Nutrition and health

Objectives:
Several previous meta-analyses show a consistent inverse association between nut consumption and all-cause mortality, but the associations with cause-specific mortality remain uncertain. Therefore, this meta-analysis (review article) has been conducted.

Does nut consumption reduce all-cause and cause-specific mortality?

Study design:
This review article included 18 prospective cohort studies with 81,034 deaths.

Results and conclusions:
The investigators found random-effects meta-analysis of 18 studies with 81,034 deaths showed a significant reduced risk of 19% [summary RR = 0.81, 95% CI = 0.78-0.84] for all-cause mortality for high compared with low nut consumption. This significant reduced risk was broadly consistent within subgroups according to various study and population characteristics and within sensitivity analyses that took into account potential confounders.

The investigators found random-effects meta-analysis of 17 studies with 20,381 deaths showed a significant reduced risk of 25% [summary RR = 0.75, 95% CI = 0.71-0.79] for cardiovascular mortality for high compared with low nut consumption. This significant reduced risk was broadly consistent within subgroups according to various study and population characteristics and within sensitivity analyses that took into account potential confounders.

The investigators found random-effects meta-analysis of 14 studies with 10,438 deaths showed a significant reduced risk of 27% [summary RR = 0.73, 95% CI = 0.67-0.80] for coronary heart disease mortality for high compared with low nut consumption. This significant reduced risk was broadly consistent within subgroups according to various study and population characteristics and within sensitivity analyses that took into account potential confounders.

The investigators found random-effects meta-analysis of 13 studies with 4,850 deaths showed a significant reduced risk of 18% [summary RR = 0.82, 95% CI = 0.73-0.91] for stroke mortality for high compared with low nut consumption. This significant reduced risk was broadly consistent within subgroups according to various study and population characteristics and within sensitivity analyses that took into account potential confounders.

The investigators found random-effects meta-analysis of 11 studies with 21,353 deaths showed a significant reduced risk of 13% [summary RR = 0.87, 95% CI = 0.80-0.93] for cancer mortality for high compared with low nut consumption. This significant reduced risk was broadly consistent within subgroups according to various study and population characteristics and within sensitivity analyses that took into account potential confounders.

The investigators found peanut (5 studies) and tree nut (3 studies) consumption were similarly associated with mortality risks.

The investigators found dose-response analyses suggested evidence for nonlinear associations between nut consumption and mortality [p-nonlinearity 0.001 for all outcomes except cancer mortality], with mortality risk levelling off at the consumption of about 3 servings per week (12g/day).

The investigators concluded that nut consumption is associated with reduced all-cause and cause-specific mortality, with the strongest reduction for coronary heart disease (CHD) mortality. Both tree nuts and peanuts lower mortality and most of the survival benefits could be achieved at a relative low level of nut consumption (up to 12g/day).

Original title:
Nut consumption in relation to all-cause and cause-specific mortality: a meta-analysis 18 prospective studies by Chen GC, Zhang R, [...], Qin LQ.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28875220

Additional information of El Mondo:
Find more information/studies on nut consumption, cancer, cardiovascular disease and stroke right here.
 

Objectives:
The results of randomized controlled trials (RCTs) investigating resveratrol supplementation on risk factors of non-communicable diseases (NCDs) have been inconsistent. Therefore, this review article (meta-analysis) has been conducted.

Does resveratrol supplementation reduce risk of non-communicable diseases?

Study design:
This review article included 29 RCTs (30 treatment arms) with 1069 participants.

Results and conclusions:
The investigators found that resveratrol supplementation significantly reduced the concentrations of:
-fasting glucose [-4.77 mg/dL, 95% CI = -9.33 to -0.21 mg/dL, p = 0.040];
-total cholesterol (TC) [-9.75 mg/dL, 95% CI = -17.04 to -2.46 mg/dL, p = 0.009] and;
-C-reactive protein (CRP) [-0.81 mg/L, 95% CI = -1.42 to -0.21 mg/L, p = 0.009].

The investigators found that resveratrol intervention exerted significant reductions in systolic blood pressure (SBP) and diastolic blood pressure (DBP) in subjects with type 2 diabetes mellitus (T2DM).

The investigators found subgroup analysis also showed that the trials with resveratrol intervention ≥3 months significantly reduced the low-density lipoprotein (LDL) cholesterol (bad cholesterol), diastolic blood pressure and glycated hemoglobin (HbA1c) values.

The investigators found that resveratrol intervention had no favourable effects in altering high-density lipoprotein (HDL) cholesterol (good cholesterol), triglyceride (TAG) and homeostasis model assessment of insulin resistance (HOMA-IR).

The investigators concluded resveratrol supplementation ≥3 months has favourable effects on several risk factors of non-communicable diseases.

Original title:
Effects of resveratrol supplementation on risk factors of non-communicable diseases: A meta-analysis of randomized controlled trials by Guo XF, Li JM, [...], Li D.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28933578

Additional information of El Mondo:
Find more information/studies on flavonoids, cholesterol, blood pressure, diabetes and chronic diseases right here.

Non-communicable or chronic diseases are diseases of long duration and generally slow progression. The four main types of non-communicable diseases are cardiovascular diseases (like heart attacks and stroke), cancer, chronic respiratory diseases (such as chronic obstructed pulmonary disease and asthma) and diabetes.

Non-communicable diseases are by far the leading cause of death in the world.
 

Objectives:
Micronutrient deficiencies are common among women in low-income and middle-income countries. Data from randomised trials suggest that maternal multiple micronutrient supplementation decreases the risk of low birthweight and potentially improves other infant health outcomes. However, heterogeneity across studies suggests influence from effect modifiers. Therefore, this review article (meta-analysis) has been conducted.

What are the effects of individual-level modifiers of multiple micronutrient supplements on stillbirth, birth outcomes and infant mortality in low-income and middle-income countries?

Study design:
This review article included 17 RCTs, done in 14 low-income and middle-income countries, which compared multiple micronutrient supplements containing iron-folic acid versus iron-folic acid alone in 112,953 pregnant women.

All trials used multiple micronutrient supplements preparations that included at least eight micronutrients in addition to iron-folic acid. Eight trials used the United Nations multiple micronutrient preparation.

All trials were graded low or moderate risk of bias. Funnel plots did not provide clear evidence of publication bias or small study effects.

Results and conclusions:
The investigators found multiple micronutrient supplements containing iron-folic acid (≤30 mg iron) provided a significantly 15% reduction in neonatal mortality for female neonates compared with male neonates [RR = 0.85, 95% CI = 0.75-0.96, p value for interaction = 0.007].

The investigators found iron-folic acid supplementation alone (60 mg iron) provided a non-significantly 6% higher neonatal mortality risk for female neonates compared with male neonates [RR = 1.06, 95% CI = 0.95-1.17].

The investigators found multiple micronutrient supplements resulted in greater reductions in
-low birthweight [RR = 0.81, 95% CI = 0.74-0.89, p value for interaction = 0.049];
-small-for-gestational-age births [RR = 0.92, 95% CI = 0.87-0.97, p = 0.03] and;
-6-month mortality [RR = 0.71, 95% CI = 0.60-0.86, p = 0.04] in anaemic pregnant women (haemoglobin 110g/L) as compared with non-anaemic pregnant women.

The investigators found multiple micronutrient supplements also significantly reduced risk of preterm birth among underweight pregnant women (BMI 18.5 kg/m²) with 16% [RR = 0.84, 95% CI = 0.78-0.91, p = 0.01].

The investigators found initiation of multiple micronutrient supplements before 20 weeks gestation provided greater reductions in preterm birth risk [RR = 0.89, 95% CI = 0.85-0.93, p = 0.03].

The investigators found generally, the survival and birth outcome effects of multiple micronutrient supplementation were greater with high adherence (≥95%) to supplementation.

The investigators found multiple micronutrient supplements did not significantly increase the risk of stillbirth or neonatal, 6-month, or infant mortality, neither overall or in any of the 26 examined subgroups.

The investigators concluded antenatal multiple micronutrient supplements improve survival for female neonates and provide greater birth-outcome benefits for infants born to undernourished and anaemic pregnant women. Early initiation in pregnancy (before 20 weeks gestation) and high adherence (≥95%) to multiple micronutrient supplements also provide greater overall benefits. Studies should now aim to elucidate the mechanisms accounting for differences in the effect of antenatal multiple micronutrient supplements on infant health by maternal nutrition status and sex.

