Conclusion: No significant differences in the two treatment groups were seen; in both groups, the... more Conclusion: No significant differences in the two treatment groups were seen; in both groups, the changes in several joint pain parameters, leucotriene B 4 level of plasma, and serum fatty acid profile were putatively favourable. ª
Background/Aim: Subjective food hypersensitivity is prevalent in the general population. The aim ... more Background/Aim: Subjective food hypersensitivity is prevalent in the general population. The aim of this study was to seek objective evidence of food hypersensitivity by analyzing intestinal permeability and inflammation markers in gut lavage fluid. Methods: Fifty-two patients with abdominal complaints self-attributed to food hypersensitivity were examined by skin prick test, serum IgE analysis, double-blind, placebo-controlled food challenge (DBPCFC), and intestinal
A high dietary intake of n-6 compared to n-3 fatty acids (FAs) may promote the production of pro-... more A high dietary intake of n-6 compared to n-3 fatty acids (FAs) may promote the production of pro-inflammatory eicosanoids and cytokines. In two recent studies, short-term (10-day) duodenal administration of n-3 polyunsaturated fatty acid rich seal oil ameliorated joint pain in patients with inflammatory bowel disease (IBD). Using unpublished data from these two studies we here investigated whether normalisation of the n-6 to n-3 FA ratio in blood and tissues by seal oil administration was associated with improved health related quality of life (HRQOL) as assessed by the generic short-form 36 (SF-36) questionnaire. In the first pilot study, baseline n-6 to n-3 FA ratio in rectal mucosal biopsies from 10 patients with IBD (9 of those had joint pain) was significantly increased compared with that in 10 control patients without IBD or joint pain. Following seal oil administration, the n-6 to n-3 FA ratio of the IBD-patients was significantly lowered to the level seen in untreated contro...
The 3-thia fatty acids, tetradecylthioacetic acid and 3,10-dithiadicarboxylic acid are mitochondr... more The 3-thia fatty acids, tetradecylthioacetic acid and 3,10-dithiadicarboxylic acid are mitochondrion and peroxisome proliferators. Administration of these promotes an increased transport of endogenous fatty acids to these organelles and a higher capacity of beta-oxidation. Administration of 3-thia fatty acids to rats resulted in a significant decrease of the hepatic level of docosahexaenoic acid (DHA) (17-24%) and especially eicosapentaenoic acid (EPA) (40-80%) accompanied by increased gene expression of mitochondrial 2,4-dienoyl-CoA reductase and enoyl-CoA isomerase. The mitochondrial oxidation of EPA was increased more than 4-fold after administration of 3-thia fatty acids. EPA-CoA was a good substrate for mitochondrial carnitine acyltransferase-I and treatment with 3-thia fatty acids increased the activity 1.7-fold. DHA was a poor substrate for both mitochondrial and peroxisomal beta-oxidation. DHA-CoA was a very poor substrate for mitochondrial carnitine acyltransferase-I and -I...
The aim of the present study was to investigate the effects of Atlantic salmon consumption on und... more The aim of the present study was to investigate the effects of Atlantic salmon consumption on underlying biological mechanisms associated with anxiety such as heart rate variability (HRV) and heart rate (HR) as well as a measure of self-reported anxiety. Moreover, these biological and self-reported outcome measures were investigated in relation to specific nutrients; vitamin D status, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Ninety-five male forensic inpatients were randomly assigned into a Fish (Atlantic salmon three times per week from September to February) or a Control group (alternative meal, e.g., chicken, pork, or beef three times per week during the same period). HRV measured as the root mean square of successive differences (rMSSD), HR, state-and trait-anxiety (STAI), were assessed before (pre-test) and at the end of the 23 weeks dietary
Background: Omega-3 (n-3) polyunsaturated fatty acids (PUFAs) have modulating effects in several ... more Background: Omega-3 (n-3) polyunsaturated fatty acids (PUFAs) have modulating effects in several chronic infl amma- tory conditions. The aim of the present study was to test whether prior short-term dietary supplementation with n-3 (fi sh or seal oil) or n-6 (soy oil) PUFA rich oils would protect the development of dextran sulfate sodium (DSS)-induced colitis in rats. Methods: Forty-eight male Wistar rats were divided into 6 groups: no intervention, sham, DSS, seal oil + DSS, fi sh oil + DSS and soy oil + DSS. Following 7 days of acclimatisation, 1 mL oil (seal, fi sh or soy) or distilled water (sham) was administered by gavage day 8 to 14. Colitis was induced by 5% DSS in drinking water from day 15 to 21. Rats were sacri- fi ced on day 23. Histological colitis (crypt and infl ammation) scores, faecal granulocyte marker protein (GMP) and quan- titative fatty acid composition in red blood cells were measured. Results: Pretreatment with fi sh or seal oils did not signifi cantly infl u...
