Does dietary fat affect inflammatory markers in overweight and obese individuals?-a review of randomized controlled trials from 2010 to 2016

Background

Obesity, a major cause of death and disability, is increasing worldwide. Obesity is characterized by a chronic, low-grade inflammatory state which is suggested to play a critical role in the development of obesity-related diseases like cardiovascular diseases and type 2 diabetes. In fact, in the hours following consumption of a meal, a transient increase in inflammatory markers occurs, a response that is exaggerated in obese subjects. Dietary composition, including content of dietary fatty acids, may affect this inflammatory response both acutely and chronically, and thereby be predictive of progression of disease. The aim of the review was to summarize the literature from 2010 to 2016 regarding the effects of dietary fat intake on levels of inflammatory markers in overweight and obesity in human randomized controlled trials.

Methods and results

We performed a literature search in MEDLINE, EMBASE, and PubMed databases. The literature search included human randomized controlled trials, both postprandial and long-term interventions, from January 2010 to September 2016. In total, 37 articles were included. Interventions with dairy products, vegetable oils, or nuts showed minor effects on inflammatory markers. The most consistent inflammatory-mediating effects were found in intervention with whole diets, which suggests that many components of the diet reduce inflammation synergistically. Furthermore, interventions with weight reduction and different fatty acids did not clearly show beneficial effects on inflammatory markers.

Conclusion

Most interventions showed either no or minor effects of dietary fat intake on inflammatory markers in overweight and obese subjects. To progress our understanding on how diet and dietary components affect our health, mechanistic studies are required. Hence, future studies should include whole diets and characterization of obese phenotypes at a molecular level, including omics data and gut microbiota.

Comprehensive lipid and metabolite profiling of children with and without familial hypercholesterolemia: A cross-sectional study

BACKGROUND AND AIMS

Individuals with familial hypercholesterolemia (FH) have elevated low-density lipoprotein cholesterol (LDL-C), accelerated atherosclerosis, and premature cardiovascular disease. Whereas children with lifestyle-induced dyslipidemias often present with complex lipid abnormalities, children with FH have isolated hypercholesterolemia. However, to the best of our knowledge, a comprehensive profiling of FH children is lacking. Therefore, we aimed to characterize the lipid-related and metabolic alterations associated with elevated LDL-C in children with FH and healthy children.

METHODS

We measured plasma metabolites in children with FH (n = 47) and in healthy children (n = 57) using a high-throughput nuclear magnetic resonance (NMR) spectroscopy platform, and compared the differences between FH and healthy children.

RESULTS

Both statin treated (n = 17) and non-statin treated FH children (n = 30) had higher levels of atherogenic ApoB-containing lipoproteins and lipids, and lipid fractions in lipoprotein subclasses, compared to healthy children (n = 57). FH children displayed alterations in HDL particle concentration and lipid content, compared with healthy children. Interestingly, the small HDL particles were characterized by higher content of cholesteryl esters, and lower levels of free cholesterol and phospholipids. Furthermore, plasma fatty acids were higher in non-statin treated FH children, particularly linoleic acid. Finally, acetoacetate and acetate were lower in FH children compared with healthy children.

CONCLUSIONS

Hypercholesterolemia in children associates with diverse metabolic repercussions and is more complex than previously believed. In particular, we found that hypercholesterolemia in FH children was paralleled not only by increased atherogenic ApoB-containing lipoproteins and lipid fractions, but also alterations in HDL subfractions that suggest impaired reverse cholesterol transport.

Severe hypertriglyceridemia in Norway: prevalence, clinical and genetic characteristics

BACKGROUND

There is a lack of comprehensive patient-datasets regarding prevalence of severe hypertriglyceridemia (sHTG; triglycerides ≥10 mmol/L), frequency of co-morbidities, gene mutations, and gene characterization in sHTG. Using large surveys combined with detailed analysis of sub-cohorts of sHTG patients, we here sought to address these issues.

