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Context Cottonseed oil (CSO) is higher in polyunsaturated fatty acids (PUFA) and saturated fatty acids (SFAs) than many liquid plant oils. Objectives To conduct a systematic review of randomized controlled trials (RCTs) examining effects of CSO on markers of lipid metabolism and evaluate lipid and lipoprotein effects of incorporating CSO into a healthy dietary pattern using regression equations. Data Sources A systematic search was conducted for RCTs comparing CSO with a non-CSO comparator in any population. Data Analyses The Katan regression equation was used to predict lipid/lipoprotein changes when incorporating CSO into a US-style healthy eating pattern at 25 to 100% of the total oil allowance (ie, 27 g/2000 kcal) compared with average American intake (NHANES 2017 to 2020 pre-COVID pandemic). Results In total, 3 eligible publications (n = 2 trials), with 58 participants that provided 44% and 30% of total energy as CSO, were included. Fasting low-density lipoprotein cholesterol (LDL-C; ≈ –7.7 mg/dL) and triglycerides (≈ –7.5 mg/dL) were lower after 5 days of a CSO-enriched diet vs olive oil (OO). In a 56-day trial, CSO lowered total cholesterol (TC; ≈ –14.8 mg/dL), LDL-C (≈ –14.0 mg/dL), and non–high-density lipoprotein cholesterol (≈ –14.2 mg/dL) vs OO. Postprandially, angiopoietin-like protein-3, -4, and -8 concentrations decreased with CSO and increased with OO intake. Compared with average American intake, a healthy eating pattern with 27 g of CSO was estimated to lower TC (–8.1 mg/dL) and LDL-C (–7.3 mg/dL) levels, with minimal reduction in high-density lipoprotein cholesterol (–1.1 mg/dL). Compared with the healthy eating pattern, incorporating 27 g of CSO was predicted to increase TC and LDL-C levels by 2.4 mg/dL. Conclusion Limited high-quality research suggests CSO may improve lipid/lipoprotein levels compared with OO. Cholesterol predictive equations suggest CSO can be incorporated into a healthy dietary pattern without significantly affecting lipids/lipoproteins. [ABSTRACT FROM AUTHOR]

The goal of this narrative review is to summarize the effects of prolonged fasting on various metabolic health measures, including body weight, blood pressure, plasma lipids, and glycemic control. Prolonged fasting is characterized by consciously eating little to no food or caloric beverages for several days to weeks. Results reveal that prolonged fasting for 5–20 days produces potent increases in circulating ketones, and mild to moderate weight loss of 2–10%. Approximately two-thirds of the weight lost is lean mass, and one-third is fat mass. The excessive lean mass loss suggests that prolonged fasting may increase the breakdown of muscle proteins, which is a concern. Systolic and diastolic blood pressure consistently decreased with prolonged fasting. However, the impact of these protocols on plasma lipids is less clear. While some trials demonstrate decreases in LDL cholesterol and triglycerides, others show no benefit. With regard to glycemic control, reductions in fasting glucose, fasting insulin, insulin resistance, and glycated hemoglobin (HbA1c) were noted in adults with normoglycemia. In contrast, these glucoregulatory factors remained unchanged in patients with type 1 or type 2 diabetes. The effects of refeeding were also examined in a few trials. It was shown that 3–4 months after the fast was completed, all metabolic benefits were no longer observed, even when weight loss was maintained. With regard to adverse events, metabolic acidosis, headaches, insomnia, and hunger were observed in some studies. In summary, prolonged fasting appears to be a moderately safe diet therapy that can produce clinically significant weight loss (>5%) over a few days or weeks. However, the ability of these protocols to produce sustained improvements in metabolic markers warrants further investigation. [ABSTRACT FROM AUTHOR]

