Nutritional advice

Objectives:
Clinical trials examining the cardiovascular protective effects of quercetin in humans have reported conflicting results. Therefore, this review article has been conducted.

Do quercetin supplements reduce plasma lipid levels and blood pressure?

Study design:
This review article included 17 RCTs with a total of 896 participants.

Results and conclusions:
The investigators found pooled results showed that quercetin supplements significantly lowered both systolic blood pressure [WMD = -3.09 mmHg, 95% CI = -4.59 to -1.59, p = 0.0001] and diastolic blood pressure [WMD = -2.86 mmHg, 95% CI = -5.09 to -0.63, p = 0.01].
Neither lipid profiles nor glucose concentrations changed significantly.

The investigators found in subgroup analyses, significant changes in high-density lipoprotein (HDL or good) cholesterol and triglycerides were observed in trials with a parallel design and in which participants consumed quercetin for 8 weeks or more.

The investigators concluded quercetin supplements decrease blood pressure in humans. Moreover, participants who consume quercetin for 8 weeks or more show significantly changed levels of high-density lipoprotein cholesterol (good cholesterol) and triglycerides in trials with a parallel design.  

Original title:
Effect of quercetin supplementation on plasma lipid profiles, blood pressure, and glucose levels: a systematic review and meta-analysis by Huang H, Liao D, [...], Pu R.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31940027

Additional information of El Mondo:
Find more information/studies on lowering of cholesterol level and blood pressure and cardiovascular disease right here.

Objectives:
Data from in vitro and animal studies support the preventive effect of tea (Camellia sinensis) against colorectal cancer. Further, many epidemiologic studies evaluated the association between tea consumption and colorectal cancer risk, but the results were inconsistent. Therefore, this review article has been conducted.

Does tea consumption reduce colorectal cancer risk?

Study design:
This review article included 20 cohort studies with 2,068,137 participants and 21,437 colorectal cancer cases.

Results and conclusions:
The investigators found that tea consumption had no significant association with colorectal cancer risk for the highest vs. lowest categories [combined RR = 0.97, 95% CI = 0.94-1.01, I2 = 24.0%, p = 0.093] among all studies.

The investigators found stratified analysis showed no significant differences in all subgroups.

The investigators found no significant association between tea consumption and colorectal cancer risk in male [combined RR = 0.97, 95% CI = 0.90-1.04].

The investigators found, however, tea consumption had a marginal significant inverse impact on colorectal cancer risk in female [combined RR = 0.93, 95% CI = 0.86-1.00].

The investigators found a significantly reduced risk of 10% for colorectal cancer for tea consumption among the female studies with no adjustment of coffee intake [RR = 0.90, 95% CI = 0.82-1.00, p  0.05].
However, this reduced risk was not significant among the female studies that adjusted for coffee intake [RR = 0.97, 95% CI = 0.87-1.09, p > 0.05].

The investigators concluded that tea consumption may reduce colorectal cancer risk in female. May reduced because this reduced risk was not significant among the female studies that adjusted for coffee intake.

Original title:
Tea consumption and colorectal cancer risk: a meta-analysis of prospective cohort studies by Zhu MZ, Lu DM, […], Liu ZH.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32078065

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Objectives:
There are differences among the outcomes regarding cognitive impairment in heart failure (HF) because the evidence is fragmented and sample size is small. Therefore, this review article has been conducted.

Does heart failure increase risk of dementia?

Study design:
This review article included 12 studies with 2,406,680 heart failure patients.

Begg test, Egger tests and funnel plots showed no significant risks of publication bias.

Results and conclusions:
The investigators found heart failure significantly increased risk of all-cause dementia with 28% [OR/RR  =  1.28, 95% CI = 1.15 to 1.43, I2 = 70.0%, p    0.001].
Sensitivity analysis showed no changes in the direction of effect when any one study was excluded for the studies on associations between heart failure and all-cause dementia.

The investigators found no significant association between heart failure and risk of Alzheimer's disease [OR/RR  =  1.38, 95% CI = 0.90 to 2.13, I 2 =  74.8%, p =  0.008].
Sensitivity analysis showed no changes in the direction of effect when any one study was excluded for the studies on associations between heart failure and Alzheimer's disease.

The investigators concluded heart failure increases risk of all-cause dementia. In addition, large scale prospective studies are essential to explore the associations between heart failure and risk of Alzheimer's disease.

Original title:
Associations between heart failure and risk of dementia: A PRISMA-compliant meta-analysis by Li J, Wu Y, [...], Nie J.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7004760/

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Objectives:
The benefits of LDL cholesterol-lowering treatment for the prevention of atherosclerotic cardiovascular disease are well established. However, the extent to which these effects differ by baseline LDL cholesterol, atherosclerotic cardiovascular disease risk and the presence of comorbidities remains uncertain. Therefore, this review article has been conducted.

Does LDL cholesterol-lowering treatment reduce risk of major vascular events (a composite of cardiovascular mortality, non-fatal myocardial infarction, non-fatal ischaemic stroke or coronary revascularisation)?

Study design:
This review article included 52 RCTs with a total of 327,037 patients.

Results and conclusions:
The investigators found each 1 mmol/L reduction in LDL cholesterol (bad cholesterol) was associated with a 19% relative risk (RR) reduction for major vascular events [RR = 0.81, 95% CI = 0.78 to 0.84,  p 0.0001].

The investigators found similar reductions (per 1 mmol/L reduction in LDL cholesterol) in trials with participants with LDL cholesterol level of 2.60 mmol/L or lower, 2.61-3.40 mmol/L, 3.41-4.10 mmol/L and more than 4.1 mmol/L [p = 0.232 for interaction] and in a subgroup of patients who all had a baseline LDL cholesterol level less than 2.07 mmol/L [80 mg/dL: RR = 0.83, 95% CI = 0.75-0.92, p = 0.001].

The investigators found greater RR reductions in patients at lower 10-year atherosclerotic cardiovascular disease risk [change in RR per 10% lower 10-year atherosclerotic cardiovascular disease = 0.97, 95% CI = 0.95 to 0.98, p 0.0001] and in patients at younger age across a mean age of 50-75 years [change in RR per 10 years younger age = 0.92, 95% CI = 0.83 to 0.97, p = 0.015].

The investigators found no difference in RR reduction for participants with or without diabetes [p = 0.878 for interaction] and chronic kidney disease [p = 0.934 for interaction].