This study investigated the effects of fatty fish on sleep, daily functioning and biomarkers such... more This study investigated the effects of fatty fish on sleep, daily functioning and biomarkers such as heart rate variability (HRV), vitamin D status (serum 25-hydroxyvitamin D (25OHD), and eicosapentaenoic acid (EPA, 20:5n-3) + docosahexaenoic acid (DHA, 22:6n-3) in red blood cells. Moreover the relationship among sleep, daily functioning, HRV, vitamin D status, and levels of EPA+DHA was investigated. Ninety-five male forensic patients from a secure forensic inpatient facility in the USA were randomly assigned into a Fish or a Control group. The Fish group received Atlantic salmon three times per week from September to February, and the Control group was provided an alternative meal (e.g., chicken, pork, beef), but with the same nutritional value as their habitual diet, three times per week during the same period. Sleep (sleep latency, sleep efficiency, actual sleep time, and actual wake time), self-perceived sleep quality and daily functioning, as well as vitamin D status, EPA+DHA, and HRV, were assessed pre- and post-intervention period. There was a significant increase in sleep latency from pre- to post-test in the Control group. The Fish group reported better daily functioning than the Control group during post-test. Fish consumption throughout the wintertime had also an effect on resting HRV and EPA+DHA, but not on vitamin D status. However, at post-test, the vitamin D status in the Fish group was still closer to the level regarded as optimal compared to the Control group. Vitamin D status correlated negatively with actual wake time and positively with sleep efficiency during pre-test, as well as positively with daily functioning and sleep quality during post-test. Finally, HRV correlated negatively with sleep latency and positively with daily functioning. Fish consumption seemed to have a positive impact on sleep in general and also on daily functioning, which may be related to vitamin D status and HRV.
We investigated whether the hypolipidaemic effect of fenofibrate and fasting observed in most omn... more We investigated whether the hypolipidaemic effect of fenofibrate and fasting observed in most omnivorous mammals may also apply to herbivorous fish. Grass carp (Ctenopharyngodon idella) fed a high-fat (8 %) diet exhibited a marked increase in blood lipids and body fat after 6 weeks. They were then treated with fenofibrate (100 mg/kg body weight) in the same high-fat diet for 2 weeks, followed by fasting for 1 week. Plasma lipid concentration, body fat amount, fatty acid composition, plasma thiobarbituric acid-reactive substances and some parameters related to hepatic fatty acid oxidation were measured, and liver samples were stained for histological examination. Fenofibrate treatment decreased TAG and cholesterol concentrations in plasma, total lipids of the whole body and liver, and EPA and DHA contents in tissues. Further, a mobilisation of mesenteric fat concomitant with an increase in hepatic peroxisomal fatty acid oxidation and lipid peroxidation was observed. Compared with fenofibrate treatment, fasting decreased body weight and plasma TAG, but not plasma cholesterol. It also reduced the fat content of the whole body and increased the EPA and DHA contents in the liver and other tissues. Fatty acid oxidation was stimulated by fasting in mitochondria, but not in peroxisomes. These data suggest that fenofibrate and fasting regulate the lipid metabolism in grass carp through different metabolic pathways. The grass carp is moderately responsive to a fibrate derivative in comparison with the well-known excess responsiveness of the rat model, and so it could be used for the study of lipid abnormalities as a herbivorous model.
Though liquid chromatography electrospray tandem mass spectrometry (LC-ESI-MS 2 ) has been widely... more Though liquid chromatography electrospray tandem mass spectrometry (LC-ESI-MS 2 ) has been widely used in the structural elucidation of triacylglycerols (TAG) in vegetable oils, its potentiality for the identification of TAG molecules in omega-3 rich oils remains unexplored till date. Hence, this article investigates the applicability of LC-ESI-MS 2 for the structural characterization of naturally occurring TAG in cod liver oil without the TAG fractionation during the sample preparation. A computational algorithm was developed to automatically interpret the mass spectra and elucidate the TAG structures respectively. The results were compared against the lipase benchmark method. A principal component analysis study revealed that it is possible to discriminate genuine from adulterated cod liver oil.
Background: Polyunsaturated n-3 fatty acids (n-3 PUFAs) are reported to protect against high fat ... more Background: Polyunsaturated n-3 fatty acids (n-3 PUFAs) are reported to protect against high fat diet-induced obesity and inflammation in adipose tissue. Here we aimed to investigate if the amount of sucrose in the background diet influences the ability of n-3 PUFAs to protect against diet-induced obesity, adipose tissue inflammation and glucose intolerance.
Background: Dietary interventions are critical in the prevention of metabolic diseases. Yet, the ... more Background: Dietary interventions are critical in the prevention of metabolic diseases. Yet, the effects of fatty fish consumption on type 2 diabetes remain unclear. The aim of this study was to investigate whether a diet containing farmed salmon prevents or contributes to insulin resistance in mice.
