Benefits of salmon eating on traditional and novel vascular risk factors in young, non-obese healthy subjects

Reducing persistent organic pollutants while maintaining long chain omega-3 fatty acid in farmed Atlantic salmon using decontaminated fish oils for an entire production cycle

Oily fish are an important source of health promoting nutrients such as the very long chain marine omega-3 (VLC-n3) fatty acids and simultaneously a source of potentially hazardous contaminants. Fish oils that are used in fish feed are the main source for both contaminants and VLC-n3. Decontamination techniques have recently been developed to effectively remove persistent organic contaminants from fish oils. The aim of the present study was to assess the level of potentially hazardous contaminants and the health beneficial fatty acids in Atlantic salmon reared on novel decontaminated feeds. Atlantic salmon were fed for 18 months (an entire seawater production cycle) on diets based on decontaminated or non-treated (control) fish oils until market size (approximately 5 kg). The level of known notorious persistent organic pollutants (POPs, i.e. dioxins, dioxin-like polychlorinated biphenyls (DL-PCBs), non dioxin-like PCBs, poly brominated diphenyl ethers (PBDE), and organochlorine pesticides), as well as fatty acid composition were analysed in fish oils, the two diets, and Atlantic salmon fillet. The oil decontamination process was a two-step procedure using active carbon and short path distillation. The fillet levels of POPs in market size fish were reduced by 68-85% while the concentration of very long chain omega-3 fatty acids was reduced by 4-7%. No differences in biomarkers of dioxin-like component exposures, such as hepatic gene expression of CYP1A or AhR2B, CYP1A protein expression and 7-ethoxyresorufin O-deethylase (EROD) activity, were observed between salmon raised on normal or decontaminated feeds, thus indicating that the difference in POPs levels were of no biological significance to the fish. Atlantic salmon reared on decontaminated feeds had sum polychlorinated dibenzodioxins/furans (PCDD/Fs) and DL-PCB concentrations that were comparable with terrestrial food products such as beef, while the level of marine omega-3 fatty acids remained as high as for commercially farmed Atlantic salmon.

Supplementation with EPA or fish oil for 11 months lowers circulating lipids, but does not delay the onset of diabetes in UC Davis-type 2 diabetes mellitus rats

EPA or fish oil supplementation has been suggested as treatments for the prevention of type 2 diabetes mellitus (T2DM) due to their lipid-lowering and potential insulin-sensitising effects. We investigated the effects of supplementation with EPA (1 g/kg body weight per d) or fish oil (3 g/kg body weight per d) on the age of onset of T2DM and circulating glucose, insulin, lipids, leptin and adiponectin in UC Davis (UCD)-T2DM rats. Animals were divided into three groups starting at 1 month of age: control, EPA and fish oil. All the animals were followed until diabetes onset or for up to 12 months of age. Monthly fasting blood samples were collected for the measurement of glucose, lipids, hormones and C-reactive protein (CRP). Neither EPA nor fish oil delayed the onset of T2DM or altered fasting plasma glucose, insulin, CRP, adiponectin or leptin concentrations. The groups did not differ in energy intake or body weight. Fish oil treatment lowered fasting plasma TAG concentrations by 39 (sd 7) % (P < 0.001) and EPA lowered fasting plasma NEFA concentrations by 23 (sd 5) % (P < 0.05) at 4 months of age compared with the control group. EPA and fish oil lowered fasting plasma cholesterol concentrations at 4 months of age by 19 (sd 4) and 22 (sd 4) % compared with the control group, respectively (both P < 0.01). In conclusion, EPA and fish oil supplementation lowers circulating lipid concentrations, but does not delay the onset of T2DM in UCD-T2DM rats.

The effect of farmed trout on cardiovascular risk markers in healthy men

Increased intake of marine long-chain n-3 PUFA (n-3 LCPUFA) may decrease the risk of CVD and reduce mortality by lowering serum TAG and blood pressure (BP). Furthermore, n-3 LCPUFA may affect novel CVD risk markers related to inflammation and vascular function. The objective of the present study was to examine the effect of farmed trout on novel and traditional CVD risk markers in healthy men, and to evaluate whether this was affected by the aquacultural feed regime. We performed a parallel, 8-week intervention study in which sixty-eight healthy male volunteers were randomised to consume either a daily meal with 150 g farmed trout raised on either marine or vegetable-based feed, or a reference meal containing 150 g chicken. Twenty-four hour BP, pulse wave velocity, augmentation index, fatty acid composition of erythrocyte (RBC), and concentrations of TAG, HDL-cholesterol, LDL-cholesterol, glucose, insulin, C-reactive protein (CRP) and other markers of inflammation were measured at weeks 0 and 8. RBC content of total n-3 LCPUFA, both EPA and DHA, was significantly higher among men consuming trout raised on marine feed compared with men consuming the vegetable-fed trout or chicken. The three intervention groups did not differ significantly with respect to any of the other outcome variables, although there were trends towards associations between the changes in RBC n-3 LCPUFA and those in BP and CRP. In the present study, we conclude that we could not confirm the fish oil-induced reduction in CVD risk markers after daily consumption of trout with high or low n-3 LCPUFA content. However, trout raised on vegetable-based feed had less pronounced impact on RBC n-3 LCPUFA status.