The investigators concluded for each 1 mmol/L LDL cholesterol lowering, the risk reduction of major vascular events is independent of the starting LDL cholesterol or the presence of diabetes or chronic kidney disease. Patients at lower cardiovascular risk and younger age might have a similar relative reduction in risk with LDL-cholesterol lowering therapies and future studies should investigate the potential benefits of earlier intervention.

Original title:
Intensive LDL cholesterol-lowering treatment beyond current recommendations for the prevention of major vascular events: a systematic review and meta-analysis of randomised trials including 327 037 participants by Wang N, Fulcher J, […], Lal S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31862150

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Find more information/studies on lowering of cholesterol level and cardiovascular disease right here.

Objectives:
Evidence has shown that essential nutrients are highly correlated with the occurrence of esophageal cancer (EC). However, findings from observational studies on the associations between dietary carbohydrate, salt consumption and the risk of esophageal cancer remain controversial. Therefore, this review article has been conducted.

Does carbohydrate or salt consumption (dietary salt intake) increase risk of esophageal cancer?

Study design:
This review article included 11 case-control studies and 1 cohort study, examined carbohydrates consumption and 16 case-control studies and 2 cohort studies, examined salt consumption.

Results and conclusions:
The investigators found dietary carbohydrate intake significantly reduced risk of esophageal cancer with 38% [pooled OR = 0.62, 95% CI = 0.50-0.77].

The investigators found dietary salt intake significantly increased risk of esophageal cancer with 97% [OR = 1.97, 95% CI = 1.50-2.61] in case-control studies.

The investigators found dietary salt intake significantly increased risk of esophageal cancer with 4% [RR = 1.04, 95% CI = 1.00-1.08] in cohort studies.

The investigators concluded dietary salt intake increases risk of esophageal cancer.

Original title:
Associations of dietary carbohydrate and salt consumption with esophageal cancer risk: a systematic review and meta-analysis of observational studies by Banda KJ, Chiu HY, [...], Huang HC.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31995192

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Find more information/studies on carbohydrate, salt and cancer right here.

According to WHO, a high salt intake is a salt intake of more than 5 grams salt per day.

A diet with more than 5 grams salt per day is a diet with mainly products/meals with more than 0.25 grams salt per 100 kcal. Check here which products contain maximum 5 grams salt per 100 kcal.
Use the 7-points nutritional profile app to see whether your daily diet contains maximum 5 grams salt per 100 kcal.

 

Objectives:
Genistein (4',5,7-trihydroxyisoflavone) is a phytoestrogen with potential health benefits in the prevention of cardiovascular disease. However, the evidence regarding its effects on hypertension has not been conclusive. Therefore, this review article has been conducted.

Do genistein supplements reduce blood pressure?

Study design:
This review article included 4 RCTs (4 treatment arms).

Results and conclusions:
The investigators found genistein supplements did not show any significant reduction of systolic blood pressure [WMD = -5.32 mmHg, 95% CI = -14.59 to 3.96] and diastolic blood pressure [WMD = -2.06 mmHg, 95% CI = -6.41 to 2.28] compared to that of the placebo group.

The investigators found, however, subgroup analysis by intervention duration showed that more than 6 months genistein supplementation in metabolic syndrome patients significantly decreased systolic blood pressure [WMD = -13.73 mmHg, 95% CI = -18.10 to -9.37] and diastolic blood pressure [WMD = -5.18 mmHg, 95% CI = -6.62 to -3.74].

The investigators concluded genistein supplementation of more than 6 months reduces blood pressure among metabolic syndrome patients.

Original title:
Effects of genistein on blood pressure: A systematic review and meta-analysis by Hemati N, Asis M, […], Abdollahi M.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31955737

Additional information of El Mondo:
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Objectives:
Low-carbohydrate diets are associated with cardiovascular risk factors; however, the results of different studies are inconsistent. Therefore, this review article has been conducted.

Do low-carbohydrate diets (diets with less than 40 En% carbohydrates) reduce cardiovascular risk factors?

Study design:
This review article included 12 RCTs with a total of 820 in the observation group (intervention group or low carbohydrate group) and 820 in the control group. The largest sample size was 403 cases and the smallest was 42 cases. The patients’ ages ranged from 31 to 65 years old.
The intervention was a diet with less than 40 En% carbohydrates in the observation group and a diet with 45 En% to 55 En% carbohydrates in the control group.

Results and conclusions:
The investigators found compared with the control group, the triglyceride levels of the low-carbohydrate group (less than 40 En% carbohydrates) significantly decreased by 0.15 mmol/L [95% CI = -0.23 to -0.07, I2 = 75%, p = 0.001].
The results remained unchanged in the sensitivity analysis (after subtracting each of the included studies individually).

The results of the publication bias analysis showed that the funnel plot was not symmetric. The asymmetry of the funnel plot may have been caused by publication bias and other issues.

The investigators found in subgroup analyses, low-carbohydrate diet interventions lasting less than 6 months significantly decreased the triglyceride levels by 0.23 mmol/L [95% CI = -0.32 to -0.15] and those of 12-23 months decreased the levels by 0.17 mmol/L [95% CI = -0.32 to -0.01].

The investigators found compared with the control group, the plasma HDL-cholesterol level (good cholesterol) of the low-carbohydrate group significantly increased by 0.1 mmol/L [95% CI = 0.08 to 0.12, I2 = 41%, p = 0.02].
The results remained unchanged in the sensitivity analysis (after subtracting each of the included studies individually).

The investigators found in subgroup analyses, the increase in plasma HDL-cholesterol levels was 0.08 mmol/L [95% CI = 0.27 to 0.57] for interventions lasting less than 6 months, 0.12 mmol/L [95% CI = 0.09 to 0.15] for those lasting 6-11 months, 0.12 mmol/L [95% CI = 0.08 to 0.15] for those lasting 12-23 months and 0.08 mmol/L [95% CI = 0.04 to 0.12] for those lasting 24 months. 

The investigators found compared with the control group, the serum total cholesterol level of the low-carbohydrate group significantly increased by 0.13 mmol/L [95% CI = 0.08 to 0.19].
The results remained unchanged in the sensitivity analysis (after subtracting each of the included studies individually).

The investigators found compared with the control group, the plasma LDL-cholesterol level (bad cholesterol) of the low-carbohydrate group significantly increased by 0.11 mmol/L [95% CI = 0.02 to 0.19, I2 = 71%, p = 0.0001].
The results remained unchanged in the sensitivity analysis (after subtracting each of the included studies individually).

