Nutrition and health

Objectives:
Does dehydroepiandrosterone (DHEA) supplementation improve the outcomes of in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) in women with diminished ovarian reserve (DOR) and/or poor ovarian response (POR)?

Study design:
This review article included 9 RCTs, published between 2010 and 2017.
The sample sizes ranged from 24 to 208, with a total of 862 patients.
All of included patients had been diagnosed with diminished ovarian reserve (DOR) and/or poor ovarian response (POR).

The treatment intervention was 75 mg daily DHEA versus placebo.

The lack of significant asymmetry of funnel plot indicated the lack of potential publication bias in the included studies.

Results and conclusions:
The investigators found in a pooled analysis using the random effects model revealed a statistically significant increase in retrieved oocytes in the DHEA group, compared to the control group [MD = 0.91, 95% CI = 0.23 -1.59, p = 0.009, I2  = 53%, p = 0.06].

The investigators found in 8 studies (405 in the DHEA group and 415 in the control group) a statistically significant increase in the clinical pregnancy rate in the DHEA group compared to the control group [RR = 1.27, 95% CI = 1.01 -1.61, p = 0.04, I2 = 0%, p = 0.57].

The investigators found in 5 studies (189 in the DHEA group and 190 in the control group) a statistically significant increase in the live birth rate in the DHEA group, compared to the control group [RR = 1.76, 95% CI = 1.17 -2.63, p = 0.006, I2  = 0%, p = 0.43].

The investigators found in 3 studies (96 in the DHEA group and 99 in the control group) no significant difference in the miscarriage rates between the DHEA and control groups [RR = 0.37, 95% CI = 0.12-1.13, p = 0.08, I2 = 25%, p = 0.26].

The investigators concluded 75 mg daily DHEA supplementation increases the retrieved oocytes, clinical pregnancy rate and live birth rate in women with diminished ovarian reserve and/or poor ovarian response, who are undergoing in vitro fertilization or intracytoplasmic sperm injection.

Original title:
The Effect of Dehydroepiandrosterone (DHEA) Supplementation on IVF or ICSI: A Meta-Analysis of Randomized Controlled Trials by Xu L, Hu C, […], Li Y.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6620181/

Additional information of El Mondo:
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Your body naturally produces the hormone dehydroepiandrosterone (DHEA) in the adrenal gland. In turn, DHEA helps produce other hormones, like testosterone and estrogen. Natural dehydroepiandrosterone levels peak in early adulthood and then slowly fall as you age.

 

Objectives:
Free fatty acids, also known as nonesterified fatty acids, are proinflammatory molecules that induce insulin resistance in nonpregnant individuals. Nevertheless, the concentration of these molecules has not been systematically addressed in pregnant women. Therefore, this review article has been conducted.

Do higher plasma levels of free fatty acids increase risk of gestational diabetes mellitus?

Study design:
This review article included 12 case-control studies with a total of 2,426 women, from these, 21% (507/2,426) had a diagnosis of having gestational diabetes.

The mean gestational age at inclusion was 30.3 weeks of gestation.
The mean maternal age was 29 years.
No significant publication bias was found nor a trend towards greater results in small studies.

Results and conclusions:
The investigators found in random-effects model, when compared to controls, women with gestational diabetes had higher levels of free fatty acids [SMD = 0.86, 95% CI = 0.54-1.18, p 0.001, I2 = 91%].
Pooled results showed higher plasma levels of free fatty acid among women with gestational diabetes mellitus during the second trimester of pregnancy [SMD = 1.05 vs. 0.75].

The investigators found meta-regression analysis showed that the gestational age at inclusion was the only cofactor influencing the mean levels of free fatty acids, indicating a trend towards lower plasma levels of free fatty acids later in gestation [estimate = -0.074, 95% CI = -0.143 to -0.004, p = 0.036].

The investigators concluded that plasma levels of free fatty acids are higher in women diagnosed with gestational diabetes mellitus and that this difference is higher during the second trimester of pregnancy. However, more investigation is needed to assess the potential role of free fatty acids in the prediction of gestational diabetes earlier in pregnancy.

Original title:
Plasma Levels of Free Fatty Acids in Women with Gestational Diabetes and Its Intrinsic and Extrinsic Determinants: Systematic Review and Meta-Analysis by Villafan-Bernal JR, Acevedo-Alba M, […], Martinez-Portilla RJ.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6721400/

Additional information of El Mondo:
Find more information/studies on fatty acids and pregnancy right here.
 

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

Additional information of El Mondo:
Find more information/studies on vitamin K, significantly/review article and cardiovascular disease right here.

