Nutritional advice

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/

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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/

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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

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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

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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

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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

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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

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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

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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/

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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

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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

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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

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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

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Find more information/studies on fruit and vegetable consumption, coronary heart disease and cancer right here.

Objectives:
Lutein and zeaxanthin are thought to have beneficial effects on protecting the lens against cataract formation, but findings from epidemiologic studies have been inconsistent. Therefore, this review article has been conducted.

Does dietary lutein and zeaxanthin intake reduce age-related cataract risk?

Study design:
This review article included 6 prospective cohort studies, involving 4416 cases and 41999 participants.

Results and conclusions:
The investigators found for comparing the highest with the lowest categories of dietary lutein and zeaxanthin intake, a significant reduced risk for nuclear cataract of 25% [RR = 0.75, 95% CI = 0.65-0.85], but the reduced risk was not significant for cortical cataract [RR = 0.85, 95% CI = 0.53-1.17] and for posterior subcapsular cataract [RR = 0.77, 95% CI = 0.40-1.13]. Significant means, there is an association with a 95% confidence.

The investigators found in dose-response analysis that every 300 μg/d increment in dietary lutein and zeaxanthin intake was significantly associated with a 3% [RR = 0.97, 95% CI = 0.94-0.99] reduction in the risk of nuclear cataract.

The investigators found in dose-response analysis that every 300 μg/d increment in dietary lutein and zeaxanthin intake was non-significantly associated with a 1% [RR = 0.99, 95% CI = 0.95-1.02] reduction in the risk of cortical cataract. Non-significantly means, there is no association with a 95% confidence.

The investigators found in dose-response analysis that every 300 μg/d increment in dietary lutein and zeaxanthin intake was non-significantly associated with a 3% [RR = 0.97, 95% CI = 0.93-1.01] reduction in the risk of posterior subcapsular cataract. Non-significantly because RR of 1 was found in 95% CI of 0.93 to 1.01. RR of 1 means no risk.

The investigators concluded dietary lutein and zeaxanthin intake (at least 300 μg/d) is associated with a reduced risk of age-related cataract, especially nuclear cataract in a dose-response manner, indicating a beneficial effect of lutein and zeaxanthin in age-related cataract prevention.

Original title:
A dose–response meta-analysis of dietary lutein and zeaxanthin intake in relation to risk of age-related cataract by Ma L, Hao ZX, [...], Pan JP.

Link:
http://link.springer.com/article/10.1007/s00417-013-2492-3

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Objectives:
Does a low salt intake reduce blood pressure?

Study design:
This review article included 34 randomized trials with 3230 participants (the median age was 50 (range 22-73)), of which 22 were in hypertensive individuals and 12 in normotensive individuals. Of the 34 trials, 23 used crossover design and 11 used paralleled comparisons. 22 of the 34 trials were double blind, in 11 the observer was blind to blood pressure and one did not report any blinding procedure.

The study duration varied from 4 weeks to 3 years (median 4 weeks). With the usual salt intake the median 24 hour urinary sodium was 160 mmol (range 125-200 mmol), equivalent to a salt intake of 9.4 g/day (range 7.3-11.7 g/day) and the median blood pressure was 141/86 mmHg.

Despite the fact that only 7 out of 34 trials performed intention to treat analysis, the percentage of participants lost to follow-up after randomization was small (6.7% on average).

Results and conclusions:
The investigators found meta-analysis showed that the mean change in urinary sodium (reduced salt v usual salt) was -75 mmol/24 h (equivalent to a reduction of 4.4 g/day salt), and with this reduction in salt intake, the mean change in blood pressure was -4.18 mmHg [95% CI = -5.18 to -3.18, I2 = 75%] for systolic blood pressure and -2.06 mmHg [95% CI = -2.67 to -1.45, I2 = 68%] for diastolic blood pressure.

The investigators found meta-regression showed that age, ethnic group, blood pressure status (hypertensive or normotensive) and the change in 24 hour urinary sodium were all significantly associated with the fall in systolic blood pressure, explaining 68% of the variance between studies.

The investigators found a 100 mmol reduction in 24 hour urinary sodium (equivalent to a reduction 6 g/day salt) was associated with a fall in systolic blood pressure of 5.8 mmHg [95% CI = -2.5 to -9.2,  p = 0.001] after adjustment for age, ethnic group and blood pressure status.
For diastolic blood pressure, age, ethnic group, blood pressure status and the change in 24 hour urinary sodium explained 41% of the variance between studies.

The investigators found meta-analysis by subgroup showed that in people with hypertension the mean effect was -5.39 mmHg [95% CI = -6.62 to -4.15, I2 = 61%] for systolic blood pressure and -2.82 mmHg [95% CI = -3.54 to -2.11, I2 = 52%] for diastolic blood pressure.
In normotensive people, the figures were -2.42 mmHg [95% CI = -3.56 to -1.29, I2 = 66%] and -1.00 mmHg [95% CI = -1.85 to -0.15, I2 = 66%], respectively.