The investigators found compared with the control group, the body weight of the low-carbohydrate group significantly decreased by 1.58 kg [95% CI = -1.58 to -0.75, I2 = 49%, p = 0.01].
The results remained unchanged in the sensitivity analysis (after subtracting each of the included studies individually).

The investigators found in subgroup analyses, the decrease in body weight was 1.14 kg [95% CI = -1.65 to -0.63] for interventions lasting less than 6 months and 1.73 kg [95% CI = -2.7 to -0.76] for those lasting 6-11 months.

The investigators found compared with the control group, the overall systolic blood pressure of the low-carbohydrate group significantly decreased by 1.41 mmHg [95% CI = -2.26 to -0.56, I2 = 0%, p = 0.84].
The results remained unchanged in the sensitivity analysis (after subtracting each of the included studies individually).

The investigators found in subgroup analyses, the overall systolic blood pressure significantly decreased by 2.97 mmHg [95% CI = -4.62 to -1.31] in the group that received interventions lasting less than 6 months.

The investigators found compared with the control group, the diastolic blood pressure of the low-carbohydrate group significantly decreased by 1.71 mmHg [95% CI = -2.36 to -1.06, I2 = 14%, p = 0.29].
The results remained unchanged in the sensitivity analysis (after subtracting each of the included studies individually).

The investigators found in subgroup analyses, the diastolic blood pressure significantly decreased by 2.76 mmHg [95% CI = -4.07 to -1.46] in the group that received interventions lasting less than 6 months and 2.11 mmHg [95% CI = -3.28 to -0.93] for those lasting 6-11 months.

The investigators concluded low-carbohydrate diets (diets less than 40 En% carbohydrates) have beneficial effects on cardiovascular risk factors at less than 6 months and 6-11 months, but after 2 years of a low-carbohydrate diet, there is no significant effect on cardiovascular risk factors.

Original title:
The effects of low-carbohydrate diets on cardiovascular risk factors: A meta-analysis by Dong T, Guo M, [...], Chen B.

Link:
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0225348

Additional information of El Mondo:
Find more information/studies on carbohydrate consumption and cardiovascular diseases right here.

40 En% carbohydrates means that the total amounts of carbohydrate make up for a 40% of the total kcal of the diet. The easiest way to follow this diet is to choose only meals/products that also contain 40 En% carbohydrates. These products in the supermarket contain 40 En% carbohydrates.

Objectives:
The relationship between serum copper (Cu) level and overweight/obesity remains controversial. Therefore, this review article (meta-analysis) has been conducted.

Does a high serum copper level increase overweight/obesity risk?

Study design:
This review article included 21 articles.

Results and conclusions:
The investigators found compared with controls, serum copper level was significantly higher in obese children [SMD = 0.74, 95% CI = 0.16 to 1.32] and in obese adults [SMD = 0.39, 95% CI = 0.02 to 0.76].

The investigators found no significant difference in serum copper level between overweight and control groups in children [SMD = 1.52, 95% CI = -0.07 to 3.12] and in adults [SMD = 0.16, 95% CI = -0.06 to 0.38].

The investigators found subgroup analysis revealed a higher serum copper level in obese children [SMD = 0.90, 95% CI = 0.36 to 1.45] and obese adults [SMD = 0.47, 95% CI = 0.05 to 0.88] compared with healthy weight controls.

The investigators found the SMD differed significantly between obese children diagnosed by weight-for-height and controls [SMD = 1.56, 95% CI = 0.57 to 2.55] and there was a significant difference of serum copper level between obese adults diagnosed by BMI (WHO) and controls [SMD = 0.54, 95% CI = 0.08 to 1.01].

The investigators concluded that a higher serum copper level increases risk of obesity in children and adults and these findings need to be further confirmed.

Original title:
The Relationship Between Serum Copper and Overweight/Obesity: a Meta-analysis by Gu K, Li X, […], Jiang X.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31300957

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Objectives:
Does vitamin K reduce risk of cardiovascular disease (CVD) events and mortality?

Study design:
This review article included 21 articles with 222,592 participants.

Results and conclusions:
The investigators found dietary phylloquinone (vitamin K1) intake significantly reduced risk of total cardiovascular disease with 8% [pooled HR = 0.92, 95% CI = 0.84 to 0.99, I2 = 0%, 4 studies].
Significant means that there is an association with a 95% confidence.

The investigators found dietary menaquinone (vitamin K2) intake significantly reduced risk of total cardiovascular disease with 30% [pooled HR = 0.70, 95% CI = 0.53 to 0.93, I2 = 32.1%, 2 studies].
Significant because HR of 1 was not found in the 95% CI of 0.53 to 0.93. HR of 1 means no risk/association.

The investigators found no significant association between dietary vitamin K and all-cause mortality, cardiovascular disease mortality or stroke.

The investigators found elevated plasma desphospho-uncarboxylated MGP (dp-ucMGP), a marker of vitamin K deficiency, was associated with an increased risk of 84% [HR = 1.84, 95% CI = 1.48 to 2.28, I2 = 16.8%, 5 studies] for all-cause mortality.

The investigators found elevated plasma desphospho-uncarboxylated MGP (dp-ucMGP), a marker of vitamin K deficiency, was associated with an increased risk of 96% [HR = 1.96, 95% CI = 1.47 to 2.61, I2 = 0%, 2 studies] for cardiovascular disease mortality.

The investigators found no significant association between circulating total osteocalcin and all-cause mortality or total cardiovascular disease.

The investigators concluded higher dietary vitamin K consumption reduces risk of cardiovascular disease and higher plasma dp-ucMGP concentration, but not total circulating osteocalcin, increases risk of all-cause and cardiovascular disease mortality. However, causal relations cannot be established because of limited number of available studies and larger prospective studies and randomized clinical trials are needed to validate these findings.  

Original title:
Association of vitamin K with cardiovascular events and all-cause mortality: a systematic review and meta-analysis by Chen HG, Sheng LT, […], Pan A.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31119401

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100 grams of fresh parsley provide 548 micrograms (548 mcg) of vitamin K1 or 4.5 days.
 

Objectives:
Does consumption of fruit or vegetables reduce risk of metabolic syndrome (MetS)?

Study design:
This review article included 9 observational studies (7 cross-sectional studies and 2 cohort studies).

