Marine Oil from C. finmarchicus Enhances Glucose Homeostasis and Liver Insulin Resistance in Obese Prediabetic Individuals

The intermediate state between normal glucose tolerance and overt type 2 diabetes mellitus is associated with micro- and macrovascular diseases, requiring safe and cost-effective treatment measures interventions. A novel source of LC n-3 FAs is Calanus finmarchicus Oil, which showed promising effects on glucose homeostasis in preclinical studies due to anti-obesity effects and/or anti-inflammatory properties. In total, 43 obese patients (BMI: 31.7 ± 5.2 kg/m²) were allocated in the following two groups: (1) Calanus oil group (2 g CO/day) and (2) placebo group (2 g paraffin oil/day). Markers of glucose metabolism, body composition and energy intake were measured at the beginning (t0), after 12 weeks (t₁₂) and 16 weeks (t₁₆). Overall, parameters reflecting abnormal glucose homeostasis and insulin resistance in the liver, including fasting insulin (−2.9 mU/L ± 4.10, p < 0.05), HOMA-IR (−0.9 ± 1.28, p < 0.05) and hepatic insulin resistance index (−1.06 ± 1.72 × 10⁶, p < 0.05) significantly enhanced after a 12-week CO-intervention, while no differences were observed in HbA1c, AUC_0–2h Glucose, AUC_0–2h Insulin, 2 h plasma glucose and muscle insulin sensitivity index. Our results indicate that Calanus oil causes beneficial effects on glucose metabolism and insulin resistance in obese patients, with clinical relevance to be verified in further studies. In addition, the possible active compounds and their mechanisms of action should be elucidated.

Dietary cis-9, trans-11-conjugated linoleic acid reduces amyloid β-protein accumulation and upregulates anti-inflammatory cytokines in an Alzheimer's disease mouse model

Conjugated linoleic acid (CLA) is an isomer of linoleic acid (LA). The predominant dietary CLA is cis-9, trans-11-CLA (c-9, t-11-CLA), which constitutes up to ~ 90% of total CLA and is thought to be responsible for the positive health benefits associated with CLA. However, the effects of c-9, t-11-CLA on Alzheimer's disease (AD) remain to be elucidated. In this study, we investigated the effect of dietary intake of c-9, t-11-CLA on the pathogenesis of an AD mouse model. We found that c-9, t-11-CLA diet-fed AD model mice significantly exhibited (1) a decrease in amyloid-β protein (Aβ) levels in the hippocampus, (2) an increase in the number of microglia, and (3) an increase in the number of astrocytes expressing the anti-inflammatory cytokines, interleukin-10 and 19 (IL-10, IL-19), with no change in the total number of astrocytes. In addition, liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatographic analysis revealed that the levels of lysophosphatidylcholine (LPC) containing c-9, t-11-CLA (CLA-LPC) and free c-9, t-11-CLA were significantly increased in the brain of c-9, t-11-CLA diet-fed mice. Thus, dietary c-9, t-11-CLA entered the brain and appeared to exhibit beneficial effects on AD, including a decrease in Aβ levels and suppression of inflammation.

Omega-3, omega-6, and total dietary polyunsaturated fat for prevention and treatment of type 2 diabetes mellitus: systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

To assess effects of increasing omega-3, omega-6, and total polyunsaturated fatty acids (PUFA) on diabetes diagnosis and glucose metabolism.

DESIGN

Systematic review and meta-analyses.

DATA SOURCES

Medline, Embase, Cochrane CENTRAL, WHO International Clinical Trials Registry Platform, Clinicaltrials.gov, and trials in relevant systematic reviews.

ELIGIBILITY CRITERIA

Randomised controlled trials of at least 24 weeks' duration assessing effects of increasing α-linolenic acid, long chain omega-3, omega-6, or total PUFA, which collected data on diabetes diagnoses, fasting glucose or insulin, glycated haemoglobin (HbA_1c), and/or homoeostatic model assessment for insulin resistance (HOMA-IR).

DATA SYNTHESIS

Statistical analysis included random effects meta-analyses using relative risk and mean difference, and sensitivity analyses. Funnel plots were examined and subgrouping assessed effects of intervention type, replacement, baseline risk of diabetes and use of antidiabetes drugs, trial duration, and dose. Risk of bias was assessed with the Cochrane tool and quality of evidence with GRADE.

RESULTS

83 randomised controlled trials (mainly assessing effects of supplementary long chain omega-3) were included; 10 were at low summary risk of bias. Long chain omega-3 had little or no effect on likelihood of diagnosis of diabetes (relative risk 1.00, 95% confidence interval 0.85 to 1.17; 58 643 participants, 3.7% developed diabetes) or measures of glucose metabolism (HbA_1c mean difference -0.02%, 95% confidence interval -0.07% to 0.04%; plasma glucose 0.04, 0.02 to 0.07, mmol/L; fasting insulin 1.02, -4.34 to 6.37, pmol/L; HOMA-IR 0.06, -0.21 to 0.33). A suggestion of negative outcomes was observed when dose of supplemental long chain omega-3 was above 4.4 g/d. Effects of α-linolenic acid, omega-6, and total PUFA on diagnosis of diabetes were unclear (as the evidence was of very low quality), but little or no effect on measures of glucose metabolism was seen, except that increasing α-linolenic acid may increase fasting insulin (by about 7%). No evidence was found that the omega-3/omega-6 ratio is important for diabetes or glucose metabolism.

CONCLUSIONS

This is the most extensive systematic review of trials to date to assess effects of polyunsaturated fats on newly diagnosed diabetes and glucose metabolism, including previously unpublished data following contact with authors. Evidence suggests that increasing omega-3, omega-6, or total PUFA has little or no effect on prevention and treatment of type 2 diabetes mellitus.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017064110.

A Prenatal DHA Test to Help Identify Women at Increased Risk for Early Preterm Birth: A Proposal

Fish intake and docosahexaenoic acid (DHA), a nutrient found in fish, have been favorably linked to several pregnancy outcomes. The risk of early preterm birth (ePT, <34 weeks gestation) is associated with low fish intake and DHA blood levels and can be reduced by supplemental DHA. Here, we summarize the evidence linking blood DHA levels with risk for ePT birth, and based on the available studies, propose that women who are pregnant or trying to become pregnant aim for a red blood cell (RBC) DHA value of at least 5% (of total RBC fatty acids). In the US, ~70% of women of childbearing age are likely below this cut-point, and dietary intake data suggest that this group, including pregnant women, consumes ~60 mg/day DHA and that >90% of this group do not take an omega-3 supplement. Since the recommendations for women to consume fish and to take a 200 mg DHA supplement during pregnancy are not being heeded generally, there is a need to motivate practitioners and pregnant women to attend to these recommendations. Having an objective prenatal blood DHA test could provide such motivation. More research is needed to test the clinical utility of this proposed target prenatal DHA level.

