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Supplementation with oil rich in eicosapentaenoic acid, but not in docosahexaenoic acid, improves global cognitive function in healthy, young adults: results from randomized controlled trials.
Patan, MJ, Kennedy, DO, Husberg, C, Hustvedt, SO, Calder, PC, Khan, J, Forster, J, Jackson, PA
The American journal of clinical nutrition. 2021;(3):914-924
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Abstract
BACKGROUND Evidence regarding the effects of the omega-3 (ɷ-3) PUFAs (n-3 PUFAs) DHA and EPA on cognition is lacking. OBJECTIVES We investigated whether supplementation with oils rich in EPA or DHA improves cognition, prefrontal cortex (PFC) hemoglobin (Hb) oxygenation, and memory consolidation. METHODS Healthy adults (n = 310; age range: 25-49 y) completed a 26-wk randomized controlled trial in which they consumed either 900 mg DHA/d and 270 mg EPA/d (DHA-rich oil), 360 mg DHA/d and 900 mg EPA/d (EPA-rich oil), or 3000 mg/d refined olive oil (placebo). Cognitive performance and memory consolidation were assessed via computerized cognitive test battery. PFC Hb oxygenation was measured using near infrared spectroscopy (NIRS). RESULTS Both global accuracy and speed improved with EPA-rich oil compared with placebo and DHA-rich oil [EPA vs. placebo accuracy: estimated marginal mean (EMM) = 0.17 (95% CI: 0.09, 0.24) vs. EMM = 0.03 (95% CI = -0.04, 0.11); P = 0.044; EPA vs. placebo speed: EMM = -0.15 (95% CI: -0.22, -0.07) vs. EMM = 0.03 (95% CI: -0.05, 0.10); P = 0.003]. Accuracy of memory was improved with EPA compared with DHA [EMM = 0.66 (95% CI: 0.26, 1.06) vs. EMM = -0.08 (95% CI: -0.49, 0.33); P = 0.034]. Both EPA- and DHA-rich oils showed trends towards reduced PFC oxygenated Hb (oxy-Hb) compared with placebo [placebo: EMM = 27.36 µM (95% CI: 25.73, 28.98); DHA: EMM = 24.62 µM (95% CI: 22.75, 26.48); P = 0.060; EPA: EMM = 24.97 µM (95% CI: 23.35, 26.59); P = 0.082]. CONCLUSIONS EPA supplementation improved global cognitive function and was superior to the oil enriched with DHA. Interpreted within a neural efficiency framework, reduced PFC oxygenated Hb suggests that n-3 PUFAs may be associated with increased efficiency.These trials were registered in the clinical trials registry (https://clinicaltrials.gov/) as NCT03158545, NCT03592251, NCT02763514.
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Effects of Delayed-Release Olive Oil and Hydrolyzed Pine Nut Oil on Glucose Tolerance, Incretin Secretion and Appetite in Humans.
Sørensen, KV, Kaspersen, MH, Ekberg, JH, Bauer-Brandl, A, Ulven, T, Højlund, K
Nutrients. 2021;(10)
Abstract
BACKGROUND To investigate the potential synergistic effects of olive oil releasing 2-oleoylglycerol and hydrolyzed pine nut oil containing 20% pinolenic acid on GLP-1 secretion, glucose tolerance, insulin secretion and appetite in healthy individuals, when delivered to the small intestine as potential agonists of GPR119, FFA1 and FFA4. METHODS Nine overweight/obese individuals completed three 6-h oral glucose tolerance tests (OGTTs) in a crossover design. At -30 min, participants consumed either: no oil, 6 g of hydrolyzed pine nut oil (PNO-FFA), or a combination of 3 g hydrolyzed pine nut oil and 3 g olive oil (PNO-OO) in delayed-release capsules. Repeated measures of glucose, insulin, C-peptide, GLP-1, GIP, ghrelin, subjective appetite and gastrointestinal tolerability were done. RESULTS PNO-FFA augmented GLP-1 secretion from 0-360 min compared to no oil and PNO-OO (p < 0.01). GIP secretion was increased from 240-360 min after both PNO-FFA and PNO-OO versus no oil (p < 0.01). Both oil treatments suppressed subjective appetite by reducing hunger and prospective food consumption and increasing satiety (p < 0.05). CONCLUSIONS In support of previous findings, 6 g of delayed-release hydrolyzed pine nut oil enhanced postprandial GLP-1 secretion and reduced appetite. However, no synergistic effect of combining hydrolyzed pine nut oil and olive oil on GLP-1 secretion was observed. These results need further evaluation in long-term studies including effects on bodyweight and insulin sensitivity.
