Nutrition and health

Objectives:
Studies have shown that creatine supplementation increases intramuscular creatine concentrations, favoring the energy system of phosphagens, which may help explain the observed improvements in high-intensity exercise performance. However, research on physical performance in soccer has shown controversial results, in part because the energy system used is not taken into account. Therefore, this review article (meta-analysis) has been conducted.

Does creatine supplementation improve physical performance in soccer players?

Study design:
This review article included 9 RCTs with a total sample of 168 soccer players (118 males, 50 females) with an average age of 20.3 ± 2.0 years (from 15 to 30 years, as an average for the experimental sample).

The meta-analysis was performed using the random effects model and pooled standardized mean differences (SMD) (Hedges's g).

Results and conclusions:
The investigators found that creatine supplementation did not present beneficial effects on aerobic performance tests [SMD = -0.05, 95% CI = -0.37 to 0.28, p = 0.78] and phosphagen metabolism performance tests (strength, single jump, single sprint and agility tests: SMD = 0.21, 95% CI = -0.03 to 0.45, p = 0.08].

The investigators found, however, creatine supplementation showed beneficial effects on anaerobic performance tests [SMD = 1.23, 95% CI = 0.55 to 1.91, p 0.001].
Concretely, creatine supplementation demonstrated a large and significant effect on Wingate test performance [SMD = 2.26, 95% CI = 1.40 to 3.11, p 0.001].

The investigators concluded creatine supplementation with a loading dose of 20-30 g/day, divided 3-4 times per day, ingested for 6 to 7 days and followed by 5 g/day for 9 weeks or with a low dose of 3 mg/kg/day for 14 days presents positive effects on improving physical performance tests related to anaerobic metabolism, especially anaerobic power, in soccer players.

Original title:
Effects of Creatine Supplementation on Athletic Performance in Soccer Players: A Systematic Review and Meta-Analysis by Mielgo-Ayuso J, Calleja-Gonzalez J, […], Fernández-Lázaro D.

Link:
https://www.mdpi.com/2072-6643/11/4/757/htm

Additional information of El Mondo:
Find here more information/studies about sport nutrition and creatine.

Objectives:
Malaria clinical outcomes vary by erythrocyte characteristics, including ABO blood group, but the effect of ABO blood group on asymptomatic, uncomplicated and placental Plasmodium falciparum (P. falciparum) infection remains unclear. Therefore, this review article has been conducted.

What are the effects of ABO blood group on asymptomatic, uncomplicated and placental Plasmodium falciparum (P. falciparum) infection (malaria infection) in the published literature?

Study design:
This review article included 42 for systematic review and 37 for meta-analysis. Most studies (n = 30) were cross-sectional, 7 were prospective cohort and 5 were case-control studies.

Results and conclusions:
The investigators found meta-analysis showed similar odds of uncomplicated P. falciparum infection among individuals with blood group A [summary OR = 0.96, 95% CI = 0.81-1.12, I2 43.5%, 15 studies], B [summary OR = 0.89, 95% CI = 0.72-1.06, I2 = 57.8%, 15 studies], AB [summary OR = 0.85, 95% CI = 0.59-1.10, I2 = 48.0%, 10 studies] and non-O [summary OR = 0.95, 95% CI = 0.81-1.09, I2 = 55.3%, 17 studies] as compared to those with blood group O.

The investigators found meta-analysis of 4 cohort studies also showed similar risk of uncomplicated P. falciparum infection among individuals with blood group non-O and those with blood group O [summary relative risk = 1.03, 95% CI = 0.84-1.22, I2 = 57.3%].

The investigators found meta-analysis of 6 studies showed similar odds of asymptomatic P. falciparum infection among individuals with blood group A [OR = OR 1.05, 95% CI = 0.84-1.27, I2 = 0.0%], B [OR = 1.03, 95% CI = 0.82-1.24, I2 = 22.2%], AB [OR = 1.23, 95% CI = 0.82-1.64, I2 = 0.0%] and non-O [OR = 1.07, 95% CI = 0.90-1.24, I2 = 23.1%] when compared to those with blood group O.
However, odds of active placental P. falciparum infection was significantly lower in primiparous women with non-O blood groups [OR = 0.46, 95% CI = 0.23-0.69, I2 = 0.0%, 3 studies], particularly in those with blood group A [OR = 0.41, 95% CI = 0.003-0.82, I2 = 1.4%, 4 studies] than those with blood group O.

The investigators concluded that ABO blood group does not affect susceptibility to asymptomatic and/or uncomplicated P. falciparum infection. However, blood group O primiparous women are more susceptible to active placental P. falciparum infection.

Original title:
Effect of ABO blood group on asymptomatic, uncomplicated and placental Plasmodium falciparum infection: systematic review and meta-analysis by Degarege A, Gebrezgi MT, […], Madhivanan P.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6346527/

Additional information of El Mondo:
Find more information/studies on food fortification/malnutrition and malaria 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:
Although the relationship between dietary intake and serum levels of trans fatty acids and risk of breast cancer has been investigated extensively, findings are inconsistent. Therefore, this review article has been conducted.

Do dietary intake and serum levels of trans fatty acids increase risk of breast cancer?

Study design:
This review article included 6 cohort studies and 1 nested case-control study on total dietary trans fat intake and 1 cohort study and 4 nested case-control studies on serum trans fatty acids.

Participants were apparently healthy aged 26 years or older.

