-
1.
Comparative effects of vitamin and mineral supplements in the management of type 2 diabetes in primary care: A systematic review and network meta-analysis of randomized controlled trials.
Xia, J, Yu, J, Xu, H, Zhou, Y, Li, H, Yin, S, Xu, D, Wang, Y, Xia, H, Liao, W, et al
Pharmacological research. 2023;188:106647
-
-
-
-
Free full text
-
Plain language summary
Type 2 diabetes mellitus (T2DM), characterised by sustained hyperglycaemia and insulin resistance, remains a severe driver of chronic metabolic diseases such as cardiovascular diseases. The aim of this study was to investigate and compare the efficacy of vitamin and mineral supplements in the management of glycaemic control and lipid metabolism for type 2 diabetic patients to inform clinical practice. This study is a systematic review and meta-analysis of one hundred and seventy articles with a total of 4223 adults with T2DM. Participants were randomised to either the placebo/no treatment group (n= 6345) or to the treatment group (n= 7878). Results show that: - chromium was the most effective micronutrient for decreasing fasting blood glucose and insulin resistance. - vitamin K was the top-ranked micronutrient in reducing haemoglobin A1C and fasting insulin levels. - vanadium was the top-ranked micronutrient in total cholesterol reductions. - niacin was ranked as the most effective in triglycerides reductions and increasing high-density lipoprotein cholesterol levels. - vitamin E was the top-ranked micronutrient in low-density lipoprotein cholesterol reductions. Authors conclude that micronutrient supplements especially chromium, vitamin E, vitamin K, vanadium, and niacin supplements, may be more effective in the management of T2DM compared with other micronutrients.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Clinicians could consider the adjunctive effect of micronutrients supplements, such as chromium, vitamin E, vitamin K, vanadium, and niacin supplements in a nutrition protocol to manage T2DM and slow or prevent its complications.
- The study authors state that the vitamin and mineral supplements under review had a statistically significant improvement, however they did not reach the study threshold for clinical significance. Therefore they advise caution in utilising micronutrient supplements in the management of glucose and lipid metabolism for T2DM.
Evidence Category:
-
X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
-
B: Systematic reviews including RCTs of limited number
-
C: Non-randomized trials, observational studies, narrative reviews
-
D: Case-reports, evidence-based clinical findings
-
E: Opinion piece, other
Summary Review:
Objectives
The aim of this systematic review was to evaluate the comparative effects of vitamin and mineral supplements on managing glycemic control and lipid metabolism for type 2 diabetes mellitus (T2DM).
Methodology
This systematic review is registered with PROSPERO and adhered to PRISMA-2020 guidelines for network meta-analysis
The Cochrane Collaboration’s risk-of-bias tool was used to assess eligible randomised trials
8 prespecified markers identified and assessed in this study : 1) HbA1c (%), 2) fasting blood glucose (mmol/L), 3) total cholesterol (mmol/L), 4) triglycerides (mmol/L), 5) fasting insulin (μIU/mL), 6) HOMA-IR, 7) LDL-c (mmol/L), and 8) HDL-c (mmol/L).
Results
- 170 RCT trials of 14223 participants with T2DM treated with vitamin supplements, mineral supplements, or placebo/no treatment were included
- Low to very low certainty evidence established chromium supplements as the most effective in reducing fasting blood glucose levels and homeostasis model assessment of insulin resistance (SUCRAs: 90.4% and 78.3%, respectively)
- Vitamin K supplements ranked best in reducing glycated haemoglobin A1c and fasting insulin levels (SUCRAs: 97.0% and 82.3%, respectively), with moderate to very low certainty evidence
- Vanadium supplements ranked best in lowering total cholesterol levels with very low evidence certainty (SUCRAs:100%)
- Niacin supplements ranked best in triglyceride reductions and increasing high-density lipo-protein cholesterol levels with low to very low evidence certainty (SUCRAs:93.7% and 94.6%, respectively)
- Vitamin E supplements ranked best in reducing low-density lipoprotein cholesterol levels with very low evidence certainty (SUCRAs:80.0%).
Conclusion
- Micronutrient supplements, such as chromium, vitamin E, vitamin K, vanadium, and niacin supplements, may be efficacious in managing T2DM
- It should be noted that the evidence certainty for all was low.
Clinical practice applications:
- Chromium plays an important role in carbohydrate and lipid metabolism and was the most effective micronutrient for decreasing fasting blood glucose, HbA1c, fasting insulin, and HOMA-IR reductions. More pronounced effects were seen for chromium than vitamin E, vitamin C, niacin, selenium, and magnesium supplements
- Vitamin K was the top-ranked micronutrient in reducing HbA1c and fasting insulin levels. The mechanism through which Vitamin K affects glucose metabolism is proposed as activation of the AMP-activated protein kinase/sirtuin 1, that in turn increases phosphocreatine 3-kinase and glucose transporter 2 to decrease insulin resistance and fasting glucose.
- Vanadium was the top-ranked micronutrient in total cholesterol (TC) reductions, where supplementation dosage should be carefully considered, as vanadium compounds can be moderately or highly toxic. Vanadium supplementation is only recommended in cases of vanadium deficiency or diabetes, hyperlipidemia, and hypertension, where the intake of vanadium from food should be enhanced in preference to supplementation
- Niacin was ranked as the most effective in triglyceride (TG) reductions and increasing HDL cholesterol levels. The dose of niacin could not be determined
- Vitamin E was the top-ranked micronutrient in low-density lipo- protein (LDL) cholesterol reductions.
