Interactions between genetic variants and dietary lipid composition: effects on circulating LDL cholesterol in children.

BACKGROUND: Elevated serum low-density lipoprotein (LDL) cholesterol is a predictor of cardiovascular disease events, and the quality of dietary fat is known to influence serum concentrations of LDL cholesterol in children. Interindividual differences in response to diet exist, but the underlying genetic factors remain largely unknown. OBJECTIVE: We aimed to identify genetic variants that modify the variation in serum lipid response to dietary fat quality. DESIGN: We used data from 2 longitudinal Finnish cohorts designed to study risk factors for cardiovascular diseases. Large-scale genotyping was performed with Metabochip in a long-term randomized controlled dietary intervention trial, the Special Turku Coronary Risk Factor Intervention Project (STRIP), for discovery of genetic polymorphisms. The observational Cardiovascular Risk in Young Finns Study (YFS) with genome-wide genetic data was used as a replication sample for the initial findings. Dietary records were used to calculate the ratio of unsaturated to saturated fats. Interaction models and multiple follow-ups were used in the analysis. RESULTS: In the STRIP cohort, a variant within the PARK2 locus, rs9364628, showed moderate interaction with dietary fat quality and a consistent direction of effect in both scans on serum LDL-cholesterol concentration in children aged 5 and 7 y (P < 0.0084 and P < 0.0057, respectively). In the YFS cohort, we were unable to replicate the initial discovery signal, but rs12207186 within the PARK2 locus and dietary lipid quality had a stronger interaction effect on serum LDL-cholesterol concentration (P < 9.44 × 10(-5)) than did rs9364628 in children aged 6 y. CONCLUSION: This genotyping study involving 2 cohorts of healthy Finnish children indicates a possible interaction between PARK2 variants and dietary fat quality on serum LDL-cholesterol concentration. This trial was registered at clinicaltrials.gov as NCT00223600.

Effects of whole grain, fish and bilberries on serum metabolic profile and lipid transfer protein activities: a randomized trial (Sysdimet).

OBJECTIVE: We studied the combined effects of wholegrain, fish and bilberries on serum metabolic profile and lipid transfer protein activities in subjects with the metabolic syndrome. METHODS: Altogether 131 subjects (40-70 y, BMI 26-39 kg/m(2)) with impaired glucose metabolism and features of the metabolic syndrome were randomized into three groups with 12-week periods according to a parallel study design. They consumed either: a) wholegrain and low postprandial insulin response grain products, fatty fish 3 times a week, and bilberries 3 portions per day (HealthyDiet), b) wholegrain and low postprandial insulin response grain products (WGED), or c) refined wheat breads as cereal products (Control). Altogether 106 subjects completed the study. Serum metabolic profile was studied using an NMR-based platform providing information on lipoprotein subclasses and lipids as well as low-molecular-weight metabolites. RESULTS: There were no significant differences in clinical characteristics between the groups at baseline or at the end of the intervention. Mixed model analyses revealed significant changes in lipid metabolites in the HealthyDiet group during the intervention compared to the Control group. All changes reflected increased polyunsaturation in plasma fatty acids, especially in n-3 PUFAs, while n-6 and n-7 fatty acids decreased. According to tertiles of changes in fish intake, a greater increase of fish intake was associated with increased concentration of large HDL particles, larger average diameter of HDL particles, and increased concentrations of large HDL lipid components, even though total levels of HDL cholesterol remained stable. CONCLUSIONS: The results suggest that consumption of diet rich in whole grain, bilberries and especially fatty fish causes changes in HDL particles shifting their subclass distribution toward larger particles. These changes may be related to known protective functions of HDL such as reverse cholesterol transport and could partly explain the known protective effects of fish consumption against atherosclerosis. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov NCT00573781.

Cross-sectional and longitudinal associations of circulating omega-3 and omega-6 fatty acids with lipoprotein particle concentrations and sizes: population-based cohort study with 6-year follow-up.