Periodontitis is associated with altered plasma fatty acids and cardiovascular risk markers

BACKGROUND AND AIMS

In periodontitis it has been found that some perturbation exists in lipid biomarkers, such as increased serum total cholesterol and low-density lipoprotein cholesterol. Nevertheless, the relationship between fatty acids and periodontitis has been demonstrated only in a few studies and remains controversial. The aim of this investigation was to explore the effects of periodontitis on a cluster of traditional and novel cardiovascular risk factors such as plasma-lipids profile, types of plasma fatty acids, adhesion molecules and systemic inflammatory markers.

METHODS AND RESULTS

At a university dental school, 56 patients all over 35 years old were enrolled and invited to participate in the study. Total plasma fatty acids, saturated, n-6 polyunsaturated and monounsaturated fatty acids, peroxidability index, soluble VCAM, TNF-alpha, cholesterol, triacylglycerols, and VLDL-c were significantly higher in the periodontitis group compared to the non-periodontitis group.

CONCLUSIONS

This close association found between plasma triacylglycerols, LDL-c, saturated fatty acids, polyunsaturated fatty acids, total amount of fatty acids and coenzyme Q(10) with some periodontal data such as periodontal probing depth, recession of the gingival margin and clinical attachment level (Pearson correlation between 0.3 and 0.6), leads to the conclusion that there is an inter-relationship between periodontitis, plasma fatty acids profile and the increase in metabolic risk factors for cardiovascular diseases.

Moderate consumption of fatty fish reduces diastolic blood pressure in overweight and obese European young adults during energy restriction

OBJECTIVE

Dietary intervention studies suggest that a daily fish meal can improve blood pressure (BP); however, such a dietary regimen might be difficult to sustain. The objective of the present study was to investigate whether salmon consumption three times per week improves BP during energy restriction in young adults.

METHODS

In this 8-wk intervention, 324 subjects (20-40 y of age, body mass index 27.5-32.5kg/m(2), from Iceland, Spain, and Ireland) were randomized to one of four energy-restricted diets (-30% relative to estimated requirements): salmon (150g three times per week, resulting in a daily consumption of 2.1g of omega-3 long-chain polyunsaturated fatty acids [omega-3 LC-PUFAs]), cod (150g three times per week, 0.3g of omega-3 LC-PUFAs per day), fish oil capsules (1.3g of omega-3 LC-PUFAs per day), or control (sunflower oil capsules, no seafood). Body weight, diastolic BP (DBP), systolic BP (SBP), and docosahexaenoic acid (DHA) in erythrocyte membrane were measured at baseline and endpoint.

RESULTS

Participants showed weight loss (-5.2+/-3.2kg, P<0.001) and decreases in SBP (-4.4+/-8.6 mmHg, P<0.001) and DBP (-4.1+/-7.4 mmHg, P<0.001) after the intervention. The salmon (B=-2.71, P=0.032) and fish oil (B=-2.48, P=0.044) groups had significantly lower endpoint DPB than the cod group, but not significantly different from control. Lower baseline DHA (percentage) in erythrocytes was associated with greater DBP reductions (B=0.576, P=0.017).

CONCLUSION

Salmon consumption three times per week can decrease DBP similar to fish oil and significantly more than lean fish during an 8-wk energy restriction in young overweight individuals. A lower DHA content in erythrocyte membrane at baseline, which might indentify infrequent fish eaters, is associated with a greater DBP reduction in the course of an 8-wk dietary intervention providing fatty seafood.

Lipid, inflammatory and haemorheological profiles are significantly affected by farmed fish eating: an intervention study

AIM

The objective of the present study was to evaluate the influence of short-term dietary intake of farmed fish on biomarkers related to the atherosclerotic process.