Original title:
Modifiers of the effect of maternal multiple micronutrient supplementation on stillbirth, birth outcomes, and infant mortality: a meta-analysis of individual patient data from 17 randomised trials in low-income and middle-income countries by Smith ER, Shankar AH, […], Sudfeld CR.

Link:
http://www.thelancet.com/journals/langlo/article/PIIS2214-109X(17)30371-6/fulltext

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

Objectives:
Increasing evidence suggests that high consumption of meat is linked to lung cancer but the previous meta-analyses did not properly address the role of tobacco smoking as a potential confounder. Therefore, this review article (meta-analysis) has been conducted.

Does high consumption of meat increase lung cancer risk among never and non-smokers?

Study design:
This review article included 14 independent observational studies and a total of 5,368 subjects with lung cancer.
There was no indication of publication bias.

Results and conclusions:
The investigators found in 11 studies, a statistically significant 24% increased risk of lung cancer for high consumption of red meat [Summary Relative Risk = 1.24, 95% CI = 1.01-1.51, I2 = 31%].

The investigators found no significant associations between high consumption of other types of meat, fish or for heterocyclic amines and lung cancer risk.

The investigators found no significant risk estimates for the increase of one serving per week of any type of meat or fish.

The investigators concluded a high intake of red meat increases the risk of lung cancer among never and non-smokers.

Original title:
Carcinogenicity of High Consumption of Meat and Lung Cancer Risk Among Non-Smokers: A Comprehensive Meta-Analysis by Gnagnarella P, Caini S, […], Gandini S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29016198

Additional information of El Mondo:
Find more information/studies on meat consumption, randomized controlled trials/cohort studies/subgroup analysis and cancer right here.

According to international recommendations, adults should aim to have a maximum of 70g red meat per day or 500g per week (cooked weight).
 

Objectives:
Anthocyanins are of interest due to their anti-oxidative and vasodilatory properties. Earlier reviews have shown that berries and other anthocyanin rich foods or extracts can improve vascular health. However, the effect of anthocyanins on vascular function has not yet been reviewed. Therefore, this review article (meta-analysis) has been conducted.

Does anthocyanin supplementation improve vascular function?

Study design:
This review article included 29 RCTs (15 were parallel and 14 were crossover designs).
Anthocyanin intakes ranged from 1 to 724 mg/day.
Most studies (n = 19) involved participants in the middle to older age group (mean age ≥ 40 years).
The number of participants that completed each study ranged from 10 to 146.
Intervention durations ranged from 1 h to 6 h in the acute studies and one week to six months in the chronic studies.

There was no publication bias.

Results and conclusions:
The investigators found compared to placebo-control, acute anthocyanin supplementation (1-8 h post consumption of anthocyanin doses between 7 and 724 mg) significantly improved FMD [SMD = 3.92%, 95% CI = 1.47 to 6.38, p = 0.002, I2 = 91.8%].
No improvements were observed in PAT-RHI [SMD = 0.08, 95% CI = -0.34 to 0.50, p = 0.71, I2 = 0%].
Collectively, (i.e., the pooling of studies using FMD and/or PAT-RHI) anthocyanins may improve vascular reactivity [overall SMD = 2.41, 95% CI = 0.91 to 3.91, p = 0.002, I2 = 92.6%].

The investigators found compared to placebo-control, acute anthocyanin supplementation (1-8 h post consumption of anthocyanin doses between 7 and 724 mg) also significantly improved arterial stiffness, using PWV [SMD = -1.27 m/s, 95% CI = -1.96 to -0.58, p = 0.000, I2 = 17.9%].

The investigators found pulse wave velocity was improved following acute anthocyanin supplementation only [SMD = -1.27 m/s, 95% CI = -1.96 to -0.58, p = 0.000, I2 = 17.8%]. 

The investigators found compared to placebo-control, chronic anthocyanin supplementation (one week to six months and used anthocyanin doses of 12 to 320 mg/day) significantly improved FMD [SMD = 0.84%, 95% CI = 0.55 to 1.12, p = 0.000, I2 = 62.5%].
Collectively (i.e., the pooling of studies using FMD and/or PAT-RHI), chronic anthocyanin supplementation may improve vascular reactivity [overall SMD = 0.77, 95% CI = 0.37 to 1.16, p = 0.000, I2 = 85.3%].

The investigators concluded that both acute and chronic anthocyanin supplementation improve vascular health, particularly with respect to vascular reactivity measured by FMD. However, more research is required to determine the optimal dosage and the long-term effects of anthocyanin consumption.

Original title:
The Effect of Anthocyanin-Rich Foods or Extracts on Vascular Function in Adults: A Systematic Review and Meta-Analysis of Randomised Controlled Trials by Fairlie-Jones L, Davison K, […], Hill AM.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5579701/

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Find more information/studies on flavonoids and cardiovascular diseases right here.  

Objectives:
2-6 million stillbirths occur annually worldwide. The association between malaria in pregnancy and stillbirth has yet to be comprehensively quantified. Therefore, this review article (meta-analysis) has been conducted.

Does malaria in pregnancy increases stillbirth risk?

Study design:
This review article included 59 studies (population-based cross-sectional, cohort or case-control studies and randomised controlled trials, identified before Feb 28, 2017) consisting of 141,415 women and 3,387 stillbirths.

Results and conclusions:
The investigators found plasmodium falciparum malaria detected at delivery in peripheral samples significantly increased the risk of stillbirth with 81% [OR = 1.81, 95% CI = 1.42-2.30, I2 = 26.1%, 34 estimates].

The investigators found plasmodium falciparum malaria detected at delivery in placental samples significantly increased the risk of stillbirth with 95% [OR = 1.95, 95% CI = 1.48-2.57, I2 = 33.6%, 31 estimates].

The investigators found plasmodium falciparum malaria detected and treated during pregnancy was also associated with stillbirth, but to a lesser extent [OR = 1.47, 95% CI = 1.13-1.92, 19 estimates].

The investigators found plasmodium vivax malaria detected at delivery non-significantly increased the risk of stillbirth with 181% [OR = 2.81, 95% CI= 0.77-10.22, 3 estimates].

The investigators found plasmodium vivax malaria detected and treated during pregnancy non-significantly increased the risk of stillbirth with 9% [OR = 1.09, 95% CI= 0.76-1.57, 4 estimates].

The investigators found the association between plasmodium falciparum malaria in pregnancy and stillbirth was two times greater in areas of low-to-intermediate endemicity than in areas of high endemicity [OR = 1.96, 95% CI = 1.34-2.89]. 

The investigators concluded plasmodium falciparum malaria in pregnancy increases stillbirth risk. The risk of malaria-associated stillbirth is likely to increase as endemicity declines. There is a pressing need for context-appropriate, evidence-based interventions for malaria in pregnancy in low-endemicity settings.
Assuming all women with malaria are still parasitaemic at delivery, an estimated 20% of the 1,059,700 stillbirths in malaria-endemic sub-Saharan Africa are attributed to plasmodium falciparum malaria in pregnancy; the population attributable fraction decreases to 12%, assuming all women with malaria are treated during pregnancy.

Original title:
Quantification of the association between malaria in pregnancy and stillbirth: a systematic review and meta-analysis by Moore KA, Simpson JA, […], Fowkes FJI.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28967610

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

Malaria is a life-threatening disease and is caused by Plasmodium parasites. The parasites are spread to people through the bites of infected female Anopheles mosquitoes, called "malaria vectors". There are 5 parasite species that cause malaria in humans and 2 of these species - Plasmodium falciparum and Plasmodium vivax - pose the greatest threat.

1. Plasmodium falciparum is responsible for the majority of malaria deaths globally and is the most prevalent species in sub-Saharan Africa. The remaining species are not typically as life threatening as Plasmodium falciparum.
2. Plasmodium vivax, is the second most significant species and is prevalent in Southeast Asia and Latin America. Plasmodium vivax and Plasmodium ovale have the added complication of a dormant liver stage, which can be reactivated in the absence of a mosquito bite, leading to clinical symptoms.
3. Plasmodium ovale represents only a small percentage of infections.
4. Plasmodium malariae represents only a small percentage of infections.
5. A fifth species Plasmodium knowlesi - a species that infects primates - has led to human malaria, but the exact mode of transmission remains unclear.