Results and conclusions:
The investigators found in a dose-response analysis of 2 cohort studies and 7 cross-sectional studies, that an increase of 100 g/d in fruit consumption significantly reduced risk of metabolic syndrome with 3% [OR = 0.97, 95% CI = 0.95 to 0.99, I2 = 26.7%], whereas an increase of 100 g/d in vegetable consumption (9 studies) was not associated with a reduction in the metabolic syndrome [OR = 0.98, 95% CI = 0.96 to 1.01, I2 = 54.6%].

The investigators concluded 100 g/d fruit consumption reduces risk of metabolic syndrome. However, prospective studies or randomised clinical trials are needed to identify the effects of fruits by variety on the risk of the metabolic syndrome.

Original title:
Fruit and vegetable consumption and the metabolic syndrome: a systematic review and dose-response meta-analysis by Lee M, Lim M and Kim J.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31514758

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Objectives:
Is there a causal relationship between grape product supplementation and improved lipid profiles in adults?

Study design:
This review article included 48 RCTs.

Results and conclusions:
The investigators found meta-analysis indicated that consumption of grape products significantly reduced the concentration of total cholesterol [MD = -6.196 mg/dL, 95% CI = -9.203 to -3.189], low-density lipoprotein cholesterol (bad cholesterol) [MD = -4.964 mg/dL, 95% CI = -7.594 to -2.334] and triglyceride [MD = -7.641 mg/dL, 95% CI = -12.120 to -3.162].

The investigators found grape product supplementation changed the HDL and LDL in a non-linear fashion based on the dose of polyphenols.

The investigators concluded that grape products have a favorable role in the achievement of a lipid profile target in adults, particularly total cholesterol, low-density lipoprotein cholesterol (bad cholesterol) and triglyceride levels.

Original title:
Effects of grape products on blood lipids: a systematic review and dose-response meta-analysis of randomized controlled trials by Ghaedi E, Moradi S, [...], Mohammadi H.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31517353

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Objectives:
Does green coffee bean extract (GCBE) supplementation reduce blood pressure?

Study design:
This review article included 9 RCTs.

Results and conclusions:
The investigators found a significant reduction in systolic blood pressure (SBP) [WMD = -3.093 mmHg, 95% CI = -3.914 to -2.273, I2 = 0.0%] and diastolic blood pressure (DBP) [WMD = -2.170 mmHg, 95% CI = -2.749 to -1.590, I2 = 46.5%] after green coffee supplementation with low heterogeneity among the studies.

The investigators found in subgroup analysis, a significant reduction in systolic blood pressure and diastolic blood pressure in studies with hypertensive patients, green coffee dosage 400 mg per day and administered for 4 weeks.

The investigators concluded 400 mg coffee bean extract supplementation per day during 4 weeks reduces systolic blood pressure and diastolic blood pressure in hypertensive patients.

Original title:
The effect of green coffee extract supplementation on blood pressure: A systematic review and meta-analysis of randomized controlled trials by Han B, Nazary-Vannani A, […], Kord-Varkaneh H.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31429515

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Objectives:
The lipid distribution in people who are overweight and obese is directly related to metabolic diseases. Quercetin supplementation may be an appropriate approach for reducing the risk factors of metabolic diseases in people who are obese. Therefore, this review article has been conducted.

Does quercetin supplementation reduce risk factors of metabolic diseases in people who are obese?

Study design:
This review article included 5 RCTs.

Results and conclusions:
The investigators found ≥150 mg/day quercetin supplementation during >6 weeks significantly reduced LDL-cholesterol (bad cholesterol) levels in people who are obese [SMD = -0.8, 95% CI = -1.21 to -0.39, p 0.00001].

The investigators concluded ≥150 mg/day quercetin supplementation during >6 weeks reduces LDL-cholesterol levels in people who are obese.

Original title:
Quercetin Actions on Lipid Profiles in Overweight and Obese Individuals: A Systematic Review and Meta-analysis by Guo W, Gong X and Li M.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31465275

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Find more information/studies on quercetin, cholesterol and obesity/overweight right here.

Objectives:
L-carnitine plays a fundamental biological role in the metabolism of lipids and may positively affect blood pressure by decreasing insulin resistance, although the latter remains less clear. Therefore, this review article has been conducted.

Does L-carnitine supplementation reduce blood pressure?

Study design:
This review article included 10 RCTs using a random-effects model to estimate the pooled effect sizes of L-carnitine supplementation on systolic (SBP) and diastolic blood pressure (DBP).

Results were expressed as weighted mean difference (WMD) and 95% confidence intervals (CI).

No evidence of publication bias was observed about the effects of L-carnitine supplementation on systolic blood pressure [p = 0.307] and diastolic blood pressure [p = 0.729], as evidenced by the results of the Egger's test.

Results and conclusions:
The investigators found L-carnitine supplementation decreased diastolic blood pressure [WMD = -1.162 mmHg, 95% CI = -2.020 to -0.303, p = 0.008] without changing systolic blood pressure levels [WMD = -0.085 mmHg, 95% CI = -1.455 to 1.285, p = 0.903].

The investigators found results of subgroup analyses revealed L-carnitine supplementation decreased diastolic blood pressure levels in participants with overweight and obesity [WMD = -1.232 mmHg, 95% CI = -2.297 to -0.167, p = 0.023] and with doses of 2 g/d [WMD = -1.639 mmHg, 95% CI = -3.038 to -0.240, p = 0.022].

The investigators concluded that 2 g/d L-carnitine supplementation decreases diastolic blood pressure in participants with overweight and obesity. However, more research is required to determine the molecular mechanism underlying the relationship between of L-carnitine on blood pressure.

Original title:
Effects of L-carnitine supplementation on blood pressure: a systematic review and meta-analysis of randomized controlled trials by Askarpour M, Hadi A, […], Ghaedi E.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31481697

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Objectives:
Epidemiological investigations evaluating the association of dietary calcium intake with metabolic syndrome (MetS) risk have yielded controversial results. Therefore, this review article has been conducted.

Does dietary calcium intake reduce risk of metabolic syndrome?

Study design:
This review article included a total 15 cross-sectional studies for dietary calcium intake.

Results and conclusions:
The investigators found for the highest versus lowest category of dietary calcium intake, a significantly reduced risk of 20% [combined OR = 0.80, 95% CI = 0.70 to 0.91] for metabolic syndrome.

The investigators found in dose-response analysis, a non-linear relationship between dietary intake of calcium and risk of metabolic syndrome [p non-linearity > 0.001].