Considerations for future research:
- Considering the clinical importance of these findings, new research is needed to get better insight into the efficacy of micronutrient supplements in managing T2DM
- Selenium homeostasis, selenoprotein, insulin signaling/secretion, and carbohydrate/lipid metabolism are linked in multiple and complex ways but the authors could not explain why chromium supplementation would lower blood glucose more effectively than selenium supplementation, and suggest more research is needed to clarify this
- While vitamin K status could be an emerging treatment target in T2DM prevention and management, it remains to be determined whether vitamin K supplementation has an advantage over other nutrients in terms of hypoglycemic effect, and further research is necessary
- The beneficial effect of vitamin E and niacin supplements regarding lipid metabolism warrant investigation through more rigorous comparative studies.
Abstract
Medical nutrition treatment can manage diabetes and slow or prevent its complications. The comparative effects of micronutrient supplements, however, have not yet been well established. We aimed at evaluating the comparative effects of vitamin and mineral supplements on managing glycemic control and lipid metabolism for type 2 diabetes mellitus (T2DM) to inform clinical practice. Electronic and hand searches for randomized controlled trials (RCTs) were performed until June 1, 2022. We selected RCTs enrolling patients with T2DM who were treated with vitamin supplements, mineral supplements, or placebo/no treatment. Data were pooled via frequentist random-effects network meta-analyses. A total of 170 eligible trials and 14223 participants were included. Low to very low certainty evidence established chromium supplements as the most effective in reducing fasting blood glucose levels and homeostasis model assessment of insulin resistance (SUCRAs: 90.4% and 78.3%, respectively). Vitamin K supplements ranked best in reducing glycated hemoglobin A1c and fasting insulin levels (SUCRAs: 97.0% and 82.3%, respectively), with moderate to very low certainty evidence. Vanadium supplements ranked best in lowering total cholesterol levels with very low evidence certainty (SUCRAs:100%). Niacin supplements ranked best in triglyceride reductions and increasing high-density lipoprotein cholesterol levels with low to very low evidence certainty (SUCRAs:93.7% and 94.6%, respectively). Vitamin E supplements ranked best in reducing low-density lipoprotein cholesterol levels with very low evidence certainty (SUCRAs:80.0%). Our analyses indicated that micronutrient supplements, especially chromium, vitamin E, vitamin K, vanadium, and niacin supplements, may be more efficacious in managing T2DM than other micronutrients. Considering the clinical importance of these findings, new research is needed to get better insight into this issue.
-
2.
Egg and Dietary Cholesterol Intake and Risk of All-Cause, Cardiovascular, and Cancer Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies.
Darooghegi Mofrad, M, Naghshi, S, Lotfi, K, Beyene, J, Hypponen, E, Pirouzi, A, Sadeghi, O
Frontiers in nutrition. 2022;9:878979
-
-
-
Free full text
Plain language summary
Eggs are a rich source of vitamins, carotenoids, and dietary cholesterol. However, dietary cholesterol may contribute to an imbalance in blood lipid levels, increasing the risk of developing cardiovascular disease (CVD) and cancer. Therefore, this systematic review and dose-response meta-analysis evaluated the impact of egg and dietary cholesterol on the risk of CVD, cancer, and all-cause mortality. This systematic review and meta-analysis included fifty-five prospective cohort studies. This research showed a positive association between egg and dietary cholesterol consumption with all-cause mortality and cancer mortality. However, daily consumption of up to 1.5 eggs or 450 mg of dietary cholesterol did not affect the mortality risk. Further robust studies are required due to the high heterogeneity between the included studies. Nevertheless, healthcare professionals can use the results of this research to understand the impact of egg and dietary cholesterol consumption on CVD, cancer and all-cause mortality.
Abstract
OBJECTIVE This systematic review and meta-analysis of prospective cohort studies examined the associations between egg and dietary cholesterol intake and the risk of mortality from all causes, including cardiovascular disease (CVD) and cancer. METHODS We searched PubMed, Scopus, ISI Web of Knowledge, and Google Scholar until April 2021, as well as references to the relevant articles retrieved. Random-effects models were used to calculate summary relative risk (RR) and 95% confidence intervals (CIs) for the highest vs. lowest categories of egg and dietary cholesterol intake. Also, linear and non-linear dose-response analyses were conducted to examine the dose-response relationships. RESULTS We included 55 studies, comprising data from 2,772,486 individuals with 228,425, 71,745, and 67,211 cases of all-cause, CVD, and cancer mortality, respectively. Intake of each additional egg per day was associated with a 7% higher risk of all-cause (1.07, 95% CI: 1.02-1.12, I2 = 84.8%) and a 13% higher risk of cancer mortality (1.13, 95% CI: 1.06-1.20, I2 = 54.2%), but was not associated with CVD mortality (1.00, 95% CI: 0.92-1.09, I2 = 81.5%). Non-linear analyses showed increased risks for egg consumption of more than 1.5 and 0.5 eggs/day, respectively. Each 100 mg/day increment in dietary cholesterol intake was associated with a 6% higher risk of all-cause mortality (1.06, 95% CI: 1.03-1.08, I2 = 34.5%) and a 6% higher risk of cancer mortality (1.06, 95% CI: 1.05-1.07, I2 = 0%), but was not associated with CVD mortality (1.04, 95% CI: 0.99-1.10, I2 = 85.9%). Non-linear analyses demonstrated elevated risks of CVD and cancer mortality for intakes more than 450 and 250 mg/day, respectively. CONCLUSIONS AND RELEVANCE High-dietary intake of eggs and cholesterol was associated with all-cause and cancer mortality. Little evidence for elevated risks was seen for intakes below 0.5 egg/day or 250 mg/day of dietary cholesterol. Our findings should be considered with caution because of small risk estimates and moderate between-study heterogeneity. SYSTEMATIC REVIEW REGISTRATION https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=252564, PROSPERO, identifier: CRD42021252564.
