, the short chain and trans fatty acids contained in dairy products, and the polyunsaturated fatty acids contained in marine products.

Background The imbalance of the n-3/n-6 ratio in the Western diet is characterised by a low intake of n-3 long-chain (LC) PUFA and a concurrent high intake of n-6 PUFA. Fish, in particular marine fish, is a unique source of n-3 LC PUFA. However, FA composition of consumed fish changed, due to the increasing usage of n-6 PUFA-rich vegetable oils in aquaculture feed and in fish processing (frying) which both lead to a further shift in n-6 PUFA to the detriment of n-3 LC PUFA. The aim of this study was to determine the ratio of n-3/n-6 including the contents of EPA and DHA in fish fillets and fish products from the German market (n=123). Furthermore, the study focussed on the FA content in farmed salmon compared to wild salmon as well as in processed Alaska pollock fillet, e.g., fish fingers. Results Total fat and FA content in fish products varied considerably depending on fish species, feed management, and food processing. Mackerel, herring and trout fillets characteristically contained adequate dietary amounts of absolute EPA and DHA, due to their high fat contents. However, despite a lower fat content, tuna, pollock, and Alaska pollock can contribute considerable amounts of EPA and DHA to the human supply. Farmed salmon are an appropriate source of EPA and DHA owing to their higher fat content compared to wild salmon (12.3 vs. 2.1 wt %), however with elevated SFA, n-9 and n-6 FA contents representing the use of vegetable oils and oilseeds in aquaculture feed. The n-3/n-6 ratio was deteriorated (2.9 vs. 12.4) but still acceptable. Compared to pure fish fillets, breaded and pre-fried Alaska pollock fillet contained extraordinarily high fat and n-6 PUFA levels. Conclusions Since fish species vary with respect to their n-3 LC PUFA contents, eating a variety of fish is advisable. High n-6 PUFA containing pre-fried fish support the imbalance of n-3/n-6 ratio in the Western diet. Thus, consumption of pure fish fillets is to be favoured. The lower n-3 PUFA portion in farmed fish can be offset by the higher fat content, however, with an unfavourable FA distribution compared to wild fellows.

Background Increasing land restrictions and a reduced livestock-to-human ratio during the 20th century led the Maasai to lead a more sedentary, market-orientated lifestyle. Although plant-derived food nowadays contributes substantially to their diet, dairy products being high in saturated fatty acids (SFA) and low in polyunsaturated fatty acids (PUFA) still are an important energy source. Since reliable data regarding the Maasai diet date back to the 1980s, the study objective was to document current diet practices in a Kenyan Maasai community and to investigate the fatty acid distribution in diet and red blood cells. Methods A cross-sectional study was conducted among 26 Maasai (20 women, 6 men) from Loodokilani, Kajiado District, Kenya. Food intake was described by the subjects via 24-h recall, and both food and blood samples were analysed. Results Two main foods - milk and ugali - constituted the Maasai diet in this region. A total of 0.9 L of milk and 0.6 kg of ugali were consumed per person and day to yield an energy intake of 7.6 MJ/d per person. A major proportion of ingested food contributing 58.3% to the total dietary energy (en%) was plant-derived, followed by dairy products representing 41.1 en%. Fat consumed (30.5 en%) was high in SFA (63.8%) and low in PUFA (9.2%). Long-chain n-3 PUFA (EPA, DPA and DHA) made up only 0.15% of the ingested fatty acids, but 5.9% of red blood cell fatty acids. Conclusion The study indicates the Maasai diet is rich in SFA and low in PUFA. Nevertheless, red blood cells are composed of comparable proportions of long-chain n-3 PUFA to populations consuming higher amounts of this fatty acid group.