METHODS

We used data from several large Norwegian surveys that included 681,990 subjects, to estimate the prevalence. Sixty-five sHTG patients were investigated to obtain clinical profiles and candidate disease genes. We obtained peripheral blood mononuclear cells (PBMC) from six male patients and nine healthy controls and examined expression of mRNAs involved in lipid metabolism.

RESULTS

The prevalence of sHTG was 0.13 (95% CI 0.12-0.14)%, and highest in men aged 40-49 years and in women 60-69 years. Among the 65 sHTG patients, a possible genetic cause was found in four and 11 had experienced acute pancreatitis. The mRNA expression levels of carnitine palmitoyltransferase (CPT)-1A, CPT2, and hormone-sensitive lipase, were significantly higher in patients compared to controls, whereas those of ATP-binding cassette, sub-family G, member 1 were significantly lower.

CONCLUSIONS

In Norway, sHTG is present in 0.1%, carries considerable co-morbidity and is associated with an imbalance of genes involved in lipid metabolism, all potentially contributing to increased cardiovascular morbidity in sHTG.

Recommended Nordic diet and risk markers for cardiovascular disease

BACKGROUND

Cardiovascular diseases are among the main causes of morbidity and mortality in Norway. The objective of this article is to provide an overview of literature that describes the effect of a Nordic diet in line with the authorities’ dietary advice on risk factors for cardiovascular disease.

METHOD

Electronic literature searches were undertaken in the PubMed, Cochrane and Embase databases. Randomised, controlled studies that described the Nordic diet and cardiovascular disease were included. A total of 15 articles were included. These are based on four dietary intervention studies conducted in the Nordic countries.

RESULTS

All of the dietary intervention studies indicated effects on blood lipids. In one of the studies, a Nordic diet caused a 21 % reduction in LDL cholesterol levels. Three of the studies showed that a Nordic diet reduces blood pressure. Results from two of the studies showed that it also improved glucose and insulin sensitivity, but after adjustment for weight loss, this effect disappeared. Three of the studies showed that a Nordic diet may positively affect inflammation.

INTERPRETATION

A diet based on the authorities’ dietary recommendation and consisting of Nordic ingredients improves the risk profile in those who are predisposed to developing cardiovascular disease.

Gene expression is differentially regulated in skeletal muscle and circulating immune cells in response to an acute bout of high-load strength exercise

Background

High-intensity exercise induces many metabolic responses. In is unknown whether the response in the peripheral blood mononuclear cells (PBMCs) reflects the response in skeletal muscle and whether mRNA expression after exercise can be modulated by nutritional intake.

The aims were to (i) investigate the effect of dairy proteins on acute responses to exercise in skeletal muscle and PBMCs measuring gene expression and (ii) compare this response in young and older subjects.

Methods

We performed two separate studies in young (20–40 years) and older subjects (≥70 years). Subjects were randomly allocated to a milk group or a whey group. Supplements were provided immediately after a standardized exercise session. We measured mRNA expression of selected genes after a standardized breakfast and 60/120 min after finishing the exercise, using RT-qPCR.

Results

We observed no significant differences in mRNA expression between the milk and the whey group; thus, we merged both groups for further analysis. The mRNA expression of IL6, TNF, and CCL2 in skeletal muscle increased significantly after exercise compared with smaller or no increase, in mRNA expression in PBMCs in all participants. The mRNA expression of IL1RN, IL8, and IL10 increased significantly in skeletal muscle and PBMCs. Some mRNA transcripts were differently regulated in older compared to younger participants in PBMCs.

Conclusions

An acute bout of heavy-load strength exercise, followed by protein supplementation, caused overlapping, but also unique, responses in skeletal muscle and PBMCs, suggesting tissue-specific functions in response to exercise. However, no different effects of the different protein supplements were observed. Altered mRNA expressions in PBMCs of older participants may affect regenerative mechanisms.