Context Nonalcoholic fatty liver disease (NAFLD) is prevalent in 25–30% of British and European populations, representing a potential global public health crisis. Marine omega-3 (n-3) polyunsaturated fatty acids offer well-evidenced benefits to NAFLD biomarkers; however, the effect of plant-based n-3 has not been evaluated with a systematic review and meta-analysis. Objective The review aimed to systematically evaluate the effect of plant-based n-3 supplementation on NAFLD surrogate biomarkers and parameters. Data Sources Medline (EBSCO), PubMed, CINAHL (EBSCO), Cochrane Central Register of Controlled Trials, the International Clinical Trials Registry Platform, and Google Scholar databases were searched to identify randomized controlled trials published between January 1970 and March 2022 evaluating the impact of plant-based n-3 interventions on diagnosed NAFLD. The review followed the PRISMA checklist and is PROSPERO registered (CRD42021251980). Data Extraction A random-effects model and generic inverse variance methods synthesized quantitative data, followed by a leave-one-out method for sensitivity analysis. We identified 986 articles; after the application of selection criteria, six studies remained with 362 patients with NAFLD. Results The meta-analysis showed that plant-based n-3 fatty acid supplementation significantly reduced alanine aminotransferase (ALT) (mean difference: 8.04 IU/L; 95% confidence interval: 14.70, 1.38; I2 = 48.61%) and plasma/serum triglycerides (44.51 mg/dL; 95% confidence interval: –76.93, –12.08; I2 = 69.93%), alongside body-composition markers in patients with NAFLD (P < 0.05). Conclusion Plant-based n-3 fatty acid supplementation improves ALT enzyme biomarkers, triglycerides, body mass index, waist circumference, and weight loss when combined with lifestyle interventions to increase physical activity and a calorie-controlled diet. Further research is needed to identify the most effective plant-based n-3 sources in larger numbers of patients with NAFLD over longer study durations. Systematic Review Registration PROSPERO registration no. CRD42021251980. [ABSTRACT FROM AUTHOR]

Context Cardiovascular disease is the leading cause of death worldwide. Low-calorie, low-fat therapeutic diets (TDs) developed by the US National Cholesterol Education Program, ie, the Step I and II diets and the therapeutic lifestyle changes diet, are approximately similar and are the initial therapeutic interventional approaches for lifestyle modification. Objective This systematic review with meta-analysis was undertaken to evaluate the effects of TDs diet on blood lipids, apolipoprotein A-1, apolipoprotein B, blood pressure, fasting blood glucose, and insulin. Data Sources A comprehensive search of the PubMed/MEDLINE, Web of Science, Scopus, and Google Scholar databases until October 2022 was performed to identify clinical trials investigating the effects of TDs on the aforementioned parameters. Data Extraction One investigator screened the records and extracted data, and another reviewed the extracted data. Data Analysis A total of 910 records were retrieved. After records were screened for eligibility, 34 clinical trials met the inclusion criteria. The pooled analysis from the random-effects model revealed a significant reduction in total cholesterol, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, apolipoprotein A-1, and apolipoprotein B in the TD intervention group vs the control group. The overall effects of TDs on fasting blood glucose, insulin, and blood pressure were not significant, but the results of subgroup analysis revealed a significant reduction in fasting blood glucose with the Step II diet and an intervention duration of more than 24 weeks. For blood pressure, the Step I diet and an intervention duration of more than 24 weeks resulted in significant reduction. There was no evidence of publication bias, but strong heterogeneity was observed. Conclusion Therapeutic diets have promising effects on lipid profile parameters, glycemic indexes, and blood pressure, which can promote cardiovascular health. Systematic Review Registration PROSPERO registration no. CRD42021259355. [ABSTRACT FROM AUTHOR]