BACKGROUND: Cross-sectional studies have suggested that serum omega-3 (n-3) and omega-6 (n-6) polyunsaturated fatty acids (PUFAs) are related to favorable lipoprotein particle concentrations. We explored the associations of serum n-3 and n-6 PUFAs with lipoprotein particle concentrations and sizes in a general population cohort at baseline and after 6 years. FINDINGS: The cohort included 665 adults (274 men) with a 6-year follow-up. Nutritional counseling was given at baseline. Serum n-3 and n-6 PUFAs and lipoprotein particle concentrations and the mean particle sizes of VLDL, LDL, and HDL were quantified by nuclear magnetic resonance (NMR) spectroscopy for all baseline and follow-up samples at the same time. Concentrations of n-3 and n-6 PUFAs were expressed relative to total fatty acids. At baseline, n-3 PUFAs were not associated with lipoprotein particle concentrations. A weak negative association was observed for VLDL (P = 0.021) and positive for HDL (P = 0.011) particle size. n-6 PUFA was negatively associated with VLDL particle concentration and positively with LDL (P < 0.001) and HDL particle size (P < 0.001). The 6-year change in n-3 PUFA correlated positively with the change in particle size for HDL and LDL lipoproteins but negatively with VLDL particle size. An increase in 6-year levels of n-6 PUFAs was negatively correlated with the change in VLDL particle concentration and size, and positively with LDL particle size. CONCLUSION: Change in circulating levels of both n-3 and n-6 PUFAs, relative to total fatty acids, during 6 years of follow-up are associated with changes in lipoprotein particle size and concentrations at the population level.

Effect of fatty and lean fish intake on lipoprotein subclasses in subjects with coronary heart disease: a controlled trial.

BACKGROUND: Fish oil intake reduces serum triglycerides; however, little is known about the effects of dietary fish intake on lipoprotein subclasses. OBJECTIVE: We aimed at assessing the effect of fatty and lean fish intake on the lipoprotein subclasses in an intervention study. METHODS: The intervention study included 33 patients with coronary heart disease, who were aged 61.0 ± 5.8 (mean ± SD) years. The subjects were randomly assigned to a fatty fish (n = 11), lean fish (n = 12), or control (n = 10) diet for 8 weeks. Fish diets included at least 4 fish meals per week. Subjects in the control group consumed lean beef, pork, and chicken. Lipoprotein subclasses and their lipid components were determined by nuclear magnetic resonance spectroscopy. RESULTS: Concentrations of n-3 fatty acids and docosahexaenoic acid increased in the fatty fish group. The concentrations of cholesterol, cholesterol esters, and total lipids in very large high-density lipoproteins (HDLs) increased in the fatty fish group (overall difference P = .005, P = .002, and P = .007, respectively; false discovery rate P = .04, P = .04, and P = .05, respectively). The mean size of HDL particles increased in the fatty fish group (9.8 ± 0.3 nm at baseline and 9.9 ± 0.4 nm at end of study; overall difference P = .004, false discovery rate P = .04). The fish diets did not affect very-low-density lipoprotein or low-density lipoprotein size. CONCLUSION: Fatty fish intake at least 4 times per week increases HDL particle size which might have beneficial effect in patients with coronary heart disease.

Metabolite profiling of leek (Allium porrum L) cultivars by (1) H NMR and HPLC-MS.

INTRODUCTION: Leek (Allium ampeloprasum var. porrum) is consumed as a vegetable throughout the world. However, little is known about the metabolites of leek cultivars, especially those with potentially important beneficial properties for human health. OBJECTIVE: We provide new information for the overall metabolite composition of several leek cultivars grown in Europe by using HPLC-MS and (1) H NMR. METHODS: The use of a novel CTLS/NMR (constrained total-line-shape nuclear magnetic resonance) approach was found to be capable of reliable quantification, even with overlapping metabolite signals in the (1) H NMR of plant metabolites. Additionally, a new application for leek flavonoids was optimised for HPLC-MS. RESULTS: The total concentration of carbohydrates (glucose, fructose, kestose/nystose and sucrose) and nine amino acids varied by fourfold in leek juice from different cultivars, while the total concentrations of four organic acids were similar in all cultivars. All the quantified flavonols were kaempferol derivatives or quercetin derivatives and threefold differences in flavonol concentrations were detected between cultivars. CONCLUSION: In this study, various phytochemical profiles were determined for several leek cultivars by (1) H NMR spectroscopy with CTLS combined with HPLC-MS. The wide variation in bioactive compounds among commercial leek cultivars offers promising opportunities for breeders to raise the levels of important biochemical compounds in leek breeding lines, and also provides some objective measure for quality assurance for the leek industry.

Effects of sea buckthorn and bilberry on serum metabolites differ according to baseline metabolic profiles in overweight women: a randomized crossover trial.

