Helen Lindqvist

Herring ( Clupea harengus) intake influences lipoproteins but not inflammatory and oxidation markers in overweight men.

Fish consumption is associated with a lower incidence of CVD and decreases in risk factors for atherosclerosis. Although fish contains other interesting components than fish oil, few studies focus on total fish composition and the influence food preparation might have on health-beneficial components. In the present cross-over intervention study the effect of a 6-week herring diet compared with a reference diet on CVD risk factors was investigated. Thirty-five healthy, but overweight, men (mean BMI 28.3 kg/m2) were randomised to a 6-week herring diet (150 g baked herring fillets/d, 5 d/week) or a reference diet (150 g baked lean pork and chicken fillets/d, 5 d/week). Diets were switched after a 12-week washout period. Plasma total cholesterol, TAG, HDL, HDL2, HDL3, LDL, C-reactive protein, IL-6, IL-18, intercellular adhesion molecule-1, oxidised LDL, oxygen radical absorbance capacity using perchloric acid (ORACPCA), whole-blood fatty acids, bleeding time and blood pressure were measured at the beginning and end of each dietary period. HDL was significantly higher after the herring diet period compared with after the reference diet period: 1.04 v. 0.99 mmol/l. TAG decreased after both diets, with no significant difference between the two diets. ORACPCA values did not indicate lower concentrations of non-protein plasma antioxidants, and oxidised LDL was not higher after the herring diet than after the reference diet. To conclude, a 6-week herring-rich diet significantly raised HDL compared with a diet of matched lean pork and chicken dishes. No adverse effects on in vivo oxidation or serum antioxidants were found after herring intake.

Efficacy of fish intake on vitamin D status: a meta-analysis of randomized controlled trials

BACKGROUND It is well known that fish is the major natural source of vitamin D in the diet; therefore, this meta-analysis investigated the influence of fish consumption in randomized controlled trials (RCTs) on serum 25-hydroxyvitamin D [25(OH)D] concentrations. OBJECTIVE A literature search was carried out in Medline, Embase, Web of Science, and the Cochrane Library (up to February 2014) for RCTs that investigated the effect of fish consumption on 25(OH)D concentrations in comparison to other dietary interventions. RESULTS Seven articles and 2 unpublished study data sets with 640 subjects and 14 study groups met the inclusion criteria and were included in this meta-analysis. Compared with controls, the consumption of fish increased 25(OH)D concentrations, on average, by 4.4 nmol/L (95% CI: 1.7, 7.1 nmol/L; P < 0.0001, I(2) = 25%; 9 studies).The type of the fish also played a key role: the consumption of fatty fish resulted in a mean difference of 6.8 nmol/L (95% CI: 3.7, 9.9 nmol/L; P < 0.0001, I(2) = 0%; 7 study groups), whereas for lean fish the mean difference was 1.9 nmol/L (95% CI: -2.3, 6.0 nmol/L; P < 0.38, I(2) = 37%; 7 study groups). Short-term studies (4-8 wk) showed a mean difference of 3.8 nmol/L (95% CI: 0.6, 6.9 nmol/L; P < 0.02, I(2) = 38%; 10 study groups), whereas in long-term studies (∼6 mo) the mean difference was 8.3 nmol/L (95% CI: 2.1, 14.5 nmol/L; P < 0.009, I(2) = 0%; 4 study groups). CONCLUSION As the major food source of vitamin D, fish consumption increases concentrations of 25(OH)D, although recommended fish intakes cannot optimize vitamin D status.

Herring (Clupea harengus) supplemented diet influences risk factors for CVD in overweight subjects

Objective:To assess the effect of a 4-week herring diet compared to a reference diet on biomarkers for cardiovascular disease in obese subjects.Design:Randomized crossover trial.Setting:Department of Internal Medicine, Sahlgrenska University Hospital.Subjects:Fifteen healthy obese men and women (age 24–70 years) included, 13 completed.Intervention:Subjects were randomly assigned to four weeks of herring diet (150 g baked herring fillets/day 5, days/week) or reference diet (pork and chicken fillets) and switched diets after 2 weeks washout. P-total cholesterol, p-TAG, p-HDL, p-HDL2, p-HDL3, p-LDL, p-apolipoprotein A, p-apolipoprotein B, p-Lipoprotein (a), p-fibrinogen, p-C- reactive protein and p-antioxidative capacity were analysed at 0,2,4,6,8 and 10 weeks.Results:P-HDL was significantly higher after the herring diet period compared to after the reference diet period; 1.22 vs 1.13 mmol/l (P=0.036). There was a small, but not statistically significant, decrease in TAG but no effect on other biomarkers. TEAC and FRAP, but not ORAC-values, indicated that plasma antioxidants may have been reduced. CRP tended to be lower after the herring diet compared to after the reference diet.Conclusions:Consumption of oven-baked herring (150g/day, 5 days/week) for 4 weeks, compared to consumption of pork and chicken fillets, significantly increased p-HDL. Patients with insulin resistance and obesity, who commonly have low HDL, may therefore benefit from addition of herring to the diet.Sponsorship:Region Västra Götaland, National board of fisheries (Dr 223-2451-01), Sweden (EU structural funds), The Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (FORMAS) (Grant No 2001-1246).