-
3.
The Effect of Walnut Intake on Lipids: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
Alshahrani, SM, Mashat, RM, Almutairi, D, Mathkour, A, Alqahtani, SS, Alasmari, A, Alzahrani, AH, Ayed, R, Asiri, MY, Elsherif, A, et al
Nutrients. 2022;14(21)
-
-
-
Free full text
Plain language summary
The prevalence of cardiovascular disease increases as the modifiable risk factors increase, such as metabolic syndrome, obesity, type 2 diabetes, dyslipidaemia, and high blood pressure. Walnuts are a rich source of anti-inflammatory polyunsaturated fatty acids and omega-3 fatty acids. Walnuts are also known for their antioxidant properties and have been found to improve dyslipidaemia by reducing total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-c). This systematic review and meta-analysis of thirteen randomised controlled trials evaluated the effects of walnut intake on lipid profile. Most of the included studies used walnut dosage ranging from 15 g to 99 g/day for six to sixteen weeks of intervention. The results of this systematic review and meta-analysis showed significant improvements in TC, LDL-c, and triglyceride (TG) levels. Subgroup analysis revealed greater improvement in TC, LDL-c, and TG in overweight and other comorbidities but had normal levels of TC and LDL-C. Additionally, female participants showed greater improvements in TG levels, followed by the walnut intervention. Intervention duration also affected the beneficial effect of the walnut intervention. Further robust studies are required to determine the effects of walnut intake on cardiovascular disease risk reduction due to the high heterogeneity between the included studies. However, healthcare professionals can use the results of this research to understand the benefits of including walnuts as part of a healthy diet and their impact on reducing dyslipidaemia.
Abstract
Cardiovascular diseases (CVD) are the leading causes of death worldwide. Dyslipidemia is a cardiometabolic risk factor of CVD, yet it can be modifiable. Walnuts have been suggested as a dietary intervention to improve the lipid profile. Therefore, we reviewed the literature to assess the evidence linking walnut intake to the improvement of blood lipids, including total cholesterol (TC), low-density lipoprotein (LDL-C) cholesterol, high-density lipoprotein (HDL-C) cholesterol, and triglycerides (TG). PubMed and Embase databases were searched from 2010 up to March 2022. We limited our search to randomized controlled trials conducted on humans and published in English during the specified period. Cochrane's risk of bias tool for interventional studies was used. A random-effects model was used for the meta-analysis, and weighted mean differences were obtained (WMD) Thirteen trials from the U.S., Europe, and Asia were included. Walnut intake was associated with significant reductions in TC (WMD: -8.58 mg/dL), LDL-C (WMD: -5.68 mg/dL), and TG (WMD: -10.94 mg/dL). Walnut consumption was not associated with HDL-C. Subgroup analysis showed that overweight/obese and those with comorbidities had more lipid improvement. A longer trial duration did result in further improvements. However, our results may be prone to bias due to extraneous confounding factors. Additionally, levels of heterogeneity were considerable for some outcomes of interest. Results from this meta-analysis provide evidence for the health benefits of walnuts on blood lipids. Walnuts possibly reduce the risk of CVD; thus, they can be successfully added to a dietary pattern to enhance health benefits.
-
4.
Moderate alcohol consumption and lipoprotein subfractions: a systematic review of intervention and observational studies.
Wilkens, TL, Tranæs, K, Eriksen, JN, Dragsted, LO
Nutrition reviews. 2022;80(5):1311-1339
-
-
-
Free full text
-
Plain language summary
Moderate consumption of alcohol has been considered as cardioprotective as it may reduce the risk of cardiovascular diseases by improving the lipid profile. This systematic review investigated the effects of regular moderate alcohol consumption of up to 60 g/day on lipoprotein subfraction changes and underlying mechanisms. A total of one hundred and fourteen studies were included in this review. The results showed that up to 60 g/day of alcohol intake increased the high-density lipoprotein (HDL) subfractions. Alcohol also increased the cardioprotective effect by increasing the cholesterol efflux capacity and paraoxonase activity in moderate drinkers. Moderate intake may also positively affect the low-density lipoprotein size. Further robust studies are required to investigate the effects of alcohol consumption on LDL subfractions and apoB lipoproteins in people with chronic diseases. Healthcare professionals can use the results of this research to understand the impact of moderate alcohol intake on HDL subfractions and its association with cardiovascular disease.