Electronic supplementary material

The online version of this article (doi:10.1186/s12263-017-0556-4) contains supplementary material, which is available to authorized users.

Intake of a Protein-Enriched Milk and Effects on Muscle Mass and Strength. A 12-Week Randomized Placebo Controlled Trial among Community-Dwelling Older Adults

OBJECTIVES

To investigate the effect of 20 g protein with breakfast and evening meal on muscle mass, muscle strength and functional performance in older adults.

DESIGN

A double-blinded randomized controlled study.

SETTING

Oslo and Akershus University College of Applied Sciences, Norway.

PARTICIPANTS

Healthy community-dwelling men and women (≥ 70 years) with reduced physical strength and/or performance.

INTERVENTION

Subjects were randomly assigned to receive either protein-enriched milk (2 x 0.4 L/d; protein group) or an isocaloric carbohydrate drink (2 x 0.4 L/d; control group) with breakfast and evening meal for 12 weeks.

MEASUREMENTS

The primary endpoints were muscle mass measured by dual X-ray absorptiometry, and tests of muscle strength (one repetition maximum test of chest press and leg press) and functional performance (handgrip strength, stair calimb and repeated chair rise).

RESULTS

In total, 438 subjects were screened, 50 subjects were randomized and 36 completed the study. Chest press improved significantly in the protein (1.3 kg (0.1-2.5), p=0.03) and the control group (1.5 kg (0.0-3.0), p=0.048), but with no difference between the groups (p=0.85). No significant change in leg press (p=0.93) or muscle mass (p=0.54) were observed between the protein and the control group. Nor did we observe any significant differences in the functional performance tests (p>0.05 for all tests) between the groups.

CONCLUSION

Increased protein intake (2 x 20 g/d) did not significantly improve muscle mass, muscle strength or functional performance in healthy older weight stable adults. Whether intake of > 20 g protein to each meal is necessary for preservation of muscle mass and strength in older adults should be further investigated in a larger study. This underscores the need for well-designed studies that can differentiate between the effect of protein intake and increased energy. This trial was registered at Clinicaltrials.gov (ID no. NCT02218333).

Data on circulating leukocyte subpopulations and inflammatory proteins in children with familial hypercholesterolemia and healthy children

The data in this relies on a previous publication: "Altered leukocyte distribution under hypercholesterolemia: a cross-sectional study in children with familial hypercholesterolemia" (Christensen et al. 2016) [1]. In the present paper, whole blood leukocyte distribution and plasma inflammatory proteins were measured for association with cholesterol concentration and CRP in children with familial hypercholesterolemia (FH) and healthy children.

Cardiovascular disease mortality in patients with genetically verified familial hypercholesterolemia in Norway during 1992-2013

Background Patients with familial hypercholesterolemia have increased cardiovascular disease mortality but the magnitude of the increased risk is uncertain. The primary aim of this study was to investigate all causes of death and place and manner of deaths in a large sample of genotyped familial hypercholesterolemia patients. Design, methods and results In this registry study data on 5518 patients with genotyped familial hypercholesterolemia were linked to the Norwegian Cause of Death Registry during 1992-2013. Standardized mortality ratios and 95% confidence intervals (CIs) were estimated. There were in total 189 deaths. Cardiovascular disease was the most common cause of death (42.3%). Mean age at cardiovascular disease death was 64.5 years (range 33-91). Cardiovascular disease mortality including all cardiovascular disease deaths mentioning any place on the death certificate was significantly higher in familial hypercholesterolemia patients compared to the general Norwegian population under 70 years of age. Standardized mortality ratio (95% CI) was highest in the 20-39 years age group; 4.12 (1.85-9.18) decreasing to 0.77 (0.50-1.19) for those over 80 years. For total cardiovascular disease deaths occurring out of hospital, standardized mortality ratio was 12.35 (5.14-29.70) for those aged 20-39 years. Conclusion Familial hypercholesterolemia patients under 70 years of age have significantly higher cardiovascular disease mortality compared to the general Norwegian population. For those aged 20-39 years the risk of cardiovascular disease deaths occurring out of hospital was increased 12-fold. In spite of genotyped familial hypercholesterolemia and premature cardiovascular disease deaths, the majority of all death certificates did not include familial hypercholesterolemia among any of the contributing causes of death.