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

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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Find more information/studies on fruits, meta-analysis and cholesterol right here.
 

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

Additional information of El Mondo:
Find more information/studies on coffee and reducing blood pressure right here.
 

Objectives:
Maternal folic acid supplementation is considered mandatory in almost every country in the world to prevent congenital malformations. However, little is known about the association of maternal folic acid intake with the occurrence of childhood cancer. Therefore, this review article has been conducted.

Does maternal folic acid supplementation during pregnancy reduce risk of childhood cancer?

Study design:
This review article included 17 case-control studies.

Results and conclusions:
The investigators found in random-effects model, maternal folic acid supplementation during pregnancy significantly reduced risk of childhood acute lymphoblastic leukaemia with 25% [OR = 0.75, 95% CI = 0.66 to 0.86].
Significantly because OR of 1 was not found in the 95% CI of 0.66 to 0.86. OR of 1 means no risk/association.

The investigators found in random-effects model, there was no significant association between maternal folic acid supplementation during pregnancy and acute myeloid leukaemia [OR = 0.70, 95% CI = 0.46 to 1.06] or childhood brain tumours [OR = 1.02, 95% CI = 0.88 to 1.19].
No significant because OR of 1 was found in the 95% CI of 0.88 to 1.19. OR of 1 means no risk/association.

The investigators concluded maternal folic acid supplementation during pregnancy reduces risk of childhood acute lymphoblastic leukaemia. Thus, healthcare professionals are recommended to provide regular health education and health promotion to the community on the benefits of folic acid supplementation during pregnancy.

Original title:
The Protective Effect of Maternal Folic Acid Supplementation on Childhood Cancer: A Systematic Review and Meta-analysis of Case-control Studies by Wan Ismail WR, Abdul Rahman R, […],Nawi AM.

Link:
https://www.jpmph.org/journal/view.php?doi=10.3961/jpmph.19.020

Additional information of El Mondo:
Find more information/studies on folic acid and pregnancy 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

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

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:
Find more information/studies on cashew consumption, cholesterol and cardiovascular diseases right here.

Objectives:
Does calcium supplement with or without other drugs reduce risk of preeclampsia and gestational hypertension?

Study design:
This review article included 27 RCTs, with 28,492 pregnant women.

Results and conclusions:
The investigators found calcium supplement significantly reduced risk of preeclampsia with 49% [RR = 0.51, 95% CI = 0.40 to 0.64].

The investigators found calcium supplement significantly reduced risk of gestational hypertension with 30% [RR = 0.70, 95% CI = 0.60 to 0.82].

The investigators found sub-analyses revealed high-dose (1.2-2 g/day), moderate-dose (0.6-1.2 g/day) and low-dose (0.6 g/day) of calcium supplement significantly reduced risk of preeclampsia.

The investigators found sub-analyses revealed high-dose (1.2-2 g/day) and moderate-dose (0.6-1.2 g/day) of calcium supplement significantly reduced risk of gestational hypertension.

The investigators concluded high-dose (1.2-2 g/day) and moderate-dose (0.6-1.2 g/day) of calcium supplement reduced both risk of preeclampsia and gestational hypertension. However, further studies with direct comparison of different dose of calcium supplementation are needed to explore the ideal dose of calcium supplementation to prevent preeclampsia and gestational hypertension.

Original title:
The association between calcium supplement and preeclampsia and gestational hypertension: a systematic review and meta-analysis of randomized trials by Sun X, Li H, [...], Zhang X.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30935246

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

 

Objectives:
The role of chromium as a weight loss agent remains questionable and although previous meta-analyses findings have reported small reductions in body weight in individuals with overweight/obesity following chromium supplementation, there have been significant limitations with these findings. Therefore, this review article has been conducted.

Do individuals with overweight/obesity benefit from chromium supplementation?

Study design:
This review article included 21 RCTs with a total of 1,316 participants.

Results and conclusions:
The investigators found pooled analysis showed significant reductions in anthropometric indices associated with body composition for:
-weight loss [WMD = -0.75 kg, 95% CI = -1.04 to -0.45, p  0.001];
-body mass index (BMI) [WMD = -0.40, 95% CI = -0.66 to -0.13, p = 0.003] and;
-body fat percentage [WMD = -0.68%, 95% CI = -1.32 to -0.03, p = 0.04] in individuals with overweight/obesity following chromium supplementation. No changes were detected in controls.

The investigators found subgroup analysis showed significant improvements in weight loss and body fat percentage, particularly for study durations ≤12 weeks and doses ≤400 μg/d chromium.