Abstract
CONTEXT Moderate alcohol consumption is associated with decreased risk of cardiovascular disease (CVD) and improvement in cardiovascular risk markers, including lipoproteins and lipoprotein subfractions. OBJECTIVE To systematically review the relationship between moderate alcohol intake, lipoprotein subfractions, and related mechanisms. DATA SOURCES Following PRISMA, all human and ex vivo studies with an alcohol intake up to 60 g/d were included from 8 databases. DATA EXTRACTION A total of 17 478 studies were screened, and data were extracted from 37 intervention and 77 observational studies. RESULTS Alcohol intake was positively associated with all HDL subfractions. A few studies found lower levels of small LDLs, increased average LDL particle size, and nonlinear relationships to apolipoprotein B-containing lipoproteins. Cholesterol efflux capacity and paraoxonase activity were consistently increased. Several studies had unclear or high risk of bias, and heterogeneous laboratory methods restricted comparability between studies. CONCLUSIONS Up to 60 g/d alcohol can cause changes in lipoprotein subfractions and related mechanisms that could influence cardiovascular health. SYSTEMATIC REVIEW REGISTRATION PROSPERO registration no. 98955.
-
5.
Effect of Peanut Consumption on Cardiovascular Risk Factors: A Randomized Clinical Trial and Meta-Analysis.
Parilli-Moser, I, Hurtado-Barroso, S, Guasch-Ferré, M, Lamuela-Raventós, RM
Frontiers in nutrition. 2022;9:853378
-
-
-
Free full text
Plain language summary
Peanuts contain bioactive substances that are beneficial for cardiovascular health. This three-arm, parallel-group randomised controlled trial (ARISTOTLE) and meta-analysis evaluated the beneficial effects of high-oleic peanuts and peanut butter in improving cardiometabolic health. Participants in the randomised controlled trial consumed 25 g of skin-roasted peanuts or 32 g of peanut butter, or a control butter made with peanut oil without fibre and polyphenols for six months. The skin-roasted peanuts group showed a reduction in total cholesterol/HDL-cholesterol and LDL-cholesterol/HDL-cholesterol ratios. The meta-analysis was highly heterogeneous in participant ethnicity, health status, peanut intervention dosage and duration. The dosage of peanuts, peanut butter and high oleic peanuts used was between 25 and 200 g/day. The participants were healthy, with metabolic syndrome (MeS), or at risk of MeS. There was a significant increase in body weight among those with or at risk of MeS. In addition, healthy participants showed reduced triglycerides, total cholesterol, and LDL-cholesterol/HDL-cholesterol ratios. Healthcare professionals can use the results of this research to understand the beneficial impact of peanut consumption on the lipid profile. However, further robust studies are required due to the high heterogeneity of the included studies in the meta-analysis.
Abstract
UNLABELLED Although numerous studies have reported the protective effect of nut consumption on cardiovascular risk, evidence for the role of peanuts in maintaining cardiometabolic health is inconclusive. Presented here are the results from the ARISTOTLE study, a parallel randomized controlled trial evaluating the impact of regular peanut intake on anthropometric, biochemical, and clinical measurements. The 63 healthy subjects that completed the study consumed their habitual diet plus either: a) 25 g/day of skin roasted peanuts (SRP, n = 21), b) two tablespoons (32 g)/day of peanut butter (PB, n = 23) or c) two tablespoons (32 g)/day of a control butter based on peanut oil (CB, n = 19) for 6 months. In addition, a meta-analysis of clinical trials, including data from the ARISTOTLE study, was carried out to update the evidence for the effects of consuming peanuts, including high-oleic peanuts, and peanut butter on healthy subjects and those at high cardiometabolic risk. After a systematic search on PubMed, Web of Science, Cochrane Library and Scopus databases up to July 2021, 11 studies were found to meet the eligibility criteria. In the ARISTOTLE study, lower total cholesterol/HDL-cholesterol and LDL-cholesterol/HDL-cholesterol ratios were found in the SRP group compared to the CB group (p = 0.019 and p = 0.008). The meta-analysis of clinical trials revealed that peanut consumption is associated with a decrease in triglycerides (MD: -0.13; 95% CI, -0.20 to -0.07; p < 0.0001) and that healthy consumers had lower total cholesterol and LDL-cholesterol/HDL-cholesterol ratios compared to the control groups (MD: -0.40; 95% CI, -0.71 to -0.09; p = 0.01 and MD: -0.19; 95% CI, -0.36 to -0.01; p = 0.03, respectively). However, individuals at high cardiometabolic risk experienced an increase in body weight after the peanut interventions (MD: 0.97; 95% CI, 0.54 to 1.41; p < 0.0001), although not in body fat or body mass index. According to the dose-response analyses, body weight increased slightly with higher doses of peanuts. In conclusion, a regular consumption of peanuts seems to modulate lipid metabolism, reducing triglyceride blood levels. SYSTEMATIC REVIEW REGISTRATION https://osf.io/jx34y/, identifier: 10.17605/OSF.IO/MK35Y.
-
6.
Effects of tart cherry juice consumption on cardio-metabolic risk factors: A systematic review and meta-analysis of randomized-controlled trials.