The time from the initial malaria infection until symptoms appear - incubation period - typically ranges from:

• 9 to 14 days for Plasmodium falciparum.
• 12 to 18 days for Plasmodium vivax and Plasmodium ovale.
• 18 to 40 days for Plasmodium malariae.
• 11 to 12 days for Plasmodium knowlesi.

Malaria is preventable and curable.

Objectives:
Several studies have investigated the relationship between serum selenium concentration and cervical cancer, but the results were inconsistent. Therefore, this review article (meta-analysis) has been conducted.

Do high serum selenium levels reduce risk of cervical cancer among women?

Study design:
This review article included 12 studies investigating the association by univariate analysis and 5 studies by multivariate analysis.

Results and conclusions:
The investigators found in univariate analysis, that serum selenium levels in women with cervical cancer were significantly lower than in women without cervical cancer [SMD = -4.86, 95% CI = -6.03 to -3.69]. Subgroup analysis showed consistent results.

The investigators found in multivariate analysis, that serum selenium levels in women with cervical cancer were significantly lower than in women without cervical cancer [OR = 0.55, 95% CI = 0.42-0.73].

The investigators found after treatment, the serum selenium levels increased significantly [SMD = 2.59, 95% CI = 0.50-4.69].

The investigators concluded high serum selenium levels reduce risk of cervical cancer among women.

Original title:
Serum Selenium Levels and Cervical Cancer: Systematic Review and Meta-Analysis by He D, Wang Z, […], Chen D.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28255860

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Find more information/studies on selenium, randomized controlled trials/cohort studies/subgroup analysis and cancer right here.

Univariate analysis is the simplest form of analyzing data. "Uni" means "one", thus in other words your data has only one variable.

High serum selenium levels can be obtained by consuming selenium-rich food items and/or taking selenium supplements.
 

Objectives:
Whether iron is associated with the development of gestational diabetes mellitus (GDM) is not clear. Therefore, this review article (meta-analysis) has been conducted.

Do increased dietary intake of iron and body iron status increase risk of gestational diabetes mellitus in pregnant women? 

Study design:
This review article included 12 case-control  studies, 9 cohort studies and  2  randomized  controlled  studies (RCT) with in total, 3,034 gestational diabetes mellitus pregnant women and 26,344 non-gestational diabetes mellitus pregnant women.

Results and conclusions:
The investigators found high dietary intake of heme iron was significantly associated with a 65% gestational diabetes mellitus risk [RR = 1.65, 95% CI = 1.28 to 2.12, I2 = 0%].

The investigators found for each 1 mg/day increment of dietary heme iron intake a significantly 38% gestational diabetes mellitus risk [RR = 1.38, 95% CI = 1.19 to 1.61, I2 = 0%].

The investigators found higher body iron stores, as represented by serum ferritin level, were correlated with a significantly increased gestational diabetes mellitus risk of 64% [RR = 1.64, 95% CI = 1.27 to 2.11, I2% = 7%].

The investigators found no association between gestational diabetes mellitus and the intakes of nonheme iron, total iron or supplemental iron.

The investigators concluded increased dietary intake of heme iron (at least 1 mg/day) and body iron status are positively associated with the risk of gestational diabetes mellitus development in pregnant women. Future studies are warranted to better understand the role of iron in gestational diabetes mellitus development.

Original title:
Dietary intake of heme iron and body iron status are associated with the risk of gestational diabetes mellitus: a systematic review and meta-analysis by Zhao L, Lian J, [...], Wang F.

Link:
http://apjcn.nhri.org.tw/server/APJCN/26/6/1092.pdf

Additional information of El Mondo:
Find more information/studies on iron, pregnancy and review article/significant/95% CI right here.

Gestational diabetes mellitus is a condition in which a woman without diabetes develops high blood sugar levels during pregnancy. Gestational diabetes mellitus affects between 2% and 5% of pregnant women.

Objectives:
Killed whole-cell oral cholera vaccines (kOCVs) are becoming a standard cholera control and prevention tool. However, vaccine efficacy and direct effectiveness estimates have varied, with differences in study design, location, follow-up duration and vaccine composition posing challenges for public health decision making. Therefore, this review article (meta-analysis) has been conducted.

Do 2 doses of killed whole-cell oral cholera vaccine provide sufficient protection against cholera?

Study design:
This review article included 7 RCTs with 695 patients with cholera and 6 observational studies (4 case-control studies,1 cohort study and 1 case-cohort study) with 217 patients with cholera).

The duration between the first two vaccine doses in RCTs ranged from 14 to 42 days.
The duration between the two primary vaccine doses in observational studies ranged from 12 to 25 days.
There were no signs of publication bias from a visual assessment of funnel plots for observational studies and RCTs, separately.

Results and conclusions:
The investigators found in pooled analyses an average two-dose efficacy of 58% [95% CI = 42-69, I2 = 58%] and effectiveness of 76% [95% CI = 62-85, I2 = 0%].

The investigators found in pooled analyses an average two-dose efficacy in children younger than 5 years [30%, 95% CI = 15-42, I2 = 0%] was lower than in those 5 years or older [64%, 95 CI = 58-70, I2 = 0%, p 0.0001].

The investigators found in pooled analyses two-dose efficacy estimates of kOCV were similar during the first 2 years after vaccination, with estimates of 56% [95% CI = 42-66, I2 = 45%] in the first year and 59% [95% CI = 49-67, I2 = 0%] in the second year. However, the efficacy reduced to 39% [95% CI = 13 to 57, I2 = 48%] in the third year and 26% [95% CI = -46 to 63, I2 = 74%] in the fourth year.

The investigators concluded 2 kOCV doses provide protection against cholera for at least 3 years. Children younger than 5 years were observed to have lower efficacy than those aged 5 years and older. Although vaccination alone will probably not lead to elimination of cholera, it can provide an important stopgap while improved water, sanitation and health-care infrastructure are provided to vulnerable populations. More work is needed to understand how and when to best use existing vaccines and to design new and more effective ones. However, the past three decades of evidence points towards kOCV being a safe, effective, and important tool to fight cholera.

Original title:
Protection against cholera from killed whole-cell oral cholera vaccines: a systematic review and meta-analysis by Bi Q, Ferreras E, […], Azman AS.

Link:
http://www.thelancet.com/pdfs/journals/laninf/PIIS1473-3099(17)30359-6.pdf

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

Objectives:
Do patients with type 2 diabetes benefit from a low carbohydrate diet?

Study design:
This review article included a total of 9 RCTs with 734 patients with type 2 diabetes.

Results and conclusions:
The investigators found that low carbohydrate diet significantly reduced HbA1c level [WMD = -0.44, 95% CI = -0.61 to -0.26, p= 0.00] of patients with type 2 diabetes.

The investigators found that low carbohydrate diet significantly reduced triglycerides concentration [WMD = -0.33, 95% CI = -0.45 to -0.21, p = 0.00] of patients with type 2 diabetes.

The investigators found that low carbohydrate diet significantly increased HDL cholesterol concentration (WMD = 0.07, 95% CI = 0.03 to 0.11, p = 0.00] of patients with type 2 diabetes.

The investigators found that low carbohydrate diet was not associated with decreased level of total cholesterol and LDL cholesterol.

The investigators found subgroup analyses showed that short term intervention of low carbohydrate diet was effective for weight loss [WMD = -1.18, 95% CI = -2.32 to -0.04, p = 0.04] in patients with type 2 diabetes.

The investigators concluded there is a beneficial effect of low carbohydrate diet intervention on glucose control in patients with type 2 diabetes. The low carbohydrate diet intervention also has a positive effect on triglycerides and HDL cholesterol concentrations, but without significant effect on long term weight loss.

Original title:
Efficacy of low carbohydrate diet for type 2 diabetes mellitus management: A systematic review and meta-analysis of randomized controlled trials by Meng Y, Bai H, […], Chen L.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28750216

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

A low carbohydrate diet is a diet that is largely made up of meals/products with 20-40 En% carbohydrate. Practically, this means that all meals/products that you eat on a daily basis should on average contain 20-40 En% carbohydrate.
20-40 En% carbohydrate means that the total amounts of carbohydrate make up for a 20-40% of the total kcal of the diet. Check here which products contain 20-40 En% carbohydrate.