The investigators found 280 mg/d dietary calcium intake significantly reduced risk of metabolic syndrome with 13% [OR = 0.87, 95% CI = 0.82 to 0.93].

The investigators concluded 280 mg/d dietary calcium intake may reduce risk of metabolic syndrome. May reduce because this review article only included cross-sectional studies and no cohort studies. Therefore, these findings should need to be further confirmed by larger prospective cohort studies.

Original title:
Dietary calcium intake and the risk of metabolic syndrome: evidence from observational studies by Cheng L, Hu D and Jiang W.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30846011

Additional information of El Mondo:
Find more information/studies on calcium and obesity/overweight right here.

Objectives:
Do dietary intakes or circulating concentration of major dietary antioxidants, like vitamin C, E and beta-carotene reduce risk of total cardiovascular mortality?

Study design:
This review article included a total of 15 prospective cohort studies and 3 prospective evaluations within interventional studies with 320,548 participants and 16,974 deaths from total cardiovascular mortality.

Results and conclusions:
The investigators found compared to the lowest category, the highest category of dietary vitamin C intake significantly reduced risk of total cardiovascular mortality with 21% [relative risk = 0.79, 95% CI = 0.68 to 0.89, I2 = 46%, n = 10].

The investigators found compared to the lowest category, the highest category of circulating concentration of vitamin C significantly reduced risk of total cardiovascular mortality with 40% [relative risk = 0.60, 95% CI = 0.42 to 0.78, I2 = 65%, n = 6].

The investigators found compared to the lowest category, the highest category of circulating concentration of vitamin E (α-tocopherol) significantly reduced risk of total cardiovascular mortality with 18% [relative risk = 0.82, 95% CI = 0.76 to 0.88, I2 = 0%, n = 5].

The investigators found compared to the lowest category, the highest category of circulating concentration of β-carotene significantly reduced risk of total cardiovascular mortality with 32% [relative risks = 0.68, 95% CI = 0.52 to 0.83, I2 = 50%, n = 6].

The investigators found dose-response meta-analyses demonstrated that the circulating biomarkers of antioxidants were more strongly associated with risk of total cardiovascular mortality than dietary intakes.

The investigators concluded that higher dietary vitamin C intakes and higher circulating concentrations of vitamin C, vitamin E and β-carotene are associated with a lower risk of total cardiovascular mortality.

Original title:
Dietary and circulating vitamin C, vitamin E, β-carotene and risk of total cardiovascular mortality: a systematic review and dose-response meta-analysis of prospective observational studies by Jayedi A, Rashidy-Pour A, […], Shab-Bidar S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30630552

Additional information of El Mondo:
Find more information/studies on antioxidants, vitamin C, E, β-carotene and cardiovascular diseases right here.

Circulating concentration of vitamin C in blood can be increased by eating foods that are high in vitamin C and/or taking vitamin C supplements.

Objectives:
Dietary polyphenols, including flavonoids, have been the focus of major recent attentions due to their wide content in a variety of foods commonly consumed and the findings from numerous studies showing evidence of an association with positive outcomes on human health. Therefore, this review article has been conducted.

Does dietary intake of flavonoids (e.g., anthocyanins, isoflavones, flavones, flavonols, flavanones, flavan-3-ols) reduce hypertension?

Study design:
This review article included 15 cross-sectional investigations and 7 prospective cohort studies (1 study reported on 3 prospective cohort studies).
5 prospective cohort studies, comprising 200,256 individuals and 45,732 cases of hypertension were included in the quantitative analysis.

All studies included covariates that may have significantly influenced the endpoint outcome (hypertension), such as age, sex (when not analyzed separately), BMI, education, physical activity and smoking status. However, not all studies adjusted for key dietary factors that might influence risk of hypertension, such as sodium and potassium intake.

There was no publication bias.

Results and conclusions:
The investigators found analysis by extreme quantiles of intake of flavonoid showed a non-significant association with decreased risk of hypertension [risk ratio = 0.96, 95% CI = 0.89 to 1.03, I2 = 74%, p = 0.01].
Non-significant because RR of 1 was found in the 95% CI of 0.89 to 1.03. RR of 1 means no risk/association.

The investigators found taking into consideration individual flavonoid subclasses, dietary intake of anthocyanins was associated with 8% reduction in risk of hypertension, when comparing highest vs. lowest exposure [risk ratio = 0.92, 95% CI = 0.88 to 0.97].
Significant because RR of 1 was not found in the 95% CI of 0.88 to 0.97. RR of 1 means no risk/association.

The investigators concluded dietary intakes of anthocyanins reduce risk of hypertension. However, further studies are needed to elucidate the retrieved association between polyphenol consumption and decreased risk of hypertension and to clarify whether individual subclasses, rather than the total content of polyphenols, may exert beneficial effects on blood pressure.

Original title:
Dietary Polyphenol Intake, Blood Pressure, and Hypertension: A Systematic Review and Meta-Analysis of Observational Studies by Godos J, Vitale M, […], Grosso G.

Link:
https://www.mdpi.com/2076-3921/8/6/152/htm

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Objectives:
Preventing cardiovascular disease (CVD) is the top priority in public health. Hyperlipidemia and hypertension are key contributors to cardiovascular disease which can be easily modified with dietary and lifestyle interventions. Therefore, this review article has been conducted.

Does cashew consumption reduce blood lipids levels (i.e., triglyceride, total cholesterol, HDL cholesterol (good cholesterol) and LDL cholesterol (bad cholesterol) and blood pressure?

Study design:
This review article included 5 RCTs with 246 participants receiving cashew nut (intervention group) and 235 receiving placebo (placebo group).

There was no publication bias.

Results and conclusions:
The investigators found overall analysis showed a statistically significant reducing effect of cashew nut consumption on triglyceride levels [WMD = -14.39, 95% CI = -27.30 to -1.49, I2 = 82%].
Significant means that there is an association with a 95% confidence.

The investigators found overall analysis showed a statistically significant reducing effect of cashew nut consumption on systolic blood pressure [WMD = -1 mm/Hg, 95% CI = -5.12 to -3.01, I2 = 0%].

The investigators found overall analysis showed a statistically significant reducing effect of cashew nut consumption on diastolic blood pressure [WMD = -4.06 mm/Hg, 95% CI = -1.65 to -0.35, I2 = 0%].