BACKGROUND: Berries are associated with health benefits. Little is known about the effect of baseline metabolome on the overall metabolic responses to berry intake. OBJECTIVE: We studied the effects of berries on serum metabolome. DESIGN: Eighty overweight women completed this randomized crossover study. During the interventions of 30 d, subjects consumed dried sea buckthorn berries (SBs), sea buckthorn oil (SBo), sea buckthorn phenolics ethanol extract mixed with maltodextrin (SBe+MD) (1:1), or frozen bilberries. Metabolic profiles were quantified from serum samples by using (1)H nuclear magnetic resonance spectroscopy. RESULTS: All interventions induced a significant (P < 0.001-0.003) effect on the overall metabolic profiles. The effect was observed both in participants who had a metabolic profile that reflected higher cardiometabolic risk at baseline (group B: P = 0.001-0.008) and in participants who had a lower-risk profile (group A: P < 0.001-0.009). Although most of the changes in individual metabolites were not statistically significant after correction for multiplicity, clear trends were observed. SB-induced effects were mainly on serum triglycerides and very-low-density lipoprotein (VLDL) and its subclasses, which decreased in metabolic group B. SBo induced a decreasing trend in serum total, intermediate-density lipoprotein (IDL), and low-density lipoprotein (LDL) cholesterol and subfractions of IDL and LDL in group B. During the SBe+MD treatment, VLDL fractions and serum triglycerides increased. Bilberries caused beneficial changes in serum lipids and lipoproteins in group B, whereas the opposite was true in group A. CONCLUSION: Berry intake has overall metabolic effects, which depend on the cardiometabolic risk profile at baseline. This trial was registered at clinicaltrials.gov as NCT01860547.

Fetal growth, omega-3 (n-3) fatty acids, and progression of subclinical atherosclerosis: preventing fetal origins of disease? The Cardiovascular Risk in Young Finns Study.

BACKGROUND: Impaired fetal growth is independently associated with an increased risk of cardiovascular events in adulthood. Prevention strategies that can be implemented during adulthood have not been identified. OBJECTIVE: The objective was to determine whether habitual omega-3 (n-3) fatty acid intake is associated with the rate of increase of carotid intima-media thickness during adulthood in individuals with impaired fetal growth. DESIGN: This was a population-based, prospective cohort study of 1573 adults in Finland. Carotid intima-media thickness was assessed in 2001 (at ages 24-39 y) and in 2007. Participants were categorized as having had impaired fetal growth (term birth with birth weight <10th percentile for sex or preterm birth with birth weight <25th percentile for gestational age and sex; n = 193) or normal fetal growth (all other participants; n = 1380). Omega-3 fatty acid intake was assessed by using a food-frequency questionnaire and on the basis of serum fatty acid concentrations. RESULTS: In multivariable models, the 6-y progression of carotid intima-media thickness was inversely associated with dietary omega-3 fatty acids in those with impaired fetal growth (P = 0.04). Similarly, serum omega-3 fatty acid concentrations were inversely associated with the 6-y progression of carotid intima-media thickness in those with impaired fetal growth (P = 0.04) but were not noted in those with normal fetal growth (P = 0.94 and P = 0.26, respectively). CONCLUSION: Dietary intake of omega-3 fatty acids is associated with a slower rate of increase in carotid intima-media thickness in those with impaired fetal growth.

Serum omega-6 polyunsaturated fatty acids and the metabolic syndrome: a longitudinal population-based cohort study.

The serum fatty acid composition reflects the dietary fatty acid composition from the past few days to several weeks. However, the role of serum omega-3 (from fish and fish oils) and omega-6 (from vegetable oils) polyunsaturated fatty acids (PUFAs) in the course of metabolic syndrome is poorly understood. At the Primary Health Care Unit in Pieksämäki, Finland, all subjects born in 1942, 1947, 1952, 1957, and 1962 (n = 1,294) were invited for health checkups in 1997-1998 and 2003-2004. Metabolic syndrome was defined by using the new, harmonized criteria. The serum omega-3 PUFAs, omega-6 PUFAs, and total fatty acids were analyzed by proton nuclear magnetic resonance spectroscopy. Altogether, data from both checkups were available for 665 subjects. After adjustment for age, sex, and baseline body mass index, the incidence of metabolic syndrome between the 2 checkups with a 6.4-year follow-up was inversely associated (P < 0.001) with the increased relative proportion of omega-6 PUFAs in serum lipids. Further adjustment for body mass index change, lipid medication, smoking, alcohol intake, and physical activity conveyed similar results. The authors did not find any significant associations between omega-3 PUFAs and the incidence of metabolic syndrome. Therefore, their results suggest that the change in the relative proportion of omega-6 PUFAs in serum lipids is inversely related to the incidence of metabolic syndrome.