Objectives:
World Health Assembly member states have committed to ambitious global targets for reductions in stunting and wasting by 2025. Improving complementary diets of children aged 6-23 months is a recommended approach for reducing stunting in children 5 y old. Less is known about the potential of these interventions to prevent wasting. Therefore, this review article (meta-analysis) has been conducted.

What is the impact of complementary feeding interventions on linear [length-for-age z score (LAZ)] and ponderal [weight-for-length z score (WLZ)] growth of children aged 6-23 months?

Study design:
This review article included studies of the previous LiST review and articles published since January 2012. The studies were longitudinal trials that compared children aged 6-23 months who received 1 of 2 types of complementary feeding interventions (nutrition education or counseling alone or complementary food supplementation with or without nutrition education or counseling) with a no-intervention control.

Results and conclusions:
The investigators found interventions that provided nutrition education or counseling had a small but significant impact on linear growth in food-secure populations [LAZ standardized mean difference (SMD) = 0.11, 95% CI = 0.01-0.22] but not on ponderal growth.

The investigators found complementary food supplementation interventions with or without nutrition education also had a small, significant effect in food-insecure settings on both LAZ [SMD = 0.08, 95% CI = 0.04-0.13] and WLZ [SMD = 0.05, 95% CI = 0.01-0.08].

The investigators concluded nutrition education and complementary feeding interventions both had a small but significant impact on linear growth and complementary feeding interventions also had an impact on ponderal growth of children aged 6-23 months in low- and middle-income countries.

Original title:
Complementary Feeding Interventions Have a Small but Significant Impact on Linear and Ponderal Growth of Children in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis by Panjwani A and Heidkamp R.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28904113

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

Objectives:
Several epidemiological studies have suggested that vitamin E could reduce the risk of uterine cervical neoplasm. However, controversial data were presented by different reports. Therefore, this review article (meta-analysis) has been conducted.

Do both high vitamin E intake and circulating vitamin E levels reduce risk of uterine cervical neoplasm?

Study design:
This review article included 15 case-control studies, involving 3,741 cases (those with uterine cervical neoplasm) and 6,328 controls (those without uterine cervical neoplasm).

There was no obvious publication bias.

Results and conclusions:
The investigators found in pooled analysis that the highest intake of vitamin E significantly reduced risk of cervical neoplasia with 42% [OR = 0.58, 95% CI = 0.47-0.72, I2 = 83%]. In addition, both vitamin E intake and blood levels of vitamin E were negatively correlated with cervical neoplasia risk.

The investigators found in subgroup analysis that the highest intake of dietary vitamin E significantly reduced risk of cervical neoplasia with 32% [OR = 0.68, 95% CI = 0.49-0.94, I2 = 70%].

The investigators found in subgroup analysis that the highest vitamin E blood levels significantly reduced risk of cervical neoplasia with 48% [OR = 0.52, 95% CI = 0.40-0.69, I2 = 86%].

The investigators found in subgroup analysis that vitamin E significantly reduced risk of cervical neoplasia with 40% [OR = 0.60, 95% CI = 0.45-0.78, I2 = 84%] in studies conducted in America and Europe.

The investigators found in subgroup analysis that the highest intake of vitamin E significantly reduced risk of cervical neoplasia with 46% [OR = 0.54, 95% CI = 0.39-0.76, I2 = 75%] in studies conducted in Asia.

The investigators found subgroup analysis stratified by different types of cervical neoplasm indicated that the highest intake (or serum level) of vitamin E significantly decreased risk of cervical cancer with 47% [OR = 0.53, 95% CI = 0.390.73, I2 = 77%] and cervical intraepithelial neoplasia (CIN) with 46% [OR = 0.54, 95% CI = 0.43-0.70, I2 = 79%]. Meanwhile, sensitivity analysis to assess the influence of each single study on the pooled ORs by omitting a research in each turn, showed combined ORs were not substantially different, indicating that the results of this meta-analysis were stable and reliable.

The investigators concluded that both vitamin E intake and circulating vitamin E levels could reduce cervical neoplasia risk, including cervical cancer and cervical intraepithelial neoplasia. In other words, sufficient supplementation of vitamin E might reduce the risk of cervical neoplasia. However, more randomized controlled trials and cohort studies with high quality are required to further validate this inverse relationship.

Original title:
Effect of vitamin E supplementation on uterine cervical neoplasm: A meta-analysis of case-control studies by Hu X, Li S, [...], Zhu X.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5567498/

Additional information of El Mondo:
Find more information/studies on vitamin E, randomized controlled trials/cohort studies/subgroup analysis and cancer right here.

Higher intake of vitamin E is an intake which covers the recommended daily allowance of vitamin E of at least 1 day.

Objectives:
Dietary fat may play a role in lung carcinogenesis. Findings from epidemiologic studies, however, remain inconsistent. Therefore, this review article (meta-analysis) has been conducted.

Is there an association between dietary fat intake and the risk of lung cancer?

Study design:
This review article included 10 prospective cohort studies with a total of 1,445,850 participants, of which 18,822 incident cases (subjects with lung cancer).

The mean follow-up was 9.4 years. 

Results and conclusions:
The investigators found high intakes of total fat were associated with a 7% significant increased risk of lung cancer [for highest v lowest quintile: HR = 1.07, 95% CI = 1.00 to 1.15].

The investigators found high intakes of saturated fat were associated with a 14% significant increased risk of lung cancer [for highest v lowest quintile: HR = 1.14, 95% CI = 1.07 to 1.22].

The investigators found high intakes of saturated fat were associated with a 23% significant increased risk of lung cancer among current smokers [for highest v lowest quintile: HR = 1.23, 95% CI = 1.13 to 1.35, p for trend 0.001].

The investigators found high intakes of saturated fat were associated with a 61% significant increased risk of squamous cell lung cancer [for highest v lowest quintile: HR = 1.61, 95% CI = 1.38 to 1.88].

The investigators found high intakes of saturated fat were associated with a 40% significant increased risk of small cell carcinoma lung cancer [for highest v lowest quintile: HR = 1.40, 95% CI = 1.17 to 1.67].

The investigators found a high intake of polyunsaturated fat was associated with a 8% significant decreased risk of lung cancer [for highest v lowest quintile: HR = 0.92, 95% CI = 0.87 to 0.98, p for trend = 0.02].

The investigators found a 5% energy substitution of saturated fat with polyunsaturated fat was associated with a 16% and 17% lower risk of small cell and squamous cell carcinoma, respectively.

The investigators found no associations for monounsaturated fat.

The investigators concluded that high intakes of polyunsaturated fat decrease risk of lung cancer, while high intakes of saturated fat increase risk of lung cancer, particularly among smokers and for squamous cell and small cell carcinoma.

Original title:
Dietary Fat Intake and Lung Cancer Risk: A Pooled Analysis by Yang JJ, Yu D1, […], Shu XO.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28742456

Additional information of El Mondo:
Find more information/studies on fat and cancer right here.

A daily diet with high intakes of saturated fat is a diet that is largely made up of meals/products with more than 10 En% saturated fat, with a small part of meals/products with less than 10 En% saturated fat. Practically, this means that all meals/products that you eat on a daily basis should contain on average more than 10 En% saturated fat.
Check here which products contain more than 10% En% saturated fat.

A daily diet with low intakes of saturated fat is a diet that is largely made up of meals/products with less than 7 En% saturated fat, with a small part of meals/products with more than 7 En% saturated fat. Practically, this means that all meals/products that you eat on a daily basis should contain on average less than 7 En% saturated fat.
Check here which products contain less than 7% En% saturated fat.

Objectives:
The relationships between metabolic syndrome (MetS) and risk of incident stroke are inconsistent. Therefore, this review article (meta-analysis) has been conducted.

Does metabolic syndrome increase risk of stroke?

Study design:
This review article included a total of 16 prospective cohort studies, including 116,496 participants who were initially free of cardiovascular diseases.