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Beneficial Role of Replacing Dietary Saturated Fatty Acids with Polyunsaturated Fatty Acids in the Prevention of Sarcopenia: Findings from the NU-AGE Cohort.
Montiel-Rojas, D, Santoro, A, Nilsson, A, Franceschi, C, Capri, M, Bazzocchi, A, Battista, G, de Groot, LCPGM, Feskens, EJM, Berendsen, AAM, et al
Nutrients. 2020;(10)
Abstract
Dietary fat subtypes may play an important role in the regulation of muscle mass and function during ageing. The aim of the present study was to determine the impact of isocaloric macronutrient substitutions, including different fat subtypes, on sarcopenia risk in older men and women, while accounting for physical activity (PA) and metabolic risk. A total of 986 participants, aged 65-79 years, completed a 7-day food record and wore an accelerometer for a week. A continuous sex-specific sarcopenia risk score (SRS), including skeletal muscle mass assessed by dual-energy X-ray absorptiometry (DXA) and handgrip strength, was derived. The impact of the isocaloric replacement of saturated fatty acids (SFAs) by either mono- (MUFAs) or poly-unsaturated (PUFAs) fatty acids on SRS was determined using regression analysis based on the whole sample and stratified by adherence to a recommended protein intake (1.1 g/BW). Isocaloric reduction of SFAs for the benefit of PUFAs was associated with a lower SRS in the whole population, and in those with a protein intake below 1.1 g/BW, after accounting for age, smoking habits, metabolic disturbances, and adherence to PA guidelines. The present study highlighted the potential of promoting healthy diets with optimised fat subtype distribution in the prevention of sarcopenia in older adults.
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The Effects of Linoleic Acid Consumption on Lipid Risk Markers for Cardiovascular Disease in Healthy Individuals: A Review of Human Intervention Trials.
Froyen, E, Burns-Whitmore, B
Nutrients. 2020;(8)
Abstract
Cardiovascular disease (CVD) is the leading cause of death worldwide. Risk factors for developing this disease include high serum concentrations of total cholesterol, triglycerides, low-density lipoproteins, very-low density lipoproteins, and low concentrations of high-density lipoproteins. One proposed dietary strategy for decreasing risk factors involves replacing a portion of dietary saturated fatty acids with mono- and polyunsaturated fatty acids (PUFAs). The essential omega-6 PUFA, linoleic acid (LA), is suggested to decrease the risk for CVD by affecting these lipid risk markers. Reviewing human intervention trials will provide further evidence of the effects of LA consumption on risk factors for CVD. PubMed was used to search for peer-reviewed articles. The purpose of this review was: (1) To summarize human intervention trials that studied the effects of LA consumption on lipid risk markers for CVD in healthy individuals, (2) to provide mechanistic details, and (3) to provide recommendations regarding the consumption of LA to decrease the lipid risk markers for CVD. The results from this review provided evidence that LA consumption decreases CVD lipid risk markers in healthy individuals.
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Fried food consumption and risk of coronary artery disease: The Million Veteran Program.