NMR protocol for determination of oxidation susceptibility of serum lipids and application of the protocol to a chocolate study.

A protocol for determination of oxidation susceptibility of serum lipids based on proton nuclear magnetic resonance ((1)H NMR) spectroscopy is presented and compared to the commonly used spectrophotometric method. Even though there are methodological differences between these two methods, the NMR-based oxidation susceptibility correlates well (r(2) = 0.73) with the lag time determined spectrophotometrically. In addition to the oxidizability of serum lipids, the NMR method provides also information about the lipid profile. The NMR oxidation assay was applied to the chocolate study including fasting serum samples (n = 45) from subjects who had consumed white (WC), dark (DC) or high-polyphenol chocolate (HPC) daily for 3 weeks. The oxidation susceptibility of serum lipids decreased in the HPC group, and there was a significant difference between the WC and HPC groups (P = 0.031). According to the random forest analysis, the consumption of the HPC chocolate induced changes to the amounts of HDL, phosphatidylcholine, sphingomyelin, and nervonic, docosahexaenoic and myristic acids. Furthermore, arachidonic, docosahexaenoic, docosapentaenoic and palmitic acids, gamma-glutamyl transferase, hemoglobin, HDL, phosphatidylcholine and choline containing phospholipids explained about 60% of the oxidation susceptibility values. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11306-011-0323-2) contains supplementary material, which is available to authorized users.

Screening of binding activity of Streptococcus pneumoniae, Streptococcus agalactiae and Streptococcus suis to berries and juices.

Antiadhesion therapy is a promising approach to the fight against pathogens. Antibiotic resistance and the lack of effective vaccines have increased the search for new methods to prevent infectious diseases. Previous studies have shown the antiadhesion activity of juice from cultivated cranberries (Vaccinium macrocarpon Ait.) against bacteria, especially E. coli. In this study, the binding of two streptococcal strains, Streptococcus pneumoniae and Streptococcus agalactiae, to molecular size fractions (FI, FII and FIII, <10 kDa, 10-100 kDa, and >100 kDa, respectively) of berries and berry and fruit juices from 12 plant species were studied using a microtiter well assay. For Streptococcus suis a hemagglutination inhibition assay was used. In general, binding activity was detected especially to wild cranberry (Vaccinium oxycoccos L.) and to other Vaccinium species. S. pneumoniae cells bound most to cranberry juice fraction FI and S. agalactiae cells to cranberry fraction FIII. Hemagglutination induced by S. suis was most effectively inhibited by cranberry fraction FII. NMR spectra of some characteristic active and non-active fractions were also measured. They indicate that fractions FII and FIII contained proanthocyanidins and/or other phenolic compounds. The results suggest Vaccinium berries as possible sources of antiadhesives against bacterial infections.

High-throughput serum NMR metabonomics for cost-effective holistic studies on systemic metabolism.

A high-throughput proton (1H) nuclear magnetic resonance (NMR) metabonomics approach is introduced to characterise systemic metabolic phenotypes. The methodology combines two molecular windows that contain the majority of the metabolic information available by 1H NMR from native serum, e.g. serum lipids, lipoprotein subclasses as well as various low-molecular-weight metabolites. The experimentation is robotics-controlled and fully automated with a capacity of about 150-180 samples in 24 h. To the best of our knowledge, the presented set-up is unique in the sense of experimental high-throughput, cost-effectiveness, and automated multi-metabolic data analyses. As an example, we demonstrate that the NMR data as such reveal associations between systemic metabolic phenotypes and the metabolic syndrome (n = 4407). The high-throughput of up to 50,000 serum samples per year is also paving the way for this technology in large-scale clinical and epidemiological studies. In contradiction to single 'biomarkers', the application of this holistic NMR approach and the integrated computational methods provides a data-driven systems biology approach to biomedical research.

NMR and UPLC-qTOF-MS/MS characterisation of novel phenylethanol derivatives of phenylpropanoid glucosides from the leaves of strawberry (Fragaria x ananassa cv. Jonsok).