LIGHT/TNFSF14 is increased in patients with type 2 diabetes mellitus and promotes islet cell dysfunction and endothelial cell inflammation in vitro

AIMS/HYPOTHESIS

Activation of inflammatory pathways is involved in the pathogenesis of type 2 diabetes mellitus. On the basis of its role in vascular inflammation and in metabolic disorders, we hypothesised that the TNF superfamily (TNFSF) member 14 (LIGHT/TNFSF14) could be involved in the pathogenesis of type 2 diabetes mellitus.

METHODS

Plasma levels of LIGHT were measured in two cohorts of type 2 diabetes mellitus patients (191 Italian and 40 Norwegian). Human pancreatic islet cells and arterial endothelial cells were used to explore regulation and relevant effects of LIGHT in vitro.

RESULTS

Our major findings were: (1) in both diabetic cohorts, plasma levels of LIGHT were significantly raised compared with sex- and age-matched healthy controls (n = 32); (2) enhanced release from activated platelets seems to be an important contributor to the raised LIGHT levels in type 2 diabetes mellitus; (3) in human pancreatic islet cells, inflammatory cytokines increased the release of LIGHT and upregulated mRNA and protein levels of the LIGHT receptors lymphotoxin β receptor (LTβR) and TNF receptor superfamily member 14 (HVEM/TNFRSF14); (4) in these cells, LIGHT attenuated the insulin release in response to high glucose at least partly via pro-apoptotic effects; and (5) in human arterial endothelial cells, glucose boosted inflammatory response to LIGHT, accompanied by an upregulation of mRNA levels of HVEM (also known as TNFRSF14) and LTβR (also known as LTBR).

CONCLUSIONS/INTERPRETATION

Our findings show that patients with type 2 diabetes mellitus are characterised by increased plasma LIGHT levels. Our in vitro findings suggest that LIGHT may contribute to the progression of type 2 diabetes mellitus by attenuating insulin secretion in pancreatic islet cells and by contributing to vascular inflammation.

Lack of Effects of a Single High-Fat Meal Enriched with Vegetable n-3 or a Combination of Vegetable and Marine n-3 Fatty Acids on Intestinal Peptide Release and Adipokines in Healthy Female Subjects

Peptides released from the small intestine and colon regulate short-term food intake by suppressing appetite and inducing satiety. Intake of marine omega-3 (n-3) fatty acids (FAs) from fish and fish oils is associated with beneficial health effects, whereas the relation between intake of the vegetable n-3 fatty acid α-linolenic acid and diseases is less clear. The aim of the present study was to investigate the postprandial effects of a single high-fat meal enriched with vegetable n-3 or a combination of vegetable and marine n-3 FAs with their different unsaturated fatty acid composition on intestinal peptide release and the adipose tissue. Fourteen healthy lean females consumed three test meals with different fat quality in a fixed order. The test meal consisted of three cakes enriched with coconut fat, linseed oil, and a combination of linseed and cod liver oil. The test days were separated by 2 weeks. Fasting and postprandial blood samples at 3 and 6 h after intake were analyzed. A significant postprandial effect was observed for cholecystokinin, peptide YY, glucose-dependent insulinotropic polypeptide, amylin and insulin, which increased, while leptin decreased postprandially independent of the fat composition in the high-fat meal. In conclusion, in healthy, young, lean females, an intake of a high-fat meal enriched with n-3 FAs from different origin stimulates intestinal peptide release without any difference between the different fat compositions.

Does intrauterine exposure to hypercholesterolemia adversely affect familial hypercholesterolemia phenotype?