The investigators found, however, no statistically significant changes of other cardiovascular risk markers including total cholesterol [WMD = -1.89, 95% CI = -9.17 to 5.39, p = 0.61], LDL cholesterol [WMD = -5.49, 95% CI = -16.76 to 5.78, p = 0.34] and HDL cholesterol [WMD = -0.67, 95% CI = -2.54 to 1.19, p = 0.48] were observed after cashew nut consumption.
No statistically significant because the calculated p-values of e.g. 0.61 or 0.34 were larger than the p-value of 0.05.

The investigators concluded that cashew consumption improves triglyceride levels as well as systolic and diastolic blood pressure with no significant effects on other cardiometabolic factors (i.e., total cholesterol, HDL cholesterol (good cholesterol) and LDL cholesterol (bad cholesterol)). Further studies are warranted with different calories and dietary compositions.

Original title:
The Effect of Cashew Nut on Cardiovascular Risk Factors and Blood Pressure: A Systematic Review and Meta-analysis (P06-117-19) by Mahboobi S.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6573847/

Additional information of El Mondo:
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Objectives:
Does coenzyme Q10 (CoQ10) supplementation improve biomarkers of inflammation and oxidative stress among patients with coronary artery disease (CAD)?

Study design:
This review article included 13 RCTs.

Given the presence of heterogeneity, random-effects model or fixed-effect model were used to pool standardized mean differences (SMDs) as summary effect sizes.

Results and conclusions:
The investigators found pooled findings for biomarkers of inflammation and oxidative stress demonstrated that coenzyme Q10 supplementation significantly increased superoxide dismutase (SOD) [SMD = 2.63, 95% CI = 1.17 to 4.09, p  0.001, I2 = 94.5%] and catalase (CAT) levels [SMD = 1.00, 95% CI = 0.57 to 1.43, p  0.001, I2 = 24.5%] among patients with coronary artery disease.

The investigators found pooled findings for biomarkers of inflammation and oxidative stress demonstrated that coenzyme Q10 supplementation significantly reduced malondialdehyde (MDA) [SMD = -4.29, 95% CI = -6.72 to -1.86, p = 0.001, I2 = 97.6%] and diene levels [SMD = -2.40, 95% CI = -3.11 to -1.68, p  0.001, I2 = 72.6%] among patients with coronary artery disease.

The investigators found among patients with coronary artery disease no significant effect of coenzyme Q10 supplementation on:
-C-reactive protein (CRP) [SMD = -0.62, 95% CI = -1.31 to 0.08, p = 0.08, I2 = 87.9%];
-tumor necrosis factor alpha (TNF-α) [SMD = 0.22, 95% CI = -1.07 to 1.51, p = 0.73, I2 = 89.7%];
-interleukin-6 (IL-6) [SMD = -1.63, 95% CI = -3.43 to 0.17, p = 0.07, I2 = 95.2%] and;
-glutathione peroxidase (GPx) levels [SMD = 0.14, 95% CI = -0.77 to 1.04, p = 0.76, I2 = 78.7%].
No significant because the calculated p-values were larger than the p-value of 0.05.

The investigators concluded coenzyme Q10 supplementation increases superoxide dismutase and catalase and decreases malondialdehyde and diene levels, but has no affect on C-reactive protein, tumor necrosis factor alpha, interleukin-6 and glutathione peroxidase levels among patients with coronary artery disease.

Original title:
The effects of coenzyme Q10 supplementation on biomarkers of inflammation and oxidative stress in among coronary artery disease: a systematic review and meta-analysis of randomized controlled trials by Jorat MV, Tabrizi R, […], Asemi Z.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30758695

Additional information of El Mondo:
Find more information/studies on coenzyme Q10 and cardiovascular diseases right here.

Malondialdehyde and diene are biomarkers of oxidative stress. Oxidative stress can arise when human cells cannot adequately destroy the excess of free radicals formed.

Free radicals can be rendered harmless by antioxidants such as vitamins C and E and by antioxidative enzymes such as superoxide dismutase and catalase.

Objectives:
Does kiwifruit improve metabolic health in participants with cardiovascular risk factors, including hypercholesterolemia, hypertension, diabetes type 2 and smokers?

Study design:
This review article included 5 RCTs involving 489 participants.

Results and conclusions:
The investigators found no significant effect of kiwifruit on:
-systolic blood pressure (SBP) [MD = -1.72 mmHg, 95% CI = -4.27 to 0.84];
-diastolic blood pressure (DBP) [MD = -2.35 mmHg, 95% CI = -5.10 to 0.41];
-total cholesterol (TC) [MD = -0.14 mmol/L, 95% CI = -0.71 to 0.43];
-triglyceride (TG) [MD = -0.23 mmol/L, 95% CI = -0.66 to 0.20];
-low-density lipoprotein cholesterol (bad cholesterol or LDL) [MD = -0.41 mmol/L, 95% CI = -0.99 to 0.18];
-high-density lipoprotein cholesterol (good cholesterol or HDL) [MD = 0.15 mmol/L, 95% CI = -0.18 to 0.48];
-fasting plasma glucose (FPG) [MD = -0.08 mmol/L, 95% CI = -0.37 to 0.21];
-homeostasis model assessment of insulin resistance (HOMA-IR) [MD = -0.29, 95% CI = -0.61 to 0.02] and;
-body weight (BW) [MD = 1.08 kg, 95% CI = -4.22 to 2.05].

The investigators found subgroup analysis limiting to studies of whole kiwifruit and duration of intervention of at least 8 weeks again revealed no such effect of kiwifruit on total cholesterol, triglyceride, LDL cholesterol and HDL cholesterol.

The investigators concluded kiwifruit has no effect on metabolic health, as measured by systolic blood pressure, diastolic blood pressure, total cholesterol, triglycerides, LDL cholesterol and HDL cholesterol, fasting plasma glucose, homeostasis model assessment of insulin resistance (HOMA-IR) and body weight in participants with cardiovascular risk factors including hypercholesterolemia, hypertension, diabetes type 2 and smokers. Due to limited evidence and high heterogeneity of the study results, the potential of kiwifruit as a nonpharmaceutical alternative for metabolic health should be further evaluated in well-defined, well-controlled trials with larger sample size and standardized preparation.

Original title:
Effect of kiwifruit on metabolic health in patients with cardiovascular risk factors: a systematic review and meta-analysis by Suksomboon N, Poolsup N and Lin W.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6350646/

Additional information of El Mondo:
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Objectives:
Several epidemiological studies have investigated the association between dietary fat intake and cardiovascular disease. However, dietary recommendations based on systematic review and meta-analysis might be more credible. Therefore, this review article has been conducted.