METHODS AND RESULTS

Lipid, inflammatory, and haemorheological variables before (T0) and after a dietary intervention with about 800 g Orbetello farmed sea bass per week for 10 weeks (T1) were evaluated in nine dyslipidemic subjects. Fish intake significantly decreased triacylglycerols (T1, 140.2+/-20.3 mg/dl versus T0, 183.3+/-29.2 mg/dl; P =0.04), whereas no significant changes for the other lipid variables have been observed. Moreover, dietary intervention significantly (P <0.05) decreased all of the inflammatory parameters investigated; namely, high-sensitivity C-reactive protein, interleukin-6, and interleukin-8. Furthermore, a significant (P =0.04) improvement in erythrocytes' deformability index was reported after 10 weeks of fish dietary intake (9.0+/-0.7% versus 5.4+/-1.0% for T1 and T0, respectively).

CONCLUSION

Dietary short-term intake of farmed fish seems to impose favourable biochemical changes in dyslipidemic subjects.

Omega-3 fatty acids and the cardiometabolic syndrome

Benefits of fish consumption in patients with the cardiometabolic syndrome relate to the high biologic value of protein, omega-3 fatty acids, as well as certain minerals and vitamins in fish. Recently, the American Heart Association issued new guidelines for the intake of omega-3 oils for the prevention of coronary heart disease. The objective of this paper is to evaluate the potential health benefits of fish consumption and/or fish oil supplements in reducing cardiometabolic syndrome risk factors. The consumption of fish or fish oil containing omega-3 polyunsaturated fatty acids reduces the risk of coronary heart disease, decreases triglyceride, blood pressure, and inflammatory markers, improves endothelial function, prevents certain cardiac arrhythmias, reduces platelet aggregation (including reactivity and adhesion), reduces vasoconstriction, enhances fibrinolysis, reduces fibrin formation, and decreases the risk of microalbuminuria and sudden cardiac death. Thus, fish intake or fish oil supplement use is beneficial to reduce cardiometabolic risk factors.

Inulin-enriched pasta affects lipid profile and Lp(a) concentrations in Italian young healthy male volunteers

BACKGROUND

Inulin has been suggested to have beneficial effects on lipids, especially on triglyceridemia. Few data are available about the effects of inulin on Lipoprotein(a), a low-density lipoprotein-like particle considered as an independent risk factor for atherosclerosis. Adding inulin to pasta could be a preventive strategy for delaying the onset of atherosclerosis.

AIM OF THE STUDY

was to evaluate the effects of inulin-enriched pasta on lipid profile and on Lipoprotein(a) in young healthy subjects.

METHODS

Twenty-two young healthy male volunteers entered a randomized double blind cross-over study consisting of a 2-weeks run-in period, a baseline assessment, two 5-weeks study periods (11% inulin-enriched or control pasta), and an 8-weeks wash-out period in between. Serum lipid concentrations were evaluated by routine biochemical analyses and plasma Lipoprotein(a) concentrations by ELISA. The size of apolipoprotein(a) isoforms was determined by Western blot and immunodetection.

RESULTS

Significant differences at baseline and in the treatment groups were found for HDL-cholesterol (P = 0.004), total cholesterol/HDL-cholesterol ratio (P = 0.006), triglycerides (P = 0.04), and Lipoprotein(a) (P = 0.02) concentrations (data analyzed by Friedman test). Dunn's multiple comparison test was used to assess the significance of differences between inulin-enriched pasta diet vs. baseline. HDL-cholesterol concentrations increased by 35.9%; total cholesterol/HDL-cholesterol ratio, triglycerides, and Lipoprotein(a) concentrations decreased by 22.2, 23.4, and 16.5% respectively.

CONCLUSIONS

Inulin-enriched pasta administration induced significant effects on lipid pattern parameters in young healthy volunteers, including a significant reduction in Lipoprotein(a) concentrations.

Physiological, pharmacological, and nutritional regulation of circulating adiponectin concentrations in humans

