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It is conjectured that all perturbative approaches to quantum electrodynamics (QED) break down in the collision of a high-energy electron beam with an intense laser, when the laser fields are boosted to ‘supercritical’ strengths far greater than the critical field of QED. As field strengths increase toward this regime, cascades of photon emission and electron–positron pair creation are expected, as well as the onset of substantial radiative corrections. Here we identify the important role played by the collision angle in mitigating energy losses to photon emission that would otherwise prevent the electrons reaching the supercritical regime. We show that a collision between an electron beam with energy in the tens of GeV and a laser pulse of intensity ${10}^{24}\,{\rm{W}}\,{\mathrm{cm}}^{-2}$ at oblique, or even normal, incidence is a viable platform for studying the breakdown of perturbative strong-field QED. Our results have implications for the design of near-term experiments as they predict that certain quantum effects are enhanced at oblique incidence.

Modern laser technology is now sufficiently advanced that collisions between high-intensity laser pulses and laser-wakefield-accelerated (LWFA) electron beams can reach the strong-field regime, so that it is possible to measure the transition between the classical and quantum regimes of light–matter interactions. However, the energy spectrum of LWFA electron beams can fluctuate significantly from shot to shot, making it difficult to clearly discern quantum effects in radiation reaction (RR), for example. Here we show how this can be accomplished in only a single laser shot. A millimetre-scale pre-collision drift allows the electron beam to expand to a size larger than the laser focal spot and develop a correlation between transverse position and angular divergence. In contrast to previous studies, this means that a measurement of the beam’s energy-divergence spectrum automatically distinguishes components of the beam that hit or miss the laser focal spot and therefore do and do not experience RR.

An ultrarelativistic electron beam passing through an intense laser pulse emits radiation around its direction of propagation into a characteristic angular profile. Here, we show that measurement of the variances of this profile in the planes parallel and perpendicular to the laser polarization, and the mean initial and final energies of the electron beam, allows the intensity of the laser pulse to be inferred in a way that is independent of the model of the electron dynamics. The method presented applies whether radiation reaction is important or not, and whether it is classical or quantum in nature, with an accuracy of a few percent across 3 orders of magnitude in intensity. It is tolerant of electron beams with a broad energy spread and finite divergence. In laser-electron-beam collision experiments, where spatiotemporal fluctuations cause the alignment of the beams to vary from shot to shot, this permits inference of the laser intensity at the collision point, thereby facilitating comparisons between theoretical calculations and experimental data.

The dynamics of energetic particles in strong electromagnetic fields can be heavily influenced by the energy loss arising from the emission of radiation during acceleration, known as radiation reaction. When interacting with a high-energy electron beam, today’s lasers are sufficiently intense to explore the transition between the classical and quantum radiation reaction regimes. We present evidence of radiation reaction in the collision of an ultrarelativistic electron beam generated by laser-wakefield acceleration (ϵ>500 MeV) with an intense laser pulse (a_{0}>10). We measure an energy loss in the postcollision electron spectrum that is correlated with the detected signal of hard photons (γ rays), consistent with a quantum description of radiation reaction. The generated γ rays have the highest energies yet reported from an all-optical inverse Compton scattering scheme, with critical energy ϵ_{crit}>30 MeV.

Although continuous positive airway pressure (CPAP) is considered to represent the standard treatment for patients with moderate-to-severe obstructive sleep apnoea/hypopnoea syndrome (OSAHS), poor treatment compliance and/or refusal is an issue in 20–30% of these patients. As an alternative to life-long CPAP treatment, conservative procedures exist with dental appliances for mandibular advancement, as well as curative surgical techniques. Surgical treatment of OSAHS can be divided into the following two main groups: 1) upper airway surgery by soft tissue resection (uvulopalatopharyngoplasty, etc.), and 2) skeletal procedures, such as maxillo-mandibular advancement. Proper selection of patients for the different treatment modalities is the key for full treatment success. Patient-related factors, such as the site of upper airway collapse, craniofacial characteristics, dental health, obesity, age, profession and positional dependence, as well as treatment-related factors, should be evaluated before a final proposal for these treatment alternatives is formulated.