Results and conclusions:
The investigators found comparing the persons without metabolic syndrome, those with metabolic syndrome had a significantly higher risk of 70% for incident stroke [pooled relative risk (RR) = 1.70, 95% CI = 1.49-1.95]. Significant means that there is an association with a 95% confidence.

The investigators found in subgroup analyses that women with metabolic syndrome had a significantly higher risk of 83% for incident stroke [pooled relative risk (RR) = 1.83, 95% CI = 1.31-2.56]. Significant because RR of 1 was not found in the 95% CI of 1.31 to 2.56. RR of 1 means no risk/association.

The investigators found in subgroup analyses that men with metabolic syndrome had a significantly higher risk of 47% for incident stroke [pooled relative risk (RR) = 1.47, 95% CI = 1.22-1.78].

The investigators found in subgroup analyses that those with metabolic syndrome had a significantly higher risk of 112% for ischemic stroke [pooled relative risk (RR) = 2.12, 95% CI = 1.46-3.08].

The investigators found in subgroup analyses that those with metabolic syndrome had a non-significantly higher risk of 48% for hemorrhagic stroke [pooled relative risk (RR) = 1.48, 95% CI = 0.98-2.24].

The investigators concluded metabolic syndrome increases risk of stroke, particularly among women and those with ischemic stroke.

Original title:
Metabolic syndrome and stroke: A meta-analysis of prospective cohort studies by Li X, Li X, […], Gao Q.

Link:
http://www.sciencedirect.com/science/article/pii/S0967586816311079

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

Find out whether you are overweight or not right here.

Those with metabolic syndrome are advised to select the following food items.

Objectives:
Nutritional supplements may be important on cognition but the evidence is heterogeneous. Therefore, this review article (meta-analysis) has been conducted.

Do both childhood nutritional supplementation and antenatal nutritional supplementation improve cognitive development of children in developing countries?

Study design:
This review article included 48 studies with 29814 children (16944 and 12870 children were in the intervention and control arms, respectively) from 20 developing countries.
Childhood nutritional supplements included iron (25 interventions), zinc (23), folic acid (18), lipid/fat (13), calcium (14), vitamin A (14), vitamin B2 (13), protein (11) and vitamins B1, B3, B12 (9).
Antenatal nutritional supplements given to mothers during pregnancy included zinc (15), iron (10), vitamin A (10), vitamins B1, B2, B3, B12 (10), vitamin C (9) and iodine and selenium (8).
Funnel plots and Egger regression tests showed no publication bias in both childhood and antenatal supplementation.

Results and conclusions:
The investigators found childhood nutritional supplementation significantly improved children's cognitive development [d = 0.05, 95% CI = 0.004-0.10, p = 0.03, n = 44] and those with ≥5 nutrients was particularly beneficial [d = 0.15, 95% CI = 0.08-0.22, p  0.0001, n = 16].

The investigators found antenatal nutritional interventions non-significantly improved children's cognitive development [d = 0.02, 95% CI = -0.01 to 0.06, p = 0.20, I2 = 47.45%, p  0.0001, n = 23].

The investigators found timing of nutritional supplements was also associated with the cognitive benefits of supplementation.
Antenatal supplementation appeared to have the strongest benefit when started in the first trimester of pregnancy [d = 0.15, 95% CI = 0.03-0.28, p = 0.02, n = 4]; supplementation started later did not yield any significant benefits.
Similarly, supplementation on children aged 6-18 months had significant benefit [d = 0.09, 95% CI = 0.02-0.15, p = 0.009, n = 27] whereas those of older children did not [d = 0.04, 95% CI = -0.06 to 0.16, p = 0.37, n = 15].

The investigators found duration of follow-up (i.e. the time between intervention completion and outcome assessment) was significantly associated with the benefits of antenatal supplementation.
Interventions with ≥5 years of follow-up had significantly stronger benefits [d = 0.10, 95% CI = 0.02-0.19, p = 0.02, n = 5] than the others [d = 0.005, 95% CI = -0.04 to 0.05, p = 0.94, n = 19].
Such phenomenon was not observed in childhood supplementation.

The investigators found in childhood interventions, several nutrient types were associated with cognitive benefits:
-iron [d = 0.09, 95% CI = 0.03-0.15, p = 0.01, n = 25];
-zinc [d = 0.09, 95% CI = 0.02-0.15, p = 0.01, n = 23];
-calcium [d = 0.14, 95% CI = 0.07-0.21, p = 0.0002, n = 14];
-vitamin B2 [d = 0.11, 95% CI = 0.03-0.19, p = 0.01, n = 13] and
 -protein [d = 0.13, 95% CI = 0.03-0.22, p = 0.01, n = 11].

The investigators found in antenatal supplementation, several nutrient types were associated with cognitive benefits:
 -iron [d = 0.05, 95% CI = 0.002-0.10, p = 0.04, n = 10];
-vitamins B1, B2, B3, B12 [d = 0.05, 95% CI = 0.01-0.10, p = 0.02, n = 10] and
-vitamin C [d = 0.07, 95% CI = 0.02-0.12, p = 0.004, n = 9].

The investigators concluded childhood nutritional supplementation, especially those with ≥5 nutrients, is effective in improving cognitive development of children in developing countries. However, future supplementation should aim to provide multiple nutrients to younger children and pregnancy women at the first trimester. To identify the optimal supplementation, future studies should include both short- and long-term assessments on the cognitive performance of children and consider the potential interactive effects of different nutrients.

Original title:
Impact of nutritional supplements on cognitive development of children in developing countries: A meta-analysis by Ip P, Ho FKW, […], Hon KL.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5587553/

Additional information of El Mondo:
Find more information/studies on food fortification/malnutrition, pregnancy, vitamins and minerals right here.
 

Objectives:
Bacillus Calmette-Guérin (BCG), diphtheria-tetanus-pertussis (DTP) and standard titre measles containing vaccines (MCV) have prevented countless illnesses and deaths among infants and children worldwide, especially those living in the world’s poorest countries.

The objectives of this review article are to review evidence on associations between receipt of these vaccines and childhood mortality, with a focus on effects beyond those attributable to the targeted diseases.

Study design:
This review article included 34 birth cohort studies (17 birth cohorts for BCG vaccine, 17 birth cohorts for DTP vaccine and 27 birth cohorts for MCV. 5 results for BCG vaccine were from clinical trials, as were 4 results for MCV. Three, zero and seven articles reported results for non-specific mortality for BCG, DTP and MCV, respectively).
Most studies reported on all cause (rather than non-specific) mortality.
Ages at MCV vaccination were available, they were typically around 9 months, ranging from 4.5 months in a clinical trial to median 15.8 months in a cohort study.
There was insufficient evidence to determine whether any difference exists in effect of DTP according to vitamin A supplementation status.

Results and conclusions:
The investigators found in 5 clinical trials that BCG vaccine non-significantly reduced all cause mortality with 30% [average relative risk = 0.70, 95% CI = 0.49 to 1.01].

The investigators found in 9 observational studies at high risk of bias that BCG vaccine significantly reduced all cause mortality with 53% [average relative risk = 0.47, 95% CI = 0.32 to 0.69, I2 = 63%].

The investigators found in 10 studies at high risk of bias that DTP vaccine (almost always with oral polio vaccine) non-significantly increased all cause mortality with 38% [relative risk = 1.38, 95% CI = 0.92 to 2.08]; this effect seemed stronger in girls than in boys.

The investigators found in 4 clinical trials that standard titre MCV non-significantly decreased all cause mortality with 26% [relative risk = 0.74, 95% CI = 0.51 to 1.07, I2 = 0%]; this effect seemed stronger in girls than in boys.

The investigators found in 18 observational studies at high risk of bias that standard titre MCV significantly decreased all cause mortality with 49% [relative risk = 0.51, 95% CI = 0.42 to 0.63, I2 = 64%]; this effect seemed stronger in girls than in boys.

The investigators found in 7 observational studies at high risk of bias that administering DTP with or after MCV may be associated with higher mortality than administering it before MCV.

The investigators concluded evidence suggests that receipt of BCG and MCV reduce overall mortality by more than would be expected through their effects on the diseases they prevent, and receipt of DTP may be associated with an increase in all cause mortality. Although efforts should be made to ensure that all children are immunised on schedule with BCG, DTP and MCV, randomised trials are needed to compare the effects of different sequences.