Results and conclusions:
The investigators found no significant relationship between dietary intake of total trans fatty acids and risk of breast cancer [pooled effect size = 1.02, 95% CI = 0.95-1.10, p = 0.403].

The investigators found in 3 effect sizes from 2 cohort studies and 1 nested case-control study, no significant relation between dietary intake of conjugated linoleic acid (CLA) and risk of breast cancer [pooled effect size = 1.05, 95% CI = 0.95-1.17, p = 0.513].

The investigators found based on 5 effect sizes, each additional 1 g/day dietary intake of total trans fats was not significantly associated with risk of breast cancer [RR = 1.00, 95% CI = 0.99-1.01].

The investigators found high serum levels of trans fats were associated with an increased risk of 37% of breast cancer among postmenopausal women [pooled effect size = 1.37, 95% CI = 1.04-1.81, p = 0.02].

The investigators concluded dietary intake of trans fatty acids (also called trans fats) is not associated with risk of breast cancer. However, a significant positive association is seen between serum trans fats and risk of breast cancer in postmenopausal women.

Original title:
Dietary intake and serum levels of trans fatty acids and risk of breast cancer: A systematic review and dose-response meta-analysis of prospective studies by Anjom-Shoae J, Sadeghi O, […], Esmaillzadeh A.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30954361

Additional information of El Mondo:
Find more information/studies on trans fatty acids consumption, review article/significantly and breastcancer right here.

Objectives:
Exclusive breastfeeding (EBF) rates until 6 months in most low and middle income countries (LMICs) are well below the 90% World Health Organization benchmark. Therefore, this review article has been conducted.

The goal of this review article is to provide evidence on effectiveness of various interventions on exclusive breastfeeding until 6 months in low and middle income countries, compared with standard care.

Study design:
This review article included 67 studies (experimental and observational) with 79 comparisons from 30 low and middle income countries.

Results and conclusions:
The investigators found at 6 months, intervention group infants were more likely to be exclusively breastfed than controls [RR = 2.19, 95% CI = 1.73 to 2.77, I2 = 78.4%, 25 randomized controlled trials].

The investigators found larger effects were obtained from interventions delivered by a combination of professional and laypersons [RR = 3.90, 95% CI = 1.25, 12.21, I2 = 46.7%], in interventions spanning antenatal and post-natal periods [RR = 2.40, 95% CI = 1.70 to 3.38, I2 = 83.6%] and when intensity was between 4 to 8 contacts/sessions [RR = 3.20, 95% CI = 2.30 to 4.45, I2 = 53.8%].

The investigators concluded exclusive breastfeeding until 6 months in low and middle income countries can be improved by a combination of professional and laypersons, interventions spanning antenatal and post-natal periods and when intensity was between 4 to 8 contacts/sessions. Therefore, choice of intervention should be driven by feasibility of delivery in the local context to reduce infant mortality.

Original title:
Improving exclusive breastfeeding in low and middle-income countries: A systematic review by Olufunlayo TF, Roberts AA, […], Jolly K.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30665273

Additional information of El Mondo:
Find more information/studies on food fortification/malnutrition and breastfeeding right here.

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.

 

Objectives:
Is there an association between potato consumption and risk of all-cause, cancer and cardiovascular mortality in adults?

Study design:
This review article included 20  prospective cohort studies with 25,208 cases of all-cause mortality, 4,877 of cancer mortality and 2,366 of cardiovascular mortality.

There was no evidence for publication bias.

Results and conclusions:
The investigators found no significant association between potato consumption and risk of all-cause [RR = 0.90, 95% CI = 0.8 to 1.02, p = 0.096] and cancer [RR = 1.09, 95% CI = 0.96 to 1.24, p = 0.204] mortality.

The investigators found, in addition, no significant linear association between each 100 g/d increments in potato consumption and risk of all-cause [p = 0.7] and cancer [p = 0.09] mortality.
Moreover, nonlinear association between potato consumption and risk of cancer mortality was non-significant [p-nonlinearity = 0.99].

The investigators found, in addition, 2 of 3 studies which examined the association of potato consumption with cardiovascular mortality did not find any significant relationship.

The investigators concluded there is no association between potato consumption and risk of all-cause, cancer and cardiovascular mortality in adults.

Original title:
Potato consumption and risk of all cause, cancer and cardiovascular mortality: a systematic review and dose-response meta-analysis of prospective cohort studies by Darooghegi Mofrad M, Milajerdi A, […], Azadbakht L.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30638040

Additional information of El Mondo:
Find more information/studies on of potato consumption and elderly right here.
 

Objectives:
Previous meta-analysis showed an inverse association between coffee consumption and all-cause mortality. However, the relationship between caffeinated and decaffeinated coffee consumption and all-cause mortality is inconsistent. Therefore, this review article has been conducted.

Do both caffeinated and decaffeinated coffee consumption reduce all-cause mortality?

Study design:
This review article included 21 cohort studies with a total of 10,103,115 study participants and 240,303 deaths.

Results and conclusions:
The investigators found a nonlinear association between coffee consumption and all-cause mortality [p nonlinearity 0.001].

The investigators found compared with no or rare coffee consumption that 3 cups/d coffee consumption significantly reduced risk of all-cause mortality with 13% [RR = 0.87, 95% CI = 0.84 to 0.89].

The investigators concluded that 3 cups/d coffee consumption reduce risk of all-cause mortality. The reduced risks are similar for caffeinated coffee and decaffeinated coffee.

