The More, the Better: High-Dose Omega-3 Fatty Acids Improve Behavioural and Molecular Outcomes in Preclinical Models in Mild Brain Injury.

PURPOSE OF REVIEW: Mild traumatic brain injury (mTBI) is a continuing healthcare concern worldwide contributing to significant cognitive and neurological impairment, consequently affecting activities of daily living. While mTBI recovery is becoming well studied, there are no interventions to reduce the known impairments of mTBI. Omega-3 fatty acids (N-3FA) are safe and beneficial for brain health; however, their potential effects in a pathophysiological environment such as that seen post-mTBI are unknown. RECENT FINDINGS: Preclinical studies using rodent models are key to understanding molecular mechanisms underlying improvements post-injury. Studies to date have shown improved outcomes in rodent models following mTBI protocols, but these data have not been quantified using a systematic review and meta-analysis approach. Our systematic review assessed 291 studies identified from the literature. Of these studies, 18 studies met inclusion criteria. We conducted a meta-analysis examining the effect of high-dose n-3FA vs placebo on neurological, cognitive and molecular changes following mTBI. Quality of studies was rated as moderate to high quality, and while mostly compliant, some areas of risk of bias were identified. Results showed that preclinical doses of 10-370 mg/kg/day of n-3FA per day in rodents (equivalent to high clinical doses) resulted in improvements in neurological and cognitive performance (pooled effect sizes ranging between 1.52 and 3.55). Similarly, improvements in molecular and inflammatory markers were observed in treated rodents vs control (pooled effect sizes: 3.73-6.55). Overall, these findings highlight the potential for high-dose n-3FA for human clinical studies following mTBI.

Microencapsulated krill and tuna oil blend raises plasma long-chain n-3 polyunsaturated fatty acid levels compared to tuna oil with similar increases in ileal contractility in rats.

Long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) may be more bioavailable from krill oil compared to fish oil due to their phospholipid structure. We tested whether a microencapsulated krill and tuna oil blend (ME-TOKO) provided greater LC n-3 PUFA bioavailability, improved blood lipid profiles and increased intestinal contractility compared to microencapsulated tuna oil (ME-TO). Rats were divided into three groups to receive isocaloric diets containing ME-TO, ME-TOKO and microencapsulated olive oil (ME-OO) at 0.3 or 2 g/100 g for 4 weeks. Final body and organ weights, feed intake and waste output were similar. ME-TOKO rats had higher plasma total LC n-3 PUFA levels compared to ME-TO, but liver LC n-3 PUFA levels and plasma triglyceride and cholesterol levels were similar in non-fasted rats. Diets containing 2% ME-TO and ME-TOKO also showed similar increases in ileal contractility. In summary, ME-TO bioavailability of LC n-3 PUFA was similar to ME-TOKO.

Plant sterols as dietary adjuvants in the reduction of cardiovascular risk: theory and evidence.

Plant sterol-enriched foods are an effective dietary adjuvant in reducing cardiovascular risk by lowering total cholesterol and low density lipoprotein-cholesterol (LDL-C) in serum by up to approximately 15%. The mechanism of action of plant sterols is different from those of 3-hydroxy-3-methylglutaryl coenzyme A inhibitors (statins) and thus their effect is additive. Combining plant sterols with other dietary components known to reduce cholesterol in a portfolio approach has proven to be most effective for reduction of hypercholesterolemia and provide an alternative treatment option for clinicians. Plant sterol-enriched foods provides clinicians with a relatively cheap, safe, and effective way to help patients manage their cardiovascular risk.

Plant sterol/stanol prescription is an effective treatment strategy for managing hypercholesterolemia in outpatient clinical practice.