Although the beneficial effects of n-3 fatty acids on several physiologic functions have been wid... more Although the beneficial effects of n-3 fatty acids on several physiologic functions have been widely reported, information about the effects of oily fish in the Asian diet on cardiovascular disease (CVD) risk is diminutive. We hypothesize that daily inclusion of oily fish for 8 weeks in the Chinese diet will elevate serum eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels and reduce CVD risk markers in dyslipidemic adult men, comparable with the effects generally observed by inclusion of oily fish in the Western diet. In this 8-week randomized, parallel-arm, food-based intervention study, lunches were prepared with 500 g pork/chicken/beef, typically consumed fish (hairtail and freshwater carp), or oily fish (salmon). Male subjects aged between 35 and 70 years with hyperlipidemia were randomly assigned to eat lunches with pork/chicken/beef (n = 30 subjects at 8 weeks), freshwater fish (n = 30), or oily fish (n = 32). Circulating markers were measured at baseline and at 8 weeks. In the oily fish diet, dietary EPA and DHA levels were significantly increased as compared with other diets; and the n-6:n-3 polyunsaturated fatty acid ratio was decreased (P b .05). Thus, the oily fish diet significantly elevated serum EPA and DHA concentrations (P b .01) and lowered serum n-6:n-3 ratio at 8 weeks (P b .05). Furthermore, oily fish intake significantly reduced serum levels of triglycerides (P b .05) and interleukin-6 (P b .01) and increased levels of highdensity lipoprotein cholesterol (P b .01). In conclusion, daily inclusion of oily fish as part of the Chinese diet for 8 weeks is sufficient to significantly increase the serum content of long-chain n-3 polyunsaturated fatty acids and reduce levels of CVD risk markers in dyslipidemic adult men.
Fish oils rich in n-3 fatty acids have been shown to decrease plasma lipid levels, but the underl... more Fish oils rich in n-3 fatty acids have been shown to decrease plasma lipid levels, but the underlying mechanism has not yet been elucidated. This investigation was performed in order to further clarify the effects of purified ethyl esters of eicosapentaenoic acid (EPA-EE) and docosahexaenoic acid (DHA-EE) on lipid metabolism in rats. The animals were fed EPA-EE, DHA-EE, palmitic acid, or corn oil (1 g/kg/d) by orogastrif intubation along with a chow background diet for three months. At the end the animals were sacrificed. Plasma and liver lipids were measured, as well as lipid-related enzyme activities and mRNA levels. The fatty acid composition of plasma and different tissues was also determined. This study shows that, compared to the corn oil control, EPA-EE and DHA-EE lowered plasma cholesterol level, whereas only EPA-EE lowered the amount of plasma triacylglycerol. In liver peroxisomes, both EE preparations increased fatty acyI-CoA oxidase FAO activities, and neither altered 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase activities. In liver microsomes, EPA-EE raised HMG-CoA reductase and acyI-CoAicholesterol acyltransferase activities, whereas DHA-EE lowered the former and did not affect the latter. Neither product altered mRNA levels for HMG-CoA reductase, low density lipoprotein-receptor, or low density lipoprotein-receptor related protein. EPA-EE lowered plasma triacylglycerol, reflecting lowered very low density lipoprotein secretion, thus the cholesterol lowering effect in EPA-EE-treated rats may be secondary to the hypotriacylglycerolemic effect. An inhibition of HMG-CoA reductase activity in DHA-EE treated rats may contribute to the hypocholesterolemic effect. The present study reports that 20:5n-3, and not 22:6n-3, is the fatty acid primarily responsible for the triacylglycerol lowering effect of fish oil. Finally, 20:5n-3 was not converted to 22:6n-3, whereas retroconversion of 22:6n-3 to 20:5n-3 was observed. Abbreviations: ACAT, acyl-CoA:cholesterol acyltransferase; DHA, docosahexaenoic acid; DHA-EE, DHA as ethyl ester; EPA, eicosapentaenoic acid; EPA-EE, EPA as ethyl ester; HMGq2oA, 3-hydroxy-3-methylglutaryl-CoA; LDL, low density lipoprotein; LRP-4, LDL-receptor related protein; VLDL, very low density lipoprotein.
Exploring the capabilities of instrumental techniques for discriminating n-3 rich oils derived fr... more Exploring the capabilities of instrumental techniques for discriminating n-3 rich oils derived from animals is a very important though much neglected area that was emphasized more than 100 years ago. In this study the potential of gas chromatography (GC) for discriminating full fatty acid methyl ester (FAME) profiles from fish (cod liver and salmon) and marine mammal (seal and whale) oils is evaluated by means of principal component analysis (PCA). The FAME profiles from plant oils such as rapeseed, linseed and soy oils and seven different brands of n-3 supplements are also used in the discrimination process. The results from the PCA plots can reliably distinguish between plant, n-3 supplements, fish and marine mammal oils. By removing the contribution of the n-3 supplements and plant oils it is possible to discriminate between types of fish and marine animal oils. GC offers a rapid, simple and convenient means of discriminating oils from different species, brands and grades.
