The Climate Wise slides: An evaluation of planetary health lecture slides for medical education.

EDUCATIONAL CHALLENGE: There is an urgent need for innovations in planetary health medical education. Physicians must be prepared to provide high-value, low-carbon healthcare for patients increasingly impacted by the health consequences of climate change. PROPOSED SOLUTION: The Climate Wise slides, an evidence-based, open-access pedagogical tool that provides didactic planetary health medical education organized by medical subspecialty, was developed and evaluated by a virtual lecture session that presented a subset of the slides to N = 75 Canadian medical students. Each participant completed a questionnaire before and after the Climate Wise virtual lecture that included multiple choice questions to assess their planetary health knowledge and a rating of their interest in including the Climate Wise slides in medical curricula. LESSONS LEARNED: Participants showed significantly improved planetary health knowledge scores (p < 0.0001) and increased interest in including the Climate Wise slides in medical curricula (p < 0.001) after the virtual Climate Wise lecture session. This study demonstrates that the Climate Wise slides are a valuable pedagogical tool to advance planetary health medical education. NEXT STEPS: Future directions include evaluating faculty perspectives on the Climate Wise slides, learning outcomes of the slides implemented longitudinally in medical curricula, and developing higher-order problem-based and simulation-based planetary health medical education resources. Given the urgent need for planetary health medical education, we recommend the global sharing of teaching resources to facilitate the rapid upscaling of validated pedagogical tools internationally.

Urgent air transfers for acute respiratory infections among children from Northern Canada, 2005-2014.

BACKGROUND: The incidence of hospitalizations for acute respiratory infections (ARI) among young Indigenous children from Northern Canada is consistently high. ARIs requiring urgent air transfer can be life-threatening and costly. We aimed to describe their epidemiology, estimate age-specific incidences, and explore factors associated with level of care required. METHODS: We undertook a retrospective cohort study of children <5 years old from Northern Canada transferred by urgent air transport for ARI from 2005 through 2014 to 5 pediatric tertiary care centers in Vancouver, Edmonton, Winnipeg, Ottawa and Montreal. Admissions were identified via ARI-related ICD-9/10 coding and forward sortation area. Descriptive statistics and univariable analyses were performed. RESULTS: Among 650 urgent air transfers, the majority were from Nunavut (n = 349, 53.7%) or Nunavik (n = 166, 25.5%), <6 months old (n = 372, 57.2%), and without underlying comorbidity (n = 458; 70.5%). Estimated annual tertiary care ARI admission rates in infants <1 year old from Nunavut (40.7/1000) and Nunavik (44.5/1000) were tenfold higher than in children aged 1 to 4 years. Bronchiolitis (n = 333, 51.2%) and pneumonia (n = 208, 32.0%) were the most common primary discharge diagnoses. Nearly half required critical care (n = 316, 48.6%); mechanical ventilation rates ranged from 7.2% to 55.9% across centres. The most common primary pathogen was respiratory syncytial virus (n = 196, 30.1%). Influenza A or B was identified in 35 cases (5.4%) and vaccine-preventable bacterial infections in 27 (4.1%) cases. INTERPRETATION: Urgent air transfers for ARI from Northern Canada are associated with high acuity. Variations in levels of care were seen across referral centers, age groups and pathogens.

Barriers and facilitators to implementing bubble CPAP to improve neonatal health in sub-Saharan Africa: a systematic review.