Electromagnetic cascades have the potential to act as a high-energy photon source of unprecedented brightness. Such a source would offer new experimental possibilities in fundamental science, but in the cascade process radiation reaction and rapid electron-positron plasma production seemingly restrict the efficient production of photons to sub-GeV energies. Here, we show how to overcome these energetic restrictions and how to create a directed GeV photon source, with unique capabilities as compared to existing sources. Our new source concept is based on a controlled interplay between the cascade and anomalous radiative trapping. Using specially designed advanced numerical models supported with analytical estimates, we demonstrate that the concept becomes feasible at laser powers of around 7 PW, which is accessible at soon-to-be-available facilities. A higher peak power of 40 PW can provide 10^{9} photons with GeV energies in a well-collimated 3-fs beam, achieving peak brilliance 9×10^{24} ph s^{−1} mrad^{-2} mm^{−2}/0.1%BW.

A novel approach to implement and control electron injection into the accelerating phase of a laser wakefield accelerator is presented. It utilizes a wire, which is introduced into the flow of a supersonic gas jet creating shock waves and three regions of differing plasma electron density. If tailored appropriately, the laser plasma interaction takes place in three stages: Laser self-compression, electron injection, and acceleration in the second plasma wave period. Compared to self-injection by wave breaking of a nonlinear plasma wave in a constant density plasma, this scheme increases beam charge by up to 1 order of magnitude in the quasimonoenergetic regime. Electron acceleration in the second plasma wave period reduces electron beam divergence by ≈25%, and the localized injection at the density downramps results in spectra with less than a few percent relative spread.

AbstractThe existence of magnetosonic solitons in dusty plasmas is investigated. The nonlinear magnetohydrodynamic equations for a warm dusty magnetoplasma are thus derived. A solution of the nonlinear equations is presented. It is shown that, owing to the presence of dust, static structures are allowed. This is in sharp contrast to the formation of the so-called shocklets in usual magnetoplasmas. A comparatively small number of dust particles can thus drastically alter the behavior of the nonlinear structures in magnetized plasmas. [ABSTRACT FROM AUTHOR]

Electron–positron pairs are produced through the Breit–Wheeler process when energetic photons traverse electromagnetic fields of sufficient strength. Here we consider a possible experimental geometry for observation of pair creation in the highly nonlinear regime, in which bremsstrahlung of an ultrarelativistic electron beam in a high-Z target is used to produce γ rays that collide with a counter-propagating laser pulse. We show how the target thickness may be chosen to optimize the yield of Breit–Wheeler positrons, and verify our analytical predictions with simulations of the cascade in the material and in the laser pulse. The electron beam energy and laser intensity required are well within the capability of today’s high-intensity laser facilities. [ABSTRACT FROM AUTHOR]

Current experiments investigating radiation reaction employ high energy electron beams together with tightly focused laser pulses in order to reach the quantum regime, as expressed through the quantum nonlinearity parameter χ. Such experiments are often complicated by the large number of latent variables, including the precise structure of the electron bunch. Here we examine a correlation between the electron spatial and energy distributions, called an energy chirp, investigate its significance to the laser-electron beam interaction and show that the resulting effect cannot be trivially ignored when analyzing current experiments. In particular, we show that the energy chirp has a large effect on the second central moment of the electron energy, but a lesser impact on the first electron energy moment or the photon critical energy. These results show the importance of improved characterization and control over electron bunch parameters on a shot-to-shot basis in such experiments.