Salmon farmers are currently using high-energy feeds containing up to 35% fat; the fish's capabil... more Salmon farmers are currently using high-energy feeds containing up to 35% fat; the fish's capability of fully utilizing these high-energy feeds has received little attention. Carnitine is an essential component in the process of mitochondrial fatty acid oxidation and, with the cooperation of two carnitine palmitoyltransferases (CPT-I and CPT-II) and a carnitine acylcarnitine transporter across the inner mitochondrial membrane, acts as a carrier for acyl groups into the mitochondrial matrix where β-oxidation occurs. However, no reports are available differentiating between CPT-I and CPT-II activities in fish. In order to investigate the potential for fatty acid catabolism, the activities of key enzymes involved in fatty acid oxidation were determined in different tissues from farmed Atlantic salmon (Salmo salar), i.e., acyl-CoA oxidase (ACO) and CPT-I and CPT-II. Malonyl-CoA was a potent inhibitor of CPT-I activity not only in red muscle but also in liver, white muscle, and heart. By expressing the enzyme activities per wet tissue, the CPT-I activity of white muscle equaled that of the red muscle, both being >> liver. CPT-II dominated in red muscle whereas the liver and white muscle activities were comparable. ACO activity was high in the liver regardless of how the data were calculated. Based on the CPT-II activity and total palmitoyl-L-carnitine oxidation in white muscle, the white muscle might have a profound role in the overall fatty acid oxidation capacity in fish. Lipids 33, 923-930 (1998).
Dietary intake of linoleic acid (LNA, 18:2n-6) has increased dramatically during the 20th century... more Dietary intake of linoleic acid (LNA, 18:2n-6) has increased dramatically during the 20th century and is associated with greater prevalence of obesity. The endocannabinoid system is involved in regulation of energy balance and a sustained hyperactivity of the endocannabinoid system may contribute to obesity. Arachidonic acid (ARA, 20:4n-6) is the precursor for 2-AG and anandamide (AEA), and we sought to determine if low fat diets (LFD) could be made obesogenic by increasing the endocannabinoid precursor pool of ARA, causing excessive endocannabinoid signaling leading to weight gain and a metabolic profile associated with obesity. Mice (C57BL/6j, 6 weeks of age) were fed 1 en% LNA and 8 en% LNA in low fat (12.5 en%) and medium fat diets (MFD, 35 en%) for 16 weeks. We found that increasing dietary LNA from 1 to 8 en% in LFD and MFD significantly increased ARA in phospholipids (ARA-PL), elevated 2-AG and AEA in liver, elevated plasma leptin, and resulted in larger adipocytes and more macrophage infiltration in adipose tissue. In LFD, dietary LNA of 8 en% increased feed efficiency and caused greater weight gain than in an isocaloric reduction to 1 en% LNA. Increasing dietary LNA from 1 to 8 en% elevates liver endocannabinoid levels and increases the risk of developing obesity. Thus a high dietary content of LNA (8 en%) increases the adipogenic properties of a low fat diet.
Arachidonic acid inhibits adipocyte differentiation of 3T3-L1 cells via a prostaglandin synthesis... more Arachidonic acid inhibits adipocyte differentiation of 3T3-L1 cells via a prostaglandin synthesis-dependent pathway. Here we show that this inhibition requires the presence of a cAMP-elevating agent during the first two days of treatment. Suppression of protein kinase A activity by H-89 restored differentiation in the presence of arachidonic acid. Arachidonic acid treatment led to a prolonged activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2), and suppression of ERK1/2 activity by the addition of U0126 rescued differentiation. Upon induction of differentiation, expression of cyclooxygenase-2 (COX-2) was transiently induced and then declined, whereas COX-1 expression declined gradually as differentiation progressed. Treatment with arachidonic acid led to sustained expression of COX-1 and COX-2. Omission of a cAMP-elevating agent or addition of H-89 or U0126 prevented sustained expression of COX-2. Unexpectedly, we observed that selective COX-1 or COX-2 inhibitors rescued adipocyte differentiation in the presence of arachidonic acid as effectively as did the nonselective COX-inhibitor indomethacin. De novo fatty acid synthesis, diacylglycerol acyltransferase (DGAT) activity, and triacylglycerol accumulation were repressed in cells treated with arachidonic acid. Indomethacin restored DGAT activity and triacylglycerol accumulation without restoring de novo fatty acid synthesis, resulting in an enhanced incorporation of arachidonic acid into cellular triacylglycerolsArachidonic aciddependent inhibition of adipocyte differentiation requires PKA activity and is associated with sustained expression of cyclooxygenases. J. Lipid Res. 2003. 44: 2320-2330.