OBJECTIVE: To determine the effectiveness of prescribing 2 g plant sterols/stanols per day as an addition to standard practice in a dietary outpatient clinic. DESIGN: A randomized parallel design of comparative 12-week interventions. SUBJECTS/SETTING: Patients referred by a general practitioner to a dietary outpatient clinic for the management of hyperlipidemia were eligible. Twenty-five patients (15 women and 10 men) completed the study. INTERVENTION: Counseling regarding diet for hyperlipidemia was based on the National Cholesterol Education Program guidelines. The intervention group was instructed to incorporate approximately 25 g/day of margarine, containing plant sterols/stanols, which delivered approximately 2 g plant sterols/stanols. MAIN OUTCOME MEASURE: Changes in diet, body weight, and serum total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides were measured. STATISTICAL ANALYSIS PERFORMED: Changes in dietary and biochemical outcomes were assessed using Student's t test. For nonnormally distributed data, Wilcoxon signed rank test was used, and Mann-Whitney U tests were conducted to determine the proportion of subjects reaching defined goals. The number needed to treat index was used to report effectiveness of the intervention. RESULTS: Five of 14 subjects in the intervention group compared with 0 of 11 in the control group achieved a reduction in serum cholesterol of >/=15% ( P <.05). Using the number needed to treat index, for each 2.8 patients counseled with routine prescription of plant sterols/stanols, one additional patient would obtain a reduction in cholesterol by >/=15% compared with conventional management. This was achieved without any detrimental effects on the dietary fatty acid profile. CONCLUSIONS: Routine prescription of margarine containing plant sterol/stanol is an effective strategy in the management of hypercholesterolemic patients in the clinical setting.

Structured dietary advice incorporating walnuts achieves optimal fat and energy balance in patients with type 2 diabetes mellitus.

OBJECTIVE: A cardioprotective dietary fat profile is recommended for the treatment of type 2 diabetes. The clinical feasibility of advice strategies targeting specific fatty acid intakes and the extent to which they can be achieved by free-living populations needs to be tested. Walnuts, with high n-3 polyunsaturated fatty acid (PUFA) content, may help optimize fatty acid intakes, but regular consumption might increase total fat and energy intakes. This study examined whether advice that refers to a total dietary pattern inclusive of walnuts would result in low-fat energy-controlled diets with optimal dietary fat proportions for patients with type 2 diabetes mellitus. RESEARCH DESIGN AND METHODS: A parallel-design, controlled trial was completed by 55 free-living men and women with established type 2 diabetes mellitus. Participants were randomly assigned to one of three groups: low-fat (general advice), modified low-fat (total diet advice using exchange lists to differentiate PUFA-rich foods), walnut-specific (modified low fat including 30 g walnuts/day). Dietary intakes and clinical outcomes were measured at baseline, and at 3 and 6 months. Dietary goals were: less than 10% of energy from saturated fat, 7% to 10% of energy from PUFA, adequate n-3 PUFA (>or=2.22 g alpha-linolenic acid, >or=0.65 g eicosapentaenoic acid [EPA]+docosahexaenoic acid [DHA]) and n-6 to n-3 ratio less than 10. The proportion of subjects achieving dietary goals and major food sources of fat were determined. RESULTS: At baseline, dietary intakes were not significantly different between groups. No group and few individuals (10%) were consuming adequate PUFA, with meat the main source of dietary fat (22% total dietary fat). At 3 and 6 months, energy and macronutrient intakes were similar among groups. The walnut group, however, was the only group to achieve all fatty acid intake targets (P <.01), and had the greatest proportion of subjects achieving targets ( P <.05). Walnuts were the main source of dietary fat (31%) and n-3 PUFA (50%), while 350 g oily fish/day provided a further 17% n-3 PUFA consumed by this group. CONCLUSIONS: Specific advice for the regular inclusion of walnuts in the context of the total diet helps achieve optimal fat intake proportions without adverse effects on total fat or energy intakes in patients with type 2 diabetes mellitus.

The use of novel foods enriched with long-chain n-3 fatty acids to increase dietary intake: a comparison of methodologies assessing nutrient intake.