The availability of ever stronger, laser-generated electromagnetic fields underpins continuing progress in the study and application of nonlinear phenomena in basic physical systems, ranging from molecules and atoms to relativistic plasmas and quantum electrodynamics. This raises the question: how far will we be able to go with future lasers? One exciting prospect is the attainment of field strengths approaching the Schwinger critical field ${E}_{\mathrm{cr}}$ in the laboratory frame, such that the field invariant ${E}^2-{c}^2{B}^2>{E}_{\mathrm{cr}}^2$ is reached. The feasibility of doing so has been questioned, on the basis that cascade generation of dense electron–positron plasma would inevitably lead to absorption or screening of the incident light. Here we discuss the potential for future lasers to overcome such obstacles, by combining the concept of multiple colliding laser pulses with that of frequency upshifting via a tailored laser–plasma interaction. This compresses the electromagnetic field energy into a region of nanometre size and attosecond duration, which increases the field magnitude at fixed power but also suppresses pair cascades. Our results indicate that laser facilities with peak power of tens of PW could be capable of reaching ${E}_{\mathrm{cr}}$ . Such a scenario opens up prospects for the experimental investigation of phenomena previously considered to occur only in the most extreme environments in the universe.

We report on systematic and high-precision measurements of the evolution of electron beams in a laser-wakefield accelerator (LWFA). Utilizing shock-front injection, a technique providing stable, tunable and high-quality electron bunches, acceleration and deceleration of few-MeV quasimonoenergetic beams were measured with cutting-edge technology sub-5-fs and 8-fs laser pulses. We explain the observations with dephasing, an effect that fundamentally limits the performance of LWFAs. Typical density dependent electron energy evolution with 57–300 μm dephasing length and 6–20 MeV peak energy was observed and is well described by a parabolic fit. This is a promising electron source for time-resolved few-fs electron diffraction.