Original title:
Association of BCG, DTP, and measles containing vaccines with childhood mortality: systematic review by Higgins JP, Soares-Weiser K, […], Reingold AL.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5063034/

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

Objectives:
Polyunsaturated fats (PUFAs) have been shown to reduce type 2 diabetes (T2DM) risk and improve insulin responsiveness in T2DM subjects, but whether the plant sources of omega-3 PUFA (alpha-linolenic acid [ALA]) have an effect on glycemic control requires further investigation. Therefore, this review article (meta-analysis) has been conducted.

Does alpha-linolenic acid dietary intake reduce diabetes risk?

Study design:
This review article included a total of 8 RCTs involving 212 participants with type 2 diabetes.
5 trials (62.5%) were parallel designs and 3 (37.5%) were crossover designs.
Participants were generally middle-aged (median age  =  54 years, range  =  47-64 years) and overweight or obese (median BMI  =  30.7, range  =  28.0-33.2).
Overall, participants had controlled diabetes (median HbA1c = 6.8%, median FBG = 7.95 mmol/L) and the majority of studies indicated the use of hypoglycemic drugs or other medications, although all studies excluded the use of insulin therapy.
The dose of ALA ranged from 1.5 to 7.4 g/day with a median assigned dose of 4.4, 5.4 and 5.4 g/day of ALA for trials that reported HbA1c, FBG and FBI, respectively.
The median duration of the treatment was 3 months, ranging from 2 to 12 months.
7 studies (87.5%) were considered high quality (MQS ≥8).

Results and conclusions:
The investigators found compared to a control diet, a median dose of 4.4 g/day of alpha-linolenic acid intake for a median duration of 3 months did not affect HbA1c (%) of patients with type 2 diabetes [MD =  -0.01, 95% = -0.32 to 0.31, p  =  0.96].

The investigators found compared to a control diet, a median alpha-linolenic acid dose of 5.4 g/day did not lower fasting blood glucose (FBG) of patients with type 2 diabetes [MD  = 0 .07, 95% CI = -0.61 to 0.76, p  = 0 .84] or fasting blood insulin (FBI) of patients with type 2 diabetes [MD  =  7.03, 95% CI = -5.84 to 19.89, p  = 0 .28].

The investigators found summary effect estimates were generally compromised by considerable and unexplained heterogeneity [I2 ≥ 75%].

The investigators found in the subgroup analysis of continuous predictors, a reduction in HbA1c (%) and FBG (mmol/L) was significantly associated with an increased intake of ALA.

The investigators found further adjustment for publication bias using Duval and Tweedie's trim-and-fill analysis provided an adjusted, significant MD of 0.25 [95% CI = -0.38 to -0.12, 0.001) for HbA1c (%).

The investigators concluded alpha-linolenic acid-enriched diet with a median alpha-linolenic acid dose of 4.4 g/day during 3 months has no effects on HbA1c, FBG or FBI in patients with type 2 diabetes. The scarce number of existing RCTs and the presence of heterogeneity in the meta-analysis limit the ability to make firm conclusions about alpha-linolenic acid in type 2 diabetes management. The potential for alpha-linolenic acid to have dose-dependent effects warrants further research in this area.

Original title:
The effect of alpha-linolenic acid on glycemic control in individuals with type 2 diabetes: A systematic review and meta-analysis of randomized controlled clinical trials by Jovanovski E1, Li D, […], Vuksan V.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5457843/

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

4.4 g/day alpha-linolenic acid can be achieved by taking 1 to 2 tablespoons of flax or salba-chia seeds or about 12 whole walnuts per day.

 

Objectives:
Four studies previously indicated that the effect of malaria infection during pregnancy on the risk of low birthweight (LBW 2,500g) may depend upon maternal nutritional status. Therefore, this review article has been conducted.

Does malaria during pregnancy increase risk of having a low birthweight and is there a synergistic interaction between malaria and malnutrition?

Study design:
This review article included pooled data from 14,633 pregnancies from 13 studies (6 cohort studies and 7 randomized controlled trials) conducted in Africa and the Western Pacific from 1996-2015.

The major limitations of the study included availability of only 2 cross-sectional measurements of malaria and the limited availability of ultrasound-based pregnancy dating to assess impacts on preterm birth and fetal growth in all studies.

Results and conclusions:
The investigators found the adjusted risk of delivering a baby with a low birthweight was 8.8% among women with malaria infection at antenatal enrollment compared to 7.7% among uninfected women [adjusted risk ratio = 1.14, 95% CI = 0.91 to 1.42, n = 13,613 pregnancies].

The investigators found the adjusted risk of delivering a baby with a low birthweight was 10.5% among women with malaria infection at delivery compared to 7.9% among uninfected women [adjusted risk ratio = 1.32, 95% CI = 1.08 to 1.62, n = 11,826 pregnancies].

The investigators found the adjusted risk of delivering a baby with a low birthweight was 15.3% among women with low mid-upper arm circumference (MUAC 23 cm) at enrollment compared to 9.5% among women with MUAC ≥ 23 cm [adjusted risk ratio = 1.60, 95% CI = 1.36 to 1.87, n = 9,008 pregnancies).

The investigators found the adjusted risk of delivering a baby with a low birthweight was 17.8% among women with both malaria infection and low mid-upper arm circumference at enrollment compared to 8.4% among uninfected women with mid-upper arm circumference ≥ 23 cm [joint adjusted risk ratio = 2.13, 95% CI = 1.21 to 3.73, n = 8,152 pregnancies].

The investigators found no evidence of synergism (i.e., excess risk due to interaction) between malaria infection and mid-upper arm circumference on the multiplicative [p = 0.5] or additive scale [p = 0.9]. Results were similar using body mass index (BMI) as an anthropometric indicator of nutritional status.

The investigators found meta-regression results indicated that there may be multiplicative interaction between malaria infection at enrollment and low mid-upper arm circumference within studies conducted in Africa. However, this finding was not consistent on the additive scale, when accounting for multiple comparisons or when using other definitions of malaria and malnutrition. 

The investigators concluded pregnant women with malnutrition and malaria infection are at increased risk of low birthweight compared to women with only 1 risk factor or none, but malaria and malnutrition do not act synergistically.

Original title:
Malaria, malnutrition, and birthweight: A meta-analysis using individual participant data by Cates JE, Unger HW, […], Rogerson S.

Link:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5549702/

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

Objectives:
Available studies in the literature on the selenium levels in Alzheimer's disease (AD) are inconsistent with some studies reporting its decrease in the circulation, while others reported an increase or no change as compared to controls. Therefore, this meta-analysis (review article) has been conducted.

Do lower circulatory (plasma/serum and blood), erythrocyte and cerebrospinal fluid (CSF) selenium levels increase Alzheimer's disease risk?

Study design:
This review article included 12 case-control/observational studies reporting selenium concentrations in Alzheimer's disease and controls.

Results and conclusions:
The investigators found random-effects meta-analysis indicated a decrease in circulatory [SMD = -0.44], erythrocellular [SMD = -0.52] and cerebrospinal fluid [SMD = -0.14] selenium levels in Alzheimer's disease patients compared to controls

The investigators found stratified meta-analysis demonstrated that the selenium levels were decreased in both the subgroups with [SMD = -0.55] and without [SMD = -0.37] age matching between Alzheimer's disease and controls.

The investigators also found a direct association between decreased selenium levels and glutathione peroxidase (GPx) in Alzheimer's disease.

The investigators concluded that circulatory selenium concentration is significantly lower in Alzheimer's disease patients compared to controls and this decrease in selenium is directly correlated with an important antioxidant enzyme, the glutathione peroxidase, in Alzheimer's disease.

Original title:
A systematic review and meta-analysis of the circulatory, erythrocellular and CSF selenium levels in Alzheimer's disease: A metal meta-analysis (AMMA study-I) by Reddya VS, Bukkeb S, […], Pandeye AK.

Link:
http://www.sciencedirect.com/science/article/pii/S0946672X1630205X%20

Additional information of El Mondo:
Find more information/studies on selenium and dementia right here.
 