OBJECTIVE: To evaluate the effect of consuming a variety of foods enriched in long-chain n-3 fatty acids in low fish eaters. DESIGN: Evaluation of reported dietary intakes in a 6-month, double-blind, randomized, controlled parallel design trial. SUBJECTS/SETTING: Eighty-five men and women with overweight and mildly elevated triglyceride levels who have a low habitual intake of fish. INTERVENTION: Subjects were randomized to consume foods either enriched in long-chain n-3 fats or control foods (not enriched). Subjects were asked to consume eight portions per day (equivalent to approximately 1 g/day long-chain n-3 fatty acid if randomized to the intervention). MAIN OUTCOME MEASURE: Reported energy, macronutrient, and fatty acid intakes were measured by diet history, 3-day food records, and body weight. STATISTICAL ANALYSES: Repeated measures analysis of variance, Kruskall-Wallis test, Pearson's correlation coefficient, and Bland-Altman plots were conducted. RESULTS: The two groups did not differ in mean dietary intake of long-chain n-3 fatty acid intake at baseline (258 mg and 313 mg for the intervention and control groups, respectively). At 6 months the intervention group members increased their intake of long-chain n-3 fats 4.5-fold compared with baseline and with the control group (P<.001). The data from the diet histories correlated well with the food records for all reported macronutrient and fatty acid values. Food pattern analysis showed that milk (13.8%), cereal (12.1%), and bread (11.3%) contributed the most to the overall long-chain n-3 fatty acid intake in the intervention group. CONCLUSIONS: This long-term study in free-living subjects indicates that population intakes of long-chain n-3 fatty acids could be substantially increased through the availability of a variety of n-3 fatty acid-enriched processed foods.

Overweight consumers' salient beliefs on omega-3-enriched functional foods in Australia's Illawarra region.

OBJECTIVE: To determine consumer salient beliefs toward functional foods enriched with omega-3 fatty acids. DESIGN: Focus group interviews with adult consumers using the Theory of Planned Behavior (TPB) as a theoretical framework. SETTING: Community-based residents living in the Illawarra region of New South Wales, Australia. PARTICIPANTS: Forty-two overweight participants (29 female, 13 male) aged 30 to 80 years recruited by advertisement and attending 1 of 6 focus groups, which were recorded and transcribed verbatim. ANALYSIS: Content analysis was carried out, and subcategories were developed to capture the emerging themes according to the TPB model. RESULTS: Most participants were aware of a range of potential benefits of omega-3 fatty acids, but they had reservations about the ability of omega-3-enriched foods to deliver a health benefit. They were concerned about whether these foods were labeled clearly and about the possibility of overdosing. Family and friends were viewed as important in introducing participants to novel foods on the market. Participants regarded dietitians as a credible source and were least trusting of food companies and scientists. Overall, participants reported that cost was a major barrier, and that they would not necessarily trade taste for health benefits. Adding omega-3 fatty acids to foods regarded as less healthful was viewed more as a gimmick rather than a real health benefit. CONCLUSIONS AND IMPLICATIONS: The consumer attitudes and purchase intentions identified in this study will be helpful to educators as they plan messages and strategies to guide dietary choices related to products enriched with omega-3 fatty acids.

Attitudes and intentions toward purchasing novel foods enriched with omega-3 fatty acids.

OBJECTIVE: To identify the nature, strength, and relative importance of influences on intentions to consume foods that are enriched with omega-3 fatty acids using the Theory of Planned Behavior (TPB). DESIGN: A cross-sectional self-administered questionnaire. SETTING: Community-based residents living in the Illawarra region of New South Wales, Australia. SUBJECTS: Two subsamples were surveyed via questionnaire: community members who responded to a local media advertisement (n = 79), and subjects in a dietary intervention trial for type 2 diabetes mellitus (n = 50). VARIABLES MEASURED: Using the TPB variables-intention, attitude, subjective norm, and perceived behavioral control-questionnaire items were constructed to measure intention to consume omega-3-enriched novel foods. ANALYSIS: The results from subsamples did not differ and were combined for analysis. The determinants of intention defined in the TPB were investigated using multiple linear regressions. RESULTS: Regression analysis showed that the model was a significant determinant of intention (R2 = .725; P < .001). Attitude was a significant determinant of intention, whereas subjective norms and control beliefs were not. DISCUSSION: With attitude having the greatest influence on intentions, immediate prospects for modifying behavior are likely to come through a change in attitude, specifically in beliefs about the effectiveness of enriched products in achieving specific health benefits. CONCLUSIONS AND IMPLICATIONS: Promoters of omega-3-enriched foods would be advised to direct their promotions toward changing the attitudes of consumers about the effectiveness of the functional ingredient.