Context A recent US national survey of the health status of the male transgender population has raised awareness about the little-studied relationship between testosterone hormone therapy in transgender men and cardiovascular outcomes. Objective The aim of this systematic review was to assess the relationship between cross-sex hormone therapy in transgender men and lipid profiles and cardiovascular risk. Data Sources The PubMed, SciELO, SpringerLink, and EBSCOhost databases were searched up to March 2021 for studies assessing the association between cross-sex hormone therapy and the incidence of outcomes related to cardiovascular disease in transgender men over 18 years of age. Data Extraction Data extracted were sorted into clinical data (systolic, diastolic, and mean blood pressure), anthropometric data (body mass index, weight, waist circumference, fat mass, and lean mass), and biochemical data (triglycerides, total cholesterol, low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], very low-density lipoprotein cholesterol [VLDL-C], and the HDL-C to LDL-C ratio). Data Analysis Study quality was appraised independently by two reviewers using the Cochrane tools for assessment of methodological quality or risk of bias in nonrandomized studies, and the Newcastle-Ottawa Scale was applied. Of 735 studies identified, 11 were included in the review. Most studies reported no change in cholesterol or triglyceride levels after hormone treatment. A reduction in HDL-C levels was observed in 7 of 11 studies, although this alone cannot be considered a cardiovascular risk factor. Likewise, clinical and anthropometric findings showed no changes predictive of cardiovascular risk. Conclusions Although these findings suggest that hormone therapy may lead to a decrease in HDL-C levels and an increase in LDL-C levels, they are insufficient to establish a relationship with cardiovascular disease. Furthermore, no significant effects on metabolic and anthropometric values were found. Further studies with higher quality and longer follow-up periods are needed to establish cardiovascular risk. Systematic Review Registration PROSPERO registration number CRD 42020212560. [ABSTRACT FROM AUTHOR]

Context There is renewed interest in using very low-carbohydrate ketogenic (VLCK) diets to manage diabetes. Many clinical trials have been published, often with mixed results. Objective This meta-analysis compares the effect of a VLCK diet on glycemic control, body weight, lipid profile, medication use, and dropouts with that of recommended diets for 12 weeks or longer in people with type 2 diabetes. Data Sources Ovid MEDLINE, Ovid Embase, CENTRAL, and CINAHL databases were searched (January 1980 through September 2019). Study Selection Two authors independently reviewed search results to select randomized controlled trials (RCTs) comparing a VLCK diet (carbohydrate intake < 50 g/d or < 10% of total energy) with any recommended diet for type 2 diabetes in adults. Discrepancies were resolved after consulting with the third author. Data Extraction Eight RCTs with 648 participants were identified. Results Compared with control diets, the VLCK diet resulted in a greater decrease in hemoglobin A1c after 3 months (weighted mean difference[WMD]: −6.7 mmol/mol; 95%CI, −9.0 to −4.4) (WMD: −0.61%; 95%CI, −0.82 to −0.40; P  < 0.001; moderate-certainty evidence) and after 6 months (WMD: −6.3 mmol/mol; 95%CI, −9.3 to −3.5) (WMD: −0.58%; 95%CI, −0.85 to −0.32; low-certainty evidence). There was a significantly greater weight loss with the VLCK diet after 3 months (WMD: −2.91 kg; 95%CI, −4.88 to −0.95; low-certainty evidence) and after 6 months (WMD: −2.84 kg; 95%CI, −5.29 to −0.39; low-certainty evidence). The VLCK diet was not better than a control diet after 12 months. It was superior in decreasing triglyceride levels, increasing high-density lipoprotein cholesterol levels, and reducing the use of antidiabetic medications for up to 12 months. Conclusion The VLCK diet appears to control glycemia and decrease body weight for up to 6 months in people with obesity and diabetes. Beneficial changes in serum triglycerides and high-density lipoprotein cholesterol, along with reductions in antidiabetic medications, continued in the VLCK group until 12 months. However, the quality of currently available evidence is not sufficient to recommend VLCK diets. A major limitation of the VLCK diet is patients' lack of adherence to carbohydrate restriction. Systematic Review Registration PROSPERO registration number CRD42020154700 [ABSTRACT FROM AUTHOR]