Original title:
Caffeinated and decaffeinated coffee consumption and risk of all-cause mortality: a dose-response meta-analysis of cohort studies by Li Q, Liu Y, […], Hu D.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30786114

Additional information of El Mondo:
Find here more information/studies about coffee consumption and chronic diseases.
 

Objectives:
The prevalence of Clostridium difficile infection is rapidly increasing worldwide, but prevalence is difficult to estimate in developing countries where awareness, diagnostic resources and surveillance protocols are limited. Therefore, this review article has been conducted.

The goal of this review article is to determine the current prevalence and incidence density rates of first episodes of Clostridium difficile-associated diarrhea in developing countries.

Study design:
This review article included studies with data providing prevalence or incidence rates of Clostridium difficile-associated diarrhea in developing countries within four regions: Africa-Middle East, developing Asia, Latin America and China.

Results and conclusions:
The investigators found within the regions, the prevalence of Clostridium difficile infection in patients with diarrhea was 15% [95% CI = 13-17%] (including community and hospitalized patients), with no significant difference across regions.

The investigators found the incidence of Clostridium difficile infection in 17 studies including this information was 8.5 per 10,000 patient-days [95% CI = 5.83-12.46]. Prevalence was significantly higher in hospitalized patients versus community patients [p = 0.0227].

The investigators concluded the prevalence estimate of 15% is concerning; however, low awareness and inconsistent diagnostic and surveillance protocols suggest this is markedly underestimated. Enhanced awareness and management of Clostridium difficile infection in patients with diarrhea, along with improvements in infection control and surveillance practices, should be implemented to reduce prevalence of Clostridium difficile-associated diarrhea in developing countries.

Original title:
Clostridium difficile-associated Diarrhea in Developing Countries: A Systematic Review and Meta-Analysis by Curcio D, Cané A, […], Correa J.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30659481

Additional information of El Mondo:
Find more information/studies on food fortification/malnutrition right here.

Objectives:
Fish consumption and dietary intake of n-3 polyunsaturated acids (PUFAs) may be associated with inflammatory bowel disease (IBD). Therefore, this review article has been conducted.

Is there an association between fish consumption or dietary intake of n-3 polyunsaturated acids (PUFAs) and inflammatory bowel disease risk?

Study design:
This review article included 5 prospective cohort studies and 7 case-control studies with a total sample size of 282,610 participants which 2,002 of them were cases of inflammatory bowel disease (1,061 Crohn's disease (CD) and 937 ulcerative colitis (UC)).

Results and conclusions:
The investigators found fish consumption significantly reduced risk of Crohn's disease with 46% [pooled effect size = 0.54, 95% CI = 0.31-0.96, p = 0.03].

The investigators found there was no relationship between total dietary n-3 PUFAs intake and inflammatory bowel disease risk [pooled effect size = 1.17, 95% CI = 0.80-1.72, p = 0.41].

The investigators found dietary long-chain n-3 PUFAs significantly reduced ulcerative colitis risk with 25% [pooled effect size = 0.75, 95% CI = 0.57-0.98, p = 0.03].

The investigators found no association between dietary α-linolenic acid (ALA) and inflammatory bowel disease risk [pooled effect size = 1.17, 95% CI = 0.63-2.17, p = 0.62].

The investigators concluded fish consumption reduces risk of Crohn's disease and dietary intake of long-chain n-3 PUFAs reduces risk of ulcerative colitis.

Original title:
Dietary intake of fish, n-3 polyunsaturated fatty acids, and risk of inflammatory bowel disease: a systematic review and meta-analysis of observational studies by Mozaffari H, Daneshzad E, […], Azadbakht L.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30680455

Additional information of El Mondo:
Find here more information/studies about fish consumption, n-3 PUFAs and chronic diseases.
 

Objectives:
Streptococcus pneumoniae is an intermittent commensal organism in the nasopharynx. Colonisation is a prerequisite for disease and malnourished children are especially susceptible to severe infection.

The goal of this review article is to examine published prevalence rates of pneumococcal colonisation in the upper respiratory tract of chronically malnourished children 5 y of age.

Study design:
This review article included 9 observational studies.

Results and conclusions:
The investigators found the prevalence rate of Streptococcus pneumoniae colonisation in malnourished children during the first month of life ranged from 1.0 to 2.0%, increasing at 2 months to 53.9-80.0%. Carriage remained similar from 3 to 60 months at 64.1-88.0%.  

The investigators found meta-analysis showed a pooled prevalence of 67.2% [95% CI = 55.6 to 78.7] in infants 0-3 months of age, 77.9% [95% CI = 68.1 to 87.7] in infants 3-6 months of age and 77.8% [95% CI = 73.9-81.6%] in infants 6-60 months of age.

The investigators concluded in malnourished children the rates of pneumococcal colonisation are higher than in healthy, well-nourished children. Knowledge of colonisation rates can inform policies on vaccination and ancillary interventions during treatment of malnutrition. Future studies should assess the impact of reducing colonisation on disease rates or transmission in these “at-risk” individuals.

Original title:
Nasopharyngeal colonisation with Streptococcus pneumoniae in malnourished children: a systematic review and meta-analysis of prevalence by Smith HC, German E, […], Rylance J.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30624761

Additional information of El Mondo:
Find more information/studies on food fortification/malnutrition 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

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

Objectives:
Existing studies suggest that dietary vitamins and carotenoids might be associated with a reduced risk of age-related cataract (ARC), although a quantitative summary of these associations is lacking. Therefore, this review article has been conducted.

Do vitamins and carotenoids intake reduce risk of the eye disease age-related cataract? 