Honerlaw, JP, Ho, YL, Nguyen, XT, Cho, K, Vassy, JL, Gagnon, DR, O'Donnell, CJ, Gaziano, JM, Wilson, PWF, Djousse, L, et al
Clinical nutrition (Edinburgh, Scotland). 2020;(4):1203-1208
Abstract
INTRODUCTION Previous studies of the relationship between fried food consumption and coronary artery disease (CAD) have yielded conflicting results. We tested the hypothesis that frequent fried food consumption is associated with a higher risk of incident CAD events in Million Veteran Program (MVP) participants. METHODS Veterans Health Administration electronic health record data were linked to questionnaires completed at MVP enrollment. Self-reported fried food consumption at baseline was categorized: (<1, 1-3, 4-6 times per week or daily). The outcome of interest was non-fatal myocardial infarction or CAD events. We fitted a Cox regression model adjusting for age, sex, race, education, exercise, smoking and alcohol consumption. RESULTS Of 154,663 MVP enrollees with survey data, mean age was 64 years and 90% were men. During a mean follow-up of approximately 3 years, there were 6,725 CAD events. There was a positive linear relationship between frequency of fried food consumption and risk of CAD (p for trend 0.0015). Multivariable adjusted hazard ratios (95% CI) were 1.0 (ref), 1.07 (1.01-1.13), 1.08 (1.01-1.16), and 1.14 (1.03-1.27) across consecutive increasing categories of fried food intake. CONCLUSIONS In a large national cohort of U.S. Veterans, fried food consumption has a positive, dose-dependent association with CAD.
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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.
Brown, TJ, Brainard, J, Song, F, Wang, X, Abdelhamid, A, Hooper, L, ,
BMJ (Clinical research ed.). 2019;:l4697
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Abstract
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 (HbA1c), 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 (HbA1c 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.
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Effects of Replacing Dietary Monounsaturated Fat With Carbohydrate on HDL (High-Density Lipoprotein) Protein Metabolism and Proteome Composition in Humans.
Andraski, AB, Singh, SA, Lee, LH, Higashi, H, Smith, N, Zhang, B, Aikawa, M, Sacks, FM
Arteriosclerosis, thrombosis, and vascular biology. 2019;(11):2411-2430
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Abstract
OBJECTIVE Clinical evidence has linked low HDL (high-density lipoprotein) cholesterol levels with high cardiovascular disease risk; however, its significance as a therapeutic target remains unestablished. We hypothesize that HDLs functional heterogeneity is comprised of metabolically distinct proteins, each on distinct HDL sizes and that are affected by diet. Approach and Results: Twelve participants were placed on 2 healthful diets high in monounsaturated fat or carbohydrate. After 4 weeks on each diet, participants completed a metabolic tracer study. HDL was isolated by Apo (apolipoprotein) A1 immunopurification and separated into 5 sizes. Tracer enrichment and metabolic rates for 8 HDL proteins-ApoA1, ApoA2, ApoC3, ApoE, ApoJ, ApoL1, ApoM, and LCAT (lecithin-cholesterol acyltransferase)-were determined by parallel reaction monitoring and compartmental modeling, respectively. Each protein had a unique, size-specific distribution that was not altered by diet. However, carbohydrate, when replacing fat, increased the fractional catabolic rate of ApoA1 and ApoA2 on alpha3 HDL; ApoE on alpha3 and alpha1 HDL; and ApoM on alpha2 HDL. Additionally, carbohydrate increased the production of ApoC3 on alpha3 HDL and ApoJ and ApoL1 on the largest alpha0 HDL. LCAT was the only protein studied that diet did not affect. Finally, global proteomics showed that diet did not alter the distribution of the HDL proteome across HDL sizes. CONCLUSIONS This study demonstrates that HDL in humans is composed of a complex system of proteins, each with its own unique size distribution, metabolism, and diet regulation. The carbohydrate-induced hypercatabolic state of HDL proteins may represent mechanisms by which carbohydrate alters the cardioprotective properties of HDL.
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Effects of Polyunsaturated Fatty Acids on Nonspecific Typical Dry Eye Disease: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.