Including walnuts in a low-fat/modified-fat diet improves HDL cholesterol-to-total cholesterol ratios in patients with type 2 diabetes.

OBJECTIVE: The aim of this study was to examine the effect of a moderate-fat diet inclusive of walnuts on blood lipid profiles in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: This was a parallel randomized controlled trial comparing three dietary advice groups each with 30% energy as fat: low fat, modified low fat, and modified low fat inclusive of 30 g of walnuts per day. Fifty-eight men and women, mean age 59.3 +/- 8.1 years, started the trial. Dietary advice was given at baseline with monthly follow-up and fortnightly phone calls for support. Body weight, percent body fat, blood lipids, HbA1c, total antioxidant capacity, and erythrocyte fatty acid levels were measured at 0, 3, and 6 months. Data were assessed by repeated-measures ANOVA with an intention-to-treat model. RESULTS: The walnut group achieved a significantly greater increase in HDL cholesterol-to-total cholesterol ratio (P=0.049) and HDL (P=0.046) than the two other treatment groups. A 10% reduction in LDL cholesterol was also achieved in the walnut group, reflecting a significant effect by group (P=0.032) and time (P=0.036). There were no significant differences between groups for changes in body weight, percent body fat, total antioxidant capacity, or HbA1c levels. The higher dietary polyunsaturated fat-to-saturated fat ratio and intakes of omega-3 fatty acids in the walnut group were confirmed by erythrocyte biomarkers of dietary intake. CONCLUSIONS: Structured "whole of diet" advice that included 30 g of walnuts/day delivering substantial amounts of polyunsaturated fatty acid improved the lipid profile of patients with type 2 diabetes.

Impact of foods enriched with n-3 long-chain polyunsaturated fatty acids on erythrocyte n-3 levels and cardiovascular risk factors.

Consumption of fish or fish oils rich in the n-3 long chain PUFA EPA and DHA may improve multiple risk factors for CVD. The objective of this study was to determine whether regular consumption of foods enriched with n-3 long-chain PUFA can improve n-3 long-chain PUFA status (erythrocytes) and cardiovascular health. Overweight volunteers with high levels of triacylglycerols (TG; >1.6 mmol/l) were enrolled in a 6-month dietary intervention trial conducted in Adelaide (n 47) and Perth (n 39), and randomised to consume control foods or n-3-enriched foods to achieve an EPA + DHA intake of 1 g/d. Test foods were substituted for equivalent foods in their regular diet. Erythrocyte fatty acids, plasma TG and other CVD risk factors were monitored at 0, 3 and 6 months. There were no significant differences between groups for blood pressure, arterial compliance, glucose, insulin, lipids, C-reactive protein (CRP) or urinary 11-dehydro-thromboxane B2 (TXB2) over 6 months, even though regular consumption of n-3-enriched foods increased EPA + DHA intake from 0.2 to 1.0 g/d. However, the n-3 long-chain PUFA content of erythrocytes increased by 35 and 53 % at 3 and 6 months, respectively, in subjects consuming the n-3-enriched foods. These increases were positively associated with measures of arterial compliance and negatively associated with serum CRP and urinary 11-dehydro-TXB2 excretion. Sustainable increases in dietary intakes and erythrocyte levels of n-3 long-chain PUFA can be achieved through regular consumption of suitably enriched processed foods. Such increases may be associated with reduced CV risk.

Health benefits of herbs and spices: the past, the present, the future.