BACKGROUND: Bubble continuous positive airway pressure (CPAP) has been shown to be effective in supporting breathing in newborns with respiratory distress. The factors that influence implementation in resource-constrained settings remain unclear. The objective of this review is to evaluate the barriers and facilitators of CPAP implementation for newborn care at sub-Saharan African health facilities and how different facility levels and types of bubble CPAP systems may impact utilization. METHODS: A systematic search (database inception to July 2019) was performed on MEDLINE Ovid, EMBASE, CINAHL, The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), the WHO Regional Database for Africa, African Index Medicus (AIM), African Journals Online, grey literature and the references of relevant articles. Studies that met the inclusion criteria (primary research, bubble CPAP implementation with neonates ≤ 28 days old at a health facility in sub-Saharan Africa) were included in the review and assessed with National Heart, Lung, and Blood Institute of the National Institutes of Health (NIH) quality assessment tools. The review protocol was published to PROSPERO (CRD42018116082). RESULTS: Seventeen studies were included in the review. Reliable availability of equipment, effectively informing and engaging caregivers and staffing shortages were frequently mentioned barriers to the implementation of bubble CPAP. Understaffed neonatal units and high turnover of nurses and doctors compromised effective training. Provider-to-provider clinical mentorship models as well as affordability and cost-effectiveness of innovative bubble CPAP systems were identified as frequently mentioned facilitators of implementation. CONCLUSIONS: With a strong recommendation by the World Health Organization for its use with premature infants with respiratory distress, it is important to understand the barriers and facilitators that can inform the implementation of bubble CPAP. More research is needed into health system factors that can support or impede the use of this potentially promising intervention.

Evaluation of Anatomically Designed Flocked Rectal Swabs for Use with the BioFire FilmArray Gastrointestinal Panel for Detection of Enteric Pathogens in Children Admitted to Hospital with Severe Gastroenteritis.

Diagnosing diarrheal disease is difficult in part due to challenges in obtaining and transporting a bulk stool specimen, particularly in resource-limited settings. We compared the performance of flocked rectal swabs to that of traditional bulk stool samples for enteric pathogen detection using the BioFire FilmArray gastrointestinal panel in children admitted to four hospitals in Botswana with community onset severe gastroenteritis. Of the 117-matched flocked rectal swab/stool pairs, we found no significant difference in pathogen detection rates between the flocked rectal swab samples and traditional bulk stool sampling methods for any bacterial (168 versus 167, respectively), viral (94 versus 92, respectively), or protozoan (18 versus 18, respectively) targets. The combination of flocked rectal swab samples with FilmArray testing allows for the rapid diagnosis of infectious gastroenteritis, facilitating a test-and-treat approach for infections that are life-threatening in many resource-limited settings. The culture recovery rates for bacterial pathogens utilizing this approach need to be assessed.

Plasma oxylipins respond in a linear dose-response manner with increased intake of EPA and DHA: results from a randomized controlled trial in healthy humans.

BACKGROUND: The health effects of long-chain omega-3 polyunsaturated fatty acids (n-3 PUFAs) are partly mediated by their oxidized metabolites, i.e., eicosanoids and other oxylipins. Some intervention studies have demonstrated that eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) increase systemic concentrations of n-3 PUFA-derived oxylipins and moderately decrease arachidonic acid-derived oxylipins. There is no information on the dose-response of oxylipin concentrations after n-3 PUFA intake. OBJECTIVE: The aim of this study was to quantify oxylipins in human plasma samples from an intervention study in which participants were randomly assigned to different daily intakes of EPA and DHA for 12 mo. METHODS: Healthy adult men and women with low habitual fish consumption (n = 121) were randomly assigned to receive capsules providing doses of n-3 PUFAs reflecting 3 patterns of consumption of oily fish [1, 2, or 4 portions/wk with 3.27 g EPA + DHA (1:1.2, wt:wt) per portion] or placebo. Oxylipins were quantified in plasma after 3 and 12 mo. Relative and absolute changes of individual oxylipins were calculated and concentrations were correlated with the dose and the content of EPA and DHA in blood lipid pools. RESULTS: Seventy-three oxylipins, mostly hydroxy-, dihydroxy-, and epoxy-PUFAs, were quantified in the plasma samples. After 3 and 12 mo a linear increase with dose was observed for all EPA- and DHA-derived oxylipins. Cytochrome-P450-derived anti-inflammatory and cardioprotective epoxy-PUFAs increased linearly with n-3 PUFA dose and showed low interindividual variance (r2 > 0.95). Similarly, 5, 12-, and 15-lipoxygenase-derived hydroxy-PUFAs as well as those formed autoxidatively increased linearly. These include the precursors of so-called specialized pro-resolving lipid mediators (SPMs), e.g., 17-hydroxy-DHA and 18-hydroxy-EPA. CONCLUSIONS: Plasma concentrations of biologically active oxylipins derived from n-3 PUFAs, including epoxy-PUFAs and SPM-precursors, increase linearly with elevated intake of EPA and DHA. Interindividual differences in resulting plasma concentrations are low. This trial was registered at controlled-trials.com as ISRCTN48398526.