Background To date, the influence of milk and dairy products on carcinogenesis remains controversial. However, lipids of ruminant origin such as conjugated linoleic acids (CLA) are known to exhibit beneficial effects in vitro and in vivo. The aim of the present study was to determine the influence of milk lipids of different origin and varying quality presenting as free fatty acid (FFA) solutions on cellular fatty acid distribution, cellular viability, and growth of human colon adenocarcinoma cells (HT-29). Methods FAME of conventional and Alpine milk lipids (MLcon, MLalp) and cells treated with FFA derivatives of milk lipids were analyzed by means of GC-FID and Ag+-HPLC. Cellular viability and growth of the cells were determined by means of CellTiter-Blue®-assay and DAPI-assay (4',6-diamidino-2-phenylindole dihydrochloride), respectively. Results Supplementation with milk lipids significantly decreased viability and growth of HT-29 cells in a dose- and time-dependent manner. MLalp showed a lower SFA/MUFA ratio, a 8 fold increased CLA content, and different CLA profile compared to MLcon but did not demonstrate additional growth-inhibitory effects. In addition, total concentration and fatty acid distribution of cellular lipids were altered. In particular, treatment of the cells yielded highest amounts of two types of milk specific major fatty acids (μg FA/mg cellular protein) after 8 h of incubation compared to 24 h; 200 μM of MLcon (C16:0, 206 ± 43), 200 μM of MLalp (C18:1 c 9, (223 ± 19). Vaccenic acid (C18:1 t 11) contained in milk lipids was converted to c 9,t 11-CLA in HT-29 cells. Notably, the ratio of t 11,c 13-CLA/t 7,c 9-CLA, a criterion for pasture feeding of the cows, was significantly changed after incubation for 8 h with lipids from MLalp (3.6 - 4.8), compared to lipids from MLcon (0.3 - 0.6). Conclusions Natural lipids from conventional and Alpine milk showed similar growth inhibitory effects. However, different changes in cellular lipid composition suggested a milk lipid-depending influence on cell sensitivity. It is expected that similar changes may also be evident in other cell lines. To our knowledge, this is the first study showing a varied impact of complex milk lipids on fatty acid distribution in a colon cancer cell line.

The aim of this human intervention study was to evaluate the Δ9-desaturation oftrans-11–18:1 (trans-vaccenic acid;tVA) tocis-9,trans-11–18:2 (c9,t11 conjugated linoleic acid; CLA) and oftrans-12–18:1 (t12) tocis-9,trans-12–18:2 after a short-term (7d) and a long-term (42d) supplementation period. The conversion rates of bothtrans-18:1 isomers were estimated by lipid analysis of serum and red blood cell membranes (RBCM). Subjects started with a 2-week adaptation period without supplements. During the 42d intervention period, the diet of the test group was supplemented with 3g/d oftVA and 3g/d oft12. The diet of the control group was supplemented with a control oil. SerumtVA andt12 levels in the test group increased by fivefold and ninefold after 7d, respectively, and by eight- and 12-fold after 42d, respectively, when compared with the adaptation period (p≤0·002). The serumc9,t11CLA levels increased by 1·7- and 2·0-fold after 7d and 42d, respectively (p≤0·001). After 42d, the test group's RBCMc9,t11CLA content was elevated by 20% (p=0·021), whereas in the control group it was decreased by 50% (p=0·002). The conversion rate oftVA was estimated at 24% by serum and 19% by RBCM. No increase inc9,t12–18:2 was observed in the serum and RBCM, and thus no conversion oft12 could be determined. In conclusion, the endogenous conversion of dietarytVA toc9,t11CLA contributes approximately one quarter to the human CLA pool and should be considered when determining the CLA supply.

Background/objective : An adequate supply of long-chain polyunsaturated fatty acids (LC PUFA) promotes foetal health and development, whereas generally, trans fatty acids ( t FA) are considered to negatively interfere with LC PUFA metabolism. Nevertheless, to date, limited data concerning separate trans C18:1, such as t 9 and t 11, are available for maternal and foetal blood. Therefore, in this study the portions of individual trans C18:1, LC n-6, and n-3 PUFA in lipids of maternal and foetal plasma and erythrocyte membranes of German mother and child pairs ( n= 40) were analysed. Results : Portions of linoleic acid and α-linolenic acid as LC precursors were lower (~0.4-fold); whereas the metabolites arachidonic acid (AA, n-6) and docosahexaenoic acid (DHA, n-3) were significantly higher (~2-fold) in foetal than in maternal plasma and erythrocytes. The main t FA in maternal and foetal blood were elaidic acid (C18:1 t 9; t 9) and vaccenic acid (C18:1 t 11; t 11). Portions of t 9, t 10, t 11, and t 12 in foetal blood lipids were lower (~0.5-fold) compared with maternal blood. In foetal lipids, t 9 was higher than t 11. The t 9 correlated negatively with eicosapentaenoic acid (n-3) and AA in maternal and foetal lipids; whereas t 11 correlated negatively only with foetal total LC n-6 (plasma and erythrocytes) and n-3 PUFA (erythrocytes). No correlation between maternal t FA and foetal PUFA was observed. Conclusions : ‘Biomagnification’ of LC n-6 and n-3 PUFA AA and DHA in foetal blood was confirmed, whereas single trans isomers were lower compared with maternal blood. Nevertheless, t FA intake, especially from industrial sources, should be as low as possible. Keywords: conjugated linoleic acids; pregnancy; trans fatty acids; elaidic acid; vaccenic acid; ruminant fat; omega-3 fatty acids (Published: 27 November 2015) Citation: Food & Nutrition Research 2015, 59: 29348 - http://dx.doi.org/10.3402/fnr.v59.29348