Background: Excess dietary sodium is a leading cause of death and disability globally. Because packaged foods are a major source of sodium in many countries, including Australia, mandatory limits for sodium might improve population health. We aimed to estimate the long-term health and economic effect of mandating such thresholds in Australia., Methods: We used a multiple cohort, proportional, multistate, life table model to simulate the effect of mandating either the WHO global sodium benchmarks or the currently non-mandatory Australian Healthy Food Partnership (HFP) sodium targets. We compared maintaining the current sodium intake status quo with intervention scenarios, using nationally representative data on dietary intake, sodium in packaged foods, and food sales volume. Blood pressure and disease burden data were obtained from the Global Burden of Diseases, Injuries, and Risk Factors Study. The effect of sodium reduction on blood pressure and disease risk was modelled on the basis of meta-analyses of randomised trials and cohort studies. Intervention and health-care costs were used to calculate the incremental cost per health-adjusted life-year (HALY) gained. Costs and HALYs were discounted annually at 3%., Findings: Compared with the status quo intervention, mandating the WHO benchmarks could be cost saving over the first 10 years (AUD$223 [95% uncertainty interval 82-433] million saved), with 2743 (1677-3976) cardiovascular disease deaths and 43 971 (26 892-63 748) incident cardiovascular disease events averted, and 11 174 (6800-16 205) HALYs gained. Over the population's lifetime, the intervention was cost effective (100·0% probability). Mandating the HFP sodium targets was also estimated to be cost effective (100·0% probability), but with 29% of the health benefits compared with the WHO benchmarks., Interpretation: Our modelling study supports mandating sodium thresholds for packaged foods as a cost-effective strategy to prevent death and disease in Australia. Although making Australia's voluntary reformulation targets mandatory might save thousands of lives, mandating the WHO global benchmarks could yield substantially greater health gains., Funding: None., Competing Interests: Declaration of interests MM reports grant support from Resolve To Save Lives, Northwestern University, and WHO, all outside of the present work. KT is the co-Director of the WHO Collaborating Centre on Salt Reduction. LNA is supported by a National Health and Medical Research Council (NHMRC) Emerging Leadership Grant and a Honorary Heart Foundation of Australia Fellowship. LH reports grant support from the NHMRC, outside of the present study. All other authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Background: Excess dietary sodium intake has been associated with death and disability. WHO has released global sodium benchmarks for packaged foods to support countries to reduce population sodium intake. This study aimed to assess the potential health effect, costs, and cost effectiveness of implementing these WHO sodium benchmarks in India., Methods: We used a multiple cohort, proportional multistate, life table (Markov) model to estimate the health gains and cost effectiveness for adults if sodium content in packaged foods complied with the WHO benchmarks compared to the status quo. We used India-specific dietary surveys, food composition tables, foods sales data, and sodium content data from packaged food labels to estimate sodium intake before and after the intervention. Data on blood pressure, cardiovascular disease, and chronic kidney disease burden were obtained from the Global Burden of Diseases, Injuries, and Risk Factors study, and the effect of sodium reduction on blood pressure and disease risk was modelled on the basis of meta-analyses of randomised trials and cohort studies. Intervention and health-care costs were used to estimate net costs, and calculate the incremental cost per health-adjusted life-year (HALY) gained. Costs and HALYs were discounted at 3%., Findings: In the first 10 years, compliance with the WHO sodium benchmarks was estimated to avert a mean of 0·3 (95% uncertainty interval [UI] 0·2-0·5) million deaths from cardiovascular diseases and chronic kidney disease, a mean of 1·7 (95% UI 1·0-2·4) million incident cardiovascular disease events, and 0·7 (0·4-1·0) million new chronic kidney disease cases, compared with current practice. Over 10 years, the intervention was projected to be cost saving (100·0% probability), generating 1·0 (0·6 to 1·4) billion HALYs and US$0·8 (95% UI 0·3 to 1·4) million in cost savings. Over the population lifetime, the intervention could prevent 4·2 (2·4-6·0) million deaths from cardiovascular diseases and chronic kidney disease, 14·0 (8·2-20·1) million incident cardiovascular disease events, and 4·8 (2·8-6·8) new chronic kidney disease cases, with an 84·2% probability of being cost-saving and 100·0% probability of being cost-effective., Interpretation: Our modelling data suggest a high potential for compliance with WHO sodium benchmarks for packaged food being associated with substantial health gains and cost savings, making a strong case for India to mandate the implementation of the WHO sodium benchmarks, particularly as packaged food consumption continues to rise., Funding: WHO Country Office India., Competing Interests: Declaration of interests KT is co-Director of the WHO Collaborating Centre on Salt Reduction. LH reports grant support from the Australian National Health and Medical Research Council, outside of the present study. LNA is supported by an Australian National Health and Medical Research Council Investigator Grant and an Honorary Heart Foundation Fellowship. MM reports grant support from Resolve To Save Lives and Northwestern University, and travel support from the Nordic Dairy Congress 2022, all outside of the present work. RG is a staff member of WHO, and the authors alone are responsible for the views expressed in this publication, and they do not necessarily represent the views, decisions, or policies of WHO. All other authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Background: Intake of trans-fatty acids (TFAs) is an established risk factor for cardiovascular disease. In April 2023, Nigeria passed regulations limiting TFA content in foods, fats, and oils, but the current level of TFA exposure in the Nigerian population is unknown. We assessed TFA biomarkers in dried blood spots from Nigerian adults in the Federal Capital Territory before policy enforcement to establish a baseline for future evaluation., Methods: We used gas chromatography to measure TFA content in dried blood spots from adults participating in a cross-sectional household survey using a representative sampling frame. Individual TFA (t-16:1, t-18:1, and t- 18:2) and their total, were expressed as % of total fatty acids. We assessed differences in TFA levels between subgroups based on sex, age, body mass index (BMI), education, income, and local government area using multivariable-adjusted linear regression models. Mean TFA levels were compared to samples from individuals in 30 countries., Results: In 213 adults (62% females; mean age: 36 years, mean BMI: 25.9 kg/m 2 ), the mean TFA level in dried blood spots was 0.61% of total fatty acids (range: 0.23-1.31%). In multivariable-adjusted models, TFA levels were higher in younger adults (<30 years compared with ≥42 years, 0.07% [95% confidence interval (CI): 0.00,0.15], p=0.047), those without a high school degree (compared with higher education, 0.08% [95% CI: 0.01,0.16], p=0.023;), and residents of Abuja Municipal Area Council (compared with residents in Gwagwalada, 0.12% [95% CI: 0.05,0.20], p=0.001). Total TFA levels were comparable to international samples, but t-16:1 and t-18:1 appeared lower, whereas t-18:2 appeared greater (52% of all TFA), in the Nigerian samples., Conclusions: These results provide a baseline assessment of TFA exposure in Nigerian adults to evaluate implementation and effect of national regulation passed in 2023. The observed subgroup differences may help identify subpopulations for targeted interventions to reduce TFA intake., Competing Interests: Conflict of interest MM reports grant support from Resolve To Save Lives and The World Health Organization, and travel support from the Nordic Dairy Congress 2022, all outside of the present work. LRH and LVH are researchers affiliated with Northwestern University Robert J. Havey Institute for Global Health, who funded this study; the authors alone are responsible for the views expressed in this publication, and they do not necessarily represent the views, decisions, or policies of the funder. MDH has received travel support from the World Heart Federation and consulting fees from PwC Switzerland. MDH has an appointment at The George Institute for Global Health, which has a patent, license, and has received investment funding with intent to commercialize fixed-dose combination therapy through its social enterprise business, George Medicines. MDH has pending patents for heart failure polypills., (Copyright © 2024. Published by Elsevier Inc.)