Plasma phospholipid EPA and DHA in relation to atherosclerosis in 61-year-old men.

INTRODUCTION Increased intake of the n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) has been shown to decrease the risk for cardiovascular death and to reduce CVD risk factors. It has also been suggested that EPA and DHA reduce atherosclerosis progression, but data are inconclusive. Carotid intima-media thickness (IMT) is a well-established surrogate measure for sub-clinical atherosclerosis. Our aim was to examine if plasma phospholipid EPA and DHA are associated with IMT and plaque occurrence and size in the carotid and femoral arteries. METHODS IMT and plaque occurrence in carotid and femoral arteries was measured by ultrasound in 487 sixty-one-year-old men in this cross-sectional study. Plasma phospholipid levels of EPA and DHA, serum lipids, cell adhesion molecules, and blood pressure were measured, and occurrence of diabetes and socioeconomic factors were assessed. RESULTS Plasma phospholipid EPA was negatively associated with IMT in carotid and femoral arteries, and with cigarette years and cell adhesion proteins. EPA was positively associated with HDL, total cholesterol, blood pressure, plasma insulin and years of education. The association between EPA and carotid IMT remained after adjustment for blood pressure, but not for other covariates. Plasma phospholipid DHA was negatively associated with cigarette years and several endothelial markers, and positively associated with years of education and systolic blood pressure. In contrast to other studies, EPA content was higher in diabetic patients compared with patients without diabetes. CONCLUSION Plasma phospholipid EPA, but not DHA, was inversely associated with carotid and femoral IMT, as well as several endothelial markers supporting the concept of an effect of EPA on the vascular wall. This association was independent of blood pressure, but not for other covariates. There was no association between plasma phospholipid EPA or DHA and plaque occurrence in the carotid and femoral arteries.

Protein profiling of low-density lipoprotein from obese subjects

Although obesity and high levels of low‐density lipoprotein (LDL) are well‐known risk factors for cardiovascular disease, the precise role(s) of different LDL constituents in obesity has not been explored. In the present study, we compared the LDL proteome of healthy control adults (body mass index<25) and obese subjects (body mass index>30). LDL was isolated by density‐gradient ultracentrifugation and proteins were separated with 2‐D PAGE, quantified, and identified by peptide mass fingerprinting using MALDI‐TOF MS. A new LDL‐associated protein was identified as transthyretin and found to be significantly more abundant in LDL from the obese subjects. In addition, LDL from the obese subjects contained relatively more α1‐antitrypsin, apo J, apo C‐II, than LDL from controls, and also more of an acidic isoform (pI/Mr; 5.2/23 100) of apo A‐I. On the other hand, the relative amounts of apo A‐IV and the major isoform of apo A‐I (pI/Mr; 5.3/23 100) were significantly less in LDL from the obese subjects. Apo E was less and non‐sialylated apo C‐III more abundant in LDL from obese men than control men, while there were no such differences between LDL from obese and control women. These findings illustrate that obesity is not only associated with increased LDL‐cholesterol levels but also with alterations in the LDL protein composition. The presence of transthyretin in LDL from obese subjects may reflect over‐nutrition and affect the lipid metabolism in obesity.

Influence of herring (Clupea harengus) and herring fractions on metabolic status in rats fed a high energy diet.

Aim:  Few dietary studies have looked beyond fish oil to explain the beneficial metabolic effects of a fish‐containing diet. Our aim was to study whether addition of herring, or sub‐fractions of herring, could counteract negative metabolic effects known to be induced by a high‐fat, high‐sugar diet.