Lipidomic and Antioxidant Response to Grape Seed, Corn and Coconut Oils in Healthy Wistar Rats

Specialty oils differ in fatty acid, phytosterol and antioxidant content, impacting their benefits for cardiovascular health. The lipid (fatty acid, phytosterol) and antioxidant (total phenolics, radical scavenging capacity) profiles of grapeseed (GSO), corn (CO) and coconut (CNO) oils and their physiological (triacylglycerides, total and HDL-cholesterol and antioxidant capacity (FRAP) in serum and fatty acid and phytosterol hepatic deposition) and genomic (HL, LCAT, ApoA-1 and SR-BP1 mRNA hepatic levels) responses after their sub-chronic intake (10% diet for 28 days) was examined in healthy albino rats. Fatty acid, phytosterol and antioxidant profiles differed between oils (p ≤ 0.01). Serum and hepatic triacylglycerides and total cholesterol increased (p ≤ 0.01); serum HDL-Cholesterol decreased (p < 0.05); but serum FRAP did not differ (p > 0.05) in CNO-fed rats as compared to CO or GSO groups. Hepatic phytosterol deposition was higher (+2.2 mg/g; p ≤ 0.001) in CO- than GSO-fed rats, but their fatty acid deposition was similar. All but ApoA-1 mRNA level increased in GSO-fed rats as compared to other groups (p ≤ 0.01). Hepatic fatty acid handling, but not antioxidant response, nor hepatic phytosterol deposition, could be related to a more efficient reverse-cholesterol transport in GSO-fed rats as compared to CO or CNO.

Phytochemical composition and in vitro anti-tumour activities of selected tomato varieties

BACKGROUND

Previous studies indicated that tomato is a rich source of phytochemicals that act on different tumours. In this research, the phytochemical composition of selected tomato varieties was assessed by GLC and UHPLC/HPLC-MS, as well as their anti-tumour activities on HT-29 colorectal cancer cells.

RESULTS

Significant differences were found among tomato varieties; lycopene was high in Racimo, phenolics in Pera, sterols in Cherry, and linoleic acid predominated in all varieties. The MTT and LDH assays showed significant time- and concentration-dependent inhibitory/cytotoxic effects of all tomato varieties on HT-29 cells. Furthermore, the joint addition of tomato carotenoids and olive oil to HT-29 cell cultures induced inhibitory effects significantly higher than those obtained from each of them acting separately, while no actions were exercised in CCD-18 normal cells.

CONCLUSION

Tomato fruits constitute a healthy source of phytochemicals, although differences exist among varieties. In vitro, all of them inhibit colorectal cancer cell proliferation with Racimo variety at the top, and exercising a selective action on cancer cells by considering the lack of effects on CCD-18 cells. Furthermore, synergy was observed between olive oil and tomato carotenoids in inhibiting HT-29 cancer cell proliferation; conversely, phenolics showed no significant effects and hindered carotenoids actions. © 2016 Society of Chemical Industry.

Impact of Diabetes-Specific Nutritional Formulas versus Oatmeal on Postprandial Glucose, Insulin, GLP-1 and Postprandial Lipidemia

Diabetes-specific nutritional formulas (DSNFs) are frequently used as part of medical nutrition therapy for patients with diabetes. This study aims to evaluate postprandial (PP) effects of 2 DSNFs; Glucerna (GL) and Ultra Glucose Control (UGC) versus oatmeal (OM) on glucose, insulin, glucagon-like peptide-1 (GLP-1), free fatty acids (FFA) and triglycerides (TG). After an overnight fast, 22 overweight/obese patients with type 2 diabetes were given 200 kcal of each of the three meals on three separate days in random order. Blood samples were collected at baseline and at 30, 60, 90, 120, 180 and 240 min. Glucose area under the curve (AUC_0–240) after GL and UGC was lower than OM (p < 0.001 for both). Insulin positive AUC_0–120 after UGC was higher than after OM (p = 0.02). GLP-1 AUC_0–120 and AUC_0–240 after GL and UGC was higher than after OM (p < 0.001 for both). FFA and TG levels were not different between meals. Intake of DSNFs improves PP glucose for 4 h in comparison to oatmeal of similar caloric level. This is achieved by either direct stimulation of insulin secretion or indirectly by stimulating GLP-1 secretion. The difference between their effects is probably related to their unique blends of amino acids, carbohydrates and fat.

Poly is more effective than monounsaturated fat for dietary management in the metabolic syndrome: The muffin study

BACKGROUND

The metabolic syndrome (MetS) is highly prevalent and associated with an increased risk for type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). Lifestyle recommendations to treat MetS often include the replacement of saturated fats (SFAs) and monosaccharides with unsaturated fat. However, it is unclear whether metabolic parameters will improve more when the saturated fat in American Heart Association (AHA) diets is replaced with higher concentrations of monounsaturated or polyunsaturated fatty acids (MUFA or PUFA).

OBJECTIVE

To test the hypothesis that an AHA diet enriched in MUFA improves lipoprotein lipids, insulin resistance, inflammation, and endothelial function to a greater extent than a diet enriched in PUFA in middle-aged men and women with MetS.

METHODS

A prospective, open-label, parallel group design with randomization to a hypocaloric MUFA or PUFA-enriched diet after weight stabilization on an AHA step I diet. Participants consumed 3 MUFA-enriched or PUFA-enriched muffins daily with additional supplementation as required to ensure 25%-50% increases in dietary fat intake from these sources at the expense of SFA and the opposing unsaturated fat. Changes in MetS components were measured at baseline and after 6 months of dietary intervention.

RESULTS

Thirty-nine participants (mean age, 60.8 years; 79% African-American, 60% women) with MetS completed the 6-month study. Compared to baseline, assignment to either MUFA (n = 23) or PUFA (n = 16) both were associated with weight loss (MUFA: -2.3 ± 1 kg, P = .06; PUFA: -4.6 ± 2 kg; P = .002), but PUFA was also associated with reductions in triglycerides (TG) (-30 ± 18 mg/dL, P = .02), systolic blood pressure (BP) (-7 ± 3 mm Hg, P = .01), diastolic BP (DBP) (-4 ± 2 mm Hg, P = .01) and improved flow mediated dilation (FMD) (7.1% ± 1.8% vs 13.6% ± 2%, absolute increase; P = .0001). When compared to MUFA treatment, PUFA intervention was associated with reduced TG (P = .04) and DBP (P = .07) as well as increased FMD (P = .04) even after adjustment for changes in weight. There was no effect on total cholesterol, low-density lipoprotein cholesterol, glucose, high-sensitivity C-reactive protein (hs-CRP), or other inflammatory proteins. Overall, 25% (4 of 16) assigned to PUFA and 13% (3 of 23) to MUFA converted to non-MetS status.

CONCLUSION

Substitution of SFA with PUFA in patients with MetS is associated with greater reductions in TG and improvement in endothelial function than MUFA that is independent of weight loss. These preliminary findings raise the possibility that PUFA may be the unsaturated fat of choice to reduce cardiometabolic risk in patients with MetS.

Potential for dietary ω-3 fatty acids to prevent nonalcoholic fatty liver disease and reduce the risk of primary liver cancer

Nonalcoholic fatty liver disease (NAFLD) has increased in parallel with central obesity, and its prevalence is anticipated to increase as the obesity epidemic remains unabated. NAFLD is now the most common cause of chronic liver disease in developed countries and is defined as excessive lipid accumulation in the liver, that is, hepatosteatosis. NAFLD ranges in severity from benign fatty liver to nonalcoholic steatohepatitis (NASH), and NASH is characterized by hepatic injury, inflammation, oxidative stress, and fibrosis. NASH can progress to cirrhosis, and cirrhosis is a risk factor for primary hepatocellular carcinoma (HCC). The prevention of NASH will lower the risk of cirrhosis and NASH-associated HCC. Our studies have focused on NASH prevention. We developed a model of NASH by using mice with the LDL cholesterol receptor gene ablated fed the Western diet (WD). The WD induces a NASH phenotype in these mice that is similar to that seen in humans and includes robust induction of hepatic steatosis, inflammation, oxidative stress, and fibrosis. With the use of transcriptomic, lipidomic, and metabolomic approaches, we examined the capacity of 2 dietary ω-3 (n-3) polyunsaturated fatty acids, eicosapentaenoic acid (20:5ω-3; EPA) and docosahexaenoic acid (22:6ω-3; DHA), to prevent WD-induced NASH. Dietary DHA was superior to EPA at attenuating WD-induced changes in plasma lipids and hepatic injury and at reversing WD effects on hepatic metabolism, oxidative stress, and fibrosis. The outcome of these studies suggests that DHA may be useful in preventing NASH and reducing the risk of HCC.