The investigators concluded ≤400 μg/d chromium supplementation during ≤12 weeks is associated with some improvements in body composition in subjects with obesity/overweight. The effect size was medium and the clinical relevance of chromium as a weight loss aid remains uncertain. Therefore, further investigation from larger and well-designed randomized controlled studies, especially in patients with diabetes, is warranted.

Original title:
A meta-analysis of the effect of chromium supplementation on anthropometric indices of subjects with overweight or obesity by Tsang C, Taghizadeh M, […], Jafarnejad S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31115179

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Find more information/studies on chromium and obesity/overweight right here.

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:
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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/

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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:
Find more information/studies on fat consumption and cardiovascular diseases 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:
The threshold for population-level optimal red blood cell (RBC) folate concentration among women of reproductive age for the prevention of neural tube defects has been estimated at 906 nmol/L. However, the dose-response relationship between folic acid intake and blood folate concentrations is uncharacterized. Therefore, this review article has been conducted.

Is there dose-response relationship between folic acid intake and blood folate concentrations?

Study design:
This review article included 23 articles for red blood cell folate and by 97 articles for serum/plasma folate.

Results and conclusions:
The investigators found in 17 studies red blood cell (RBC) folate concentration increased 1.78 fold [95% CI = 1.66 to 1.93] from baseline to steady-state at 375-570 µg folic acid/day and it took a median of 36 weeks of folic acid intake [95% CI = 27 to 52] to achieve steady-state red blood cell folate concentrations.

The investigators found for every 100 µg/day folic acid intake, serum/plasma folate concentrations increased 11.6% [95% CI = 8.4 to 14.9] from baseline to steady-state, over a median of 13 weeks [95% CI = 10 to 16].

The investigators concluded that there is a dose-response relationship between folic acid intake and changes in blood folate concentrations. At 375-570 µg folic acid/day, red blood cell folate concentrations increase 1.78 fold from baseline to steady-state, over a median of 36 weeks. For every 100 µg/day folic acid intake, serum/plasma folate concentrations increase 11.6% from baseline to steady-state, over a median of 13 weeks. These results can inform how much additional folic acid intake is needed among populations of women whose red blood cell folate concentrations are below the optimal threshold.

Original title:
Systematic Review and Bayesian Meta-analysis of the Dose-response Relationship between Folic Acid Intake and Changes in Blood Folate Concentrations by Crider KS, Devine O, […], Berry RJ.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6356991/

Additional information of El Mondo:
Find here more information/studies about pregnancy and folaat (also called folic acid).
 

Objectives:
Diverse studies have investigated the impact of prenatal exposure to vitamin D levels on brain development. However, evidence in humans has never been systematically reviewed. Therefore, this meta-analysis (systematic review) has been conducted.

Has a high prenatal vitamin D level positive effect on brain development of the born child?

Study design:
This review article included 25 studies.

Results and conclusions:
The investigators found comparing with the lowest category of prenatal 25(OH)D levels (vitamin D level in blood), the highest prenatal 25(OH)D levels had no significant effects on cognition [pooled beta coefficients = 0.95, 95% CI = -0.03 to 1.93, p = 0.05].

The investigators found comparing with the lowest category of prenatal 25(OH)D levels (vitamin D level in blood), the highest prenatal 25(OH)D levels had no significant effects on psychomotor development [pooled beta coefficients = 0.88, 95% CI = -0.18 to 1.93, p = 0.10].

The investigators found comparing with the lowest category of prenatal 25(OH)D levels (vitamin D level in blood), the highest prenatal 25(OH)D levels significantly reduced risk of ADHD of the born child with 28% [pooled relative risk = 0.72, 95% CI = 0.59 to  0.89, p = 0.002].

The investigators found comparing with the lowest category of prenatal 25(OH)D levels (vitamin D level in blood), the highest prenatal 25(OH)D levels significantly reduced risk of autism-related traits of the born child with 58% [pooled odds ratio = 0.42, 95% CI = 0.25 to 0.71, p = 0.001].

The investigators found there was little evidence for protective effects of high prenatal 25(OH)D for language development and behaviour difficulties of the born child.

The investigators concluded this meta-analysis provides supporting evidence that increased prenatal exposure to 25(OH)D levels is associated with reduced risk of ADHD and autism-related traits of the born child later in life. Associations represent a potentially high public health burden given the current prevalence of vitamin D deficiency and insufficiency among childbearing aging and pregnant women.

Original title:
Neurodevelopmental effects of prenatal vitamin D in humans: systematic review and meta-analysis by García-Serna AM and Morales E.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30696940

Additional information of El Mondo:
Find more information/studies on vitamin D and pregnancy right here.