Context Consumption of lean fish and fish-derived proteins were effective for improving lipid profiles in published studies; however, evidence remains inconclusive. Objective To evaluate the effectiveness of lean fish or fish-derived protein on serum/plasma lipid and lipoprotein levels by conducting a systematic review of the literature and meta-analysis of available randomized controlled trials (RCTs). Data sources Medline (Ovid), Scopus, CINAHL, and Food and Nutritional Sciences databases were searched from the start date of each database to September 2019 to identify RCTs determining the effect of lean fish on lipid profile. Study selection Included RCTs investigated lean fish and fish-derived proteins intake and determined at least 1 major lipid or lipoprotein measurement. Data extraction Two reviewers independently evaluated 1217 studies against the inclusion and exclusion criteria. Relevant studies were assessed for risks of bias, and random-effects meta-analysis was conducted to generate average estimates of effect. Results A total of 24 studies met the inclusion criteria. Meta-analysis of data from 18 to 21 eligible crossover and parallel-design RCTs with a total of 1392 to 1456 participants found triacylglycerol-lowering effects for lean fish compared with no fish consumption. Lean fish intake showed no significant differences related to total cholesterol or lipoprotein levels. Subanalysis showed that parallel-group RCTs tended to find greater reduction effects on circulating triacylglycerol than did crossover RCTs. Conclusion Additional better-designed, longer, and larger RCTs, particularly crossover RCTs, are needed to clarify the impact of lean fish and fish proteins on the serum/plasma lipid profile. Findings from such studies would enable practitioners to provide their patients evidence-based recommendations to meet the American Heart Association guidelines for fish consumption to reduce cardiovascular disease risk. [ABSTRACT FROM AUTHOR]

Context Cardiovascular disease is a major public health problem and represents a significant burden of disease globally. Lifestyle interventions have their limitations and an intervention that will effectively address cardiovascular risk factors to help reduce this growing burden of disease is required. Objective Carnosine and other histidine-containing dipeptides (HCDs) have exerted positive effects on cardiovascular risk factors and diseases in animal and human studies. The authors conducted a systematic review and meta-analysis examining the effects of HCDs on cardiovascular outcomes in line with the PRISMA guidelines. Data Sources The Medline, Medline in process, Embase, Cumulative Index of Nursing and Allied Health, and All EBM databases were searched from inception until January 25, 2019, for randomized controlled trials (RCTs) examining the effects of HCDs on cardiovascular outcomes, compared with placebo or controls. Data Extraction Basic characteristics of the study and populations, interventions, and study results were extracted. The grading of recommendations assessment, development, and evaluation approach was used to assess the quality of evidence for each outcome. Data Analysis A total of 21 studies were included. Of these, 18 were pooled for meta-analysis (n  = 913). In low risk of bias studies, HCD-supplemented groups had lower total cholesterol (n = 6 RCTs; n = 401; weighted mean difference [WMD], −0.32 mmol/L [95%CI, −0.57 to −0.07], P  = 0.01) and triglyceride levels (n = 6 RCTs; n = 401; WMD, −0.14 mmol/L [95%CI, −0.20 to −0.08], P  < 0.001) compared with controls. In studies using carnosine, triglycerides levels were also lower in the intervention group vs controls (n = 5 RCTS; n = 309; P  < 0.001). There were no significant differences in blood pressure, heart rate, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C) or the total cholesterol to HDL-C ratio between groups. Conclusions Carnosine and other HCDs may have a role in improving lipid profiles. Larger studies with sufficient follow-up are necessary to confirm these findings and explore the use of HCDs in the prevention of cardiovascular diseases. Systemic Review Registration PROSPERO registration no.: CRD42017075354 [ABSTRACT FROM AUTHOR]

Context Clinical trials examining the cardiovascular protective effects of quercetin in humans have reported conflicting results. Objective The aim of this systematic review was to summarize evidence of the effects of quercetin supplementation on plasma lipid profiles, blood pressure (BP), and glucose levels in humans by performing a meta-analysis of randomized controlled trials. Data Sources MEDLINE, Embase, and Scopus databases were searched electronically from their inception to July 2018 to identify randomized controlled trials that assessed the impact of quercetin on lipid profiles, BP, and glucose levels. Study Selection Randomized controlled trials assessing the effects of quercetin or a standardized quercetin-enriched extract on plasma lipid profiles, BP, and glucose levels in humans were eligible for inclusion. Data Extraction A random-effects model was used for data analysis. Continuous variables were expressed as weighted mean differences (WMDs) and 95%CIs. Subgroup analyses were conducted to explore possible influences of study characteristics. Sensitivity analyses were also performed, as were analyses of publication bias. Results Seventeen trials (n = 896 participants total) were included in the overall analysis. Pooled results showed that quercetin significantly lowered both systolic BP (WMD, −3.09 mmHg; 95%CI, −4.59 to −1.59; P = 0.0001) and diastolic BP (WMD, −2.86 mmHg; 95%CI, −5.09 to −0.63; P = 0.01). Neither lipid profiles nor glucose concentrations changed significantly. In subgroup analyses, significant changes in high-density lipoprotein cholesterol and triglycerides were observed in trials with a parallel design and in which participants consumed quercetin for 8 weeks or more. Conclusion Quercetin intake resulted in significantly decreased BP in humans. Moreover, participants who consumed quercetin for 8 weeks or more showed significantly changed levels of high-density lipoprotein cholesterol and triglycerides in trials with a parallel design. [ABSTRACT FROM AUTHOR]