UNLABELLED: Herbs and spices have a traditional history of use, with strong roles in cultural heritage, and in the appreciation of food and its links to health. Demonstrating the benefits of foods by scientific means remains a challenge, particularly when compared with standards applied for assessing pharmaceutical agents. Pharmaceuticals are small-molecular-weight compounds consumed in a purified and concentrated form. Food is eaten in combinations, in relatively large, unmeasured quantities under highly socialised conditions. The real challenge lies not in proving whether foods, such as herbs and spices, have health benefits, but in defining what these benefits are and developing the methods to expose them by scientific means. CULTURAL ASPECTS: The place of herbs and spices in the diet needs to be considered in reviewing health benefits. This includes definitions of the food category and the way in which benefits might be viewed, and therefore researched. Research may focus on identifying bioactive substances in herbs and spices, or on their properties as a whole food, and/or be set in the context of a dietary cuisine. THE ROLE OF HERBS AND SPICES IN HEALTH: The antioxidant properties of herbs and spices are of particular interest in view of the impact of oxidative modification of low-density lipoprotein cholesterol in the development of atherosclerosis. There is level III-3 evidence (National Health and Medical Research Council [NHMRC] levels of evidence) that consuming a half to one clove of garlic (or equivalent) daily may have a cholesterol-lowering effect of up to 9%. There is level III-1 evidence that 7.2 g of aged garlic extract has been associated with anticlotting (in-vivo studies), as well as modest reductions in blood pressure (an approximate 5.5% decrease in systolic blood pressure). A range of bioactive compounds in herbs and spices have been studied for anticarcinogenic properties in animals, but the challenge lies in integrating this knowledge to ascertain whether any effects can be observed in humans, and within defined cuisines. Research on the effects of herbs and spices on mental health should distinguish between cognitive decline associated with ageing and the acute effects of psychological and cognitive function. There is level I and II evidence for the effect of some herbal supplements on psychological and cognitive function. There is very limited scientific evidence for the effects of herbs and spices on type 2 diabetes mellitus, with the best evidence being available for the effect of ginseng on glycaemia, albeit based on four studies. More research is required, particularly examining the effects of chronic consumption patterns. With increasing interest in alternatives to non-steroidal anti-inflammatory agents in the management of chronic inflammation, research is emerging on the use of food extracts. There is level II evidence for the use of ginger in ameliorating arthritic knee pain; however, the improvement is modest and the efficacy of ginger treatment is ranked below that of ibuprofen. More definitive research is required. PUBLIC HEALTH AND DIETARY IMPLICATIONS: Recommendations for intakes of food in the Australian guide to healthy eating do not yet include suggested intakes of herbs and spices. Future consideration should be given to including more explicit recommendations about their place in a healthy diet. In addition to delivering antioxidant and other properties, herbs and spices can be used in recipes to partially or wholly replace less desirable ingredients such as salt, sugar and added saturated fat in, for example, marinades and dressings, stir-fry dishes, casseroles, soups, curries and Mediterranean-style cooking. Vegetable dishes and vegetarian options may be more appetising when prepared with herbs and spices. FUTURE DIRECTIONS: As several metabolic diseases and age-related degenerative disorders are closely associated with oxidative processes in the body, the use of herbs and spices as a source of antioxidants to combat oxidation warrants further attention. Immediate studies should focus on validating the antioxidant capacity of herbs and spices after harvest, as well as testing their effects on markers of oxidation. This will work in parallel with clinical trials that are aiming to establish antioxidants as mediators of disease prevention. From a dietary perspective, the functionality of herbs and spices will be exposed through consideration of their properties as foods. As with most foods, the real benefits of including them in the diet are likely to emerge with a better understanding of the attributes of health that are best supported by food, and in methodological developments addressing the evidence base for their effects. These developments are well underway through evidence-based frameworks for substantiating health claims related to foods. At present, recommendations are warranted to support the consumption of foods rich in bioactive components, such as herbs and spices. With time, we can expect to see a greater body of scientific evidence supporting the benefits of herbs and spices in the overall maintenance of health and protection from disease.

Walnuts and dietary approaches to the prevention and management of abnormal lipid profiles in Type 2 diabetes mellitus.

Type 2 diabetes mellitus is associated with an increased risk of coronary heart disease, reflected in the presence of abnormal lipid profiles. Increasing the intake of polyunsaturated fat at the same time as reducing saturated fat can alleviate these risk factors. Including walnuts in a 'whole of diet' approach to managing fat consumption can help to ensure that the desired fatty acid profile is achieved. This comes via a food matrix that also delivers anti-oxidants, fibre and protein that may provide additional nutritional benefits. Thus there is good reason to include walnuts in dietary advice for patients with Type 2 diabetes mellitus.