APOE4 Genotype Exerts Greater Benefit in Lowering Plasma Cholesterol and Apolipoprotein B than Wild Type (E3/E3), after Replacement of Dietary Saturated Fats with Low Glycaemic Index Carbohydrates.

We examined the impact of APOE genotype on plasma lipids and glucose in a secondary analysis of data from a five-arm, randomised controlled, parallel dietary intervention trial ('RISCK' study), to investigate the impact of replacing saturated fatty acids (SFA) with either monounsaturated fat (MUFA) or carbohydrate of high or low glycaemic index (GI) on CVD risk factors and insulin sensitivity. We tested the impact of APOE genotype (carriage of E2 and E4 alleles versus E3/E3), determined retrospectively, on plasma lipids, lipoproteins and glucose homeostasis at baseline (n = 469), and on the change in these variables after 24 weeks of dietary intervention (n = 389). At baseline, carriers of E2 (n = 70), E4 (n = 125) and E3/E3 (n = 274) expressed marked differences in total plasma cholesterol (TC, p = 0.001), low density lipoprotein cholesterol (LDL-C, p < 0.0001), apolipoprotein B (apo B, p < 0.0001) and total to high density lipoprotein cholesterol ratio (TC:HDL-C, p = 0.002), with plasma concentrations decreasing in the order E4 > E3/E3 > E2. Following intervention, there was evidence of a significant diet x genotype interaction with significantly greater decreases in TC (p = 0.02) and apo B (p = 0.006) among carriers of E4 when SFA was replaced with low GI carbohydrate on a lower fat diet (TC -0.28 mmol/L p = 0.03; apo B -0.1 g/L p = 0.02), and a relative increase in TC (in comparison to E3/E3) when SFA was replaced with MUFA and high GI carbohydrates (TC 0.3 mmol/L, p = 0.03). Among carriers of E2 (compared with E3/E3) there was an increase in triacylglycerol (TAG) when SFA was replaced with MUFA and low GI carbohydrates 0.46 mmol/L p = 0.001). There were no significant interactions between APOE genotype and diet for changes in indices of glucose homeostasis. In conclusion, variations in APOE genotype led to differential effects on the lipid response to the replacement of SFA with MUFA and low GI carbohydrates.

Hepatic steatosis risk is partly driven by increased de novo lipogenesis following carbohydrate consumption.

BACKGROUND: Diet is a major contributor to metabolic disease risk, but there is controversy as to whether increased incidences of diseases such as non-alcoholic fatty liver disease arise from consumption of saturated fats or free sugars. Here, we investigate whether a sub-set of triacylglycerols (TAGs) were associated with hepatic steatosis and whether they arise from de novo lipogenesis (DNL) from the consumption of carbohydrates. RESULTS: We conduct direct infusion mass spectrometry of lipids in plasma to study the association between specific TAGs and hepatic steatosis assessed by ultrasound and fatty liver index in volunteers from the UK-based Fenland Study and evaluate clustering of TAGs in the National Survey of Health and Development UK cohort. We find that TAGs containing saturated and monounsaturated fatty acids with 16-18 carbons are specifically associated with hepatic steatosis. These TAGs are additionally associated with higher consumption of carbohydrate and saturated fat, hepatic steatosis, and variations in the gene for protein phosphatase 1, regulatory subunit 3b (PPP1R3B), which in part regulates glycogen synthesis. DNL is measured in hyperphagic ob/ob mice, mice on a western diet (high in fat and free sugar) and in healthy humans using stable isotope techniques following high carbohydrate meals, demonstrating the rate of DNL correlates with increased synthesis of this cluster of TAGs. Furthermore, these TAGs are increased in plasma from patients with biopsy-confirmed steatosis. CONCLUSION: A subset of TAGs is associated with hepatic steatosis, even when correcting for common confounding factors. We suggest that hepatic steatosis risk in western populations is in part driven by increased DNL following carbohydrate rich meals in addition to the consumption of saturated fat.