Background: The potential role of n-6 PUFAs in major health outcomes remains controversial., Objectives: To examine the relationship between the major plasma n6 PUFA, linoleic acid (LA), as well as the non-LA n6 PUFAs, and total and cause-specific mortality., Methods: This was a prospective, observational, biomarker-based study in the UK Biobank. Individuals with complete information on baseline demographic, covariate and plasma PUFA levels (percent ot total fatty acids) and mortality outcomes were included (n=257,925). Multivariable-adjusted, Cox-proportional hazards models were used to predict risk of death from all-causes, and from cardiovascular disease (CVD), cancer, and other causes as a function of plasma LA and non-LA n6 levels, both continuously and by PUFA quintile (Q)., Results: Comparing LA Q5 to Q1, the hazard ratio (HR, 95% CI) for total mortality was 0.80 (0.76, 0.84; p<0.001), and this was similar for all three cause-specific death categories. On the other hand, mortality HR for non-LA n6 was 1.12 (1.08,1.17; p<0.001), and this was primarily due to increased risk for non-CVD, noncancer deaths [HR 1.29 (1.19,1.40; p<0.001)]. Exploratory analyses among the eight next most common other causes of death suggested that both the decreased risk associated with higher LA and the increased risk associated with non-LA n6 were confined to deaths from respiratory and digestive diseases., Conclusions: These findings highlight the profound differences in mortality risk related to LA and non-LA n6 PUFA levels and underscore the inappropriateness of treating n-6 PUFAs as a homogenous class with respect to health outcomes. They also support recommendations to maintain (if not increase) current LA intakes., (Copyright © 2024 American Society for Nutrition. Published by Elsevier Inc. All rights reserved.)