Background Maternal nutrition in pregnancy has a crucial impact on the development of the fetus. Dietary trans fatty acids (t FA) are known to have adverse health effects, especially during pregnancy. However, the distribution of t FA produced via partial hydrogenation of vegetable oils (mainly elaidic acid; t 9) differs compared to ruminant-derived t FA (mainly vaccenic acid; t 11). Recent findings indicate that they may have different impact on human health. Therefore, in this study, plasma and erythrocytes of mother-child pairs (n = 55) were sampled to investigate the distribution of t FA, including individual trans C18:1 fatty acids and conjugated linoleic acids (CLA) in fetal related to maternal lipids; with additional consideration of maternal dairy fat intake. Results Portion of t 9 and t 11, but also of c 9,t 11 CLA was higher in maternal than in fetal blood lipids. The portion of t 9 in maternal and fetal lipids differed only slightly. In contrast, the portion of fetal t 11 was only half of that in maternal blood. This led to a fetal t 9/t 11-index in plasma and erythrocytes being twice as high compared to the maternal values. A high dairy fat intake resulted in elevated portions of t 11 and its Δ9-desaturation product c 9,t 11 CLA in maternal blood. In contrast, in the respective fetal blood lipids only c 9,t 11 CLA, but not t 11 was increased. Nevertheless, a positive association between maternal and fetal plasma exists for both t 11 and c 9,t 11 CLA. Furthermore, in contrast to t 9, t 11 was not negatively associated with n-3 LC-PUFA in fetal blood lipids. Conclusions Fetal blood fatty acid composition essentially depends on and is altered by the maternal fatty acid supply. However, in addition to dietary factors, other aspects also contribute to the individual fatty acid distribution (oxidation, conversion, incorporation). The lower portion of fetal t 11 compared to maternal t 11, possibly results from Δ9-desaturation to c 9,t 11 CLA and/or oxidation. Based on the fatty acid distribution, it can be concluded that t 11 differs from t 9 regarding its metabolism and their impact on fetal LC-PUFA.

Background Adequate biomarkers for the dietary supply of fatty acids (FA) are FA of adipose tissue and blood fractions. In human studies, invasive sample collection is unpleasant for subjects. In contrast, cheek cell sampling can be considered as a non-invasive alternative to investigate FA status. The aim of this study was to analyze whether cheek cell FA composition reflect the supplementation of alpha-linolenic acid (ALA) using a linseed oil mixture compared to olive oil supplementation. Additionally, it was investigated if cheek cell FA composition correlates with the FA composition of plasma, red blood cells (RBC) and peripheral blood mononuclear cells (PBMC) before and during both interventions. Methods During a 10-week randomized, controlled, double-blind human intervention study, 38 subjects provided cheek cell and blood samples. After a two-week run-in period, the test group (n = 23) received 17 g/d of an ALA-rich linseed oil mixture, while the control group (n = 15) received 17 g/d of an omega-3 (n-3) polyunsaturated FA (PUFA)-free olive oil. Cheek cells and blood were collected on days 0, 7 and 56 of the 8-week intervention period. Results Compared to olive oil, the linseed oil intervention increased ALA and also the endogenously converted long-chain n-3 metabolites eicosatetraenoic-, eicosapentaenoic- and docosapentaenoic acid in cheek cells (P ≤ 0.05). Docosahexaenoic acid remained unchanged. Reflecting the treatment, the n-6/n- 3 ratio decreased in the test group. In general, cheek cell FA reflected the changes of FA in blood fractions. Independent of treatment, significant correlations (P ≤ 0.05) of n-6 PUFA and n- 3 PUFA between cheek cells and plasma, RBC and PBMC were found, except for linoleic acid and ALA. Conclusions The changes in FA composition of cheek cells confirmed that ALA from linseed oil increased endogenously derived n- 3 PUFA in cheek cell lipids. These changes in cheek cells and their correlation to the respective FA in blood fractions indicate the cheek cell FA profile as an adequate non-invasive biomarker for short-term n-3 PUFA intake and metabolism. Therefore, cheek cell FA can be used in human intervention studies or large-scale epidemiological studies, especially for assessment of the n-3 PUFA status. Trial registration ClinicalTrials.gov, IDNCT01317290