Replacement of Dietary Saturated Fat by PUFA-Rich Pumpkin Seed Oil Attenuates Non-Alcoholic Fatty Liver Disease and Atherosclerosis Development, with Additional Health Effects of Virgin over Refined Oil

BACKGROUND AND AIMS

As dietary saturated fatty acids are associated with metabolic and cardiovascular disease, a potentially interesting strategy to reduce disease risk is modification of the quality of fat consumed. Vegetable oils represent an attractive target for intervention, as they largely determine the intake of dietary fats. Furthermore, besides potential health effects conferred by the type of fatty acids in a vegetable oil, other minor components (e.g. phytochemicals) may also have health benefits. Here, we investigated the potential long-term health effects of isocaloric substitution of dietary fat (i.e. partial replacement of saturated by unsaturated fats), as well as putative additional effects of phytochemicals present in unrefined (virgin) oil on development of non-alcoholic fatty liver disease (NAFLD) and associated atherosclerosis. For this, we used pumpkin seed oil, because it is high in unsaturated fatty acids and a rich source of phytochemicals.

METHODS

ApoE*3Leiden mice were fed a Western-type diet (CON) containing cocoa butter (15% w/w) and cholesterol (1% w/w) for 20 weeks to induce risk factors and disease endpoints. In separate groups, cocoa butter was replaced by refined (REF) or virgin (VIR) pumpkin seed oil (comparable in fatty acid composition, but different in phytochemical content).

RESULTS

Both oils improved dyslipidaemia, with decreased (V)LDL-cholesterol and triglyceride levels in comparison with CON, and additional cholesterol-lowering effects of VIR over REF. While REF did not affect plasma inflammatory markers, VIR reduced circulating serum amyloid A and soluble vascular adhesion molecule-1. NAFLD and atherosclerosis development was modestly reduced in REF, and VIR strongly decreased liver steatosis and inflammation as well as atherosclerotic lesion area and severity.

CONCLUSIONS

Overall, we show that an isocaloric switch from a diet rich in saturated fat to a diet rich in unsaturated fat can attenuate NAFLD and atherosclerosis development. Phytochemical-rich virgin pumpkin seed oil exerts additional anti-inflammatory effects resulting in more pronounced health effects.

Combined effect of unsaturated fatty acids and saturated fatty acids on the metabolic syndrome: Tehran lipid and glucose study

AIMS

The aim of this study was to investigate whether the background intakes of total dietary fat, monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) modulate the effects of dietary saturated fatty acids (SFA) on metabolic syndrome (MetS).

MATERIAL AND METHODS

This population-based cross-sectional study was conducted on a representative sample of 4,677 adults, aged 19 to 84 years. MetS was defined according to the ATP III criteria.

RESULTS

Median intakes of SFA, MUFA and PUFA were 9.5, 9.6 and 5.6% of total energy. High SFA intakes were associated with higher prevalence of MetS, in both individuals with higher and lower median intakes of total fat, MUFA and PUFA.

CONCLUSIONS

Our findings indicate that SFA intakes were positively associated with the prevalence of MetS, independent of total dietary fat, MUFA and PUFA intake.

Emerging nutrition science on fatty acids and cardiovascular disease: nutritionists' perspectives

Recent dietary guidance for heart health recommends a reduction (by ∼50%) in saturated fatty acid (SFA) intake to reduce LDL cholesterol and to decrease risk of cardiovascular disease (CVD). The 2010 Dietary Guidelines for Americans recommends substituting unsaturated fat [both polyunsaturated and monounsaturated fatty acids (PUFAs and MUFAs, respectively)] for SFAs. There are many dietary options that can be implemented to replace SFAs, given the different sources of unsaturated fats in the food supply. Compelling evidence exists for the cardioprotective benefits of n-3 (ω-3) PUFAs, both marine- and plant-derived. In addition, the evidence of cardioprotective benefits of n-6 (ω-6) PUFAs is strong, whereas that for MUFAs is mixed, although there is emerging evidence of benefits. Quantitatively, lowering SFAs by 50% will require, in part, substituting food sources of n-6 and n-3 PUFAs and MUFAs for food sources of SFAs. The use of n-3 PUFAs as a replacement for SFAs will result in a shortfall in reaching the SFA goal because of the relatively low amounts that can be incorporated in the diet, even with very high n-3 PUFA substitution. SFAs also can be replaced with dietary carbohydrate and/or protein. Replacing SFAs with carbohydrate, specifically refined sources, however, has little impact on reducing CVD risk. There is evidence about the health benefits of dietary protein on CVD risk, which merits study. Dietary guidelines have advanced considerably with the "replacement of SFA with unsaturated fat message" instead of recommending decreasing SFAs alone. A key question that remains is what is the optimal mix of macronutrients to maximally reduce CVD risk.

The addition of medium-chain triglycerides to a purified fish oil-based diet alters inflammatory profiles in mice

OBJECTIVE

Parenteral nutrition associated liver disease (PNALD) is a deadly complication of long term parenteral nutrition (PN) use in infants. Fish oil-based lipid emulsion has been shown in recent years to effectively treat PNALD. Alternative fat sources free of essential fatty acids have recently been investigated for health benefits related to decreased inflammatory response. We hypothesized that the addition of medium-chain triglycerides (MCT) to a purified fish oil-based diet would decrease the response to inflammatory challenge in mice, while allowing for sufficient growth and development.

MATERIALS/METHODS

Six groups of ten adult male C57/Bl6 mice were pair-fed different dietary treatments for a period of twelve weeks, varying only in fat source (percent calories by weight): 10.84% soybean oil (SOY), 10% coconut oil (HCO), 10% medium-chain triglycerides (MCT), 3% purified fish oil (PFO), 3% purified fish oil with 3% medium-chain triglycerides (50:50 MCT:PFO) and 3% purified fish oil with 7.59% medium-chain triglycerides (70:30 MCT:PFO). An endotoxin challenge was administered to half of the animals in each group at the completion of dietary treatment.

RESULTS

All groups demonstrated normal growth throughout the study period. Groups fed MCT and HCO diets demonstrated biochemical essential fatty acid deficiency and decreased IL-6 and TNF-α response to endotoxin challenge. Groups containing PFO had increased inflammatory response to endotoxin challenge, and the addition of MCT to PFO mitigated this inflammatory response.

CONCLUSION

These results suggest that the addition of MCT to PFO formulations may decrease the host response to inflammatory challenge, which may pose potential for optimized PN formulations. Inclusion of MCT in lipid emulsions given with PN formulations may be of use in therapeutic interventions for disease states resulting from chronic inflammation.