Conclusion: No significant differences in the two treatment groups were seen; in both groups, the... more Conclusion: No significant differences in the two treatment groups were seen; in both groups, the changes in several joint pain parameters, leucotriene B 4 level of plasma, and serum fatty acid profile were putatively favourable. ª
Background/Aim: Subjective food hypersensitivity is prevalent in the general population. The aim ... more Background/Aim: Subjective food hypersensitivity is prevalent in the general population. The aim of this study was to seek objective evidence of food hypersensitivity by analyzing intestinal permeability and inflammation markers in gut lavage fluid. Methods: Fifty-two patients with abdominal complaints self-attributed to food hypersensitivity were examined by skin prick test, serum IgE analysis, double-blind, placebo-controlled food challenge (DBPCFC), and intestinal
A high dietary intake of n-6 compared to n-3 fatty acids (FAs) may promote the production of pro-... more A high dietary intake of n-6 compared to n-3 fatty acids (FAs) may promote the production of pro-inflammatory eicosanoids and cytokines. In two recent studies, short-term (10-day) duodenal administration of n-3 polyunsaturated fatty acid rich seal oil ameliorated joint pain in patients with inflammatory bowel disease (IBD). Using unpublished data from these two studies we here investigated whether normalisation of the n-6 to n-3 FA ratio in blood and tissues by seal oil administration was associated with improved health related quality of life (HRQOL) as assessed by the generic short-form 36 (SF-36) questionnaire. In the first pilot study, baseline n-6 to n-3 FA ratio in rectal mucosal biopsies from 10 patients with IBD (9 of those had joint pain) was significantly increased compared with that in 10 control patients without IBD or joint pain. Following seal oil administration, the n-6 to n-3 FA ratio of the IBD-patients was significantly lowered to the level seen in untreated contro...
The 3-thia fatty acids, tetradecylthioacetic acid and 3,10-dithiadicarboxylic acid are mitochondr... more The 3-thia fatty acids, tetradecylthioacetic acid and 3,10-dithiadicarboxylic acid are mitochondrion and peroxisome proliferators. Administration of these promotes an increased transport of endogenous fatty acids to these organelles and a higher capacity of beta-oxidation. Administration of 3-thia fatty acids to rats resulted in a significant decrease of the hepatic level of docosahexaenoic acid (DHA) (17-24%) and especially eicosapentaenoic acid (EPA) (40-80%) accompanied by increased gene expression of mitochondrial 2,4-dienoyl-CoA reductase and enoyl-CoA isomerase. The mitochondrial oxidation of EPA was increased more than 4-fold after administration of 3-thia fatty acids. EPA-CoA was a good substrate for mitochondrial carnitine acyltransferase-I and treatment with 3-thia fatty acids increased the activity 1.7-fold. DHA was a poor substrate for both mitochondrial and peroxisomal beta-oxidation. DHA-CoA was a very poor substrate for mitochondrial carnitine acyltransferase-I and -I...
The aim of the present study was to investigate the effects of Atlantic salmon consumption on und... more The aim of the present study was to investigate the effects of Atlantic salmon consumption on underlying biological mechanisms associated with anxiety such as heart rate variability (HRV) and heart rate (HR) as well as a measure of self-reported anxiety. Moreover, these biological and self-reported outcome measures were investigated in relation to specific nutrients; vitamin D status, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Ninety-five male forensic inpatients were randomly assigned into a Fish (Atlantic salmon three times per week from September to February) or a Control group (alternative meal, e.g., chicken, pork, or beef three times per week during the same period). HRV measured as the root mean square of successive differences (rMSSD), HR, state-and trait-anxiety (STAI), were assessed before (pre-test) and at the end of the 23 weeks dietary
Background: Omega-3 (n-3) polyunsaturated fatty acids (PUFAs) have modulating effects in several ... more Background: Omega-3 (n-3) polyunsaturated fatty acids (PUFAs) have modulating effects in several chronic infl amma- tory conditions. The aim of the present study was to test whether prior short-term dietary supplementation with n-3 (fi sh or seal oil) or n-6 (soy oil) PUFA rich oils would protect the development of dextran sulfate sodium (DSS)-induced colitis in rats. Methods: Forty-eight male Wistar rats were divided into 6 groups: no intervention, sham, DSS, seal oil + DSS, fi sh oil + DSS and soy oil + DSS. Following 7 days of acclimatisation, 1 mL oil (seal, fi sh or soy) or distilled water (sham) was administered by gavage day 8 to 14. Colitis was induced by 5% DSS in drinking water from day 15 to 21. Rats were sacri- fi ced on day 23. Histological colitis (crypt and infl ammation) scores, faecal granulocyte marker protein (GMP) and quan- titative fatty acid composition in red blood cells were measured. Results: Pretreatment with fi sh or seal oils did not signifi cantly infl u...