Does dietary fat intake increase cardiovascular disease risk?

Study design:
This review article included 56 cohort studies.
Egger test showed no evidence of significant publication bias.

Results and conclusions:
The investigators found highest versus lowest levels of total dietary fat were not associated with cardiovascular disease risk [RR = 0.97, 95% CI = 0.93-1.01, I2 = 54.0%].
Sensitivity analysis showed that no individual study had an excessive influence on the pooled effect.
In addition, the analysis was repeated stratified according to each covariate. The results were consistent with that observed in meta-regression.

The investigators found highest versus lowest levels of dietary trans fatty acids intake were associated with a 14% increase of the risk of cardiovascular disease [RR = 1.14, 95% CI = 1.08-1.21, I2 = 26.1%].
Sensitivity analysis showed that no individual study had an excessive influence on the pooled effect.

The investigators found dose-response analysis showed the risk of cardiovascular disease significantly increased with 16% [RR = 1.16, 95% CI = 1.07-1.25, p-linearity = 0.033] for an increment of 2% energy/day (2 En%/day) of dietary trans fatty acids intake.

The investigators found highest versus lowest levels of dietary saturated fatty acids intake were not associated with the risk of cardiovascular disease [RR = 0.97, 95% CI = 0.93-1.02, I2 = 56.8%].
Sensitivity analysis showed that no individual study had an excessive influence on the pooled effect
In addition, the analysis was repeated stratified according to each covariate. The results were consistent with that observed in meta-regression.

The investigators found highest versus lowest levels of dietary monounsaturated fatty acids intake were not associated with the risk of cardiovascular disease [RR = 0.97, 95% CI = 0.93-1.01, I2 = 50.3%].
Sensitivity analysis showed that no individual study had an excessive influence on the pooled effect.
In addition, the analysis was repeated stratified according to each covariate. The results were consistent with that observed in meta-regression.

The investigators found highest versus lowest levels of dietary polyunsaturated fatty acids intake were not associated with the risk of cardiovascular disease [RR = 0.97, 95% CI = 0.93-1.004, I2 = 55.8%].
Sensitivity analysis showed that no individual study had an excessive influence on the pooled effect.
In addition, the analysis was repeated stratified according to each covariate. The results were consistent with that observed in meta-regression.

The investigators found in studies that has been followed up more than 10 years, that dietary polyunsaturated fatty acids intake significantly reduced cardiovascular disease risk with 5% [RR = 0.95, 95% CI = 0.91-0.99, I2 = 62.4%].

The investigators concluded there is a cardio-protective effect of dietary polyunsaturated fatty acids intake in studies that has been followed up more than 10 years. While, an increment of 2% energy/day (2 En%/day) of dietary trans fatty acids intake increases risk of cardiovascular disease.

Original title:
Dietary total fat, fatty acids intake, and risk of cardiovascular disease: a dose-response meta-analysis of cohort studies by Zhu Y, Bo Y and Liu Y.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6451787/

Additional information of El Mondo:
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Objectives:
Is there a relationship between the intake of foods (whole grains, refined grains, vegetables, fruit, nuts, legumes, eggs, dairy, fish, red meat, processed meat and sugar-sweetened beverages) and risk of general overweight/obesity, abdominal obesity and weight gain?

Study design:
This review article included 25 prospective cohort studies until August 2018.
In detail, 6 prospective cohort studies were included in the meta-analysis for consumption of whole grains, 4 studies for refined grains, 7 for vegetables, 6 for fruit, 4 for nuts, 2 for legumes, 2 for eggs, 11 for dairy products, 4 for fish, 4 for red meat, 2 for processed meat and 9 for sugar-sweetened beverages.

Results and conclusions:
The investigators found in the dose-response meta-analysis a significantly reduced risk of 7% per each increase of 30g/d whole-grain products [RR overweight/obesity = 0.93, 95% CI = 0.89 to 0.96, I2 = 0%].
There was no indication for a nonlinear association between whole-grain intake and risk of overweight/obesity [p-nonlinearity = 0.16].

The investigators found in the dose-response meta-analysis a significantly reduced risk of 7-9% per each increase of 100g/d fruit consumption [RR overweight/obesity = 0.93, 95% CI = 0.86 to 1.00, I2 = 89% and RR weight gain = 0.91, 95% CI = 0.86 to 0.97, I2 =7%].
There was no indication of a nonlinear relation [p-nonlinearity = 0.17, p-nonlinearity = 0.14, respectively].

The investigators found in the dose-response meta-analysis a significantly reduced risk of 58% per each increase of 28g/d nut consumption [RR abdominal obesity = 0.42, 95% CI = 0.31 to 0.57].

The investigators found in the dose-response meta-analysis a significantly reduced risk of 12% per each increase of 50g/d legume consumption [RR overweight/obesity = 0.88, 95% CI = 0.84 to 0.93].

The investigators found in the dose-response meta-analysis a significantly reduced risk of 17% per each increase of 100g/d fish consumption [RR abdominal obesity = 0.83, 95% CI = 0.71 to 0.97, I2 = 0%].
There was no indication of nonlinearity [p-nonlinearity = 0.07], but the graph indicated a stronger risk reduction at lower levels of fish intake and the curve reached a plateau at ∼40 g/d.

The investigators found in the dose-response meta-analysis a significantly increased risk of 5% per each increase of 30g/d refined grains consumption [RR overweight/obesity = 1.05, 95% CI = 1.00 to 1.10, I2 = 61%].
However, the nonlinear dose-response meta-analysis indicated that the association had a J-shape curve and a higher risk of overweight/obesity was identified for an intake of refined grains >90 g/d [p-nonlinearity 0.001].

The investigators found in the dose-response meta-analysis a significantly increased risk of 10-14% per each increase of 30g/d red meat consumption [RR abdominal obesity = 1.10, 95% CI = 1.04 to 1.16, I2 = 0% and RR weight gain = 1.14, 95% CI = 1.03 to 1.26].

The investigators found in the dose-response meta-analysis a significantly increased risk of 5-12% with each increase of 250 mL sugar-sweetened beverages per day consumption [RR overweight/obesity = 1.05, 95% CI = 1.00 to 1.11 and RR abdominal obesity = 1.12, 95% CI = 1.04 to 1.20, I2 = 38%].  
The increase in risk was stronger at lower amounts of sugar-sweetened beverages intake (until ∼300 mL/d), but an increase at higher intakes was still present [p-nonlinearity = 0.03].