Avocado Oil Improves Mitochondrial Function and Decreases Oxidative Stress in Brain of Diabetic Rats

Diabetic encephalopathy is a diabetic complication related to the metabolic alterations featuring diabetes. Diabetes is characterized by increased lipid peroxidation, altered glutathione redox status, exacerbated levels of ROS, and mitochondrial dysfunction. Although the pathophysiology of diabetic encephalopathy remains to be clarified, oxidative stress and mitochondrial dysfunction play a crucial role in the pathogenesis of chronic diabetic complications. Taking this into consideration, the aim of this work was to evaluate the effects of 90-day avocado oil intake in brain mitochondrial function and oxidative status in streptozotocin-induced diabetic rats (STZ rats). Avocado oil improves brain mitochondrial function in diabetic rats preventing impairment of mitochondrial respiration and mitochondrial membrane potential (ΔΨ m ), besides increasing complex III activity. Avocado oil also decreased ROS levels and lipid peroxidation and improved the GSH/GSSG ratio as well. These results demonstrate that avocado oil supplementation prevents brain mitochondrial dysfunction induced by diabetes in association with decreased oxidative stress.

Evidence for the use of glomerulomegaly as a surrogate marker of glomerular damage and for alpha-linolenic acid-rich oils in the treatment of early obesity-related glomerulopathy in a diet-induced rodent model of obesity

Obesity-related glomerulopathy (ORG) is a unique and emerging condition that can lead to renal failure. Early detection, aided by an earlier diagnostic marker, would improve patient outcomes; this could be facilitated by an accurate model. Such a model would be useful to examine interventions like dietary fatty acids, which are known to influence renal diseases in later stages. In this study, obese-prone rats were provided high-fat (55% of energy) diets for 12 weeks to generate a model of diet-induced obesity. The rats were subsequently provided dietary oils with various levels of alpha-linolenic acid (ALA) and linoleic acid (LA) for 8 weeks, as follows: (g ALA:LA per 100 g oil): canola/flax (20:18), canola (8:18), soy (9:53), high-oleic canola/canola (5:16), high-oleic canola (2:15), lard/soy (1:8), and safflower (0.2:73). The model developed obesity, glomerulomegaly, proteinuria, and scarce glomerular damage with an indolent course. Morphometry and histology revealed glomerulomegaly as the first renal structural alteration. The utility of this marker as a predictor for the presence of ORG and renal injury was evidenced by its correlation to visceral adiposity (p < 0.0001, r = 0.44), proteinuria (p < 0.0001, ρ = 0.55), change in proteinuria (p = 0.0092, ρ = 0.42), and glomerular damage (p < 0.0001, ρ = 0.48). Renal triglyceride ALA:LA was strongly correlated with dietary ALA:LA (p < 0.0005, ρ = 0.96), and inversely associated with mean glomerular volume (p = 0.02, ρ = -0.82). The diet-induced obese model accurately represents early ORG, and implicates glomerulomegaly as an early surrogate diagnostic marker. Early intervention with ALA-rich dietary oils slowed glomerular enlargement; these findings warrant further clinical investigation to promote optimal patient outcomes.

Potential of long-chain n-3 polyunsaturated fatty acids in melanoma prevention

The possible antineoplastic activity of dietary long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs) has been supported by ample preclinical studies that have identified a number of molecular factors and pathways affected by these fatty acids and involved in cell growth, apoptosis, invasion, and angiogenesis. The aim of this critical review is to assess the current state of knowledge on the potential anticancer effects of LC n-3 PUFAs against malignant melanoma, one of the most common cancers among Western populations. The results of preclinical as well as human observational and interventional studies investigating the effects of LC n-3 PUFAs in melanoma were examined. Overall, the analysis of the literature reveals that, even though a large body of information is available, further effort is needed to identify the main molecular targets of LC n-3 PUFAs in melanoma. Moreover, additional well-designed human observational studies are essential to shed further light on the issue. The results of these studies could provide support and specific information for the development of clinical studies, especially those performed in combination with conventional or innovative antineoplastic therapies.

[Lifestyle modifications for treatment of hypertriglyceridemia]

Moderation in energy intake and limiting the proportion of energy intake from animal fats are important in preventing the occurrence or recurrence of arteriosclerotic disease. Patients with hypertriglyceridemia are frequently obese, insulin-resistance, hypertensive or diabetic, all of which are risk factors for arteriosclerotic disease. Regarding therapeutic lifestyle change and hypertriglyceridemia, body weight control is critical, regular aerobic activity should be encouraged, and avoidance of high-carbohydrate (especially with refined carbohydrates) should be encouraged. Replacement of some dietary carbohydrate with unsaturated fat is most effective in lowering triglycerides. Fish oil contains high amounts of the essential fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acids (EPA). Fish oil is effective at lowering triglyceride levels. Alcohol consumption should be reduced or eliminated. In cases of severe hypertriglyceridemia, recommended fat intake is restricted to 15 % of total energy intake.

Effect of an extra-virgin olive oil enriched with probiotics or antioxidants on functional dyspepsia: a pilot study

BACKGROUND

While antioxidants and probiotics have been proposed for the treatment of functional dyspepsia, current data are still heterogeneous and studies are poorly designed. Extra-virgin olive oil, a common ingredient of Mediterranean diet, has shown antioxidant properties.

AIMS

To evaluate the effect of extra-virgin olive oil enriched with antioxidants or probiotics on functional dyspepsia.

PATIENTS AND METHODS

This study has been designed as a "proof of concept". Extra-virgin olive oil enriched with antioxidants or probiotics was blindly added to the common diet of 8 subjects with functional dyspepsia for 7 days. Dyspeptic symptoms were then evaluated in all patients.

RESULTS AND CONCLUSIONS

A significant improvement of dyspeptic symptoms was observed in subjects receiving the antioxidant or probiotic enriched oil diet, with a greater effect observed for the latter. Larger studies are now needed to confirm these data.

The impact of dietary long-chain polyunsaturated fatty acids on respiratory illness in infants and children

Increasing evidence suggests that intake of long-chain polyunsaturated fatty acids (LCPUFA), especially omega-3 LCPUFA, improves respiratory health early in life. This review summarizes publications from 2009 through July 2012 that evaluated effects of fish, fish oil or LCPUFA intake during pregnancy, lactation, and early postnatal years on allergic and infectious respiratory illnesses. Studies during pregnancy found inconsistent effects in offspring: two showed no effects and three showed protective effects of omega-3 LCPUFA on respiratory illnesses or atopic dermatitis. Two studies found that infants fed breast milk with higher omega-3 LCPUFA had reduced allergic manifestations. Earlier introduction of fish improved respiratory health or reduced allergy in four studies. Three randomized controlled trials showed that providing LCPUFA during infancy or childhood reduced allergy and/or respiratory illness while one found no effect. Potential explanations for the variability among studies and possible mechanisms of action for LCPUFA in allergy and respiratory disease are discussed.