This study investigated the effects of fatty fish on sleep, daily functioning and biomarkers such... more This study investigated the effects of fatty fish on sleep, daily functioning and biomarkers such as heart rate variability (HRV), vitamin D status (serum 25-hydroxyvitamin D (25OHD), and eicosapentaenoic acid (EPA, 20:5n-3) + docosahexaenoic acid (DHA, 22:6n-3) in red blood cells. Moreover the relationship among sleep, daily functioning, HRV, vitamin D status, and levels of EPA+DHA was investigated. Ninety-five male forensic patients from a secure forensic inpatient facility in the USA were randomly assigned into a Fish or a Control group. The Fish group received Atlantic salmon three times per week from September to February, and the Control group was provided an alternative meal (e.g., chicken, pork, beef), but with the same nutritional value as their habitual diet, three times per week during the same period. Sleep (sleep latency, sleep efficiency, actual sleep time, and actual wake time), self-perceived sleep quality and daily functioning, as well as vitamin D status, EPA+DHA, and HRV, were assessed pre- and post-intervention period. There was a significant increase in sleep latency from pre- to post-test in the Control group. The Fish group reported better daily functioning than the Control group during post-test. Fish consumption throughout the wintertime had also an effect on resting HRV and EPA+DHA, but not on vitamin D status. However, at post-test, the vitamin D status in the Fish group was still closer to the level regarded as optimal compared to the Control group. Vitamin D status correlated negatively with actual wake time and positively with sleep efficiency during pre-test, as well as positively with daily functioning and sleep quality during post-test. Finally, HRV correlated negatively with sleep latency and positively with daily functioning. Fish consumption seemed to have a positive impact on sleep in general and also on daily functioning, which may be related to vitamin D status and HRV.
We investigated whether the hypolipidaemic effect of fenofibrate and fasting observed in most omn... more We investigated whether the hypolipidaemic effect of fenofibrate and fasting observed in most omnivorous mammals may also apply to herbivorous fish. Grass carp (Ctenopharyngodon idella) fed a high-fat (8 %) diet exhibited a marked increase in blood lipids and body fat after 6 weeks. They were then treated with fenofibrate (100 mg/kg body weight) in the same high-fat diet for 2 weeks, followed by fasting for 1 week. Plasma lipid concentration, body fat amount, fatty acid composition, plasma thiobarbituric acid-reactive substances and some parameters related to hepatic fatty acid oxidation were measured, and liver samples were stained for histological examination. Fenofibrate treatment decreased TAG and cholesterol concentrations in plasma, total lipids of the whole body and liver, and EPA and DHA contents in tissues. Further, a mobilisation of mesenteric fat concomitant with an increase in hepatic peroxisomal fatty acid oxidation and lipid peroxidation was observed. Compared with fenofibrate treatment, fasting decreased body weight and plasma TAG, but not plasma cholesterol. It also reduced the fat content of the whole body and increased the EPA and DHA contents in the liver and other tissues. Fatty acid oxidation was stimulated by fasting in mitochondria, but not in peroxisomes. These data suggest that fenofibrate and fasting regulate the lipid metabolism in grass carp through different metabolic pathways. The grass carp is moderately responsive to a fibrate derivative in comparison with the well-known excess responsiveness of the rat model, and so it could be used for the study of lipid abnormalities as a herbivorous model.
Though liquid chromatography electrospray tandem mass spectrometry (LC-ESI-MS 2 ) has been widely... more Though liquid chromatography electrospray tandem mass spectrometry (LC-ESI-MS 2 ) has been widely used in the structural elucidation of triacylglycerols (TAG) in vegetable oils, its potentiality for the identification of TAG molecules in omega-3 rich oils remains unexplored till date. Hence, this article investigates the applicability of LC-ESI-MS 2 for the structural characterization of naturally occurring TAG in cod liver oil without the TAG fractionation during the sample preparation. A computational algorithm was developed to automatically interpret the mass spectra and elucidate the TAG structures respectively. The results were compared against the lipase benchmark method. A principal component analysis study revealed that it is possible to discriminate genuine from adulterated cod liver oil.
Background: Polyunsaturated n-3 fatty acids (n-3 PUFAs) are reported to protect against high fat ... more Background: Polyunsaturated n-3 fatty acids (n-3 PUFAs) are reported to protect against high fat diet-induced obesity and inflammation in adipose tissue. Here we aimed to investigate if the amount of sucrose in the background diet influences the ability of n-3 PUFAs to protect against diet-induced obesity, adipose tissue inflammation and glucose intolerance.
Background: Dietary interventions are critical in the prevention of metabolic diseases. Yet, the ... more Background: Dietary interventions are critical in the prevention of metabolic diseases. Yet, the effects of fatty fish consumption on type 2 diabetes remain unclear. The aim of this study was to investigate whether a diet containing farmed salmon prevents or contributes to insulin resistance in mice.