Study design:
This review article included 8 RCTs and 12 cohort studies.

Results and conclusions:
The investigators found in cohort studies a significantly reduced risk of 19% [RR = 0.81, 95% CI = 0.71 to 0.92, p = 0.001] of age-related cataract for dietary vitamin A intake.

The investigators found in cohort studies a significantly reduced risk of 20% [RR = 0.80, 95% CI = 0.72 to 0.88, p 0.001] of age-related cataract for dietary vitamin C intake.

The investigators found in cohort studies a significantly reduced risk of 10% [RR = 0.90, 95% CI = 0.80 to 1.00, p 0.049] of age-related cataract for dietary vitamin E intake.

The investigators found in cohort studies a significantly reduced risk of 10% [RR = 0.90, 95% CI = 0.83 to 0.99, p = 0.023] of age-related cataract for dietary β-carotene intake.

The investigators found in cohort studies a significantly reduced risk of 19% [RR = 0.81, 95% CI = 0.75 to 0.89, p 0.001] of age-related cataract for dietary β lutein or zeaxanthin intake.

The investigators found in RCTs compared with the placebo, a non-significantly reduced risk of 3% [RR = 0.97, 95% CI = 0.91 to 1.03, p 0.262] of age-related cataract for vitamin E supplementation.
Non-significantly because RR of 1 was found in the 95% CI of 0.91 to 1.03. RR of 1 means no risk/association.

The investigators found in RCTs compared with the placebo, a non-significantly reduced risk of 1% [RR = 0.99, 95% CI = 0.92 to 1.07, p 0.820] of age-related cataract for β-carotene supplementation.

The investigators found in dose-response analysis of cohort studies a significantly reduced risk of 26% [RR = 0.74, 95% CI = 0.67 to 0.80, p 0.001] of age-related cataract for every 10-mg/d increase in dietary lutein or zeaxanthin intake.

The investigators found in dose-response analysis of cohort studies a significantly reduced risk of 18% [RR = 0.82, 95% CI = 0.74 to 0.91, p 0.001] of age-related cataract for every 500-mg/d increase in dietary vitamin C intake.

The investigators found in dose-response analysis of cohort studies a significantly reduced risk of 8% [RR = 0.92, 95% CI = 0.88 to 0.96, p 0.001] of age-related cataract for every 5-mg/d increase in dietary β-carotene intake.

The investigators found in dose-response analysis of cohort studies a significantly reduced risk of 6% [RR = 0.94, 95% CI = 0.90 to 0.98, p 0.001] of age-related cataract for every 5 mg/d increase in dietary vitamin A intake.

The investigators concluded dietary intake of vitamin A (at least 5 mg per day), vitamin C (at least 500 mg per day), vitamin E, β-carotene (at least 5 mg per day) and lutein or zeaxanthin intake (at least 10 mg per day) reduce risk of age-related cataract.

Original title:
Dietary vitamin and carotenoid intake and risk of age-related cataract by Jiang H, Yin Y, […], Ma L.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30624584

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

Objectives:
The goal of this review article is to quantify the risk of P vivax parasitaemia after treatment of Plasmodium falciparum with commonly used antimalarial drugs to assess the potential benefits of radical cure for all patients with uncomplicated malaria in co-endemic regions.

Study design:
This review article included 153 studies with a total of 31,262 patients from 323 site-specific treatment groups (from 21 countries): 130 (85%) studies were from the Asia-Pacific region, 16 (10%) from the Americas and 7 (5%) from Africa.

Data for outcomes could be extracted from 106 studies for day 28, 58 studies for day 42 and 12 studies for day 63.

Studies were included if the presence or absence of P vivax parasitaemia was recorded after treatment.
The primary outcome was the risk of P vivax parasitaemia between day 7 and day 42 after initiation of antimalarial treatment for P falciparum, with the pooled risk calculated by random-effects meta-analysis.

There was substantial heterogeneity between study populations.
The mean or median age ranged from 2.9 years to 38.4 years.
Mean or median baseline parasitaemia ranged from 518 to 68 178 parasites per μL.
The prevalence of P falciparum gametocytes at baseline ranged from 0% to 52% and the mean or median baseline haemoglobin ranged from 7.8 g/dL to 14.3 g/dL.

Results and conclusions:
The investigators found the risk of P vivax parasitaemia by day 42 was 5.6% [95% CI = 4.0-7.4, I2 = 92.0%, 117 estimates].

The investigators found the risk of P vivax parasitaemia was 6.5% [95% CI = 4.6-8.6] in regions of short relapse periodicity compared with 1.9% [95% CI = 0.4-4.0] in regions of long periodicity and was greater after treatment with a more rapidly eliminated ACT: 15.3% [95% CI = 5.1-29.3] for artemether-lumefantrine compared with 4.5% [95% CI = 1.2-9.3] for dihydroartemisinin-piperaquine and 5.2% [95% CI = 2.9-7.9] for artesunate-mefloquine.

The investigators found recurrent parasitaemia was delayed in patients treated with ACTs containing mefloquine or piperaquine compared with artemether-lumefantrine, but by day 63 the risk of vivax parasitaemia was more than 15% for all ACTs assessed.