Diacylglycerol: Efficacy and Mechanism of Action of an Anti-Obesity Agent

Obesity is at the forefront of global health issues and directly contributes to many chronic illnesses. Several dietary components show promise in the treatment of obesity, one of which is oil rich in diacylglycerols (DAGs). Present objectives are to examine scientific knowledge concerning DAG to assess evidence supporting the effects on substrate oxidation rates, body weight and fat mass, and blood lipids, and to assess safety, as well as elucidate potential mechanisms of action. DAG can be synthesized by an enzymatic process to produce mainly 1,3-isoform DAG. This 1,3-DAG oil is believed to have the ability to increase beta-oxidation, to enhance body weight loss, to suppress body fat accumulation, and to lower serum triacylglycerol levels postprandially. While certain animal and human studies indicate that consumption of 1,3-DAG has positive physiological effects, others report no effect. The mechanisms of action of DAG are suggested to decrease the resynthesis of chylomicrons as well as shunting them directly to the liver through the portal vein, where they are oxidized. This increased fat oxidation may influence control of food intake by increasing satiety. Further study into the precise mechanism is required to understand its effects. Safety studies show no risks in consuming a diet rich in DAG oil. Overall, consumption of oils with higher amounts of DAG, specifically 1,3-DAG, may be useful in the battle against obesity.

Olive oil phenolics: where do we stand? Where should we go?

The formulation of an antioxidant/atherosclerosis hypothesis stimulated experimental and epidemiological studies on the possible role of micronutrients, including olive oil phenolics, in the protection from cardiovascular disease observed in the Mediterranean area. This article prospectively summarises our current knowledge of olive phenolics, underscore our gaps in information, and brings forward areas that are, as yet, to be explored.

A diet rich in unsaturated fatty acids prevents progression toward heart failure in a rabbit model of pressure and volume overload

BACKGROUND

During heart failure (HF), cardiac metabolic substrate preference changes from fatty acid (FA) toward glucose oxidation. This change may cause progression toward heart failure. We hypothesize that a diet rich in FAs may prevent this process, and that dietary ω3-FAs have an added antiarrhythmic effect based on action potential (AP) shortening in animals with HF.

METHODS AND RESULTS

Rabbits were fed a diet containing 1.25% (w/w) high oleic sunflower oil (HF-ω9, N=11), 1.25% fish oil (HF-ω3, N=11), or no supplement (HF-control, N=8). Subsequently, HF was induced by volume and pressure overload. After 4 months, HF-parameters were assessed, electrocardiograms were recorded, and blood and ventricular tissue were collected. Myocytes were isolated for patch clamp or intracellular Ca(2+)- recordings to study electrophysiologic remodeling and arrhythmogenesis. Both the HF-ω9 and the HF-ω3 groups had larger myocardial FA oxidation capacity than HF control. The HF-ω3 group had significantly lower mean (± SEM) relative heart and lung weight (3.3±0.13 and 3.2±0.12 g kg(-1), respectively) than HF control (4.8±0.30 and 4.5±0.23), and shorter QTc intervals (167±2.6 versus 182±6.4). The HF-ω9 also displayed a significantly reduced relative heart weight (3.6±0.26), but had similar QTc (179±4.3) compared with HF control. AP duration in the HF-ω3 group was ≈20% shorter due to increased I(to1) and I(K1) and triggered activity, and Ca(2+)-aftertransients were less than in the HF-ω9 group.

CONCLUSIONS

Dietary unsaturated FAs started prior to induction of HF prevent hypertrophy and HF. In addition, fish oil FAs prevent HF-induced electrophysiologic remodeling and arrhythmias.

Fish oil, but not soy bean or olive oil enriched infusion decreases histopathological severity of acute pancreatitis in rats without affecting eicosanoid synthesis

Different dietary fatty acids affect eicosanoid metabolism in different ways, thus influencing the pro- and anti-inflammatory balance of prostaglandins and leukotrienes. Therefore, we analyzed the impact of [n-3], [n-6], and [n-9] fatty acids on eicosanoid metabolism and histopathology in acute pancreatitis in rats. Seventy-five male Sprague-Dawley rats were randomized into five groups (n = 15). Group 1 underwent only laparotomy, while in groups, 2-5 pancreatitis was induced. Groups 1 and 2 were then given saline infusion, groups 3-5 received fat emulsion (group 3: rich in [n-6], group 4: rich in [n-9], group 5: rich in [n-3] fatty acids) for another 18 h. Infusion rich in [n-3] fatty acids significantly decreased histopathological severity of pancreatitis, compared to all other groups. There was no difference concerning the concentrations of prostaglandins and leukotrienes between all groups. Parenteral infusion rich in [n-3] fatty acids reduced histopathological severity of acute pancreatitis in rats without changing eicosanoid metabolism at the endpoint.

Diet intervention and cerebrospinal fluid biomarkers in amnestic mild cognitive impairment

OBJECTIVE

To compare the effects of a 4-week high-saturated fat/high-glycemic index (HIGH) diet with a low-saturated fat/low-glycemic index (LOW) diet on insulin and lipid metabolism, cerebrospinal fluid (CSF) markers of Alzheimer disease, and cognition for healthy adults and adults with amnestic mild cognitive impairment (aMCI).

DESIGN

Randomized controlled trial.

SETTING

Veterans Affairs Medical Center clinical research unit.

PARTICIPANTS

Forty-nine older adults (20 healthy adults with a mean [SD] age of 69.3 [7.4] years and 29 adults with aMCI with a mean [SD] age of 67.6 [6.8] years).

INTERVENTION

Participants received the HIGH diet (fat, 45% [saturated fat, > 25%]; carbohydrates, 35%-40% [glycemic index, > 70]; and protein, 15%-20%) or the LOW diet (fat, 25%; [saturated fat, < 7%]; carbohydrates, 55%-60% [glycemic index, < 55]; and protein, 15%-20%) for 4 weeks. Cognitive tests, an oral glucose tolerance test, and lumbar puncture were conducted at baseline and during the fourth week of the diet.

MAIN OUTCOME MEASURES

The CSF concentrations of β-amyloid (Aβ42 and Aβ40), tau protein, insulin, F2-isoprostanes, and apolipoprotein E, plasma lipids and insulin, and measures of cognition.

RESULTS

For the aMCI group, the LOW diet increased CSF Aβ42 concentrations, contrary to the pathologic pattern of lowered CSF Aβ42 typically observed in Alzheimer disease. The LOW diet had the opposite effect for healthy adults, ie, decreasing CSF Aβ42, whereas the HIGH diet increased CSF Aβ42. The CSF apolipoprotein E concentration was increased by the LOW diet and decreased by the HIGH diet for both groups. For the aMCI group, the CSF insulin concentration increased with the LOW diet, but the HIGH diet lowered the CSF insulin concentration for healthy adults. The HIGH diet increased and the LOW diet decreased plasma lipids, insulin, and CSF F2-isoprostane concentrations. Delayed visual memory improved for both groups after completion of 4 weeks of the LOW diet.

CONCLUSION

Our results suggest that diet may be a powerful environmental factor that modulates Alzheimer disease risk through its effects on central nervous system concentrations of Aβ42, lipoproteins, oxidative stress, and insulin.

ω-3 fatty acids attenuate mucosal inflammation in premature rat pups

BACKGROUND

Necrotizing enterocolitis (NEC) is a devastating intestinal disease of premature infants. Although ω-3 fatty acids are known to have antiinflammatory effects, their effect against NEC remains unclear.

METHODS

Mother rats fed a soybean-based, docosahexaenoic acid (DHA)- or eicosapentaenoic acid (EPA)-enriched diet from days 7 to 20 of gestation were examined. On day 20, the rat pups were delivered by abdominal incision, their intestines were removed, and messenger RNA was extracted. A rat NEC model was used to confirm the effects of ω-3 fatty acids on the inflamed intestine (n = 20-28). The expression of inflammatory molecules was analyzed by real-time polymerase chain reaction (n = 11-14).