The investigators found further subgroup analysis showed that the decrease in systolic blood pressure was significant in both white and black people and in men and women.

The investigators found meta-analysis of data on hormones and lipids showed that the mean change was:
0.26 ng/mL/h [95% CI = 0.17 to 0.36, I2 = 70%] for plasma renin activity;
73.20 pmol/L [95% CI = 44.92 to 101.48, I2 = 62%] for aldosterone;
187 pmol/L [95% CI = 39 to 336, I2 = 5%] for noradrenaline (norepinephrine);
37 pmol/L [95% CI = -1 to 74, I2 = 12%] for adrenaline (epinephrine);
0.05 mmol/L [95% CI = -0.02 to 0.11, I2 = 0%] for total cholesterol;
0.05 mmol/L [95% CI = -0.01 to 0.12, I2 = 0%] for low density lipoprotein cholesterol (LDL-cholesterol or bad cholesterol);
-0.02 mmol/L [95% CI = -0.06 to 0.01, I2 = 16%] high density lipoprotein cholesterol (HDL-cholesterol or good cholesterol) and:
0.04 mmol/L [95% CI = -0.02 to 0.09, I2 = 0%] for triglycerides.

The investigators concluded a modest reduction in salt intake of 4.4 g/day for 4 or more weeks causes, from a population viewpoint, important falls in blood pressure in people with both raised and normal blood pressure.
Salt reduction is associated with a small physiological increase in plasma renin activity, aldosterone and noradrenaline and no significant change in lipid concentrations.
The current recommendations to reduce salt intake from 9-12 to 5-6 g/day will have a major effect on blood pressure, but a further reduction to 3 g/day will have a greater effect and should become the long term target for population salt intake.

Original title:
Effect of longer term modest salt reduction on blood pressure: Cochrane systematic review and meta-analysis of randomised trials by He FJ, Li J and MacGregor GA.

Link:
http://www.bmj.com/content/346/bmj.f1325

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A daily diet with a maximum of 3 grams salt per day is a diet with a maximum of 0.15 gram salt per 100 kcal.
A daily diet with a maximum of 0.15 gram salt per 100 kcal is a diet with mainly products/meals with a maximum of 0.15 gram salt per 100 kcal.

Objectives:
Previous trials have shown that zinc supplementation can decrease the risk of diarrhea, pneumonia and malaria in children; however, the effects of zinc supplementation on mortality remain unclear. Therefore, this review article has been conducted.

Does zinc supplementation reduce total mortality and cause-specific mortality in preschool children?

Study design:
This review article included 8 RCTs which included 87,854 children and reported 1,558 events of mortality. The population of the trials ranged from 96 to 42,546 and the follow-up for subjects ranged from 6 to 17.6 months.

Egger and Begg tests showed no evidence of publication bias for total mortality [p value for Egger = 0.207, p value for Begg = 0.902].

Results and conclusions:
The investigators found overall, zinc supplementation had no effect on:
total mortality [RR = 0.76, 95% CI = 0.56-1.04, p = 0.084];
diarrhea-related mortality [RR = 0.80, 95% CI = 0.53-1.20, p = 0.276];
pneumonia-related mortality [RR = 0.52, 95% CI = 0.11-2.39, p = 0.399];
malaria-related mortality [RR = 0.90, 95% CI = 0.77-1.06, p = 0.196] or;  

other causes of mortality [RR = 0.98, 95% CI = 0.67-1.44, p = 0.917]. No effect because RR of 1 was found in the 95% CI of 0.67 to 1.44. RR of 1 means no risk/effect/association.

The investigators found subgroup analysis indicated that zinc supplementation was significantly associated with a reduction in total mortality risk if the participants were boys, aged greater than 12 months and the duration of the follow-up period was less than 12 months. Significant means, there is an association with a 95% confidence

The investigators concluded zinc supplementation reduces total mortality risk if the participants are boys, aged greater than 12 months and the duration of the follow-up period is less than 12 months.

Original title:
Effects of zinc supplementation on the incidence of mortality in preschool children: a meta-analysis of randomized controlled trials by Fu W, Ding LR, [...], Zhou YH.

Link:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3823854/

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Find more information/studies on malnutrition and zinc right here.
 

Objectives:
Does iron supplementation during pregnancy improve maternal haematological status and birth weight?

Study design:
This review article included 48 RCTs (17,793 women) and 44 cohort studies (1,851,682 women).

The dose of iron in RCTs ranged from 10 mg to 240 mg daily. Duration of supplementation varied from 7 to 8 weeks up to 30 weeks during pregnancy.

Significant heterogeneity existed for several outcomes that could not be explained substantially by pre-specified subgroups.

Results and conclusions:
The investigators found iron supplementation during pregnancy increased maternal mean haemoglobin concentration by 4.59 g/L [95% CI = 3.72 to 5.46] compared with controls.