Introduction: Nigeria is committed to reducing industrial trans- fatty acids (iTFA) from the food supply, but the potential health gains, costs and cost-effectiveness are unknown., Methods: The effect on ischaemic heart disease (IHD) burden, costs and cost-effectiveness of a mandatory iTFA limit (≤2% of all fats) for foods in Nigeria were estimated using Markov cohort models. Data on demographics, IHD epidemiology and trans- fatty acid intake were derived from the 2019 Global Burden of Disease Study. Avoided IHD events and deaths; health-adjusted life years (HALYs) gained; and healthcare, policy implementation and net costs were estimated over 10 years and the population's lifetime. Incremental cost-effectiveness ratios using net costs and HALYs gained (both discounted at 3%) were used to assess cost-effectiveness., Results: Over the first 10 years, a mandatory iTFA limit (assumed to eliminate iTFA intake) was estimated to prevent 9996 (95% uncertainty interval: 8870 to 11 118) IHD deaths and 66 569 (58 862 to 74 083) IHD events, and to save US$90 million (78 to 102) in healthcare costs. The corresponding lifetime estimates were 259 934 (228 736 to 290 191), 479 308 (95% UI 420 472 to 538 177) and 518 (450 to 587). Policy implementation costs were estimated at US$17 million (11 to 23) over the first 10 years, and US$26 million USD (19 to 33) over the population's lifetime. The intervention was estimated to be cost-saving, and findings were robust across several deterministic sensitivity analyses., Conclusion: Our findings support mandating a limit of iTFAs as a cost-saving strategy to reduce the IHD burden in Nigeria., Competing Interests: Competing interests: All authors have completed the ICMJE uniform disclosure form and declare the following: MM report grant support from Resolve to Save Lives and the World Health Organization; and travel support from the Nordic Dairy Congress 2022; all outside of the present work. MDH has received travel support from the American Heart Association and World Heart Federation. MDH has an appointment at The George Institute for Global Health, which has a patent, license and has received investment funding with intent to commercialise fixed-dose combination therapy through its social enterprise business, George Medicines. MDH has pending patents for heart failure polypills., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

The Salt Substitute and Stroke Study (SSaSS) demonstrated significant reductions in systolic blood pressure (SBP), and the risk of stroke, major cardiovascular events and total mortality with the use of potassium-enriched salt. The contribution of sodium reduction versus potassium increase to these effects is unknown. We identified four different data sources describing the association between sodium reduction, potassium supplementation and change in SBP. We then fitted a series of models to estimate the SBP reductions expected for the differences in sodium and potassium intake in SSaSS, derived from 24-h urine collections. The proportions of the SBP reduction separately attributable to sodium reduction and potassium supplementation were calculated. The observed SBP reduction in SSaSS was -3.3 mmHg with a corresponding mean 15.2 mmol reduction in 24-h sodium excretion and a mean 20.6 mmol increase in 24-h potassium excretion. Assuming 90% of dietary sodium intake and 70% of dietary potassium intake were excreted through urine, the models projected falls in SBP of between -1.67 (95% confidence interval: -4.06 to +0.73) mmHg and -5.33 (95% confidence interval: -8.58 to -2.08) mmHg. The estimated proportional contribution of sodium reduction to the SBP fall ranged between 12 and 39% for the different models fitted. Sensitivity analyses assuming different proportional urinary excretion of dietary sodium and potassium intake showed similar results. In every model, the majority of the SBP lowering effect in SSaSS was estimated to be attributable to the increase in dietary potassium rather than the fall in dietary sodium., (© 2024. The Author(s).)

Background: It is unknown whether dietary intake of polyunsaturated fatty acids (PUFA) modifies the cardiovascular disease (CVD) risk associated with a family history of CVD. We assessed interactions between biomarkers of low PUFA intake and a family history in relation to long-term CVD risk in a large consortium., Methods: Blood and tissue PUFA data from 40 885 CVD-free adults were assessed. PUFA levels ≤25th percentile were considered to reflect low intake of linoleic, alpha-linolenic, and eicosapentaenoic/docosahexaenoic acids (EPA/DHA). Family history was defined as having ≥1 first-degree relative who experienced a CVD event. Relative risks with 95% CI of CVD were estimated using Cox regression and meta-analyzed. Interactions were assessed by analyzing product terms and calculating relative excess risk due to interaction., Results: After multivariable adjustments, a significant interaction between low EPA/DHA and family history was observed (product term pooled RR, 1.09 [95% CI, 1.02-1.16]; P =0.01). The pooled relative risk of CVD associated with the combined exposure to low EPA/DHA, and family history was 1.41 (95% CI, 1.30-1.54), whereas it was 1.25 (95% CI, 1.16-1.33) for family history alone and 1.06 (95% CI, 0.98-1.14) for EPA/DHA alone, compared with those with neither exposure. The relative excess risk due to interaction results indicated no interactions., Conclusions: A significant interaction between biomarkers of low EPA/DHA intake, but not the other PUFA, and a family history was observed. This novel finding might suggest a need to emphasize the benefit of consuming oily fish for individuals with a family history of CVD., Competing Interests: Disclosures Dr Murphy reports having worked as a consultant for Pharmavite (until 2021). The remaining authors have reported no relationships relevant to the contents of this article. Dr Psaty serves on the steering committee of the Yale Open Data Access Project, funded by Johnson and Johnson.