RESULTS

The concentrations of DHA and EPA in the intestine were significantly increased in the DHA and EPA groups (P < .01). The expression of the antiinflammatory prostaglandin E2 receptor EP3 was increased in the DHA (P < .05) and EPA groups (P < .01). In the NEC model, the reduced incidence of colitis was confirmed in the DHA and EPA groups. The expression of peroxisome proliferator-activated receptor γ was increased (P < .05), and the inhibitor of nuclear factor-κB α/β decreased in both the DHA (P < .01) and EPA groups (P < .05).

CONCLUSION

Our findings indicate that ω-3 fatty acids are beneficial for protecting the premature intestine from inflammation by regulating eicosanoid- and nuclear factor-κB-related metabolite expression.

Dietary fish oil inhibits the early stage of recovery of atrophied soleus muscle in rats via Akt-p70s6k signaling and PGF2α

Skeletal muscle recovery from disuse atrophy requires the recruitment of insulin signaling for muscle growth, which is driven by protein synthesis. Dietary fish oil, which is rich in long-chain n-3 polyunsaturated fatty acids, is known to enhance insulin signaling and protein metabolism. Therefore, this study was performed to evaluate whether dietary fish oil facilitates muscle recovery during remobilization after disuse atrophy. Ten days of immobilization, followed by 3 or 13 days of remobilization, were applied to the hindlimbs of rats fed corn oil [corn oil diet group as control (CO)] or fish oil [fish oil diet group (FO)] as source of dietary fat. The immobilization-induced reductions in soleus muscle weight and myosin heavy-chain content were significantly restored by 3 days of remobilization in CO. However, in FO, these muscle recovery measurements did not significantly change until 13 days of remobilization. At 3 days of remobilization, both groups had significant elevations in p70 ribosomal S6 kinase (p70s6k) activation and at a greater extent in CO than in FO. The activation of Akt was also increased on Day 3, but it was not significant in FO. Throughout the remobilization period, levels of prostaglandin F2α (PGF2α) and cyclooxygenase-2 mRNA were significantly augmented. However, FO had a lesser increase in PGF2α than CO until Day 13. These findings indicate that dietary fish oil inhibits the early stage of soleus muscle recovery after disuse atrophy by suppressing the activation of Akt-p70s6k signaling and PGF2α synthesis.

Tropical oils: Nutritional and scientific issues

Individually and in combination with other oils, the tropical oils impart into manufactured foods functional properties that appeal to consumers. The use of and/or labeling in the ingredient lists give the impression that these oils are used extensively in commercially processed foods. The estimated daily intake of tropical oils by adult males is slightly more than one fourth of a tablespoon (3.8 g), 75% of which consists of saturated fatty acids. Dietary fats containing saturated fatty acids at the beta-position tend to raise plasma total and LDL-cholesterol, which, of course, contribute to atherosclerosis and coronary heart disease. Health professionals express concern that consumers who choose foods containing tropical oils unknowingly increase their intake of saturated fatty acids. The saturated fatty acid-rich tropical oils, coconut oil, hydrogenated coconut oil, and palm kernel oil, raise cholesterol levels; studies demonstrating this effect are often confounded by a developing essential fatty acid deficiency. Palm oil, an essential fatty acid-sufficient tropical oil, raises plasma cholesterol only when an excess of cholesterol is presented in the diet. The failure of palm oil to elevate blood cholesterol as predicted by the regression equations developed by Keys et al. and Hegsted et al. might be due to the dominant alpha-position location of its constituent saturated fatty acids. If so, the substitution of interesterified artificial fats for palm oil in food formulations, a recommendation of some health professionals, has the potential of raising cholesterol levels. A second rationale addresses prospective roles minor constituents of palm oil might play in health maintenance. This rationale is founded on the following observations. Dietary palm oil does not raise plasma cholesterol. Single fat studies suggests that oils richer in polyunsaturated fatty acid content tend to decrease thrombus formation. Anomalously, palm oil differs from other of the more saturated fats in tending to decrease thrombus formation. Finally, in studies comparing palm oil with other fats and oils, experimental carcinogenesis is enhanced both by vegetable oils richer in linoleic acid content and by more highly saturated animal fats. The carotenoid constituents of red palm oil are potent dietary anticarcinogens. A second group of antioxidants, the tocotrienols, are present in both palm olein and red palm oil. These vitamin E-active constituents are potent suppressors of cholesterol biosynthesis; emerging data point to their anticarcinogenic and antithrombotic activities. This review does not support claims that foods containing palm oil have no place in a prudent diet.

Fish Oil Supplementation in Pregnancy Lowers F2-isoprostanes in Neonates at High Risk of Atopy

The anti-inflammatory properties of n-3 polyunsaturated fatty acids (n-3 PUFA) have suggested a potential role of these nutrients in dietary modification for prevention of allergic disease in early life. As oxidative stress is known to modify antigen presenting cell (APC) signalling and resulting immune responses, we examined the effects of maternal n-3 PUFA supplementation in pregnancy on markers of oxidative stress and APC function in neonates at high risk of allergy. Eighty-three pregnant atopic women were randomised to receive 4 g daily of either fish oil (n = 40) or olive oil (n = 43) capsules in a controlled trial from 20 weeks gestation until delivery. Plasma (cord blood) and urinary F2-isoprostanes were measured as markers of lipid peroxidation. Cord erythrocyte fatty acids and markers of APC function (HLA-DR expression and cytokine responses) were measured and related to levels of plasma F2-isoprostanes. Maternal fish oil supplementation lowered plasma (p < 0.0001) and urinary (p = 0.06) F2-isoprostanes. HLA-DR expression on APC was not different between the groups. In multiple regression analysis, 28.8% of the variance in plasma F2-isoprostanes was explained by positive relationships with erythrocyte arachidonic acid (AA) and monocyte HLA-DR expression and a negative relationship with erythrocyte eicosapentaenoic acid (EPA). This study shows that maternal supplementation with fish oil can attenuate neonatal lipid peroxidation. Clinical follow-up of these infants will help to determine if there are sustained effects on postnatal oxidative stress and expression of allergic disease.

A good response to oil with medium- and long-chain fatty acids in body fat and blood lipid profiles of male hypertriglyceridemic subjects

A double blind clinical trial was carried out to clarify the effects of oil with medium- and long-chain triglyceride (MLCT) on body fat and blood lipid profiles in hypertriglyceridemic subjects. One-hundred-and-twelve subjects were enrolled and divided into two groups; those that consumed MLCT oil and those that consumed long-chain triglyceride (LCT) oil for 8 weeks. All subjects were requested to consume 25-30 g of the oils daily and maintain a fixed level of energy intake and exercise. Anthropometric and blood biochemical parameters were measured when the study was initiated and completed. The LCT group consisted of 50 subjects (34 men and 16 women), while the MLCT group consisted of 51 subjects (33 men and 18 women) who completed the study. Larger decreases in body weight, body mass index, waist circumference, body fat, total fat area and subcutaneous fat area in the abdomen and serum triglycerides, low-density lipoprotein cholesterol, apolipoprotein B, C2, C3 and E were observed in male subjects in the MLCT group than those in the LCT group. However, no significant differences in these parameters between the female subjects in the two groups were observed. Data from this study indicate that consumption of medium-and long-chain triglycerides can reduce body weight and body fat and improve blood lipid profiles in male hypertriglyceridemic subjects.