Moosavian, SP, Maharat, M, Chambari, M, Moradi, F, Rahimlou, M
Complementary therapies in medicine. 2022;71:102883
-
-
-
Free full text
Plain language summary
Cardiovascular disease (CVD) is a general term for disorders affecting the heart and blood vessels and is the number one cause of death world-wide. CVD risk factors include high blood pressure, high cholesterol, obesity, being overweight and diabetes. Tart cherry juice is a rich source of strong antioxidants such as proanthocyanidins, anthocyanins, and flavonols. These compounds have anti-inflammatory properties and are therefore potentially beneficial in CVD. The antioxidant potential of tart cherry juice has been extensively studied, but studies have shown contradictory results relating to the efficacy of tart cherry juice on cardio-metabolic risk factors. To date there is no meta-analysis looking at these effects. 10 RCTs were included and the results showed that cherry juice consumption led to a significant reduction in fasting blood sugar. However, there wasn’t any significant effect of cherry juice consumption on blood pressure, insulin, lipid profile levels, fat mass, and BMI. Further clinical trials using higher sample sizes are needed. The clinical importance of this study was that clinicians and nutritionists can recommend the consumption of tart cherry for the prevention and management of CVD related symptoms.
Abstract
BACKGROUND Tart cherries are rich in bioactive compounds, such as anthocyanins and other phytochemicals known to have antioxidant properties and exert cardiovascular protective effects. However, there is no definitive consensus on this context. The present systematic review and meta-analysis aimed to investigate the effect of tart cherry juice consumption on cardio-metabolic risk factors. METHODS A systematic search was conducted on electronic databases, including PubMed, Web of Science, Scopus, and Google Scholar from inception up to December 2021 to identify eligible RCT studies. A random-effect model was utilized to estimate the weighted mean difference (WMD) and 95% confidence (95% CI). RESULTS Ten RCTs were included in the present meta-analysis. The pooled analysis revealed that tart cherry juice consumption led to a significant reduction in the fasting blood sugar (FBS) levels (WMD = -0.51 mg/dl [95% CI: -0.98, -0.06]). This lowering effect of FBS was robust in subgroups with cross-over studies, participants with age range ≥ 40, duration of follow-up ≤ 4 weeks, and baseline BMI ≥ 30. In contrast, tart cherry juice had no effect on total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), insulin, body mass index (BMI), fat mass, systolic and diastolic blood pressure. However, in the subgroup analysis, some significant effects were observed for insulin, TG, TC, LDL-C, and HDL-C. CONCLUSION In summary, this meta-analysis showed that tart cherry juice mostly had a favorable effect on FBG levels. However, further RCTs with long-term intervention with different doses of administration are needed.
-
7.
Effects of Oat Beta-Glucan Intake on Lipid Profiles in Hypercholesterolemic Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
Yu, J, Xia, J, Yang, C, Pan, D, Xu, D, Sun, G, Xia, H
Nutrients. 2022;14(10)
-
-
-
-
Free full text
Plain language summary
Dyslipidaemia is one of the risk factors associated with cardiovascular disease. Beta-glucan is a viscous soluble fibre found in microalgae, fungi and grains like oats, barley, sorghum etc. This systematic review and meta-analysis included thirteen randomised controlled trials to evaluate the effectiveness of oat beta-glucans on the lipid profiles of patients with hypercholesterolemia. This research showed a significant reduction in total cholesterol and low-density lipoprotein levels in hypercholesterolemic adults after beta-glucan intake. However, beta-glucans did not impact triglyceride and high-density lipoprotein cholesterol. Beta-glucan's effect on lipid profiles depended on the severity of hypercholesterolemia, the duration of the intervention, the source of beta-glucan, and the dosage of beta-glucan. Healthcare professionals can use the results of this study to understand the lipid profile-improving effects of beta-glucans in adults with moderate hypercholesterolemia. However, further robust studies are required to evaluate the effects of beta-glucan on lipid profiles and how the effect is affected by gender differences.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Consumption of oat beta glucans may be beneficial for improving total cholesterol and LDL-c in people with mild and moderate hypercholesterolemia
- The U.S Food and Drug Administration (FDA) recommends 3g or more of oat beta glucans per day to reap the benefits. This could be from 90g of oats (3 x 30g portions) or 1 30g portion of oats, 3 oatcakes and 1-2 tbsp of oat bran.
Evidence Category:
-
X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
-
B: Systematic reviews including RCTs of limited number
-
C: Non-randomized trials, observational studies, narrative reviews
-
D: Case-reports, evidence-based clinical findings
-
E: Opinion piece, other
Summary Review:
Authors highlight that Hypercholesterolemia is a risk factor for cardiovascular disease and a symptom of Metabolic Syndrome. Hypercholesterolemia commonly includes; elevated levels of total cholesterol and low-density lipoprotein cholesterol (LDL-c) and lower levels of high-density lipoprotein cholesterol (HDL-c).
Conventional medical treatment for hypercholesterolemia is statins, however, statins can have a number of adverse side effects. For this reason, dietary interventions have been investigated including the use of oat beta-glucans for their potential lipid lowering effects.
The aim of this systematic review and meta-analysis was to synthesise and evaluate the evidence for the effects of oat beta-glucans on serum cholesterol and triglyceride (TG) levels in adults with hypercholesterolemia.
Thirteen randomised controlled trials (RCTs) published between 1999 – 2021 met the study inclusion criteria. These studies included a total population of 927 people aged between 38-76 years and from 7 different countries worldwide. The majority of participants were diagnosed with mild hypercholesterolemia.
Participants were randomised into an intervention group receiving dietary sources of oat beta-glucans or food with added oat beta-glucans or a placebo control group consisting of diets without beta-glucans.