PURPOSE OF REVIEW

There is currently limited information as to whether maternally or paternally inherited familial hypercholesterolemia confers different phenotype risk to offspring. Knowledge about the differences in risk conferred by inheritance could be important with respect to follow-up and more individually targeted treatment of subjects with familial hypercholesterolemia.

RECENT FINDINGS

Few studies have, with inconsistent results so far, investigated the significance of familial hypercholesterolemia inheritance on cardiovascular risk markers in offspring. Maternal inheritance of familial hypercholesterolemia includes hypercholesterolemic in-utero conditions for the offspring. How this may influence later risk is briefly discussed in the article.

SUMMARY

Current data suggest that the dominating factor of the familial hypercholesterolemia (FH) phenotype is the mutation and not the inheritance, however, maternal inheritance of FH has been reported to adversely affect FH phenotype in terms of increased mortality. More knowledge about how intrauterine hypercholesterolemia during pregnancy influences epigenetic modifications and later cardiovascular disease risk in offspring is needed and this may open up new avenues of treatment of pregnant women with familial hypercholesterolemia.

Dietary counseling is associated with an improved lipid profile in children with familial hypercholesterolemia

BACKGROUND AND AIMS

Familial hypercholesterolemia (FH) is a genetic disorder characterized by elevated levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C). Guidelines recommend cholesterol-lowering medication from 8 to 10 years of age and dietary recommendations. Little is known about the diet of FH children and the effect of dietary counseling. The aim of the study was to describe the diet of FH children with respect to fat quality, and to investigate if dietary counseling improved lipid profile.

METHODS

Fifty-four FH children (5-18 years) were included in the study and dietary intake was recorded with a pre-coded food diary for four days. Information about plasma lipid levels was obtained.

RESULTS

Median intake of total fat, monounsaturated fat, polyunsaturated fat (PUFA) and saturated fat (SFA) was 30.8, 10.4, 5.9 and 12.0 E %, respectively. Among non-statin treated FH children, SFA intake was significantly correlated with TC, LDL-C and apolipoprotein (apo) B (rsp = 0.55; p = 0.004, rsp = 0.46; p = 0.02, and rsp = 0.45; p = 0.02, respectively), and PUFA/SFA ratio significantly inversely correlated with TC (rsp = -0.42; p = 0.03). Compared to the first visit, non-statin and non-plant sterol treated FH children (n = 10) had significantly reduced levels of TC (p < 0.01), LDL-C (p = 0.01), high-density lipoprotein cholesterol (p = 0.02), apo B (p = 0.05) and apo A-1 (p = 0.02) levels at a later visit.

CONCLUSIONS

FH children had a higher intake of SFA than recommended and the SFA intake was positively correlated with plasma TC, LDL-C and apo B levels in FH children not using statins. Importantly, the plasma lipid profile was improved in FH children after dietary counseling where focus was on reducing intake of SFA and dietary cholesterol.

The PBMC transcriptome profile after intake of oxidized versus high-quality fish oil: an explorative study in healthy subjects

BACKGROUND

Marine long-chain polyunsaturated fatty acids are susceptible to oxidation, generating a range of different oxidation products with suggested negative health effects. The aim of the present study was to utilize sensitive high-throughput transcriptome analyses to investigate potential unfavorable effects of oxidized fish oil (PV: 18 meq/kg; AV: 9) compared to high-quality fish oil (PV: 4 meq/kg; AV: 3).

METHODS

In a double-blinded randomized controlled study for seven weeks, 35 healthy subjects were assigned to 8 g of either oxidized fish oil or high quality fish oil. The daily dose of EPA+DHA was 1.6 g. Peripheral blood mononuclear cells were isolated at baseline and after 7 weeks and transcriptome analyses were performed with the illuminaHT-12 v4 Expression BeadChip.