Chi, SC, Tuan, HI, Kang, YN
Nutrients. 2019;(5)
Abstract
To investigate the effects of polyunsaturated fatty acids (PUFAs) in patients with dry eye disease (DED), a multifactorial inflammatory disorder, we searched Cochrane Library, EMBASE, PubMed, and Web of Science for randomized clinical trials (RCTs) investigating the effect of PUFAs in patients with DED before March 2019. Two reviewers independently abstracted data of tear breakup time (TBUT), Schirmer's test, osmolarity, and ocular surface disease index (OSDI). We conducted pairwise meta-analysis using means and standard deviations (SDs) in a random-effects model for continuous outcomes. Thirteen eligible RCTs with 1782 patients with nonspecific typical DED were included. Patients who received PUFA treatment without other eye medications exhibited greater improvements in TBUT (MD = 1.80; p = 0.001), Schirmer test scores (MD = 0.50; p < 0.001), osmolarity (MD = -15.95; p < 0.001), and OSDI scores (MD = -10.19; p < 0.001) than those who received placebo treatment. However, the effects of PUFAs on TBUT (p < 0.001) and OSDI scores (p = 0.03) weakened with treatment duration. PUFAs are effective in treating nonspecific typical DED, particularly as a short-term treatment, with relatively few adverse events. Therefore, in real-world clinical practice, PUFA supplements are worth being suggested to patients with nonspecific typical DED who are not concurrently using other topical or systematic eye medications.
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Dietary unsaturated fat increases HDL metabolic pathways involving apoE favorable to reverse cholesterol transport.
Morton, AM, Furtado, JD, Mendivil, CO, Sacks, FM
JCI insight. 2019;(7)
Abstract
BACKGROUND HDL that contains apolipoprotein E (apoE) is a subspecies especially active in steps in reverse cholesterol transport, a process that brings cholesterol from peripheral cells to the liver. Here, we studied the effect of dietary unsaturated fat compared with carbohydrate on the metabolism of HDL containing apoE. METHODS We enrolled 9 adults who were overweight or obese and had below-average HDL-cholesterol in a crossover study of a high-fat diet, primarily unsaturated, and a low-fat, high-carbohydrate diet. A metabolic tracer study was performed after each diet period. RESULTS Dietary fat increased the secretion, metabolism, and clearance of HDL subspecies containing apoE. Dietary fat increased the rate of clearance of large cholesterol-rich HDL containing apoE and increased their conversion to small HDL containing apoE, indicating selective cholesterol ester delivery to the liver. The high-unsaturated-fat diet did not affect the metabolism of HDL lacking apoE. CONCLUSION HDL containing apoE is a diet-responsive metabolic pathway that renders HDL more biologically active in reverse cholesterol transport. This may be a mechanism by which unsaturated fat protects against coronary heart disease. Protein-based HDL subspecies such as HDL containing apoE may be used to identify additional atheroprotective treatment targets not evident in the total HDL-cholesterol measurement. TRIAL REGISTRATION ClinicalTrials.gov NCT01399632. FUNDING NIH and the National Center for Advancing Translational Science.
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Investigation of the effect of dietary docosahexaenoic acid (DHA) supplementation on macular function in subjects with autosomal recessive Stargardt macular dystrophy.
MacDonald, IM, Sieving, PA
Ophthalmic genetics. 2018;(4):477-486
Abstract
PURPOSE To test the effect of docosahexanoic acid (DHA) dietary supplementation on macular function in patients with Stargardt disease. MATERIALS AND METHODS A single center, double-masked, randomized placebo-controlled trial of 11 subjects (2 males, 9 females) with Stargardt disease in a crossover design (NCT00060749). Six participants were randomized to two sequences of three month periods of DHA supplementation (2000 mg/day) followed by three months of placebo. Five participants were randomized to the opposite sequence. All participants were evaluated with a food frequency and NEI-VF25 questionnaires, complete ophthalmic examination, multifocal electroretinography (ERG, primary outcome), 30-Hz flicker ERG, Humphrey 10-2 visual field, D15 color tests and serum lipid analysis. RESULTS During periods of DHA supplementation, serum rose and then fell with transition to periods of placebo. None of the participants experienced greater than 20% change from baseline values of the mfERG during periods of DHA supplementation or placebo, while the average change in peak amplitude and phase angle of the flicker ERG remained similar at all visits. No significant change was observed for any of the secondary outcome measures. Eight adverse events occurred but these were not considered to be due to the treatment. CONCLUSIONS No perceived effect of DHA supplementation on macular function was observed in a small sample of Stargardt patients who were compliant with the protocol as estimated by changes in serum DHA. This study will help design future studies of the effect of DHA supplementation on retinal function in cohorts with retinal dystrophies.