Context Vitamin D deficiency is highly prevalent across the world. The existing evidence suggests vitamin D may have beneficial effects on serum lipid profiles and thus cardiovascular health. Objective The objective of this systematic review and meta-analysis was to examine the effect of vitamin D supplementation on serum lipid profiles. Data Source Original randomized controlled trials (RCTs) examining the effect of vitamin D supplementation on serum lipid profiles and published before July 2018 were identified by searching online databases, including PubMed, Google Scholar, and ScienceDirect, using a combination of relevant keywords. Data Extraction Data on study characteristics, effect size, measure of variation, type of vitamin D supplementation, and duration of follow-up were extracted by the author. Data Analysis PRISMA guidelines for systematic reviews were followed. Random effects (DerSimonian and Laird [D-V)] models were used to pool standardized mean differences in total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides between the active and the placebo arms of RCT studies. Between-study heterogeneities were assessed using Cochrane Q and I2, and publication bias was assessed using Begg's test, Egger's test, and funnel plot. Results A total of 41 RCTs comprising 3434 participants (n = 1699 in the vitamin D supplementation arm and n = 1735 in the placebo arm) were identified and included in the meta-analysis. Approximately 63.4% of study participants were women, with 14 studies conducted entirely among women. Approximately 24% of the trials had follow-up duration >6 months, whereas the remaining 76% had follow-up duration of < 6 months. The standardized mean differences (SMDs) and 95% confidence intervals (CIs) for comparing the change from baseline to follow-up between the vitamin D supplementation arm and the placebo (control) arm were as follows: total cholesterol = –0.17 (–0.28 to –0.06); LDL cholesterol = –0.12 (–0.23 to –0.01); triglycerides = –0.12 (–0.25 to 0.01); and HDL cholesterol = –0.19 (–0.44 to 0.06). After removing a trial that was an outlier based on the magnitude of the effect size, the SMD for triglycerides was –0.15 (–0.24 to –0.06) and that for HDL cholesterol was –0.10 (–0.28 to 0.09). The improvements in total cholesterol and triglycerides were more pronounced in participants with baseline vitamin D deficiency. Conclusions Vitamin D supplementation appeared to have a beneficial effect on reducing serum total cholesterol, LDL cholesterol, and triglyceride levels but not HDL cholesterol levels. Vitamin D supplementation may be useful in hypercholesterolemia patients with vitamin D insufficiency who are at high risk of cardiovascular diseases. [ABSTRACT FROM AUTHOR]

Context Carbohydrate-restricted diets may increase low-density lipoprotein cholesterol and thereby cardiovascular risk. Objective A systematic review and meta-analyses were conducted to compare the effects of very low, low, and moderate carbohydrate, higher fat diets versus high-carbohydrate, low-fat diets on low-density lipoprotein cholesterol and other lipid markers in overweight/obese adults. Data Sources Medline, PubMed, Cochrane Central, and CINAHL Plus were searched to identify large randomized controlled trials (n > 100) with duration ≥ 6 months. Data Extraction Eight randomized controlled trials (n = 1633; 818 carbohydrate-restricted diet, 815 low-fat diet) were included. Data Analysis Quality assessment and risk of bias, a random effects model, and sensitivity and subgroup analyses based on the degree of carbohydrate restriction were performed using Cochrane Review Manager. Results were reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocol. Results Carbohydrate-restricted diets showed no significant difference in low-density lipoprotein cholesterol after 6, 12, and 24 months. Although an overall pooled analysis statistically favored low-fat diets (0.07 mmol/L; 95% confidence interval [CI], 0.02–0.13; P = 0.009], this was clinically insignificant. High-density lipoprotein cholesterol and plasma triglycerides at 6 and 12 months favored carbohydrate-restricted diets (0.08 mmol/L; 95%CI, 0.06–0.11; P < 1 × 10−5 and −0.13 mmol/L; 95%CI, −0.19 to −0.08; P < 1 × 10−5, respectively). These favorable changes were more marked in the subgroup with very-low carbohydrate content (< 50 g/d; 0.12 mmol/L; 95%CI, 0.10–0.14; P < 1 × 10−5 and −0.19 mmol/L; 95%CI, −0.26 to −0.12; P = 0.02, respectively). Conclusions Large randomized controlled trials of at least 6 months duration with carbohydrate restriction appear superior in improving lipid markers when compared with low-fat diets. Dietary guidelines should consider carbohydrate restriction as an alternative dietary strategy for the prevention/management of dyslipidemia for populations with cardiometabolic risk. [ABSTRACT FROM AUTHOR]