Although the beneficial effects of n-3 fatty acids on several physiologic functions have been wid... more Although the beneficial effects of n-3 fatty acids on several physiologic functions have been widely reported, information about the effects of oily fish in the Asian diet on cardiovascular disease (CVD) risk is diminutive. We hypothesize that daily inclusion of oily fish for 8 weeks in the Chinese diet will elevate serum eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels and reduce CVD risk markers in dyslipidemic adult men, comparable with the effects generally observed by inclusion of oily fish in the Western diet. In this 8-week randomized, parallel-arm, food-based intervention study, lunches were prepared with 500 g pork/chicken/beef, typically consumed fish (hairtail and freshwater carp), or oily fish (salmon). Male subjects aged between 35 and 70 years with hyperlipidemia were randomly assigned to eat lunches with pork/chicken/beef (n = 30 subjects at 8 weeks), freshwater fish (n = 30), or oily fish (n = 32). Circulating markers were measured at baseline and at 8 weeks. In the oily fish diet, dietary EPA and DHA levels were significantly increased as compared with other diets; and the n-6:n-3 polyunsaturated fatty acid ratio was decreased (P b .05). Thus, the oily fish diet significantly elevated serum EPA and DHA concentrations (P b .01) and lowered serum n-6:n-3 ratio at 8 weeks (P b .05). Furthermore, oily fish intake significantly reduced serum levels of triglycerides (P b .05) and interleukin-6 (P b .01) and increased levels of highdensity lipoprotein cholesterol (P b .01). In conclusion, daily inclusion of oily fish as part of the Chinese diet for 8 weeks is sufficient to significantly increase the serum content of long-chain n-3 polyunsaturated fatty acids and reduce levels of CVD risk markers in dyslipidemic adult men.
Fish oils rich in n-3 fatty acids have been shown to decrease plasma lipid levels, but the underl... more Fish oils rich in n-3 fatty acids have been shown to decrease plasma lipid levels, but the underlying mechanism has not yet been elucidated. This investigation was performed in order to further clarify the effects of purified ethyl esters of eicosapentaenoic acid (EPA-EE) and docosahexaenoic acid (DHA-EE) on lipid metabolism in rats. The animals were fed EPA-EE, DHA-EE, palmitic acid, or corn oil (1 g/kg/d) by orogastrif intubation along with a chow background diet for three months. At the end the animals were sacrificed. Plasma and liver lipids were measured, as well as lipid-related enzyme activities and mRNA levels. The fatty acid composition of plasma and different tissues was also determined. This study shows that, compared to the corn oil control, EPA-EE and DHA-EE lowered plasma cholesterol level, whereas only EPA-EE lowered the amount of plasma triacylglycerol. In liver peroxisomes, both EE preparations increased fatty acyI-CoA oxidase FAO activities, and neither altered 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase activities. In liver microsomes, EPA-EE raised HMG-CoA reductase and acyI-CoAicholesterol acyltransferase activities, whereas DHA-EE lowered the former and did not affect the latter. Neither product altered mRNA levels for HMG-CoA reductase, low density lipoprotein-receptor, or low density lipoprotein-receptor related protein. EPA-EE lowered plasma triacylglycerol, reflecting lowered very low density lipoprotein secretion, thus the cholesterol lowering effect in EPA-EE-treated rats may be secondary to the hypotriacylglycerolemic effect. An inhibition of HMG-CoA reductase activity in DHA-EE treated rats may contribute to the hypocholesterolemic effect. The present study reports that 20:5n-3, and not 22:6n-3, is the fatty acid primarily responsible for the triacylglycerol lowering effect of fish oil. Finally, 20:5n-3 was not converted to 22:6n-3, whereas retroconversion of 22:6n-3 to 20:5n-3 was observed. Abbreviations: ACAT, acyl-CoA:cholesterol acyltransferase; DHA, docosahexaenoic acid; DHA-EE, DHA as ethyl ester; EPA, eicosapentaenoic acid; EPA-EE, EPA as ethyl ester; HMGq2oA, 3-hydroxy-3-methylglutaryl-CoA; LDL, low density lipoprotein; LRP-4, LDL-receptor related protein; VLDL, very low density lipoprotein.
Exploring the capabilities of instrumental techniques for discriminating n-3 rich oils derived fr... more Exploring the capabilities of instrumental techniques for discriminating n-3 rich oils derived from animals is a very important though much neglected area that was emphasized more than 100 years ago. In this study the potential of gas chromatography (GC) for discriminating full fatty acid methyl ester (FAME) profiles from fish (cod liver and salmon) and marine mammal (seal and whale) oils is evaluated by means of principal component analysis (PCA). The FAME profiles from plant oils such as rapeseed, linseed and soy oils and seven different brands of n-3 supplements are also used in the discrimination process. The results from the PCA plots can reliably distinguish between plant, n-3 supplements, fish and marine mammal oils. By removing the contribution of the n-3 supplements and plant oils it is possible to discriminate between types of fish and marine animal oils. GC offers a rapid, simple and convenient means of discriminating oils from different species, brands and grades.