Fish oil fed prior to ethanol administration prevents acute ethanol-induced fatty liver in mice

BACKGROUND/AIMS

We examined whether dietary fish oil can prevent acute ethanol (alcohol)-induced fatty liver.

METHODS

Mice were fed safflower oil, fish oil, or safflower oil plus a PPAR alpha activator on the day prior to ethanol administration. Oil red O staining, serum analysis, and RT-PCR were used to analyze ethanol-induced fatty liver.

RESULTS

In mice fed safflower oil, ethanol increased liver TG 3-fold, with activation of SREBP-1c and ChREBP, which promote de novo lipogenesis, and increases in expression of mRNAs for PPAR gamma and DGATs mRNAs, which promote TG synthesis. When mice were fed fish oil, ethanol-induced fatty liver was reduced by 73%. Fish oil decreased SREBP-1c activity and increased PPAR alpha activity. However, levels of DGAT1, DGAT2, ChREBP, LPK, and PPAR gamma mRNAs were increased in response to ethanol in mice fed fish oil. Prior administration of Wy14643, PPAR alpha activator, did not inhibit ethanol-induced fatty liver, suggesting that PPAR alpha played little role in prevention of ethanol-induced fatty liver by fish oil.

CONCLUSIONS

A single dose of ethanol increases the liver TG level via several mechanisms; however, prior ingestion of fish oil effectively prevents ethanol-induced fatty liver, at least in part, by decreasing basal SREBP-1c activity, especially a marked reduction in SCD1.

Studies on the protective effect of dietary fish oil on gentamicin-induced nephrotoxicity and oxidative damage in rat kidney

Gentamicin (GM)-induced nephrotoxicity limits its long-term clinical use. Several agents/strategies were attempted to prevent GM nephrotoxicity but were not found suitable for clinical practice. Dietary fish oil (FO) retard the progression of certain types of cancers, cardiovascular and renal disorders. We aimed to evaluate protective effect of FO on GM-induced renal proximal tubular damage. The rats were pre-fed experimental diets for 10 days and then received GM (80 mg/kg body weight/day) treatment for 10 days while still on diet. Serum/urine parameters, enzymes of carbohydrate metabolism, brush border membrane (BBM), oxidative stress and phosphate transport in rat kidney were analyzed. GM nephrotoxicity was recorded by increased serum creatinine and blood urea nitrogen. GM increased the activities of lactate and glucose-6-phosphate dehydrogenases whereas decreased malate, isocitrate dehydrogenases; glucose-6 and fructose-1,6-bisphosphatases; superoxide dismutase, catalase, glutathione peroxidase and BBM enzymes. In contrast, FO alone increased enzyme activities of carbohydrate metabolism, BBM and oxidative stress. FO feeding to GM treated rats markedly enhanced resistance to GM elicited deleterious effects and prevented GM-induced decrease in 32Pi uptake across BBM. Dietary FO supplementation ameliorated GM-induced specific metabolic alterations and oxidative damage due to its intrinsic biochemical/antioxidant properties.

[The essential fatty acids omega-6 and omega-3: from their discovery to their use in therapy]

In 1929 Burr and Burr discovered the essential fatty acids omega-6 and omega-3. Since then, researchers have shown a growing interest in unsaturated essential fatty acids as they form the framework for the organism's cell membranes, particularly the neurones in the brain, are involved in the energy-transformation process, regulate the information flows between cells. Polyunsaturated fatty acids are also precursors of ''hormonal'' molecules, often with opposing effects, prostaglandins, prostacyclins, thromboxanes, leukotrienes, lipossines, resolvines, protectines that regulate immunity, platelet aggregation, inflammation, etc. They showed that raised levels of polyunsaturated fatty acids omega-3 in tissue correlate with a reduced incidence of degenerative cardiovascular disease, some mental illnesses such as depression, and neuro-degenerative diseases such as Alzheimer's. The balance between omega-3 and omega-6 acids allows the cell membranes to develop with exactly the right flexibility and fluidity, to carry messages between neurones, that is a determining factor in physical and mental well-being and has a profound influence on all the body's inflammatory responses. The results of a number of scientific studies suggest that omega-3 acids contribute to measuring and restricting inflammatory symptoms, whereas omega-6 acids (and saturated fats) give free range to inflammatory responses and amplify allergic reactions. Today in the Western countries, the ratio of omega-3 acids to omega-6 in the diet is weighted 1:10 in favour of omega-6 to up to 1:25 in some areas, while for proper functioning a 4:1 ratio of omega-6 acids to omega-3 acids is generally considered the optimum. In addition, the type of diet followed in the Western countries is very rich in saturated fats like butter and animal fats, but because of an excessive supply of these less noble fats, the cell membranes lose flexibility and this can affect the way they work. An appropriate supplement can be an efficient, effective and often necessary way to meet the body's needs, enhance its daily functions and promote health and longevity.

Omega-3 fatty acids: antiarrhythmic, proarrhythmic or both?

PURPOSE OF REVIEW

Recent publications seem to indicate no or an untoward effect of the marine omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid on cardiac rhythm. This review puts these developments into perspective.

RECENT FINDINGS

In-vitro or in animal models, little pro-arrhythmic effect, but many antiarrhythmic mechanisms of omega-3 fatty acids have been documented. In intervention studies in humans, eicosapentaenoic acid plus docosahexaenoic acid suppressed new atrial fibrillation in patients undergoing coronary bypass grafting. More importantly, in systematic reviews, it has been demonstrated that eicosapentaenoic acid plus docosahexaenoic acid reduce sudden cardiac death by 50%. In a recently published intervention study with eicosapentaenoic acid in patients at high cardiovascular risk in Japan, sudden cardiac death was rare. Sudden cardiac death is even rarer in the general population of Japan: it occurs 20 times less frequently than in the general population in Europe, e.g. Germany. In Japan, levels of eicosapentaenoic acid plus docosahexaenoic acid are high (omega-3 index estimated around 11%), whereas in Germany levels of eicosapentaenoic acid plus docosahexaenoic acid acids are low (omega-3 index around 4%). These and other data strengthen the concept that a low omega-3 index is a risk factor for sudden cardiac death, as a tool to assess the status of a person in terms of eicosapentaenoic acid plus docosahexaenoic acid, and as a means to monitor therapy with eicosapentaenoic acid plus docosahexaenoic acid.

SUMMARY

Concerns about pro-arrhythmic effects of eicosapentaenoic acid plus docosahexaenoic acid are largely theoretical. The evidence in favour of an antiarrhythmic effect is overwhelming, especially, when factoring in the omega-3 index.

Associations between increases in plasma n-3 polyunsaturated fatty acids following supplementation and decreases in anger and anxiety in substance abusers

OBJECTIVE

Mounting evidence indicates that low levels of n-3 polyunsaturated fatty acids (PUFAs) play a role in the pathophysiology of a large number of psychiatric disorders. In light of the suboptimal n-3 PUFAs intake due to poor dietary habits among substance abusers and the strong associations between aggression, anxiety and substance use disorders we examined if insurance of adequate intakes of n-3 PUFAs with supplementation would decrease their anger and anxiety scores.

METHOD

Substance abusers (n=22) were assigned to either 3 g of n-3 PUFAs, mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) or soybean oil in identically looking capsules. The trial was double-blind, randomized and lasted 3 months. Anger and anxiety scales were administered at baseline and once a month thereafter. Blood samples were collected at baseline and at the end of the trial.