Lipidomics Profiling of Human Adipose Tissue Identifies a Pattern of Lipids Associated with Fish Oil Supplementation.

To understand the interaction between diet and health, biomarkers that accurately reflect consumption of foods of perceived health relevance are needed. The aim of this investigation was to use direct infusion-mass spectrometry (DI-MS) lipidomics to determine the effects of fish oil supplementation on lipid profiles of human adipose tissue. Adipose tissue samples from an n-3 polyunsaturated fatty acid (PUFA) supplementation study (n = 66) were analyzed to compare the pattern following supplementation equivalent to zero or four portions of oily fish per week. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were incorporated into highly unsaturated (≥5 double bonds) triglycerides (TGs), phosphocholines, and phosphoethanolamines as well as being detected directly as the nonesterified fatty acid forms. Multivariate statistics demonstrated that phospholipids were the most accurate and sensitive lipids for the assessing EPA and DHA incorporation into adipose tissue. Potential confounding factors (adiposity, age, and sex of the subject) were also considered in the analysis, and adiposity was also associated with an increase in highly unsaturated TGs as a result of incorporation of the n-6 PUFA arachidonic acid. DI-MS provides a high-throughput analysis of fatty acid status that can monitor oily fish consumption, suitable for use in cohort studies.

The Pattern of Fatty Acids Displaced by EPA and DHA Following 12 Months Supplementation Varies between Blood Cell and Plasma Fractions.

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are increased in plasma lipids and blood cell membranes in response to supplementation. Whilst arachidonic acid (AA) is correspondingly decreased, the effect on other fatty acids (FA) is less well described and there may be site-specific differences. In response to 12 months EPA + DHA supplementation in doses equivalent to 0-4 portions of oily fish/week (1 portion: 3.27 g EPA+DHA) multinomial regression analysis was used to identify important FA changes for plasma phosphatidylcholine (PC), cholesteryl ester (CE) and triglyceride (TAG) and for blood mononuclear cells (MNC), red blood cells (RBC) and platelets (PLAT). Dose-dependent increases in EPA + DHA were matched by decreases in several n-6 polyunsaturated fatty acids (PUFA) in PC, CE, RBC and PLAT, but were predominantly compensated for by oleic acid in TAG. Changes were observed for all FA classes in MNC. Consequently the n-6:n-3 PUFA ratio was reduced in a dose-dependent manner in all pools after 12 months (37%-64% of placebo in the four portions group). We conclude that the profile of the FA decreased in exchange for the increase in EPA + DHA following supplementation differs by FA pool with implications for understanding the impact of n-3 PUFA on blood lipid and blood cell biology.

Fatty acid profile of plasma NEFA does not reflect adipose tissue fatty acid profile.

Adipose tissue (AT) fatty acid (FA) composition partly reflects habitual dietary intake. Circulating NEFA are mobilised from AT and might act as a minimally invasive surrogate marker of AT FA profile. Agreement between twenty-eight FA in AT and plasma NEFA was assessed using concordance coefficients in 204 male and female participants in a 12-month intervention using supplements to increase the intake of EPA and DHA. Concordance coefficients generally showed very poor agreement between AT FA and plasma NEFA at baseline SFA: 0·07; MUFA: 0·03; n-6 PUFA: 0·28; n-3 PUFA: 0·01). Participants were randomly divided into training (70 %) and validation (30 %) data sets, and models to predict AT and dietary FA were fitted using data from the training set, and their predictive ability was assessed using data from the validation set. AT n-6 PUFA and SFA were predicted from plasma NEFA with moderate accuracy (mean absolute percentage error n-6 PUFA: 11 % and SFA: 8 %), but predicted values were unable to distinguish between low, medium and high FA values, with only 25 % of n-6 PUFA and 33 % of SFA predicted values correctly assigned to the appropriate tertile group. Despite an association between AT and plasma NEFA EPA (P=0·001) and DHA (P=0·01) at baseline, there was no association after the intervention. To conclude, plasma NEFA are not a suitable surrogate for AT FA.