The investigators concluded meta-analysis of 31,262 patients treated for falciparum malaria shows a high risk of subsequent P vivax parasitaemia across a range of co-endemic settings. P vivax parasitaemia occurred more frequently after treatment with rapidly eliminated drugs and in regions with short relapse periodicity. The risk was particularly apparent after treatment with artemether-lumefantrine [15.3% by day 42], accounting for more than half of all recurrent parasitaemias.
These findings suggest that in some regions co-endemic for both P falciparum and P vivax, the introduction of a universal policy of radical cure for all patients with uncomplicated malaria has potential to prevent recurrent parasitaemia, reduce ongoing transmission and enhance malaria elimination efforts.

Original title:
Risk of Plasmodium vivax parasitaemia after Plasmodium falciparum infection: a systematic review and meta-analysis by Commons RJ, Simpson JA, […], Price RN.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6300482/

Additional information of El Mondo:
Find more information/studies on food fortification/malnutrition and malaria right here.

Objectives:
Epidemiological studies focusing on the association between folate and breast cancer risk reported inconsistent findings. Therefore, this review article has been conducted.

Does dietary folate intake reduce breast cancer risk?

Study design:
This review article included a total of 23 prospective cohort studies involving 41,516 cases (=women with breast cancer) among 1,171,048 individuals.

Results and conclusions:
The investigators found dietary folate intake significantly reduced risk of oestrogen-receptor-negative breast cancer with 12% [pooled risk ratio = 0.88, 95% CI = 0.78-1.00].

The investigators found dietary folate intake significantly reduced risk of oestrogen-receptor-negative/progesterone-receptor-negative breast cancer with 18% [pooled risk ratio = 0.82, 95% CI = 0.68-0.97].

The investigators found an increment of dietary folate intake of 100 μg per day was associated with a deceased risk of oestrogen-receptor-negative breast cancer with 6% [RR = 0.94, 95% CI = 0.88-0.99].

The investigators found an increment of dietary folate intake of 100 μg per day was associated with a deceased risk of oestrogen-receptor-negative/progesterone-receptor-negative breast cancer with 10% [RR = 0.90, 95% CI = 0.85-0.97].

The investigators found high dietary folate intake significantly reduced breast cancer risk in premenopausal women with 6% [RR = 0.94, 95% CI = 0.88-1.00].

The investigators found high dietary folate intake significantly reduced breast cancer risk in women with moderate or high levels of alcohol consumption with 18% [RR = 0.82, 95% CI = 0.72-0.94].

The investigators concluded that at least 100 μg per day dietary folate intake, reduce both oestrogen-receptor-negative and oestrogen-receptor-negative/progesterone-receptor-negative breast cancer, particularly among premenopausal women and women with moderate or high levels of alcohol consumption.

Original title:
Folate intake and the risk of breast cancer: an up-to-date meta-analysis of prospective studies by Zeng J, Wang K, [...], Chang H.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30647438

Additional information of El Mondo:
Find more information/studies on folate consumption, review article/significantly and breast cancer right here.

Objectives:
Evidence from randomized controlled trials (RCTs) suggests that viscous dietary fiber may offer beneficial effects on glycemic control and, thus, an improved cardiovascular disease risk profile. Therefore, this review article (meta-analysis) has been conducted.

Does viscous dietary fiber supplementation improve glycemic control in type 2 diabetes?

Study design:
This review article included 28 RCTs of ≥3 weeks in duration that assessed the effects of viscous fiber on markers of glycemic control in type 2 diabetes with a total of 1,394 participants.

Results and conclusions:
The investigators found that viscous fiber at a median dose of ∼13.1 g/day significantly reduced HbA1c in type 2 diabetes [MD = -0.58%, 95% CI = -0.88 to -0.28, p = 0.0002] compared with control and in addition to standard of care.

The investigators found that viscous fiber at a median dose of ∼13.1 g/day significantly reduced fasting blood glucose in type 2 diabetes [MD = -0.82 mmol/L, 95% CI = -1.32 to -0.31, p = 0.001] compared with control and in addition to standard of care. 

The investigators found that viscous fiber at a median dose of ∼13.1 g/day significantly reduced HOMA-insulin resistance in type 2 diabetes [MD = -1.89, 95% CI = -3.45 to -0.33, p = 0.02] compared with control and in addition to standard of care.

The investigators found the certainty of evidence was graded moderate for HbA1c, fasting glucose, fasting insulin and HOMA-IR and low for fructosamine.

The investigators concluded that 13.1 g/day viscous fiber supplements improve conventional markers of glycemic control beyond usual care and should be considered in the management of type 2 diabetes.

Original title:
Should Viscous Fiber Supplements Be Considered in Diabetes Control? Results From a Systematic Review and Meta-analysis of Randomized Controlled Trials by Jovanovski E, Khayyat R, […], Vuksan V.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30617143

Additional information of El Mondo:
Find more information/studies on diabetes and dietary fiber right here.

Objectives:
Is there an association between vitamin D and Parkinson's disease risk?

Study design:
This review article included 8 studies.

Results and conclusions:
The investigators found when compared with normal controls, 25-hydroxyvitamin D insufficiency (30 ng/mL) significantly increased risk of Parkinson's disease with 77% [OR = 1.77, 95% CI = 1.29 to 2.43, p 0.001].

The investigators found when compared with normal controls, 25-hydroxyvitamin D deficiency (20 ng/mL) significantly increased risk of Parkinson's disease with 155% [OR = 2.55, 95% CI = 1.98 to 3.27, p 0.001].

The investigators found 15 minutes/week sunlight exposure significantly decreased risk of Parkinson's disease with 98% [OR = 0.02, 95% CI = 0.00 to 0.10, p 0.001].