Objectives:
Recently, several randomized controlled trials (RCTs) reported the association between the use of vitamin or antioxidant supplements and the risk of bladder cancer. However, those findings remain inconsistent and some studies even reported that vitamin and antioxidant supplements increased the risk of bladder cancer. Therefore, this review article (meta-analysis) has been conducted.

Is there an association between the use of vitamin or antioxidant supplements and the risk of bladder cancer?

Study design:
This review article included 14 RCTs with a total of 147,383 participants, which involved 89,972 in the supplement group and 57,411 in the control group.

The supplementation and follow-up periods ranged between 1 and 13 years.

The types of vitamin and antioxidant supplements were as follows: vitamin A, vitamin B6, vitamin C, vitamin D, vitamin E, beta-carotene, folic acid and selenium.
The dosage regimens in individual trials were as follows: vitamin A (200 mg or 25,000, 36,000 or 40,000 IU daily), vitamin B6 (25 or 100 mg daily), vitamin C (2,000 mg daily), vitamin D (1,600 IU daily), vitamin E (50 mg or 400 IU daily), beta-carotene (20 or 30 mg daily; 50 mg alternate day; 75 mg daily for 3-month cycles), folic acid (1.6 mg daily) and selenium (200 μg daily).

Publication bias was not observed [Begg's funnel plot, symmetrical and Egger's test, p for bias = 0.378].

Results and conclusions:
The investigators found in fixed-effect meta-analysis of all 14 trials that vitamin or antioxidant supplementation was not associated with the risk of bladder cancer [RR = 1.04, 95% CI = 0.92-1.17, I2 = 39.7%].

The investigators found regarding types of supplements, any type of vitamin and antioxidant supplements had no beneficial effect on the risk of bladder cancer:
-vitamin A [RR = 0.86, 95% CI = 0.65-1.13, I2 = 61.7%, n = 5];
-vitamin B6 [RR = 0.77, 95% CI = 0.49-1.20, I2 = 78.8%, n = 3];
-vitamin C [RR = 0.74, 95% CI = 0.36-1.54, I2 = 88.8%, n = 2];
-vitamin D [RR = 1.05, 95% CI = 0.85-1.29, n = 1];
-vitamin E [RR = 0.91, 95% CI = 0.69-1.19, I2 = 60.9%, n = 6];
-beta-carotene [RR = 1.19, 95% CI = 0.96-1.46, I2 = 0.0%, n = 6];
-folate [RR = 1.05, 95% CI = 0.85-1.29, n = 1] and
-selenium [RR = 1.09, 95% CI = 0.81-1.46, I2 = 0.0%, n = 2].

The investigators found overall, there was no significant effect of vitamin and antioxidant supplements in the subgroup meta-analyses by various factors such as dose of supplements, type of cancer prevention, methodological quality, duration of treatment, provider of supplements, type of control and number of participants.
However, the risk of bladder cancer was marginally increased in trials with the use of beta-carotene alone [RR = 1.44, 95% CI = 1.00-2.09, I2 = 0.0%, n = 3].

The investigators concluded that vitamin and antioxidant supplements have no overall preventive effect against bladder cancer. Instead, subgroup meta-analyses showed that beta-carotene supplementation marginally increased the risk of bladder cancer. Even though further large, high-quality trials are required to confirm these associations, the effects (either beneficial or harmful) of vitamin or antioxidant supplements on bladder cancer should not be overemphasized.

Original title:
Effects of Vitamin and Antioxidant Supplements in Prevention of Bladder Cancer: a Meta-Analysis of Randomized Controlled Trials by Park SJ, Myung SK, […], Lee YJ.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5334161/

Additional information of El Mondo:
Find more information/studies on vitamins, selenium, beta-carotene, antioxidants and cancer right here.

Objectives:
Measles is an important cause of childhood morbidity and mortality globally, despite increasing vaccine coverage. Zinc plays a significant role in the maintenance of normal immunological functions, therefore supplements given to zinc-deficient children will increase the availability of zinc and could reduce measles-related morbidity and mortality. This is an update of a review first published in 2015.

Does zinc supplementation reduce measles risk in children?

Study design:
This review article included 1 RCT conducted in India, involving 85 children diagnosed with measles and pneumonia.

Results and conclusions:
The investigators found in the trial conducted in India no significant difference in mortality between children with measles and pneumonia who received zinc supplements and those who received placebo [RR = 0.34, 95% CI = 0.01 to 8.14].

The investigators also found no significant difference in time to absence of fever between children who received zinc supplements and those who did not [HR = 1.08, 95% CI = 0.67 to 1.74].

The investigators also found no treatment-related side effects in either group and the overall quality of the evidence was very low.

The investigators concluded no definitive conclusions can be drawn from this review about the effects of zinc supplementation on clinical outcomes of children with measles due to the very low quality of the evidence available. There is insufficient evidence to confirm or refute the effect of zinc supplementation in children with measles.

Original title:
Zinc supplementation for the treatment of measles in children by Awotiwon AA, Oduwole O, […], Okwundu CI.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28631310

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

Objectives:
Protective effects of calcium supplementation against colorectal adenomas have been documented in systematic reviews; however, the results have not been conclusive. Therefore, this review article (meta-analysis) has been conducted.

Does calcium supplementation reduce colorectal adenomas?

Study design:
This review article included 5 RCTs involving 2,234 patients with a history of adenomas.
Based on visual inspection of the funnel plots as well as on quantitative measurement that used the Egger regression test, there was weak evidence of publication bias.
No major serious adverse events were associated with the use of calcium, but there was an increase in the incidence of hypercalcemia [p  = 0 .0095].
Random errors were evaluated with trial sequential analyses (TSAs). However, TSA indicated a lack of firm evidence for a beneficial effect of calcium supplementation.

Results and conclusions:
The investigators found quantitative pooling of results from all 5 RCTs indicated that the use of supplemental calcium lasting 3 to 5 years showed a statistically significant 17% reduction in risk of any recurrent colorectal adenomas [RR = 0.83, 95% CI = 0.75-0.93, I2  =  8.5%, p  =  0.36].

The investigators found in the sensitivity analysis of 3 trials with low bias risk a statistically significant 12% reduction in the recurrence of any colorectal adenomas [RR = 0.88, 95% CI = 0.79-0.99, I2  =  0%, p  =  0.54] in patients who were administered supplemental calcium versus placebo.

The investigators found no association between supplemental calcium and recurrence of advanced colorectal adenomas in trials with low risk of bias [RR = 1.02, 95% CI = 0.67-1.55, I2 =  17.5%].

The investigators found in the subgroup analysis of 3 trials with elemental calcium dose ≤ 1200 mg/day, a statistically significant 16% reduction in the recurrent of any colorectal adenomas [RR = 0.84, 95% CI = 0.73-0.97, I2  =  38.5%, p  = 0 .19].

However, a greater reduction of 26% [RR = 0.74, 95% CI = 0.56-0.97, I2  =  0%, p  = 0 .70] was observed in the subgroup analysis of 2 trials with elemental calcium dose ≥ 1600 mg/day.
Subgroup analyses demonstrated no statistically significant association with the reduction of advanced colorectal adenomas in any doses.

The investigators concluded the available good quality RCTs suggests a possible beneficial effect of calcium supplementation – preferably at least 1600 mg/day elemental calcium – on the recurrence of colorectal adenomas. However, TSA indicated that the accumulated evidence is still inconclusive. Therefore, large well-designed randomized trials with low risk of bias are needed.

Original title:
Effects of calcium on the incidence of recurrent colorectal adenomas: A systematic review with meta-analysis and trial sequential analysis of randomized controlled trials by Veettil SK, Ching SM, […], Chaiyakunapruk N.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5556213/

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

Colorectal adenomas can lead to colorectal cancer.

Objectives:
Does a vegetarian diet reduce diabetes risk?

Study design:
This review article included 2 cohort studies and 12 cross-sectional studies.

Although the funnel plot showed a slight asymmetry, publication bias was not detected based on statistical tests such as the Egger’s [p = 0.465] and Begg’s tests [p = 0.584].

Results and conclusions:
The investigators found vegetarians had a 27.4% lower risk of having diabetes than omnivores [OR = 0.726, 95% CI = 0.608-0.867].