INTRODUCTION: Strawberry (Fragaria x ananassa) is rich in polyphenols, particularly anthocyanins, flavonols, condensed tannins and ellagic tannins. In addition to the fruits, the leaves of strawberry also contain a wide range of phenolic compound classes, but have not been investigated to the same extent as the fruit. OBJECTIVE: To characterise a metabolite group present in the leaves of strawberry, that was not amenable for identification based on earlier information available in the literature. METHODOLOGY: Methanolic extracts of strawberry leaves were analysed by UPLC-qTOF-MS/MS and iterative quantum mechanical NMR spectral analysis. RESULTS: The structures of phenylethanol derivatives of phenylpropanoid glucosides Eutigoside A ( F4) and its two isomeric forms 2-(4-hydroxyphenyl)ethyl-[6-O-(Z)-coumaroyl]-beta-D-glucopyranoside (F6) and 4-(2-hydroxyethyl)phenyl-[6-O-(E)-coumaroyl]-beta-D-glucopyranoside (F1) were resolved by NMR and UPLC-qTOF-MS/MS. In addition, two other derivatives of phenylpropanoid glucosides similar to Eutigoside A but possessing different phenolic acid moieties, namely Grayanoside A ( F5) and 2-(4-hydroxyphenyl)ethyl-[6-O-(E)-caffeoyl]-beta-D-glucopyranoside (F14), were similarly identified. Also, accurate characteristic coupling constants for the subunits are reported and their usefulness in structural analysis is highlighted. CONCLUSION: Chemical analysis of the leaves of strawberry (Fragaria x ananassa cv. Jonsok) resulted in the identification of a compound class, phenylethanol derivatives of phenylpropanoid glycosides, not previously found in strawberry.

A multi-metabolite analysis of serum by 1H NMR spectroscopy: early systemic signs of Alzheimer's disease.

A three-molecular-window approach for (1)H NMR spectroscopy of serum is presented to obtain specific molecular data on lipoproteins, various low-molecular-weight metabolites, and individual lipid molecules together with their degree of (poly)(un)saturation. The multiple data were analysed with self-organising maps, illustrating the strength of the approach as a holistic metabonomics framework in solely data-driven metabolic phenotyping. We studied 180 serum samples of which 30% were related to mild cognitive impairment (MCI), a neuropsychological diagnosis with severely increased risk for Alzheimer's disease (AD). The results underline the association between MCI and the metabolic syndrome (MetS). Additionally, the low relativeamount of omega-3 fatty acids appears more indicative of MCI than low serum omega-3 or polyunsaturated fatty acid concentration as such. The analyses also feature the role of elevated glycoproteins in the risk for AD, supporting the view that coexistence of inflammation and the MetS forms a high risk condition for cognitive decline.

Antioxidant and antitumor effects of hydroxymatairesinol (HM-3000, HMR), a lignan isolated from the knots of spruce.

The antioxidant properties of hydroxymatairesinol (HM-3000) were studied in vitro in lipid peroxidation, superoxide and peroxyl radical scavenging, and LDL-oxidation models in comparison with the known synthetic antioxidants Trolox (a water-soluble vitamin E derivative), butylated hydroxyanisol (BHA) and butylated hydroxytoluene (BHT). On a molar basis HM-3000 was a more effective antioxidant than Trolox in all assays and more effective than BHT or BHA in lipid peroxidation and superoxide scavenging test. The in vivo antioxidative effect (evaluated as the weight gain of C57BL/6J mice fed an alpha-tocopherol-deficient diet) of HM-3000 (500 mg/kg per day) was comparable to that of DL-alpha-tocopherol (766 mg/kg per day). The antitumor activity of HM-3000 was studied in dimethylbenz[a]anthracene (DMBA)-induced rat mammary cancer. HM-3000 had a statistically significant inhibitory effect on tumor growth. Prevention of tumor formation was also evaluated in the Apc(Min) mice model, which develops intestinal polyps spontaneously. HM-3000 was given in diet at 30 mg/kg per day and decreased the formation of polyps and prevented beta-catenin accumulation into the nucleus, the pathophysiological hallmark of polyp formation in this mouse model. In short-term toxicity studies (up to 28 days) HM-3000 was essentially non-toxic when given p.o. to rats and dogs (daily doses up to 2000 and 665 mg/kg, respectively); HM-3000 was shown to be well absorbed (> 50% of the dose) and rapidly eliminated. In human studies HM-3000 has been given in single doses up to 1350 mg to healthy male volunteers without treatment-related adverse events. Rapid absorption from the gastrointestinal tract and partial metabolism to enterolactone in humans was demonstrated. In summary, HM-3000 is a safe, novel enterolactone precursor lignan with antioxidant and antitumor properties.