The investigators found iron with folic acid was associated with a significant increase in mean haemoglobin concentration of 10.41 g/L [95% CI = 5.36 to 15.46, I2 = 0%, 9 trials] and reduction in risk of anaemia in the third trimester or at delivery of 56% [95% CI = 0.37 to 0.53, I2 = 44%, 5 trials]. Significant means there is an association with a 95% confidence.

The investigators found iron supplementation during pregnancy significantly reduced the risk of anaemia with 50% [95% CI = 0.42 to 0.59] compared with controls.

The investigators found iron supplementation during pregnancy significantly reduced the risk of iron deficiency (of the mother) with 41% [95% CI = 0.46 to 0.79] compared with controls.

The investigators found iron supplementation during pregnancy significantly reduced the risk of iron deficiency anaemia with 60% [95% CI = 0.26 to 0.60] compared with controls.

The investigators found iron supplementation during pregnancy significantly reduced the risk of low birth weight (2500 g) with 19% [95% CI = 0.71 to 0.93] compared with controls.

However, the investigators found iron supplementation during pregnancy non-significantly reduced the risk of preterm birth with 16% [95% CI = 0.68 to 1.03] compared with controls. Non-significant means there is no association with a 95% confidence.

The investigators found in cohort studies that anaemia in the first or second trimester was significantly associated with a higher risk for low birth weight of 29% [adjusted odds ratio 1.29, 95% CI = 1.09 to 1.53] and preterm birth with 21% [adjusted odds ratio = 1.21, 95% CI = 1.13 to 1.30].

The investigators found in exposure-response analysis that for every 10 mg increase in iron dose/day, up to 66 mg/day, the relative risk of maternal anaemia was significantly 0.88 [95% CI = 0.84 to 0.92, p for linear trend 0.001].

The investigators found in exposure-response analysis that birth weight increased by 15.1 g [95% CI = 6.0 to 24.2, p for linear trend = 0.005] and risk of low birth weight significantly decreased by 3% [relative risk = 0.97, 95% CI = 0.95 to 0.98, p for linear trend 0.001] every 10 mg increase in dose/day.

Furthermore, the investigators found for each 1 g/L increase in mean haemoglobin, birth weight increased by 14.0 g [95% CI = 6.8 to 21.8, p for linear trend = 0.002]. However, mean haemoglobin was not associated with the risk of low birth weight and preterm birth.

The investigators found no evidence of a significant effect on duration of gestation, small for gestational age births and birth length and duration of iron use was not significantly associated with the outcomes after adjustment for dose.

The investigators concluded daily prenatal use of iron substantially improved birth weight in a linear dose-response fashion, probably leading to a reduction in risk of low birth weight. An improvement in prenatal mean haemoglobin concentration linearly increased birth weight and a linear decrease in maternal anaemia with higher doses of iron, up to 66 mg/day.

Original title:
Anaemia, prenatal iron use, and risk of adverse pregnancy outcomes: systematic review and meta-analysis by Haider BA, Olofin I, […], Fawzi WW.

Link:
http://www.bmj.com/content/346/bmj.f3443

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Iron deficiency anaemia occurs when there isn't enough iron in the body. Anaemia is a condition where the amount of haemoglobin in the blood is below the normal level.
Iron deficiency anaemia has been defined as haemoglobin 110 g/L and serum ferritin 12 µg/L.

Objectives:
Several reviews and meta-analyses have examined the effects of iodine on mental development. However, none focused on young children, so they were incomplete in summarizing the effects on this important age group. Therefore, this review article has been conducted.

Is there a relationship between iodine and mental development of children 5 years old and under?

Study design:
This review article included 24 studies (14 cohort en 10 intervention studies).
Studies providing supplementation to women before or during pregnancy tended to give injections of iodized oil of 950 mg; only the studies conducted in China and DR Congo gave lower doses (400 and 475 mg, respectively).
The median sample size per group across the 10 intervention studies was 50 with a range of 7 to 624.

Results and conclusions:
The investigators found that the best estimate to date of the effect size of iodine supplementation on mental development in children 5 years old and under was 0.49, which translated into 7.4 IQ points lost due to iodine deficiency.

The investigators found 6.9 to 10.2 IQ points lower in iodine deficient children compared with iodine replete children.

The investigators concluded, regardless of study design, iodine deficiency has a substantial impact on mental development in children 5 years old and under. To further quantify the importance of iodine for mental development in young children, this review points to the need for well-designed randomized controlled trials with adequate sample sizes as well as studies that assess the effectiveness of iodized salt.

Original title:
Iodine and Mental Development of Children 5 Years Old and Under: A Systematic Review and Meta-Analysis by Bougma K, Aboud FE, […], Marquis GS.

Link:
http://www.mdpi.com/2072-6643/5/4/1384/htm

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