Omega-3 fatty acids: Current insights into mechanisms of action in systemic lupus erythematosus

Correction of omega-3 fatty acid deficiency and improvement in disease activity in patients with systemic lupus erythematosus treated with krill oil concentrate: a multicentre, randomised, double-blind, placebo-controlled trial

OBJECTIVE

Omega-3 polyunsaturated fatty acids (PUFAs) play a critical role in regulating inflammation and lipid metabolism. This study sought to ascertain the frequency of omega-3 deficiency in patients with SLE and investigate whether supplementation with krill oil concentrate (KOC) could replenish omega-3 levels and decrease SLE disease activity.

METHODS

A multicentre, randomised, double-blind, placebo-controlled trial was conducted in adult patients with active SLE. Eligible patients were randomised to receive 4 g/day KOC or placebo (vegetable oil mixture) for the first 24 weeks, and thereafter patients could opt to enter an open-label extension. The primary end point was improvement of the red blood cell Omega-3 Index from baseline to week 24. Changes in clinical features, including SLE Disease Activity Index 2000 (SLEDAI-2K) disease activity scores, were also monitored.

RESULTS

Seventy-eight patients met eligibility criteria and were randomised to a treatment group (n=39 per group). The baseline Omega-3 Index in the total SLE cohort was a mean 4.43% (±SD 1.04%). After 4 weeks of KOC treatment, the Omega-3 Index rapidly increased to 7.17%±1.48% (n=38) and after 24 weeks to 8.05%±1.79% (n=25) (each p<0.001 vs baseline), whereas no significant change from baseline was noted in patients receiving placebo. Increases in the Omega-3 Index in KOC-treated patients persisted through week 48. After patients switched from placebo to KOC at 24 weeks, the mean Omega-3 Index showed a rapid and significant increase (from 4.63%±1.39% at week 24 (n=26) to 7.50%±1.75% at week 48 (n=12); p<0.001). Although there were no changes in disease activity in the study population overall, SLEDAI-2K scores decreased significantly in the KOC group during the 24-week randomised period among those who had high disease activity at baseline (SLEDAI-2K ≥9) (p=0.04, p=0.02 and p=0.01 vs placebo at 4, 8 and 16 weeks, respectively; n=9 per group). KOC was well-tolerated, with no significant safety concerns.

CONCLUSION

KOC corrected omega-3 deficiency in patients with SLE. Supplementation with KOC was safe and decreased disease activity in those with more active disease. These findings warrant further evaluation of omega-3 fatty acid supplementation with KOC in the management of SLE.

TRIAL REGISTRATION NUMBER

NCT03626311.

Review of Allelopathy in Green Tides: The Case of Ulva prolifera in the South Yellow Sea

The proliferation of large green macroalgae in marine environments has led to the occurrence of green tides, particularly in the South Yellow Sea region of China, where Ulva prolifera has been identified as the primary species responsible for the world's largest green tide events. Allelopathy among plants is a critical factor influencing the dynamics of green tides. This review synthesizes previous research on allelopathic interactions within green tides, categorizing four extensively studied allelochemicals: fatty acids, aldehydes, phenols, and terpenes. The mechanisms by which these compounds regulate the physiological processes of green tide algae are examined in depth. Additionally, recent advancements in the rapid detection of allelochemicals are summarized, and their potential applications in monitoring green tide events are discussed. The integration of advanced monitoring technologies, such as satellite observation and environmental DNA (eDNA) analysis, with allelopathic substance detection is also explored. This combined approach addresses gaps in understanding the dynamic processes of green tide formation and provides a more comprehensive insight into the mechanisms driving these phenomena. The findings and new perspectives presented in this review aim to offer valuable insights and inspiration for researchers and policymakers.

Association between Unsaturated Fatty Acid-Type Diet and Systemic Lupus Erythematosus: A Systematic Review with Meta-Analyses

BACKGROUND

Systemic lupus erythematosus (SLE) is a complex autoimmune disorder that affects multiple organ systems, with a higher prevalence among women in their reproductive years. The disease's multifactorial etiology involves genetic, environmental, and hormonal components. Recent studies have highlighted the potential impact of dietary factors, particularly unsaturated fatty acids, on the modulation of SLE due to their anti-inflammatory properties. This meta-analysis aims to evaluate the association between unsaturated fatty acid consumption and the risk, progression, and clinical manifestations of SLE, providing evidence-based guidance for dietary management.