The investigators found the use of vitamin D supplements was effective in increasing 25-hydroxyvitamin D levels [SMD = 1.79, 95% CI = 1.40 to 2.18, p 0.001], but had no significant effect on motor function [MD = -1.82, 95% CI = -5.10 to 1.45, p = 0.275] in patients with Parkinson's disease.

The investigators concluded that insufficiency and deficiency of 25-hydroxyvitamin D (vitamin D in blood) and reduced exposure to sunlight increase risk of Parkinson's disease. However, vitamin D supplements show no significant benefits in improving motor function for patients with Parkinson's disease.

Original title:
The Association Between Vitamin D Status, Vitamin D Supplementation, Sunlight Exposure, and Parkinson's Disease: A Systematic Review and Meta-Analysis by Zhou Z, Zhou R, [...], Li K.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30672512

Additional information of El Mondo:
Find here more information/studies about vitamin D and chronic diseases.
 

Objectives:
Low fruit and vegetable intakes are recognized risk factors for noncommunicable diseases. Therefore, this review article has been conducted.

Do fruit or vegetables intakes reduce noncommunicable diseases, likes cancer, coronary heart disease and all-cause mortality?

Study design:
This review article included 64 reports investigating 98 risk-disease pairs. 56 pairs from 39 reports were assessed as statistically significant, involving 29 burden of diseases.

Results and conclusions:
The investigators found in linear dose analysis for each 100 g/day increase in fruit intakes a significantly reduced risk of 44% [RR = 0.56, 95% CI = 0.42 to 0.74] for esophageal cancer.
Significant means that there is an association with a 95% confidence.

The investigators found in linear dose analysis for each 100 g/day increase in fruit intakes a significantly reduced risk of 28% [RR = 0.72, 95% CI = 0.59 to 0.87] for mouth, pharynx and larynx cancer.

The investigators found in nonlinear dose analysis for the first 100 g/day increase in fruit intakes a significantly reduced risk of 14% [RR = 0.86, 95% CI = 0.84 to 0.88] for stroke.

The investigators found in nonlinear dose analysis for the first 100 g/day increase in fruit intakes a significantly reduced risk of 11% [RR = 0.89, 95% CI = 0.88 to 0.90] for all-cause mortality.

The investigators found in linear dose analysis for each 100 g/day increase in vegetable intakes a significantly reduced risk of 12% [RR = 0.88, 95% CI = 0.80 to 0.95] for renal cell cancer.

The investigators found in linear dose analysis for each 100 g/day increase in vegetable intakes a significantly reduced risk of 11% [RR = 0.89, 95% CI = 0.84 to 0.95] for non-Hodgkin lymphoma.

The investigators found in nonlinear dose analysis for the first 100 g/day increase in vegetable intakes a significantly reduced risk of 14% [RR = 0.86, 95% CI = 0.84 to 0.89] for coronary heart disease.

The investigators found in nonlinear dose analysis for the first 100 g/day increase in vegetable intakes a significantly reduced risk of 13% [RR = 0.87, 95% CI = 0.84 to 0.90] for all-cause mortality.

The investigators found in nonlinear dose analysis clear increases in protective associations were observed with the first 200 g/day of fruit or vegetable intakes, whereas little further increase or even decrease in protective associations were reported beyond 300 g/day intakes.

The investigators found canned fruit intakes were positively associated with all-cause and cardiovascular disease mortality.

The investigators found pickled vegetable intakes were positively associated with stomach cancer.

The investigators concluded that 100-300 g/day of fruit or vegetables intakes reduce certain cancers, coronary heart disease and all-cause mortality. These findings support existing recommendations for fruit and vegetable intakes. Current comparative risk assessments might significantly underestimate the protective associations of fruit and vegetable intakes.

Original title:
The Associations of Fruit and Vegetable Intakes with Burden of Diseases: A Systematic Review of Meta-Analyses by Yip CSC, Chan W and Fielding R.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30639206

Additional information of El Mondo:
Find more information/studies on fruit and vegetable consumption, coronary heart disease and cancer right here.

Objectives:
Is there a relationship between serum 25(OH)D (vitamin D blood level) and mortality risk in the general population?

Study design:
This review article included 14 prospective cohort studies that involved 5562 deaths out of 62548 individuals.
In the parametric model, which is based on 11 studies and 59231 individuals, the lowest quantile as the reference category has been used.

Evidence of heterogeneity for the RR was apparent when highest were compared with lowest categories [p = 0.008, I2 = 58%].

There was no evidence of publication bias.

Results and conclusions:
The investigators found for “highest compared with lowest” categories of 25(OH)D, a significant reduced risk of 29% for mortality [RR = 0.71, 95% CI = 0.50-0.91].

The investigators found in the parametric model, the estimated summary RRs of mortality were 0.86 [95% CI = 0.82-0.91], 0.77 [95% CI = 0.70-0.84] and 0.69 [95% CI = 0.60-0.78] for individuals with an increase of 12.5, 25 and 50 nmol 25(OH)D serum values/L, respectively, from a median reference category of ∼27.5 nmol/L.
However, no significant decrease in mortality was found above ∼87.5 nmol/L.

The investigators concluded there is a nonlinear decrease in mortality risk as circulating 25(OH)D increases, with optimal concentrations ∼75-87.5 nmol/L. Because many adults do not achieve these 25(OH)D values, large prospective randomized trials are urgently needed to investigate whether vitamin D supplementation is able to reduce mortality risk in the general population.

Original title:
Vitamin D deficiency and mortality risk in the general population: a meta-analysis of prospective cohort studies by Zittermann A, Iodice S, [...], Gandini S.