Modelling the Interplay between Lifestyle Factors and Genetic Predisposition on Markers of Type 2 Diabetes Mellitus Risk.

The risk of developing type 2 diabetes mellitus (T2DM) is determined by a complex interplay involving lifestyle factors and genetic predisposition. Despite this, many studies do not consider the relative contributions of this complex array of factors to identify relationships which are important in progression or prevention of complex diseases. We aimed to describe the integrated effect of a number of lifestyle changes (weight, diet and physical activity) in the context of genetic susceptibility, on changes in glycaemic traits in overweight or obese participants following 12-months of a weight management programme. A sample of 353 participants from a behavioural weight management intervention were included in this study. A graphical Markov model was used to describe the impact of the intervention, by dividing the effects into various pathways comprising changes in proportion of dietary saturated fat, physical activity and weight loss, and a genetic predisposition score (T2DM-GPS), on changes in insulin sensitivity (HOMA-IR), insulin secretion (HOMA-B) and short and long term glycaemia (glucose and HbA1c). We demonstrated the use of graphical Markov modelling to identify the importance and interrelationships of a number of possible variables changed as a result of a lifestyle intervention, whilst considering fixed factors such as genetic predisposition, on changes in traits. Paths which led to weight loss and change in dietary saturated fat were important factors in the change of all glycaemic traits, whereas the T2DM-GPS only made a significant direct contribution to changes in HOMA-IR and plasma glucose after considering the effects of lifestyle factors. This analysis shows that modifiable factors relating to body weight, diet, and physical activity are more likely to impact on glycaemic traits than genetic predisposition during a behavioural intervention.

Effect of reducing portion size at a compulsory meal on later energy intake, gut hormones, and appetite in overweight adults.

OBJECTIVE: Larger portion sizes (PS) are associated with greater energy intake (EI), but little evidence exists on the appetitive effects of PS reduction. This study investigated the impact of reducing breakfast PS on subsequent EI, postprandial gastrointestinal hormone responses, and appetite ratings. METHODS: In a randomized crossover design (n = 33 adults; mean BMI 29 kg/m(2) ), a compulsory breakfast was based on 25% of gender-specific estimated daily energy requirements; PS was reduced by 20% and 40%. EI was measured at an ad libitum lunch (240 min) and snack (360 min) and by weighed diet diaries until bed. Blood was sampled until lunch in 20 participants. Appetite ratings were measured using visual analogue scales. RESULTS: EI at lunch (control: 2,930 ± 203; 20% reduction: 2,853 ± 198; 40% reduction: 2,911 ± 179 kJ) and over the whole day except breakfast (control: 7,374 ± 361; 20% reduction: 7,566 ± 468; 40% reduction: 7,413 ± 417 kJ) did not differ. Postprandial PYY, GLP-1, GIP, insulin, and fullness profiles were lower and hunger, desire to eat, and prospective consumption higher following 40% reduction compared to control. Appetite ratings profiles, but not hormone concentrations, were associated with subsequent EI. CONCLUSIONS: Smaller portions at breakfast led to reductions in gastrointestinal hormone secretion but did not affect subsequent energy intake, suggesting small reductions in portion size may be a useful strategy to constrain EI.

Compared with daily, weekly n-3 PUFA intake affects the incorporation of eicosapentaenoic acid and docosahexaenoic acid into platelets and mononuclear cells in humans.