Adiponectin is an adipocyte hormone that links visceral adiposity with insulin resistance and atherosclerosis. It is unique among adipocyte-derived hormones in that its circulating concentrations are inversely proportional to adiposity, and low adiponectin concentrations predict the development of type 2 diabetes and cardiovascular disease. Consequently, in the decade since its discovery, adiponectin has generated immense interest as a potential therapeutic target for the metabolic syndrome and diabetes. This review summarizes current research regarding the regulation of circulating adiponectin concentrations by physiological, pharmacological, and nutritional factors, with an emphasis on human studies. In humans, plasma adiponectin concentrations are influenced by age and gender, and are inversely proportional to visceral adiposity. In vitro studies suggest that adiponectin production may be determined primarily by adipocyte size and insulin sensitivity, with larger, insulin-resistant adipocytes producing less adiponectin. While adiponectin concentrations are unchanged after meal ingestion, they are increased by significant weight loss, such as after bariatric surgery. In addition, adiponectin production is inhibited by a number of hormones, including testosterone, prolactin, glucocorticoids and growth hormone, and by inflammation and oxidative stress in adipose tissue. Smoking decreases, while moderate alcohol consumption increases, circulating adiponectin concentrations. Dietary fatty acid composition in rodents influences adiponectin production via ligand-activated nuclear receptors (PPARs); however, current evidence in humans is equivocal. In addition to PPAR agonists (such as thiazolidinediones and fibrates), a number of pharmacological agents (angiotensin receptor type 1 blockers, ACE inhibitors, and cannabinoid receptor antagonists) used in treatment of the metabolic syndrome also increase adiponectin concentrations in humans.

Effects of fatty and lean fish intake on blood pressure in subjects with coronary heart disease using multiple medications

BACKGROUND

Intake of fish and long-chain n-3 fatty acids has been of wide interest due to their beneficial effects on cardiovascular risk factors and lower coronary heart disease (CHD) risk.

AIM OF THE STUDY

The aim of this pilot study was to examine the effects of fatty fish and lean (white) fish on fatty acid composition of serum lipids and cardiovascular risk factors in subjects with CHD using multiple drugs for this condition.

METHODS

The study was an 8-week controlled, parallel intervention. Inclusion criteria were myocardial infarction or unstable ischemic attack, age under 70 years, use of betablockers and presence of sinus rhythm. The subjects were randomized to one of the following groups: 4 meals/week fatty fish (n = 11), 4 meals/week lean fish (n = 12) and control diet including lean meat (n = 10).

RESULTS

The mean (+/-SD) of reported fish meals per week was 4.3 +/- 0.4, 4.7 +/- 1.1 and 0.6 +/- 0.4 in the groups, respectively. The proportions of eicosapentaenoic and docosahexaenoic acids in serum lipids increased in the fatty fish group only (P < 0.05). Systolic and diastolic blood pressure levels decreased in the lean fish group (0 vs. 8 week: 3.5 +/- 3.2 and 4.6 +/- 3.6%, respectively, P < 0.05). Serum total triglyceride concentration did not significantly change. HDL cholesterol concentration change differed among groups but without significant post hoc differences. Apolipoprotein A-1 concentration decreased in the control group (0 vs. 8 week, P < 0.05). Coagulation factors, 25-hydroxy vitamin D, and heart rate variability (24 h Holter) did not change among the groups.

CONCLUSIONS

Our results suggest that intake of lean fish at least four times per week could reduce blood pressure levels in CHD patients.

Effect of dietary n-3 polyunsaturated fatty acids on plasma total and high-molecular-weight adiponectin concentrations in overweight to moderately obese men and women

BACKGROUND

Recent studies indicated that dietary n-3 polyunsaturated fatty acids (PUFAs) increase circulating adiponectin concentrations in rodents.

OBJECTIVE

We aimed to investigate whether a diet rich in n-3 PUFAs increased plasma concentrations of total or high-molecular-weight (HMW) adiponectin in healthy overweight-to-moderately obese men and women.

DESIGN

Sixteen women and 10 men with a body mass index (in kg/m(2)) between 28 and 33 were randomly assigned to consume a diet rich in n-3 PUFAs (3.5% of energy intake) from both plant and marine sources or a control diet (0.5% of energy intake from n-3 PUFAs). For the first 2 wk, these diets were consumed under isocaloric conditions; then followed a 12-wk period of ad libitum consumption that was associated with a moderate loss of approximately 3.5% of body weight in both groups. Total and HMW adiponectin plasma concentrations were measured before and after each diet phase.

RESULTS

Plasma fasting adiponectin concentrations did not change during the isocaloric period, but they increased modestly ( approximately 10%) during the ad libitum period when subjects lost weight [P = 0.009 for time in repeated-measures analysis of variance] and to a similar extent in subjects consuming the control (x +/- SD: 0.42 +/- 0.69 microg/mL) and n-3 PUFA (0.45 +/- 0.85 microg/mL) diets (P = 0.920 for time x treatment interaction). Plasma concentrations of HMW adiponectin did not change significantly during the study.

CONCLUSION

Dietary n-3 PUFAs consumed at levels of 3.5% of energy intake do not significantly increase plasma or HMW adiponectin concentrations in overweight-to-moderately obese healthy men and women over the course of 14 wk.