Metabolic profiles from two different breakfast meals characterized by H-1 NMR-based metabolomics

It is challenging to measure dietary exposure with techniques that are both accurate and applicable to free-living individuals. We performed a cross-over intervention, with 24 healthy individuals, to capture the acute metabolic response of a cereal breakfast (CB) and an egg and ham breakfast (EHB). Fasting and postprandial urine samples were analyzed using 1H nuclear magnetic resonance (NMR) spectroscopy and multivariate data analysis. Metabolic profiles were distinguished in relation to ingestion of either CB or EHB. Phosphocreatine/creatine and citrate were identified at higher concentrations after consumption of EHB. Beverage consumption (i.e., tea or coffee) could clearly be seen in the data. 2-furoylglycine and 5-hydroxymethyl-2-furoic acid - potential biomarkers for coffee consumption were identified at higher concentrations in coffee drinkers. Thus 1H NMR urine metabolomics is applicable in the characterization of acute metabolic fingerprints from meal consumption and in the identification of metabolites that may serve as potential biomarkers.

Herring and chicken/pork meals lead to differences in plasma levels of TCA intermediates and arginine metabolites in overweight and obese men and women.

Scope: What effect does replacing chicken or pork with herring as the main dietary source of protein have on the human plasma metabolome? Method and results: A randomised crossover trial with 15 healthy obese men and women (age 24–70 years). Subjects were randomly assigned to four weeks of herring diet or a reference diet of chicken and lean pork, five meals per week, followed by a washout and the other intervention arm. Fasting blood serum metabolites were analysed at 0, 2 and 4 weeks for eleven subjects with available samples, using GC‐MS based metabolomics. The herring diet decreased plasma citrate, fumarate, isocitrate, glycolate, oxalate, agmatine and methyhistidine and increased asparagine, ornithine, glutamine and the hexosamine glucosamine. Modelling found that the tricarboxylic acid cycle, glyoxylate, and arginine metabolism were affected by the intervention. The effect on arginine metabolism was supported by an increase in blood nitric oxide in males on the herring diet. Conclusion: The results suggest that eating herring instead of chicken and lean pork leads to important metabolic effects, particularly on energy and amino acid metabolism. Our findings support the hypothesis that there are metabolic effects of herring intake unrelated to the long chain n‐3 polyunsaturated fatty acid content.

Poor Dietary Quality Is Associated with Increased Inflammation in Swedish Patients with Rheumatoid Arthritis

The aim was to study whether dietary quality was associated with disease activity and inflammation among patients with rheumatoid arthritis (RA). This cross-sectional analysis included 66 Swedish participants, who each completed a food frequency questionnaire (FFQ) at screening. Food intake was scored by a dietary quality index created by the Swedish National Food Agency. Disease activity was measured as Disease Activity Score 28 (DAS28), based on erythrocyte sedimentation rate (ESR), a patient administered visual analogue scale of perceived global health and the number of tender and swollen joints out of 28 examined. Inflammation was measured as ESR and C-reactive protein (hs-CRP). Associations between dietary quality, disease activity and inflammation were evaluated using multivariable linear regression analysis. High dietary quality (high intake of fish, shellfish, whole grain, fruit and vegetables and low intake of sausages and sweets) was not related to DAS28 (B = −0.02, p = 0.787). However, dietary quality was significantly negatively associated with hs-CRP (B = −0.6, p = 0.044) and ESR (B = −2.4, p = 0.002) after adjusting for body mass index, age, education, smoking and gender. Both hs-CRP and ESR decreased with increasing dietary quality. In conclusion, among patients with RA, high dietary quality was associated with reduced inflammation but not with disease activity.

Influence of Blue Mussel (Mytilus edulis) Intake on Disease Activity in Female Patients with Rheumatoid Arthritis: The MIRA Randomized Cross-Over Dietary Intervention

Rheumatoid Arthritis (RA) is a chronic inflammatory disease. This study evaluates the effect of blue mussel intake on disease activity and quality of life in women with RA. Thirty-nine women with established RA and a disease activity score 28 (DAS28) >3.0 were recruited to a randomized 2 × 11-week cross-over dietary intervention. The participants continued with their medication and habitual diet and exchanged one cooked meal a day, five days a week, with a meal including 75 g blue mussels or 75 g meat. Diets were switched after an eight week washout period. Data regarding quality of life (SF-36), blood lipids, erythrocyte sediment rate (ESR), C-reactive protein (CRP) and tender and swollen joints were examined at the start and end of each dietary period. Thirty women completed one period, and twenty-three completed both. Intake of the blue mussel diet led to a significant reduction of DAS28-CRP (p = 0.048), but not DAS28. The number of EULAR (European League Against Rheumatism) criteria moderate and good responders were higher when consuming blue mussel diet (p = 0.036). Blood lipids did not change. To conclude, blue mussel intake reduced disease symptoms in women with RA and improved perceived health. The reported effects need to be confirmed by non-patient reported outcomes, such as inflammation markers.