Consumption of oily fish is sporadic, whereas controlled intervention studies of n-3 (ω-3) fatty acids usually provide capsules containing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) as a daily dose. This methodologic study explored whether there are differences in the short-, medium-, and long-term incorporation of EPA and DHA into blood plasma and cells with the provision of identical amounts of EPA and DHA, equivalent to 2 oily fish servings per week (or 6.54 g/wk EPA and DHA), either intermittently (i.e., 1 portion twice per week) or continuously (i.e., divided into daily amounts). The study was part of a randomized, double-blind controlled intervention lasting 12 mo, with participants stratified by age and sex. There were 5 intervention groups, 2 of which are reported here: the 2 intermittent portions (2I) and 2 continuous portions (2C) groups. EPA and DHA were measured in plasma phosphatidylcholine, platelets, and blood mononuclear cells (MNCs) at 9 time points. Sixty-five participants completed the study (2I group, n = 30, mean age of 49.2 y; 2C group, n = 35, mean age of 50.6 y). The incorporation pattern over the 12-mo intervention was different between the 2 groups in all samples (P < 0.0001, time × treatment interaction). At the end of the 12-mo intervention, the 2C group had higher EPA, DHA, and EPA + DHA in platelets (all P < 0.01) and higher EPA and EPA + DHA in MNCs (both P < 0.05) compared with the 2I group. No significant differences were shown for plasma phosphatidylcholine EPA (P = 0.1), DHA (P = 0.15), EPA + DHA (P = 0.07), or MNC DHA (P = 0.06). In conclusion, the pattern of consumption does affect the incorporation of EPA and DHA into cells used as biomarkers of intake. The differences identified here need to be considered in the design of studies and when extrapolating results from continuous capsule-based intervention studies to dietary guidelines for oily fish consumption. This trial was registered at www.controlled-trials.com as ISRCTN48398526.

Age and sex differences in the incorporation of EPA and DHA into plasma fractions, cells and adipose tissue in humans.

The aim of the present study was to determine whether age and sex influence both the status and incorporation of EPA and DHA into blood plasma, cells and tissues. The study was a double-blind, randomised, controlled intervention trial, providing EPA plus DHA equivalent to 0, 1, 2 or 4 portions of oily fish per week for 12 months. The participants were stratified by age and sex. A linear regression model was used to analyse baseline outcomes, with covariates for age or sex groups and by adjusting for BMI. The change in outcomes from baseline to 12 months was analysed with additional adjustment for treatment and average compliance. Fatty acid profiles in plasma phosphatidylcholine, cholesteryl esters, NEFA and TAG, mononuclear cells (MNC), erythrocyte membranes, platelets, buccal cells (BU) and adipose tissue (AT) were determined. At baseline, EPA concentrations in plasma NEFA and DHA concentrations in MNC, BU and AT were higher in females than in males (all P< 0·05). The concentrations of EPA in AT (P= 0·003) and those of DHA in plasma TAG (P< 0·01) and AT (P< 0·001) were higher with increasing age. Following 12-month supplementation with EPA plus DHA, adjusted mean difference for change in EPA concentrations in plasma TAG was significantly higher in females than in males (P< 0·05) and was greater with increasing age (P= 0·02). Adjusted mean difference for change in DHA concentrations in AT was significantly smaller with increasing age (P= 0·02). Although small differences in incorporation with age and sex were identified, these were not of sufficient magnitude to warrant a move away from population-level diet recommendations for n-3 PUFA.

Genetic predisposition to an adverse lipid profile limits the improvement in total cholesterol in response to weight loss.

OBJECTIVE: Overweight and obesity are associated with a dyslipidaemia which can be improved by weight loss. Whether genetic predisposition to an adverse lipid profile modifies such beneficial effects of weight loss on lipid levels in overweight and obese individuals was examined. DESIGN AND METHODS: White European participants (n = 374) who completed a 12-month weight loss trial were genotyped for 36 lipid-associated single nucleotide polymorphisms (SNPs), previously identified in genome-wide association studies (GWAS). Genetic predisposition scores (GPSs) were calculated for four lipid traits by summing the number of risk alleles (RA) for each participant. The associations of each GPS with four lipid traits were assessed at baseline, and with lipid changes in response to weight change after 12 months. RESULTS: At baseline, the trait-specific GPSs were associated with 0.11 ± 0.04 mM higher total cholesterol/RA (P = 0.004), 0.05 ± 0.02 mM higher low density lipoprotein cholesterol/RA (P = 0.005), 0.03 ± 0.007 mM lower high density lipoprotein cholesterol/RA (P = 0.00002) and 0.04 ± 0.01 mM higher triglyceride/RA (P = 0.00002). After the intervention, weight loss was associated with improvements in all lipids (P < 0.01). GPS attenuated the weight loss-associated reduction in TC so those with a higher GPS had less improvement (interaction = 0.01 ± 0.005 mM/GPS/kg weight loss, P = 0.003). A similar pattern was observed for LDLC (interaction = 0.004 ± 0.002 mM/GPS/kg weight loss, P = 0.07). There was no evidence of a GPS-modifying effect for change in HDLC or TG. CONCLUSION: Genetic predisposition is an important determinant of lipid levels and appears to limit the improvement in TC and to some extent LDLC levels, but not in other plasma lipids, in response to weight loss. © 2013 American Institute of Chemical Engineers AIChE J, 2013.