METHODS

We conducted a comprehensive search across major medical databases up to January 2024, focusing on studies that examined the intake of unsaturated fatty acids and the impact of such intake on SLE. Using the PICOS (population, intervention, comparator, outcomes, study design) framework, we included randomized controlled trials and case-control studies, assessing outcomes such as SLE activity, measured by SLE Disease Activity Index (SLEDAI) or the British Isles Lupus Assessment Group (BILAG) index, inflammation biomarkers. Studies were analyzed using either a fixed- or random-effects model based on heterogeneity (I2 statistic), with sensitivity analyses performed to assess the robustness of the findings.

RESULTS

Our search included 10 studies, encompassing a wide variety of designs and populations. The meta-analysis showed that a diet rich in unsaturated fatty acids is significantly associated with a reduction in SLEDAI scores (pooled SMD) of -0.36, 95% CI: -0.61 to -0.11, p = 0.007, indicating a beneficial effect on disease activity. Additionally, we found that unsaturated fatty acid intake has a significant impact on HDL levels, suggesting a positive effect on lipid profiles. However, no significant effects were observed on levels of the inflammatory marker IL-6 or other lipid components (LDL and cholesterol). With minimal heterogeneity among studies (I2 ≤ 15%), sensitivity analysis confirmed the stability and reliability of these results, highlighting the potential role of unsaturated fatty acids in SLE management.

CONCLUSIONS

This meta-analysis suggests that dietary intake of unsaturated fatty acids may play a positive role in reducing SLE activity and may significantly affect HDL levels without having significant effects on inflammation markers or other lipid profiles. These findings support the inclusion of unsaturated fatty acids in the dietary management of SLE patients, although further research is required to refine dietary recommendations and explore the mechanisms underlying these associations.

Fish oil supplementation and risk of incident systemic lupus erythematosus: a large population-based prospective study

BACKGROUND

Although fish oil has been considered to have an anti-inflammatory effect and has been proven to play a beneficial role in the incidence of numerous diseases, the association between fish oil supplementation and the risk of systemic lupus erythematosus (SLE) is still unknown. This study aimed at evaluating the correlation between fish oil use and incident SLE in a large population-based prospective cohort.

METHODS

390,277 participants without SLE at baseline from the UK Biobank were enrolled. Fish oil use was ascertained through a touchscreen questionnaire at baseline. The incidence of SLE was identified by the International Classification of Diseases version 10 code in medical records or self-report. Cox proportional hazard models were employed to estimate the association between fish oil use and SLE risk.

RESULTS

Fish oil users accounted for 31.47% of participants. During a median follow-up duration of 11.57 years, 141 participants without fish oil use (4.56/100 000 person-years) and 68 participants with fish oil use (4.78/100 000 person-years) developed SLE. In four models with adjustments for different amounts of confounders, there was no significant difference in the risk of SLE between fish oil users and fish oil non-users (all p-values > 0.05). In subgroup analyses, we found that fish oil supplementation was associated with a lower risk of SLE among females with ultraviolet radiation ≥ 3 h/day (hazard ratio: 0.63, 95% confidence interval: 0.40-0.98), which turned insignificant after further adjustment for female-related factors and sun protection measures.

CONCLUSIONS

No significant association between fish oil use and overall incident SLE was observed, except in females exposed to prolonged ultraviolet radiation. Subgroup analysis suggested that females exposed to prolonged ultraviolet radiation might benefit from fish oil supplementation in terms of preventing SLE, but it needs to be confirmed in further studies.