RESULTS

No gene transcripts, biological processes, pathway or network were significantly changed in the oxidized fish oil group compared to the fish oil group. Furthermore, gene sets related to oxidative stress and cardiovascular disease were not differently regulated between the groups. Within group analyses revealed a more prominent effect after intake of high quality fish oil as 11 gene transcripts were significantly (FDR < 0.1) changed from baseline versus three within the oxidized fish oil group.

CONCLUSION

The suggested concern linking lipid oxidation products to short-term unfavorable health effects may therefore not be evident at a molecular level in this explorative study.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01034423.

Effects of a healthy Nordic diet on gene expression changes in peripheral blood mononuclear cells in response to an oral glucose tolerance test in subjects with metabolic syndrome: a SYSDIET sub-study

Background

Diet has a great impact on the risk of developing features of metabolic syndrome (MetS), type 2 diabetes mellitus (T2DM), and cardiovascular diseases (CVD). We evaluated whether a long-term healthy Nordic diet (ND) can modify the expression of inflammation and lipid metabolism-related genes in peripheral blood mononuclear cells (PBMCs) during a 2-h oral glucose tolerance test (OGTT) in individuals with MetS.

Methods

A Nordic multicenter randomized dietary study included subjects (n = 213) with MetS, randomized to a ND group or a control diet (CD) group applying an isocaloric study protocol. In this sub-study, we included subjects (n = 89) from three Nordic centers: Kuopio (n = 26), Lund (n = 30), and Oulu (n = 33) with a maximum weight change of ±4 kg, high-sensitivity C-reactive protein concentration ≤10 mg L⁻¹, and baseline body mass index <39 kg m⁻². PBMCs were isolated, and the mRNA gene expression analysis was measured by quantitative real-time polymerase chain reaction (qPCR). We analyzed the mRNA expression changes of 44 genes before and after a 2hOGTT at the beginning and the end of the intervention.

Results

The healthy ND significantly down-regulated the expression of toll-like receptor 4 (TLR4), interleukin 18 (IL18), and thrombospondin receptor (CD36) mRNA transcripts and significantly up-regulated the expression of peroxisome proliferator-activated receptor delta (PPARD) mRNA transcript after the 2hOGTT compared to the CD.

Conclusions

A healthy ND is able to modify the gene expression in PBMCs after a 2hOGTT. However, more studies are needed to clarify the biological and clinical relevance of these findings.

Electronic supplementary material

The online version of this article (doi:10.1186/s12263-016-0521-4) contains supplementary material, which is available to authorized users.

Increased expression of NAMPT in PBMC from patients with acute coronary syndrome and in inflammatory M1 macrophages

AIM

The aim of the present study were to elucidate the role of NAMPT in atherosclerosis, by examine NAMPT expression in peripheral blood mononuclear cells (PBMC) in patients with coronary artery disease (CAD) and healthy controls and by examining the regulation and effect of NAMPT on macrophage polarization, hypothesizing that it could influence the polarization to inflammatory and resolving macrophages.

METHOD AND RESULTS

We analyzed RNA levels of NAMPT in PBMC from CAD and healthy controls and found NAMPT to be increased in PBMC from patients with acute coronary syndrome (n = 39) compared to healthy controls (n = 20) and patients with stable CAD (n = 22). Within the PBMC NAMPT was correlated to several inflammatory cytokines and the antioxidant enzyme superoxide dismutase 2. In vitro cell experiments revealed that NAMPT is increased both intracellular and extracellular in inflammatory M1 macrophages compared to in anti-inflammatory M2 macrophages. In addition, inhibiting NAMPT enzymatic activity inhibited M1 polarization in macrophages.

CONCLUSION

Based on our in vivo and in vitro findings we suggest that NAMPT could contribute to systemic and plaque inflammation in atherosclerotic disorders at least partly through effect on macrophages.