Stearidonic acid as a supplemental source of ω-3 polyunsaturated fatty acids to enhance status for improved human health.

There is substantial evidence to show that consumption and increased blood levels of the very long-chain (VLC) ω-3 polyunsaturated fatty acids (ω-3 PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are associated with health benefits. The consumption of oily fish is an effective way of increasing EPA and DHA intake and status, but intake in most Western countries remains below the levels recommended for optimal health. The reasons for this include not liking the taste, a concern about sustainability of fish supplies, or potential chemical and heavy metal contamination. Alternative dietary sources of ω-3 fatty acids to enhance EPA and DHA status in the body would therefore be beneficial. There are many non-fish food sources of the essential plant-derived ω-3 fatty acid α-linolenic acid, but conversion from this to longer-chain EPA and especially to DHA is poor. Stearidonic acid (SDA) is an intermediate fatty acid in the biosynthetic pathway from α-linolenic acid to VLC ω-3 PUFAs and the conversion from SDA is more efficient than from α-linolenic acid. However, there are few food sources rich in SDA. Oil crops naturally rich in SDA or enriched through genetic modification may offer an alternative supplemental oil to boost the population status of VLC ω-3 PUFAs. This review discusses the currently available evidence that increased SDA consumption can increase red blood cell EPA content, although this is less than the effect of supplementation directly with EPA. There is now a need for trials specifically designed to assess whether an increased SDA consumption would translate into improved human health outcomes.

Incorporation of eicosapentaenoic and docosahexaenoic acids into lipid pools when given as supplements providing doses equivalent to typical intakes of oily fish.

BACKGROUND: Estimation of the intake of oily fish at a population level is difficult. The measurement of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in biological samples may provide a useful biomarker of intake. OBJECTIVE: We identified the most appropriate biomarkers for the assessment of habitual oily fish intake and changes in intake by elucidating the dose- and time-dependent response of EPA and DHA incorporation into various biological samples that represent roles in fatty acid transport, function, and storage. DESIGN: This was a double-blind, randomized, controlled intervention trial in 204 men and women that lasted 12 mo. EPA and DHA capsules were provided in a manner to reflect sporadic consumption of oily fish (ie, 1, 2, or 4 times/wk). EPA and DHA were assessed at 9 time points over 12 mo in 9 sample types (red blood cells, mononuclear cells, platelets, buccal cells, adipose tissue, plasma phosphatidylcholine, triglycerides, cholesteryl esters, and nonesterified fatty acids). RESULTS: A dose response (P < 0.05) was observed for EPA and DHA in all pools except for red blood cell EPA (P = 0.057). EPA and DHA measures in plasma phosphatidylcholine and platelets were best for the discrimination between different intakes (P < 0.0001). The rate of incorporation varied between sample types, with the time to maximal incorporation ranging from days (plasma phosphatidylcholine) to months (mononuclear cells) to >12 mo (adipose tissue). CONCLUSIONS: Plasma phosphatidylcholine EPA plus DHA was identified as the most suitable biomarker of acute changes in EPA and DHA intake, and platelet and mononuclear cell EPA plus DHA were the most suitable biomarkers of habitual intake.

Ética de la investigación en sujetos humanos: investigación social y del comportamiento para investigadores

El módulo 6 del curso “Ética de la investigación en sujetos humanos” trata de la investigación social y del comportamiento para investigadores, caracterizará la investigación social y de comportamiento, presentando los riesgos más probables y típicos, así como extiende los conceptos básicos de protección a sujetos humanos en la investigación biomédica a estas situaciones. Mas especificamente sobre los riesgos y beneficios propios de ISC y puntos clave sobre el consentimiento informado.