Salmon farmers are currently using high-energy feeds containing up to 35% fat; the fish's capabil... more Salmon farmers are currently using high-energy feeds containing up to 35% fat; the fish's capability of fully utilizing these high-energy feeds has received little attention. Carnitine is an essential component in the process of mitochondrial fatty acid oxidation and, with the cooperation of two carnitine palmitoyltransferases (CPT-I and CPT-II) and a carnitine acylcarnitine transporter across the inner mitochondrial membrane, acts as a carrier for acyl groups into the mitochondrial matrix where β-oxidation occurs. However, no reports are available differentiating between CPT-I and CPT-II activities in fish. In order to investigate the potential for fatty acid catabolism, the activities of key enzymes involved in fatty acid oxidation were determined in different tissues from farmed Atlantic salmon (Salmo salar), i.e., acyl-CoA oxidase (ACO) and CPT-I and CPT-II. Malonyl-CoA was a potent inhibitor of CPT-I activity not only in red muscle but also in liver, white muscle, and heart. By expressing the enzyme activities per wet tissue, the CPT-I activity of white muscle equaled that of the red muscle, both being >> liver. CPT-II dominated in red muscle whereas the liver and white muscle activities were comparable. ACO activity was high in the liver regardless of how the data were calculated. Based on the CPT-II activity and total palmitoyl-L-carnitine oxidation in white muscle, the white muscle might have a profound role in the overall fatty acid oxidation capacity in fish. Lipids 33, 923-930 (1998).
Dietary intake of linoleic acid (LNA, 18:2n-6) has increased dramatically during the 20th century... more Dietary intake of linoleic acid (LNA, 18:2n-6) has increased dramatically during the 20th century and is associated with greater prevalence of obesity. The endocannabinoid system is involved in regulation of energy balance and a sustained hyperactivity of the endocannabinoid system may contribute to obesity. Arachidonic acid (ARA, 20:4n-6) is the precursor for 2-AG and anandamide (AEA), and we sought to determine if low fat diets (LFD) could be made obesogenic by increasing the endocannabinoid precursor pool of ARA, causing excessive endocannabinoid signaling leading to weight gain and a metabolic profile associated with obesity. Mice (C57BL/6j, 6 weeks of age) were fed 1 en% LNA and 8 en% LNA in low fat (12.5 en%) and medium fat diets (MFD, 35 en%) for 16 weeks. We found that increasing dietary LNA from 1 to 8 en% in LFD and MFD significantly increased ARA in phospholipids (ARA-PL), elevated 2-AG and AEA in liver, elevated plasma leptin, and resulted in larger adipocytes and more macrophage infiltration in adipose tissue. In LFD, dietary LNA of 8 en% increased feed efficiency and caused greater weight gain than in an isocaloric reduction to 1 en% LNA. Increasing dietary LNA from 1 to 8 en% elevates liver endocannabinoid levels and increases the risk of developing obesity. Thus a high dietary content of LNA (8 en%) increases the adipogenic properties of a low fat diet.
Arachidonic acid inhibits adipocyte differentiation of 3T3-L1 cells via a prostaglandin synthesis... more Arachidonic acid inhibits adipocyte differentiation of 3T3-L1 cells via a prostaglandin synthesis-dependent pathway. Here we show that this inhibition requires the presence of a cAMP-elevating agent during the first two days of treatment. Suppression of protein kinase A activity by H-89 restored differentiation in the presence of arachidonic acid. Arachidonic acid treatment led to a prolonged activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2), and suppression of ERK1/2 activity by the addition of U0126 rescued differentiation. Upon induction of differentiation, expression of cyclooxygenase-2 (COX-2) was transiently induced and then declined, whereas COX-1 expression declined gradually as differentiation progressed. Treatment with arachidonic acid led to sustained expression of COX-1 and COX-2. Omission of a cAMP-elevating agent or addition of H-89 or U0126 prevented sustained expression of COX-2. Unexpectedly, we observed that selective COX-1 or COX-2 inhibitors rescued adipocyte differentiation in the presence of arachidonic acid as effectively as did the nonselective COX-inhibitor indomethacin. De novo fatty acid synthesis, diacylglycerol acyltransferase (DGAT) activity, and triacylglycerol accumulation were repressed in cells treated with arachidonic acid. Indomethacin restored DGAT activity and triacylglycerol accumulation without restoring de novo fatty acid synthesis, resulting in an enhanced incorporation of arachidonic acid into cellular triacylglycerolsArachidonic aciddependent inhibition of adipocyte differentiation requires PKA activity and is associated with sustained expression of cyclooxygenases. J. Lipid Res. 2003. 44: 2320-2330.
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