Study lengths ranged from 3 to 8 weeks with doses of oat beta-glucans between 1.5g to 6g. The studies were also broken down into sub-groups for high and low doses of oat beta-glucan and mild and moderate hypercholesterolemia.
Baseline and endpoint cholesterol (total cholesterol C, HD-c & LDL-c) and triglycerides were used to assess the effectiveness of the interventions and a weighted mean difference (WMD) calculated with a 95% confidence interval (CI).
Key Findings:
- a reduction in total cholesterol (WMD = -0.24mmol/L; 95% CI)
- a reduction in LDL-c (WMD = -0.27mmol/L; 95% CI )
- Sub-groups found that oat beta-glucans reduced serum TG levels in patients with moderate hypercholesterolemia (WMD = -0.11 mmol/L; 95% CI) but not in cases of mild hypercholesterolemia. (WMD = -0.01 mmol/L; 95% CI)
- Higher daily doses of oat beta glucans had more positive effects on TG levels, however the results were not statistically significant in this meta-analysis
- <3g WMD -0.11 mmol/L; 95% CI: -0.13 to -0.08 mmol/L
- >3g WMD -0.00 mmol/L; 95% CI: -0.16 to -0.16 mmol/L
- Greater reductions in HDL -c were found in patients with moderate hypercholesterolemia (WMD-0.06 mmol/L; 95% CI; -0.07 to -0.05 mmol/L) compared to mild cases (WMD-0.01 mmol/L; 95% CI; -0.08 to -0.10 mmol/L).
Conclusion
Dietary intake of oat beta-glucans may support the reduction of total cholesterol and low density lipoprotein cholesterol, however, no significant changes were found for high density lipoprotein cholesterol or serum triglycerides. Due to the heterogeneity between studies and inconsistencies in results, more trials are needed with larger sample sizes and longer durations.
Notes: The authors reported no conflicts of interest.
Clinical practice applications:
Based on the pooled results of this meta-analysis:
- 1.5g -6g of dietary intake of oat beta-glucans could support a reduction of TC and LDL-c in cases of mild and moderate hypercholesterolemia
- Intake of oat beta glucans >3g may reduce TG levels
- HDl -c may be improved with oat beta glucan intake of between 1.5g to 6g for clients with moderate hypercholesterolemia.
Considerations for future research:
The findings of 8 of the 13 RCTs indicated that when compared to the control group, LDL-c could be lowered by oat beta-glucans whilst the other 5 trials did not. However, the cumulative results of this meta analysis found a reduction in LDL-c.
There were also several limitations to this study:
- Heterogeneity between studies and inconsistent results
- Short study duration
- Small populations and limited sample size
- The results varied for different levels of hypercholesterolemia
- Results may also differ by sex and source of oat beta glucans
Larger and longer trials are therefore needed to confirm the results.
Abstract
(1) Background: hyperlipidemia is one of the cardiovascular diseases which becomes a great threat to the health of people worldwide. Oat beta-glucan is reported to have a beneficial effect on lowering blood lipids. To probe the effect of oat beta-glucan consumption on serum lipid profiles (total cholesterol, total triglyceride, high-density lipoprotein-cholesterol, and low-density lipoprotein-cholesterol), we carried out a systematic search on randomized controlled trials of oat beta-glucan intervention on hypercholesterolemic individuals. (2) Methods: the pieces of literature were obtained from PubMed, Scopus, Cochrane Library, Web of Science, and the Embase from inception to 28 February 2022. The results were presented with the weighted mean difference (WMD) with a 95% CI. The random-effects or fixed-effects model was applied according to the heterogeneity. The subgroup analysis and meta-regression were used to identify the source of heterogeneity. (3) Results: thirteen trials with 927 participants were included in our meta-analysis. Overall, oat beta-glucan supplementation significantly reduced levels of TC (pooled WMD = -0.24 mmol/L; 95%CI: -0.28 to -0.20 mmol/L), LDL-c (pooled WMD = -0.27 mmol/L; 95%CI: -0.35 to -0.20 mmol/L). Furthermore, beta-glucan consumption did not show significant effects on TG (pooled WMD = -0.04 mmol/L; 95%CI: -0.13 to 0.05 mmol/L), HDL-c (pooled WMD = 0.00 mmol/L; 95%CI: -0.05 to 0.05 mmol/L). Subgroup analysis indicated that critical factors, such as disease severity of participants, the daily intervention of oat beta-glucan, source of oat beta-glucan, and duration of intervention had impacts on outcomes. (4) Conclusions: oat beta-glucan intake may significantly decrease the level of TC and LDL-c while no significant changes in TG and HDL-c were observed. This meta-analysis supports the health benefits of oat beta-glucan, especially for its cholesterol-lowering features, although it has some inevitable limitations.
-
8.
Effects of lifestyle interventions on cardiovascular risk factors in South Asians: a systematic review and meta-analysis.