Link:
http://ajcn.nutrition.org/content/95/1/91.full

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

Objectives:
Low glycaemic index (GI) diets are beneficial in the management of hyperglycemia. Cardiovascular diseases are the major cause of mortality in diabetes therefore it is important to understand the effects of GI on blood lipids. Therefore, this review article has been conducted.

Does a low GI diet lower the cholesterol levels?

Study design:
This review article included 28 RCTs comparing low with high GI diets over at least 4 weeks. These 28 RCTs contained 1272 participants with studies ranged from 6 to 155 participants, one was powered on blood lipids and 3 had adequate allocation concealment.

Results and conclusions:
The investigators found that compared to high GI diet low GI diet significantly reduced total cholesterol by 0.13 mmol/L [95% CI = -0.22 to -0.04, p = 0.004, 27 trials, 1441 participants]. Significantly means, it can be said with 95% confidence that low GI diet really lowered the total cholesterol levels with 0.13 mmol/L.

The investigators found that compared to high GI diet low GI diet significantly reduced LDL-cholesterol by 0.16 mmol/L [95% CI = -0.24 to -0.08, p 0.0001, 23 studies, 1281 participants]. Significantly, because the p-value was less than 0.05.

The investigators found subgroup analyses suggested that reductions in LDL-cholesterol were greatest in studies of shortest duration and greatest magnitude of GI reduction. Furthermore, lipid improvements appeared greatest and most reliable when the low GI intervention was accompanied by an increase in dietary fiber.

The investigators found sensitivity analyses, removing studies without adequate allocation concealment, lost statistical significance but retained suggested mean falls of 0.10 mmol/L in both.

The investigators found no effects on HDL-cholesterol [MD = -0.03 mmol/L, 95% CI = -0.06 to 0.00, I2 = 0%], or triglycerides [MD was 0.01 mmol/L, 95% CI = -0.06 to 0.08, I2 = 0%].

The researchers concluded that low GI diets reduce total and LDL-cholesterol (bad cholesterol) but had no effect on HDL-cholesterol (good cholesterol) or triglycerides.

Original title:
Low glycemic index diets and blood lipids: A systematic review and meta-analysis of randomized controlled trials by Goff LM, Cowland DE, [...], Frost GS.

Link:
http://www.sciencedirect.com/science/article/pii/S0939475312001524

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

High LDL-cholesterol levels and high triglyceride levels increase the risk of getting cardiovascular diseases whereas high HDL-cholesterol levels decrease the risk of getting cardiovascular diseases.

A low GI diet is a diet with a GI value of 55 or lower.

Objectives:
Does soy isoflavone reduce the frequency and severity of hot flashes?

Study design:
This review article included 19 trials (13 included hot flash frequency, of which 10 for severity and 3 for composite scores).
17 trials were selected for meta-analyses to clarify the effect of soybean isoflavones on hot flash frequency (13 trials) and severity (9 trials).

Results and conclusions:
The investigators found intake of soy isoflavones (median = 54 mg aglycone equivalents) for 6 weeks to 12 months significantly reduced the frequency (combined fixed-effect and random effects model) of hot flashes by 20.6% [95% CI = -28.38 to -12.86, p 0.00001] compared with placebo [p heterogeneity = 0.0003, I2 = 67% for random effects model].

The investigators also found isoflavones significantly reduced hot flash severity by 26.2% [95% CI = -42.23 to -10.15, p = 0.001] compared with placebo [p heterogeneity 0.00001, I2 = 86% for random effects model].

The investigators found isoflavone supplements providing more than 18.8 mg of genistein (the median for all studies) were more than twice as potent at reducing hot flash frequency than lower genistein supplements.

The investigators concluded soy isoflavone supplements (54 mg per day for 6 weeks to 12 months), derived by extraction or chemical synthesis, are significantly more effective than placebo in reducing the frequency and severity of hot flashes. Additional studies are needed to further address the complex array of factors that may affect efficacy, such as dose, isoflavone form, baseline hot flash frequency and treatment duration.

Original title:
Extracted or synthesized soybean isoflavones reduce menopausal hot flash frequency and severity: systematic review and meta-analysis of randomized controlled trials by Taku K, Melby MK, […], Messina M.

Link:
http://journals.lww.com/menopausejournal/Abstract/2012/07000/Extracted_or_synthesized_soybean_isoflavones.11.aspx

Additional information of El Mondo:
Find more studies/information on elderly and isoflavones right here.
 

Objectives:
In view of the vital role of oxidative stress in the pathogenesis of Alzheimer's disease (AD), the potential of antioxidant supplements to prevent AD have gained much interest, while there are conflicting results on this topic in recent years. Therefore, this review article has been conducted.

Does dietary intake of vitamin C and E and β-carotene decrease risk of Alzheimer's disease?

Study design:
This review article included 7 articles (dietary intake, but no supplements).

Results and conclusions:
The investigators found a significant decreased risk for Alzheimer disease of 24% [pooled relative risk = 0.76 95% CI = 0.67-0.84] for dietary intake of vitamin E and of 17% [pooled relative risk = 0.83, 95% CI = 0.72-0.94] for dietary intake of vitamin C.

However, the investigators found a non-significant decreased risk of 12% [pooled relative risk = 0.88, 95% CI = 0.73-1.03] for dietary intake of β-carotene.