Fructose content of low calorie diets: effect on cardiometabolic risk factors in obese women with polycystic ovarian syndrome: a randomized controlled trial

We aimed to examine whether a whole-grain crispbread (CB) low-fructose, low-calorie diet (LCD) might be superior to a traditional LCD based on fructose-rich liquid meal replacements (LMRs) with respect to improvement of various cardiometabolic risk factors and reproductive hormones. Parallel-group randomised controlled clinical trial. Morbidly obese women with polycystic ovarian syndrome (PCOS) were randomised to either an 8-week CB-LCD or LMR-LCD (900-1100 kcal/day, fructose 17 g/day or 85 g/day). A total of 51 women completed the study. Body weight, fat mass and waist circumference reduced by mean (s.d.) 10.0 (4.8) kg, 7.4 (4.2) kg and 8.5 (4.4) cm, with no significant differences between groups. Total-cholesterol, HDL-cholesterol and Apo-A1 were significantly reduced within both groups (all P values <0.01), with no significant between-group differences. The triacylglycerol and LDL-cholesterol levels were reduced within the LMR group only, with no significant between-group differences. Blood pressure and most measures of glucose metabolism improved significantly in both diet groups, with no significant between-group difference. Uric acid levels rose by 17.7 (46.4) and 30.6 (71.5) μmol/l in the CB and LMR group, respectively, with no significant difference between groups. Gastrointestinal discomfort was significantly and equally reduced in both intervention groups. Free testosterone index was reduced in both groups, with no significant difference between groups. Morbidly obese women with PCOS who underwent either an 8-week low or high-fructose LCD-diet had similar changes in various cardiometabolic risk factors and reproductive hormones. Registration at ClinicalTrials.gov: NCT00779571.

Comparison of bioavailability of krill oil versus fish oil and health effect

Background

The aim of this review is to summarize the effects of krill oil (KO) or fish oil (FO) on eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) incorporation in plasma phospholipids or membrane of red blood cells (RBCs) as shown in human and animal studies. Furthermore, we discuss the findings in relation to the possible different health effects, focusing on lipids, inflammatory markers, cardiovascular disease risk, and biological functions of these two sources of long-chain n-3 polyunsaturated fatty acids (PUFAs).

Methods

A literature search was conducted in PubMed in January 2015. In total, 113 articles were identified, but based on selection criteria, 14 original papers were included in the review.

Results

Studies on bioavailability of EPA and DHA from KO and FO in humans and animals are limited and the interpretation is difficult, as different amounts of EPA and DHA have been used, duration of intervention differs, and different study groups have been included. Two human studies – one postprandial study and one intervention study – used the same amount of EPA and DHA from KO or FO, and they both showed that the bioavailability of EPA and DHA from KO seems to be higher than that from FO. Limited effects of KO and FO on lipids and inflammatory markers in human and animal studies were reported. Gene expression data from animal studies showed that FO upregulated the cholesterol synthesis pathway, which was the opposite of the effect mediated by KO. KO also regulated far more metabolic pathways than FO, which may indicate different biological effects of KO and FO.

Conclusion

There seems to be a difference in bioavailability of EPA and DHA after intake of KO and FO, but more studies are needed before a firm conclusion can be made. It is also necessary to document the beneficial health effects of KO with more human studies and to elucidate if these effects differ from those after regular fish and FO intake.

Effects of Exercise on Gene Expression of Inflammatory Markers in Human Peripheral Blood Cells: A Systematic Review

Regular physical activity seems to be one of the most important contributors to prevent disease and promote health. Being physically active reduces the risk of developing chronic diseases such as cardiovascular disease, diabetes, and some types of cancers. The molecular mechanisms are however not fully elucidated. Depending on duration and intensity, exercise will cause disruption of muscle fibers triggering a temporary inflammatory response. This response may not only involve the muscle tissue, but also peripheral tissues such as white blood cells, which are important components of the immune system. The immune system plays a vital role in the development of atherosclerosis, thereby making white blood cells relevant to study when looking at molecular mechanisms induced by physical activity. In this review, we summarize the existing literature on exercise and gene expression in human white blood cells, and discuss these results in relation to inflammation and atherosclerosis.