Limbachia, J, Ajmeri, M, Keating, BJ, de Souza, RJ, Anand, SS
BMJ open. 2022;12(12):e059666
-
-
-
Free full text
Plain language summary
The prevalence of cardiovascular disease (CVD) and associated mortality risk is high in the South Asian population in western countries. Regular physical activity and a healthy diet may modify the risk factors of CVD, such as abdominal fat, high cholesterol, and blood sugar irregularities. This systematic review and meta-analysis included thirty-five randomised controlled trials to evaluate the effectiveness of diet, physical activity interventions or a combination of diet and physical activity interventions on CVD risk factors and compared it against usual care. Combining diet and physical activity interventions reduced CVD risk factors such as systolic and diastolic blood pressure, BMI, weight, waist circumference and fasting plasma glucose (FPG). Dietary interventions reduced diastolic blood pressure, triglycerides, low-density lipoprotein cholesterol, BMI, weight and FPG. Physical activity modifications improved diastolic and systolic blood pressure and high-density lipoprotein cholesterol. Healthcare professionals can use the study results to understand how tailored diet and physical activity modifications improve the CVD risk factors in South Asians. However, further robust studies are required as most of these evidences were of moderate quality and lacked clinical significance.
Abstract
BACKGROUND The cardiovascular disease (CVD) burden among South Asians is high. Lifestyle interventions have been effective in the primary prevention of CVD, but this has not been replicated, through a synthesis of randomised trials, in South Asians. METHODS Four electronic databases (MEDLINE, Embase, CENTRAL and CINAHL), two clinical trial registries and references of included articles were searched through June 2022 (featuring ≥90% South Asian participants). Random-effects pairwise meta-analyses were performed, and heterogeneity was quantified with the I2 statistic. The Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) framework was used to report on the quality of evidence (International Prospective Register of Systematic Reviews registration (PROSPERO). RESULTS Thirty-five studies were included. Twelve tested diet and physical activity interventions; 18 tested diet alone; and 5 tested physical activity alone. All reported effects of the intervention(s) on at least one established risk factor for CVD, including blood pressure (systolic blood pressure (SBP), diastolic blood pressure (DBP) and blood lipids (high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol (LDLc) or triglycerides). No trials reported clinical CVD. There is moderate-quality evidence that diet and physical activity interventions improve SBP (mean difference (MD) -2.72 mm Hg, 95% CI -4.11 to -1.33) and DBP (MD -1.53 mm Hg, 95% CI -2.57 to -0.48); high-quality to moderate-quality evidence that diet-only interventions improve DBP (MD -2.05 mm Hg, 95% CI -2.93 to -1.16) and blood lipids (triglycerides (MD -0.10 mmol/L, 95% CI -0.14 to -0.06) and LDLc (MD -0.19 mmol/L, 95% CI -0.32 to -0.06)); and moderate-quality evidence that physical activity-only interventions improve SBP (MD -9.7 mm Hg, 95% CI -11.05 to -8.35), DBP (MD -7.29 mm Hg, 95% CI -8.42 to -6.16) and HDLc (MD 0.08 mmol/L, 95% CI 0.04 to 0.11) compared with usual care. CONCLUSIONS Lifestyle interventions improve blood pressure and blood lipid profiles in adult South Asians at risk of CVD. Tailored interventions should be used to modify cardiovascular risk factors in this at-risk group. PROSPERO REGISTRATION NUMBER CRD42018090419.
-
9.
The Effects of Sesamin Supplementation on Obesity, Blood Pressure, and Lipid Profile: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
Sun, Y, Ren, J, Zhu, S, Zhang, Z, Guo, Z, An, J, Yin, B, Ma, Y
Frontiers in endocrinology. 2022;13:842152
-
-
-
Free full text
Plain language summary
Cardiovascular disease is characterised by modifiable risk factors such as hypertension, elevated cholesterol and obesity. Sesamin, a lignin found in sesame seeds, is suggested to have anti-obesity, antihypertensive, and cholesterol-lowering properties. Therefore, this systematic review and meta-analysis investigated the effectiveness of sesamin as an adjuvant therapy for cardiovascular disease. A total of seven randomised controlled trials are included in this systematic review and meta-analysis. Four studies used 200 mg/day sesamin dosage, and intervention duration ranged from twenty-eight to sixty days. This systematic review and meta-analysis showed improvements in total cholesterol, low-density lipoprotein cholesterol and systolic blood pressure. However, the improvements depended on the duration of sesamin intervention, study design and health status. Further robust studies are required to evaluate the benefits of sesamin in improving cardiovascular disease risk factors due to the high heterogeneity of the included studies in sesamin dosage, participant characteristics and study design. However, healthcare professionals can use the results of this study to understand the potential of sesamin to act as a safe, healthy, and sustainable adjuvant therapy in modifying cardiovascular disease risk factors.
Abstract
AIMS: Sesamin, the main lignin constituent of sesame, plays a pivotal role in regulating physical state. Some studies have evidenced that the supplementation of sesamin may decrease cardiovascular disease risk. The goal of this systematic review was to summarize evidence of the effects of sesamin supplementation on obesity, blood pressure, and lipid profile in humans by performing a meta-analysis of randomized controlled trials. DATA SYNTHESIS Five databases (PubMed, Cochrane Library, EMBASE, Web of Science, and Scopus) were searched electronically from inception to July 2021 to identify randomized controlled trials that assessed the impact of sesamin on obesity, blood pressure, and lipid profile. Weighted mean difference (WMD) and standard deviation (SD) were used to present the major outcomes. CONCLUSIONS Seven trials (n = 212 participants) were included in the overall analysis. Results showed that sesamin supplementation caused a great reduction in TC (WMD: -10.893 mg/dl, 95% CI: -19.745 to -2.041, p = 0.016), LDL-c (WMD: -8.429 mg/dl, 95% CI: -16.086 to -0.771, p = 0.031), and SBP (WMD: -3.662 mmHg, 95% CI: -6.220 to -1.105, p = 0.005), whereas it had no effect on HDL-c, TG, DBP, or weight. Subgroup analysis showed that duration, parallel design, and unhealthy status can affect TC, LDL-c, and SBP evidently. We did not discover a strong link between indicators' changes and duration of supplementation. Sesamin can be used as an obtainable dietary supplement to improve blood pressure and blood lipids, and further as a health product to prevent cardiovascular diseases.