Background: The effect of marine omega-3 PUFAs on risk of stroke remains unclear., Methods: We investigated the associations between circulating and tissue omega-3 PUFA levels and incident stroke (total, ischemic, and hemorrhagic) in 29 international prospective cohorts. Each site conducted a de novo individual-level analysis using a prespecified analytical protocol with defined exposures, covariates, analytical methods, and outcomes; the harmonized data from the studies were then centrally pooled. Multivariable-adjusted HRs and 95% CIs across omega-3 PUFA quintiles were computed for each stroke outcome., Results: Among 183 291 study participants, there were 10 561 total strokes, 8220 ischemic strokes, and 1142 hemorrhagic strokes recorded over a median of 14.3 years follow-up. For eicosapentaenoic acid, comparing quintile 5 (Q5, highest) with quintile 1 (Q1, lowest), total stroke incidence was 17% lower (HR, 0.83 [CI, 0.76-0.91]; P <0.0001), and ischemic stroke was 18% lower (HR, 0.82 [CI, 0.74-0.91]; P <0.0001). For docosahexaenoic acid, comparing Q5 with Q1, there was a 12% lower incidence of total stroke (HR, 0.88 [CI, 0.81-0.96]; P =0.0001) and a 14% lower incidence of ischemic stroke (HR, 0.86 [CI, 0.78-0.95]; P =0.0001). Neither eicosapentaenoic acid nor docosahexaenoic acid was associated with a risk for hemorrhagic stroke. These associations were not modified by either baseline history of AF or prevalent CVD., Conclusions: Higher omega-3 PUFA levels are associated with lower risks of total and ischemic stroke but have no association with hemorrhagic stroke., Competing Interests: Disclosures Dr O’Keefe reports major ownership interest in Cardiotabs. Dr Harris reports minor ownership interest in Omegaquant Analytics, LLC. Dr Sala-Vila reports travel and grant support from California Walnut Commission. Dr Mora reports compensation for consultant services from Quest Diagnostics. Dr Murphy reports compensation from Pharmavite for consultant services. Dr Bork reports grants from Karen Elise Jensens Fond. Dr Ärnlöv reports compensation from Astellas Pharma for other services; compensation from Boehringer Ingelheim for consultant services; compensation from AstraZeneca for other services; and compensation from Novartis for other services. Dr Geleijnse reports grants from National Institutes of Health to other; grants from Upfield Europe BV to other; and grants from The Dutch Heart Foundation to other. Dr Manson reports grants from National Institutes of Health and compensation from National Institutes of Health for other services. Dr Mora reports compensation from Pfizer for consultant services; employment by Brigham and Women’s Hospital; grants from National Institute of Diabetes and Digestive and Kidney Diseases; and grants from National Heart, Lung, and Blood Institute. Dr Melo van Lent reports grants from National Institutes of Health and grants from Alzheimer’s Association. Dr Mozaffarian reports grants from Rockefeller Foundation; compensation from Beren Therapeutics for other services; stock holdings in HumanCo; compensation from January Inc. for other services; compensation from Filtricine for other services; compensation from Perfect Day for other services; compensation from Tiny Organics for other services; grants from Bill and Melinda Gates Foundation; compensation from Calibrate for other services; grants from Vail Innovative Global Research; grants from Kaiser Permanente Fund at East Bay Community Foundation; compensation from DayTwo for other services; compensation from Instacart health for other services; compensation from Season Health for other services; grants from National Institutes of Health; compensation from Barilla for consultant services; stock holdings in Calibrate; compensation from Kaiser Permanente Fund for other services; compensation from HumanCo for other services