Context: Cheese may affect lipids and lipoproteins differently than other high-fat dairy foods. Objective: The present systematic review and meta-analysis was performed to evaluate randomized controlled trials that examined the effect of cheese consumption compared with another food product on blood lipids and lipoproteins. Data Sources: A systematic literature search of the MEDLINE, Embase, Scopus, CAB Abstracts, the Cochrane Controlled Trials Register, and the clinicaltrials.gov website was performed. Study Selection: A total of 12 randomized controlled trials (RCTs) were identified that examined the effect of cheese consumption on blood lipids and lipoproteins in healthy adults. Data Extraction: A meta-analysis of 5 RCTs that compared the effects of hard cheese and butter, both of which had a similar ratio of polyunsaturated fatty acids to saturated fatty acids (P/S ratio), was performed. Data Synthesis: Compared with butter intake, cheese intake (weighted mean difference: 145.0 g/d) reduced low-density lipoprotein cholesterol (LDL-C) by 6.5% (-0.22 mmol/l; 95%CI: -0.29 to -0.14) and high-density lipoprotein cholesterol (HDL-C) by 3.9% (-0.05 mmol/l; 95%CI: -0.09 to -0.02) but had no effect on triglycerides. Compared with intake of tofu or fat-modified cheese, cheese intake increased total cholesterol or LDL-C, as was expected on the basis of the P/S ratio of the diets. There was insufficient data to compare intake of cheese with intake of other foods. Conclusion: Despite the similar P/S ratios of hard cheese and butter, consumption of hard cheese lowers LDL-C and HDL-C when compared with consumption of butter. Whether these findings can be attributed to calcium, specific types of saturated fatty acids, or the food matrix of cheese warrants further research. [ABSTRACT FROM AUTHOR]

Hypercholesterolemia is associated with an increased risk of heart disease. The effect of garlic on blood lipids has been studied in numerous trials and summarized in meta-analyses, with conflicting results. This meta-analysis, the most comprehensive to date, includes 39 primary trials of the effect of garlic preparations on total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides. The findings suggest garlic to be effective in reducing total serum cholesterol by 17 ± 6 mg/dL and low-density lipoprotein cholesterol by 9 ± 6 mg/dL in individuals with elevated total cholesterol levels (>200 mg/dL), provided garlic is used for longer than 2 months. An 8% reduction in total serum cholesterol is of clinical relevance and is associated with a 38% reduction in risk of coronary events at 50 years of age. High-density lipoprotein cholesterol levels improved only slightly, and triglycerides were not influenced significantly. Garlic preparations were highly tolerable in all trials and were associated with minimal side effects. They might be considered as an alternative option with a higher safety profile than conventional cholesterol-lowering medications in patients with slightly elevated cholesterol. [ABSTRACT FROM AUTHOR]

Increasing evidence suggests a role for carbohydrate restriction in the dietary treatment of atherogenic dyslipidemia. The effects of carbohydrate restriction on the specific aspects of lipoprotein metabolism affected by atherogenic dyslipidemia under weight-stable and weight-loss conditions are reviewed here. [ABSTRACT FROM AUTHOR]