RESULTS

Patients' dietary intakes of n-3 PUFAs fell below recommended levels. Assignment to n-3 PUFA treatment was accompanied by significant decreases in anger and anxiety scores compared to placebo assignment. These changes were associated with increases in plasma levels of both EPA and DHA but an increase in EPA was more robustly correlated with low end-of-trial anxiety scores and an increase in DHA was more robustly correlated with low end-of-trial anger scores.

CONCLUSION

These pilot data indicate that ensuring adequate n-3 PUFA intake via supplementation benefits substance abusers by reducing their anger and anxiety levels. The strong correlations between an increase in plasma EPA and lower anxiety scores and between an increase in plasma DHA and lower anger scores suggests a need for the further exploration of the differential responses to these two n-3 PUFAs in different psychiatric conditions.

Open-label, randomized, multiple-center, parallel study comparing glycemic responses and safety profiles of Glucerna versus Fresubin in subjects of type 2 diabetes mellitus

Since the increase of prevalence of type 2 diabetes mellitus (T-2DM), the replacing quickly absorbed carbohydrates with a fat source rich in monounsaturated fatty acid to provide improved glycemic control in these patients has become an important assistant therapy. In the present study, we compared glycemic response and safety of two nutritional products, Glucerna and Fresubin, in Chinese subjects with T-2DM. Overall, 203 T-2DM subjects were randomly assigned (1:1) to either Glucerna or Fresubin. The primary endpoint was the adjusted area under the curve (adj-AUC) for plasma glucose at 0-240 min. Blood samples were collected at 0, 30, 60, 90, 120, 180, and 240 min to compare the adjusted area under the curve (AUC) for the change in plasma glucose or insulin from 0 to 240 min. Adjusted peak values and times of glucose and insulin responses and adjusted glucose and insulin values were collected at the same time points. Safety parameters were also evaluated. The adjusted AUC for the change in plasma glucose in the Glucerna group was significantly lower than in Fresubin group (5.60 +/- 5.88 mmol/l*h vs. 7.97 +/- 6.32 mmol/l*h, P = 0.0061), as was the adjusted peak value of glucose (3.51 +/- 2.04 mmol/l vs. 4.69 +/- 1.99 mmol/l, P < 0.0001). Glucerna subjects had a longer adjusted peak time to insulin response compared to Fresubin subjects (105.00 +/- 43.4 min vs. 88.81 +/- 37.69 min, P = 0.0050). Glucerna subjects also experienced more gradual changes in glucose and insulin values. In conclusion, Glucerna provided better control of postprandial plasma glucose and insulin levels in Chinese subjects with T-2DM. Variation of postprandial glucose tended to be relatively stable after patients took Glucerna. Study results suggest that Glucerna may be beneficial in the reduction of postprandial glycemia.

Colon cancer therapy: new perspectives of nutritional manipulations using polyunsaturated fatty acids

PURPOSE OF REVIEW

Recent advances in the development of new therapeutic strategies combining conventional adjuvant radio/chemotherapy with nutritional manipulations with n-3 polyunsaturated fatty acids (PUFAs) are presented.

RECENT FINDINGS

Studies in cell culture and tumour-bearing animals have reported the ability of long-chain n-3 PUFAs to enhance the cytotoxicity of several anticancer drugs. In colon cancer, combination of n-3 PUFAs with 5-fluorouracil resulted in an additive growth inhibitory effect on different cell lines. Moreover, recent findings suggest that eicosapentaenoic or docosahexaenoic acid may be used to enhance tumour radiosensitivity while reducing mucosal/epidermal radiotoxicity similar to radioprotective agents. The underlying mechanism is probably mediated through lipid peroxidation because the antitumour effect of n-3 PUFAs is shared with the n-6 PUFA, arachidonic acid, and abolished by vitamin E. In vivo, the use of n-3 PUFAs may provide an additional advantage compared with n-6 PUFAs. Downregulation of eicosanoid synthesis from cyclooxygenase II may reduce angiogenesis, inflammation and metastasis induction.

SUMMARY

New insights suggest that n-3 PUFAs may play an important role not only in cancer prevention but also in cancer management. They may act synergistically with radio/chemotherapy to kill tumour cells by increasing oxidative stress while reducing angiogenesis, inflammation and metastasis induction.

Fish oil induced increase in walking distance, but not ankle brachial pressure index, in peripheral arterial disease is dependent on both body mass index and inflammatory genotype

Peripheral arterial disease (PAD) is an atherosclerotic disease. Evidence suggests that atherosclerosis is an inflammatory condition and long chain n-3 fatty acids, found in oily fish and fish oils, have been shown to reduce inflammation. Genetic and lifestyle factors such as body mass index (BMI) also influence inflammation. In this study we have examined the effect of fish oil in patients with claudication secondary to PAD. Fish oil supplementation, providing 1g EPA and 0.7 g DHA per day for 12 weeks, increased walking distance on a treadmill set at 3.2 km/h with a 7% incline. Walking distance to first pain increased from 76.2+/-8.5 m before fish oil to 140.6+/-25.5 m after fish oil (mean+/-SEM, p=0.004) and total distance walked increased from 160.0+/-21.5 m before fish oil to 242.1+/-34.5 m after fish oil (p=0.002). Fish oil supplementation also improved ankle brachial pressure index (ABPI) from 0.599+/-0.017 before fish oil to 0.776+/-0.030 after fish oil (p<0.001). The increase in walking distance was dependent on both BMI and genotype for single nucleotide polymorphisms in the genes encoding the pro-inflammatory cytokines tumour necrosis factor-alpha and interleukin (IL)-1beta and the anti-inflammatory cytokine IL-10 (detected using amplification refractory mutation system polymerase chain reaction). Neither BMI nor any of the genotypes examined affected the ability of fish oil to increase ABPI. The mechanisms by which fish oil affects walking distance and ABPI do not appear to be the same.

Dietary red palm oil reduces ischaemia-reperfusion injury in rats fed a hypercholesterolaemic diet

We have previously shown that dietary red palm oil (RPO) supplementation improves functional recovery in hearts subjected to ischaemia-reperfusion. However, little knowledge exists concerning the effects of RPO supplementation of a high-cholesterol diet on ischaemia-reperfusion injury. The signalling mechanisms responsible for RPO's effects in the presence of cholesterol also remain to be elucidated. Therefore, the aim of the present study was to examine the effects of RPO, given with a high-cholesterol diet, on mitogen-activated protein kinase (MAPK) phosphorylation and apoptosis. Long-Evans rats were fed a control diet, a control diet containing 2% cholesterol, or a control diet containing 2% cholesterol and 7 g RPO per kg (CRPO) for 5 weeks. Hearts were excised and mounted on an isolated working heart perfusion apparatus. Cardiac function was measured after which hearts were freeze-clamped and used to assess MAPK phosphorylation and to evaluate apoptosis. Cholesterol supplementation caused a poor aortic output (AO) recovery compared with the control group (35.5 (sem 6.2) v. 55.4 (sem 2.5) %), but when RPO was added, the percentage AO increased significantly. The cholesterol group's poor AO was associated with a significant increase in p38-MAPK phosphorylation, whereas the CRPO-supplemented group showed as significant reduction in p38-MAPK phosphorylation when compared with the cholesterol-supplemented group. This significant reduction in p38-MAPK was also associated with reduced apoptosis as indicated by significant reductions in caspase-3 and poly(ADP-ribose) polymerase cleavage.