The investigators found the intake of 5 servings of whole grains/d, 3 servings of vegetables/d and 3 servings of fruit/d significantly resulted in a 38% reduction in risk of overweight/obesity compared with non-consumption of these food groups.

The investigators found the intake of 5 servings of refined grains/d and 3 servings of sugar-sweetened beverages/d significantly resulted in a 59% increased risk of overweight/obesity.

The investigators concluded that high intakes of whole grains, vegetables, fruit and probably fish as well as a low intake of refined grains, red meat and sugar-sweetened beverages are associated with a reduced risk of measures of adiposity, including overweight/obesity, abdominal obesity or weight gain, respectively. These findings are in line with current public health recommendations regarding a health-promoting diet. However, with the current evidence rated as very low to low, findings should be interpreted with caution and better-designed observational studies, more evidence from intervention trials and use of novel statistical methods (e.g., substitution analyses or network meta-analyses) are needed.

Original title:
Food Groups and Risk of Overweight, Obesity, and Weight Gain: A Systematic Review and Dose-Response Meta-Analysis of Prospective Studies by Schlesinger S, Neuenschwander M, […], Schwingshackl BH.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6416048/

Additional information of El Mondo:
Find more information/studies on different food groups and overweight right here.

Objectives:
Several studies have been conducted on the effects of peanut consumption on cardiovascular diseases (CVD) risk factors. However, the findings are conflicting and appear inconsistent. Therefore, this review article has been conducted.

Does peanut consumption reduce cardiovascular disease risk?

Study design:
This review article included 13 RCTs.

Results and conclusions:
The investigators found peanuts consumption had no significant effect on:
-weight [WMD = -0.11 kg, p = 0.773];
-waist circumference [WMD = -1.41 cm, p = 0.139];
-body mass index [WMD = -0.14 kg/m², p = 0.428];

-systolic and diastolic blood pressure [WMD = -0.09 mmHg, p = 0.939 and WMD = 0.60 mmHg, p = 0.652, respectively];
-low-density lipoprotein (LDL or bad) cholesterol [WMD = -3.31 mg/dL, p = 0.472];
-triglyceride [WMD = -7.59 mg/dL, p = 0.180];
-total cholesterol [WMD = 3.15 mg/dL, p = 0.171];
-fasting blood sugar [WMD = 0.57 mg/dL, p = 0.604] and;
-serum insulin [WMD = -0.40, p = 0.582].

The investigators found peanuts consumption had a positive significant effect on high-density lipoprotein (HDL or good) cholesterol [WMD = 2.72 mg/dL, p = 0.001].
Significant because the calculated p-value of 0.001 was smaller than the p-value of 0.05.

The investigators found peanut consumption had a positive significant effect on HDL cholesterol, especially at the type of peanut oil, high-oleic peanut and peanut sprout and in healthy subjects and for consumption more than 12 weeks, while had no significant effect on other cardiovascular diseases risk factors.

The investigators concluded both high-oleic peanut and peanut sprout consumption during at least 12 weeks increases HDL cholesterol (good cholesterol) in healthy subjects.

Original title:
Peanut and cardiovascular disease risk factors: A systematic review and meta-analysis by Jafari Azad B, Daneshzad E and Azadbakht L.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30638042

Additional information of El Mondo:
Find more information/studies on nut consumption, cholesterol and cardiovascular diseases right here.

Objectives:
Is there a relationship between nut consumption and metabolic syndrome (MetS)?

Study design:
This review article included a total of 11 observational studies (6 cross-sectional and 5 prospective cohort studies), which involved a total of 89,224 participants.

Results and conclusions:
The investigators found nut consumption significantly reduced risk of metabolic syndrome with 16% [overall multivariable adjusted RR = 0.84, 95% CI = 0.76-0.92, p  0.001].

The investigators found in subgroup analysis tree nut consumption significantly reduced risk of metabolic syndrome with 3% [RR = 0.97, 95% CI = 0.94-1.00, p =0.04]. However, this reduced risk was not significant in peanuts [RR = 1.01, 95% CI = 0.96-1.06, p = 0.68].

The investigators concluded nut consumption reduces risk of metabolic syndrome. However, this reduced risk is only found in tree nuts, not in peanuts. More well-designed studies with detailed specifications of nut varieties are needed to further elaborate the issues examined in this meta-analysis.

Original title:
Relationship Between Nut Consumption and Metabolic Syndrome: A Meta-Analysis of Observational Studies by Zhang Y and Zhang DZ.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30716015

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Objectives:
Has flavonoid supplementation potential against obesity?

Study design:
This review article included 58 RCTs.
Analysis endpoints were calculated as the mean difference between baseline and post-treatment.
Flavonoids were in subclasses of flavanols, flavonols, isoflavones, flavanones, anthocyanins and proanthocyanidins. They were mostly in the form of supplements and dosages varying from 40 to 1300 mg/day.

Results and conclusions:
The investigators found among flavonoid subclasses, flavanols showed potential for decreasing BMI, in the overall population [MD = -0.28 kg/m², p = 0.04, n = 21] and in the subgroups of Asians [MD = -0.42 kg/m², p = 0.046, n = 13], ages 50 years [MD = -0.50 kg/m², p = 0.008, n = 14], BMI ≥25 kg/m² [MD = -0.30 kg/m², p = 0.049, n = 15] and at doses ≥500 mg/day [MD = -0.36 kg/m², p = 0.049, n = 12].

The investigators found among flavonoid subclasses, isoflavones also significantly decreased BMI of non-Asian populations [MD = -0.26 kg/m², p = 0.035, n = 13] and doses ≥75 mg/day [MD = -0.34 kg/m², p = 0.027, n = 8].

The investigators found in the overall assessment, flavanols also significantly decreased waist circumference [MD = -0.60 cm, p = 0.02, n = 18] but had no significant effect on body fat percentage.

The investigators found the available trials did not reveal significant effects from flavonols, flavanones and anthocyanins on the specified anthropometric measures.

The investigators concluded that flavanols, particularly ≥500 mg/day and isoflavones, particularly ≥75 mg/day have potential against obesity.

Original title:
Flavanols are potential anti-obesity agents, a systematic review and meta-analysis of controlled clinical trials by Akhlaghi M, Ghobadi S, […], Mohammadian F.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29759310

Additional information of El Mondo:
Find more information/studies on flavonoids and overweight right here.