The investigators concluded dietary intakes of vitamin C and E lower the risk of Alzheimer's disease, with vitamin E exhibiting the most pronounced protective effects. The findings will be of significance to the prevention and interventional treatment of Alzheimer's disease.

Original title:
Dietary intakes of vitamin E, vitamin C, and β-carotene and risk of Alzheimer's disease: a meta-analysis by Li FJ, Shen L and Ji HF.

Link:
http://www.ncbi.nlm.nih.gov/pubmed/22543848

Additional information of El Mondo:
Find more information/studies on vitamin C and E and carotenoids right here. 

Objectives:
Does diabetes increase risk of incident dementia and mild cognitive impairment?

Study design:
This review article included 19 prospective longitudinal studies including 6184 subjects with diabetes and 38530 subjects without diabetes. All subjects were without dementia or mild cognitive impairment at baseline (=at the beginning of the study).

There was no publication bias.

Results and conclusions:
The investigators found persons with diabetes had a significant increased risk of 46% for Alzheimer's disease [RR = 1.46, 95% CI = 1.20-1.77]. Significant means that there is an association with a 95% confidence.

The investigators found persons with diabetes had a significant increased risk of 148% for vascular dementia [RR = 2.48, 95% CI = 2.08-2.96].

The investigators found persons with diabetes had a significant increased risk of 51% for any dementia [RR = 1.51, 95% CI = 1.31-1.74]. Significant because RR of 1 was not found in the 95% CI of 1.31 to 1.74. RR of 1 means no risk/association.

The investigators found persons with diabetes had a significant increased risk of 21% for mild cognitive impairment [RR = 1.21, 95% CI = 1.02-1.45].

The investigators concluded diabetes is a risk factor for incident dementia (including Alzheimer's disease, vascular dementia and any dementia) and mild cognitive impairment.

Original title:
Diabetes as a risk factor for dementia and mild cognitive impairment: a meta-analysis of longitudinal studies by Cheng G, Huang G, [...], Wang H.

Link:
http://onlinelibrary.wiley.com/doi/10.1111/j.1445-5994.2012.02758.x/epdf

Additional information of El Mondo:
Find more studies/information on elderly and diabetes right here.

Objectives:
An increased intake of magnesium might lower blood pressure (BP), yet evidence from clinical trials is inconsistent, perhaps as a result of small sample size or heterogeneity in study design. Therefore, this review article (meta-analysis) has been conducted.

Are there dose-dependent effects of magnesium supplementation on blood pressure?

Study design:
This review article included 20 RCTs included 14 of hypertensive and 6 of normotensive persons totaling 1220 participants.
The doses of magnesium ranged from 10 to 40 mmol/day (median: 15.4 mmol/day or 370 mg per day).

Results and conclusions:
The investigators found magnesium supplementation resulted in only a small overall non-significant reduction in blood pressure. The pooled net estimates of blood pressure change were -0.6 mmHg [95% CI = -2.2 to 1.0] for systolic blood pressure and -0.8 mmHg [95% CI = -1.9 to 0.4] for diastolic blood pressure.

However, the investigators found an apparent dose-dependent effect of magnesium, with significant reductions of 4.3 mmHg systolic blood pressure [95% CI = 6.3 to 2.2, p 0.001) and non-significant reductions of 2.3 mmHg diastolic blood pressure [95% CI = 4.9 to 0.0, p = 0.09) for each 10 mmol/day (240 mg/day) increase in magnesium dose.

The investigators concluded there is a dose-dependent blood pressure reductions, especially systolic blood pressure from magnesium supplementation. However, adequately powered trials with sufficiently high doses of magnesium supplements need to be performed to confirm this relationship.

Original title:
The effect of magnesium supplementation on blood pressure: a meta-analysis of randomized clinical trials by Jeea SH, Miller ER, [...], Klagb MJ.

Link:
http://www.sciencedirect.com/science/article/pii/S0895706102029643

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

Objectives:
Quantification of the association between the intake of fruit and vegetables and risk of esophageal squamous cell carcinoma (ESCC) is controversial even though several studies have explored this association. Therefore, this review article (meta-analysis) has been conducted.

Does a high intake of vegetables and fruit decrease risk of esophageal squamous cell carcinoma?

Study design:
This review article included a total of 32 observational studies involving 10037 cases of esophageal squamous cell carcinoma.

There was no evidence of publication bias.

Results and conclusions:
The investigators found highest vs. lowest vegetable intake, significantly reduced risk of esophageal squamous cell carcinoma with 44% [SRR = 0.56, 95% CI = 0.45-0.69, p-heterogeneity 0.001]. Significant means there is an association with a 95% confidence.

The investigators found highest vs. lowest fruit intake, significantly reduced risk of esophageal squamous cell carcinoma with 47% [SRR = 0.53, 95% CI = 0.44-0.64, p-heterogeneity 0.001].

The investigators found similar results in a linear dose-response analysis and there was evidence of non-linear associations for intakes of fruit [p non-linearity 0.001] and vegetables [p non-linearity = 0.041].

The investigators concluded that intakes of vegetables and fruit reduce risk of esophageal squamous cell carcinoma. Further investigation with prospective designs, validated questionnaires and good control of important confounders is warranted.

Original title:
Intake of fruit and vegetables and risk of esophageal squamous cell carcinoma: A meta-analysis of observational studies by Liu J, Wang J, […], Lv C.

Link:
http://www.ncbi.nlm.nih.gov/pubmed/23319052

Additional information of El Mondo:
Find more information/studies on review, 95% CI and heterogeneity, vegetables and fruits and cancer right here.