-
10.
The effects of saffron supplementation on cardiovascular risk factors in adults: A systematic review and dose-response meta-analysis.
Zamani, M, Zarei, M, Nikbaf-Shandiz, M, Gholami, F, Hosseini, AM, Nadery, M, Shiraseb, F, Asbaghi, O
Frontiers in nutrition. 2022;9:1055517
-
-
-
Free full text
Plain language summary
Cardiovascular disease (CVD) is a leading cause of death and disability around the world and presents a significant burden for healthcare systems. CVD has many risk factors, including diet and lifestyle habits. Hence, favourable interventions in those areas can help prevent and manage CVD. This systematic review examined the effects of saffron crocus on cardiovascular risk factors. Saffron is derived from the flowering plant Saffron Crocus (Crocus sativus). It contains many active compounds such as crocetin, crocin, picrocrocin, and safrana, which in various studies demonstrated positive effects on blood glucose levels, insulin resistance and sensitivity and blood fats, besides also having antioxidant and anti-inflammatory qualities. Yet, results were not always consistent, and hence this meta-analysis gathered evidence from 32 randomised controlled trials (RCTs) which included a total of 1674 subjects and investigated the effect of saffron supplements on cardiovascular risk factors such as blood fats, blood glucose control, blood pressure, anthropometric measures, and inflammatory markers. In conclusion, the analysis showed that saffron supplementation aided the reduction of some inflammatory markers (CRP, TNF-α), had favourable effects on antioxidant capacity, reduced blood fats except high-density lipoprotein (HDL), enhanced blood control and insulin sensitivity, reduced blood pressure and was linked to a reduction in waist circumference but with no significant effect on weight itself, BMI or fat mass. The authors discussed how their results relate to previous research and what underlying mechanisms can explain the effects or discrepancies. Given the positive results, saffron presents itself as a promising supplement and adjunct therapy for managing CVD and its risk factors.
Abstract
INTRODUCTION Cardiovascular disease (CVD) is one of the leading causes of death and disability in the world and is estimated to involve more people in the next years. It is said that alternative remedies such as herbs can be used to manage the complications of this disease. For this reason, we aimed to conduct this meta-analysis to systematically assess and summarize the effects of saffron supplementation as an important herb on cardiovascular risk factors in adults. METHODS A systematic search was done in PubMed, Scopus, and Web of Science to find eligible articles up to September 2022. Randomized controlled trials (RCTs) that evaluated the effects of saffron on lipid profiles, glycemic control, blood pressure, anthropometric measures, and inflammatory markers were included. In the meta-analysis, 32 studies were taken into account (n = 1674). RESULTS Consumption of saffron significantly decreased triglyceride (TG) (WMD = -8.81 mg/dl, 95%CI: -14.33, -3.28; P = 0.002), total cholesterol (TC) (WMD = -6.87 mg/dl, 95%CI: -11.19, -2.56; P = 0.002), low density lipoprotein (LDL) (WMD = -6.71 mg/dl, 95%CI: -10.51, -2.91; P = 0.001), (P = 0.660), fasting blood glucose (FBG) level (WMD = -7.59 mg/dl, 95%CI: -11.88, -3.30; P = 0.001), HbA1c (WMD = -0.18%, 95%CI: -0.21, -0.07; P < 0.001), homeostasis model assessment-insulin resistance (HOMA-IR) (WMD = -0.49, 95%CI: -0.89, -0.09; P = 0.016), systolic blood pressure (SBP) (WMD = -3.42 mmHg, 95%CI: -5.80, -1.04; P = 0.005), tumor necrosis factor α (TNF-α) (WMD = -2.54 pg/ml, 95%CI: -4.43, -0.65; P = 0.008), waist circumference (WC) (WMD = -1.50 cm; 95%CI: -2.83, -0.18; P = 0.026), malondialdehyde (MDA) (WMD = -1.50 uM/L, 95%CI: -2.42, -0.57; P = 0.001), and alanine transferase (ALT) (WMD = -2.16 U/L, 95%CI: -4.10, -0.23; P = 0.028). Also, we observed that saffron had an increasing effect on total antioxidant capacity (TAC) (WMD = 0.07 mM/L, 95%CI: 0.01, 0.13; P = 0.032). There was linear regression between FBG and the duration of saffron intake. Additionally, the non-linear dose-response analysis has shown a significant association of saffron intervention with HDL (P = 0.049), HOMA-IR (P = 0.002), weight (P = 0.036), ALP (P = 0.016), FBG (P = 0.011), HbA1c (P = 0.002), and TNF-α (P = 0.042). A non-linear association between the length of the intervention and the level of HDL and DBP was also found. DISCUSSION That seems saffron could effectively improve TG, TC, LDL, FBG, HbA1c, HOMA-IR, SBP, CRP, TNF-α, WC, MDA, TAC, and ALT.