Case series: raw, whole, plant-based nutrition protocol rapidly reverses symptoms in three women with systemic lupus erythematosus and Sjögren's syndrome

Systemic lupus erythematosus (SLE) and Sjögren's syndrome (SS) are chronic autoimmune diseases. Symptoms of SLE can vary widely but often include fatigue, pain, photosensitivity, and, in some cases, nephritis. SS is frequently characterized by extreme dry eye and mouth, resulting from damage to moisture-producing glands, and is often present in combination with SLE. While the health benefits of plant-based diets have been well-established with respect to weight and cardiometabolic outcomes, less research is available to support the role of diet in treatment and management of autoimmune disease. This case series presents three women with SLE and SS who adopted a nutrition protocol to reverse symptoms of autoimmune disease. The protocol emphasizes leafy greens, cruciferous vegetables, omega-3 polyunsaturated fatty acids, and water, and includes predominately raw foods. The three patients reported dramatic improvements in physical symptoms, with nearly all symptoms of SLE and SS resolving after 4 weeks or less of adhering to the protocol. All three patients have remained symptom-free, two of whom have remained symptom-free for 6+ years with no recent medication use. Patients and practitioners should be made aware of the promising possibility of food as medicine in the treatment of SLE and SS. Future research should explore whether dietary changes may be a potential treatment strategy for individuals suffering from severe symptoms and poor quality of life due to SLE and SS.

Genetically predicted 486 blood metabolites concerning risk of systemic lupus erythematosus: a Mendelian randomization study

Metabolic abnormalities constitute a significant characteristic of systemic lupus erythematosus (SLE). We utilised a two-sample Mendelian randomisation (MR) study to evaluate the potential causal association between 486 blood metabolites and SLE. Exposure data at the metabolite level were extracted from 7824 European Genome-wide association studies (GWAS). Preliminary analysis utilised SLE GWAS data from FinnGen. The primary method for causal analysis relied on random inverse variance weighting (IVW). To ensure robustness, sensitivity analyses included the Cochran Q test, MR-Egger intercept test, MR-PRESSO, and leave-one-out analysis. Steiger testing and linkage disequilibrium score regression were employed to validate the identified metabolites. This study identified 12 metabolites, comprising six known chemical structures: 1,5-anhydroglucitol(1,5-AG) [odds ratio (OR) = 0.100, 95% confidence interval (CI): 0.015-0.773, P = 0.027), gamma-glutamylthreonine (OR = 0.077, 95% CI: 0.010-0.574, P = 0.012), 5-dodecenoate(12:1n7) (OR = 0.205, 95% CI: 0.061-0.685, P = 0.010), linoleoylglycerophosphoethanolamine * (OR = 0.159, 95% CI: 0.027-0.933, P = 0.044), erythrose (OR = 88.331,95% CI:1.098-63.214, P = 0.040) and 1-, adrenate (22:4n6) (OR = 9.876, 95% CI: 1.753-55.639, P = 0.001)]. Additionally, we found associations between SLE and six unknown chemical structures: X-06351 (OR = 0.071, 95% CI: 0.006-0.817, P = 0.034), X-10810 (OR = 4.268 95% CI: 1.260-14.459, P = 0.020), X-11412 (OR = 5.418 95% CI: 1.068-27.487, P = 0.041), X-11905 (OR = 0.551, 95%CI: 0.304-0.997, P = 0.049), X-12038 (OR = 0.178 95%CI: 0.032-0.988, P = 0.045), X-12217 (OR = 0.174 95%CI: 0.044-0.680, P = 0.014). This study offers evidence supporting a causal relationship between SLE and 12 circulating metabolites, six of which have known chemical structures and six that remain unidentified. These findings introduce a new perspective for further exploration of SLE mechanisms.

A Review of the Potential Benefits of Herbal Medicines, Small Molecules of Natural Sources, and Supplements for Health Promotion in Lupus Conditions

The Latin word lupus, meaning wolf, was in the medical literature prior to the 1200s to describe skin lesions that devour flesh, and the resources available to physicians to help people were limited. The present text reviews the ethnobotanical and pharmacological aspects of medicinal plants and purified molecules from natural sources with efficacy against lupus conditions. Among these molecules are artemisinin and its derivatives, antroquinonol, baicalin, curcumin, emodin, mangiferin, salvianolic acid A, triptolide, the total glycosides of paeony (TGP), and other supplements such as fatty acids and vitamins. In addition, medicinal plants, herbal remedies, mushrooms, and fungi that have been investigated for their effects on different lupus conditions through clinical trials, in vivo, in vitro, or in silico studies are reviewed. A special emphasis was placed on clinical trials, active phytochemicals, and their mechanisms of action. This review can be helpful for researchers in designing new goal-oriented studies. It can also help practitioners gain insight into recent updates on supplements that might help patients suffering from lupus conditions.