The investigators found in the subgroup analyses by sex, study design, region of study and vegetarian type, the pooled OR of all subtotal estimates suggested that vegetarians had a lower prevalence or incidence of diabetes than omnivores. Vegetarian men were less likely to have diabetes than their omnivorous counterparts; in contrast, no such significant association was found in women.

The investigators found in the subgroup analysis, the inverse association between a vegetarian diet and diabetes incidence/prevalence tended to be stronger for the 3 studies conducted in the Western Pacific region [OR = 0.514, 95% CI = 0.304-0.871] and the 7 studies performed in Europe & North America [OR = 0.756, 95% CI = 0.589-0.971] than for the 4 studies conducted in Southeast Asia [OR = 0.888, 95% CI = 0.718-1.099].

The investigators found in the subgroup analysis by types of vegetarianism, most types (vegan, lacto- and lacto-ovo-vegetarians) were significantly associated with a lower prevalence or incidence of diabetes than omnivorous participants, except for pesco-vegetarians.

The investigators found the influence analysis showed that the pooled OR was not dramatically changed when it was recalculated after dropping one study at a time. In other words, no one study had a substantial impact on the pooled effect size; this is indicative of a statistically robust result.

The investigators concluded that a vegetarian diet has a protective effect against diabetes risk. However, well-designed prospective cohort studies from various countries that obtain information on the participants’ motivations for vegetarianism, the duration of adherence to a vegetarian diet and verification of a vegetarian diet are needed to strengthen these findings.

Original title:
Adherence to a Vegetarian Diet and Diabetes Risk: A Systematic Review and Meta-Analysis of Observational Studies by Lee Y and Park K.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5490582/

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

Objectives:
Although epidemiological studies have examined the role of chocolate in preventing cardiometabolic disease, the results remain inconsistent. Therefore, this review article (meta-analysis) has been conducted.

Does chocolate consumption reduce risk of coronary heart disease (CHD), stroke and diabetes?

Study design:
This review article included 14 prospective cohort studies, with 508,705 participants from six countries and 7,267 coronary heart disease (CHD) cases, 8,197 stroke cases and 13,271 diabetes cases.
The follow-up duration of the studies ranged from 5 to 16 years.
One serving was defined as 30g of chocolate.
The majority of chocolate consumed in the included studies was milk or dark chocolate.

Results and conclusions:
The investigators found in 6 cohort studies for the highest versus lowest intake of chocolate a significant reduced risk of 10% for coronary heart disease [pooled RR = 0.90, 95% CI = 0.82-0.97, I2 = 24.3%, p = 0.25]. Leave-one-out sensitivity analysis had no significant influence on the pooled results.

The investigators found regarding CHD subtype, a significant reduced risk of 14% [RR = 0.86, 95% CI = 0.77-0.96] for myocardial infarction.

The investigators found for studies with follow-up duration of 10 years a significant reduced risk of 28% for coronary heart disease [RR = 0.72, 95% CI = 0.57-0.92].

The investigators found for studies with follow-up duration of ≥10 years a significant reduced risk of 8% for coronary heart disease [RR = 0.92, 95% CI = 0.86-0.99].

The investigators found in dose-response meta-analysis of 5 studies a curvilinear association between chocolate consumption and risk of coronary heart disease [p for nonlinearity = 0.006].

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 6% for coronary heart disease for 1 serving (30g) chocolate per week [RR = 0.94, 95 CI = 0.90-0.99].   

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 9% for coronary heart disease for 3 servings (90g) chocolate per week [RR = 0.91, 95 CI = 0.85-0.97].   

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 11% for coronary heart disease for 7 servings (210g) chocolate per week [RR = 0.89, 95 CI = 0.83-0.95].   

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 12% for coronary heart disease for 10 servings (300g) chocolate per week [RR = 0.88, 95 CI = 0.81-0.95].   

The investigators found in 8 reports from 7 studies for the highest versus lowest level of chocolate consumption a significant reduced risk of 16% for stroke [pooled RR = 0.84, 95% CI = 0.78-0.90, I2 = 0%, p = 0.49]. The pooled risk of total stroke was not obviously modified in the sensitivity analysis by excluding one study at a time
Egger’s test suggested the presence of publication bias [p = 0.008]. However, after introducing the “trim and fill” method to adjust this bias, the overall risk estimate remained significant in favor of chocolate intake [RR = 0.86, 95% CI = 0.79-0.92].

The investigators found with regard to stroke subtypes, a significant reduced risk of 13% [RR = 0.87, 95% CI = 0.78-0.96] for cerebral infarction and a significant reduced risk of 17% [RR = 0.83, 95% CI = 0.71-0.97] for hemorrhagic stroke.

The investigators found in the stratified analysis by gender, a significant reduced risk of 13% of total stroke for male [RR = 0.87, 95% CI = 0.79-0.97] and a significant reduced risk of 16% of total stroke for female [RR = 0.84, 95% CI = 0.74-0.94].

The investigators found a significant reduced risk of 44% for studies with follow-up durations of 10 years [RR = 0.56, 95% CI = 0.37-0.85].

The investigators found a significant reduced risk of 15% for studies with follow-up durations of ≥10 years [RR = 0.85, 95% CI = 0.79-0.91].

The investigators found in 7 reports from 6 studies a nonlinear correlation between chocolate intake and risk of stroke [p for nonlinearity = 0.001].

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 9% for stroke for 1 serving chocolate per week [RR = 0.91, 95% CI = 0.86-0.97].   

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 13% for stroke for 3 servings chocolate per week [RR = 0.87, 95% CI = 0.81-0.94].   

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 15% for stroke for 7 servings chocolate per week [RR = 0.85, 95% CI = 0.76-0.93].   

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 17% for stroke for 10 servings chocolate per week [RR = 0.83, 95% CI = 0.72-0.94].   

The investigators found in 4 studies using “trim and fill” method, for the highest versus lowest intake of chocolate, a non-significant reduced risk of 8% for diabetes [pooled RR = 0.92, 95% CI = 0.78-1.08].

The investigators found in stratified analysis by sex, a significant reduced risk of 21% [RR = 0.79, 95% CI = 0.65-0.96] for men and a non-significant reduced risk of 8% [RR = 0.92, 95% CI = 0.72-1.17] for women.
Similarly, the risks of diabetes were not different between subsets of studies with follow-up durations of below or over 10 years [p for interaction = 0.51].

The investigators found in dose-response meta-analysis of 6 reports, a curvilinear association between chocolate intake and risk of diabetes [p for nonlinearity 0.001].

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 20% for diabetes for 1 serving chocolate per week [RR = 0.80, 95% CI = 0.71-0.91]. Significant means that there is an association with a 95% confidence.

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 24% for diabetes for 3 servings chocolate per week [RR = 0.76, 95% CI = 0.63-0.91]. Significant because RR of 1 was not found in the 95% CI of 0.63 to 0.91. RR of 1 means no risk/association.

The investigators found in dose-response meta-analysis, compared with no intake, a non-significant reduced risk of 17% for diabetes for 7 servings chocolate per week [RR = 0.83, 95% CI = 0.67-1.03]. Non-significant means it cannot be said with a 95% confidence that 7 servings chocolate per week really decreased the risk of diabetes with 17%.

The investigators found in dose-response meta-analysis, compared with no intake, a non-significant reduced risk of 11% for diabetes for 10 servings chocolate per week [RR = 0.89, 95% CI = 0.69-1.16].   

The investigators found in general, the dose-response pattern was J-shaped and the peak reduction in diabetes risk occurred at an intake of 2 servings/week [RR = 0.75, 95% CI = 0.63-0.89], with no protective effects observed when consuming chocolate > 6 servings/week.

The investigators concluded that chocolate consumption confers reduced risks of coronary heart disease, stroke and diabetes. Consuming chocolate in moderation (1-6 servings/week or 30-180g) may be optimal for the prevention of these burdensome diseases. However, additional large prospective studies are required to confirm the observed benefits of chocolate in populations with different characteristics and to establish the optimum frequency of chocolate intake for preventing cardiometabolic disease.

Original title:
Chocolate Consumption and Risk of Coronary Heart Disease, Stroke, and Diabetes: A Meta-Analysis of Prospective Studies by Yuan S, Li X, […], Lu J.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5537803/

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

Objectives:
With only 5-10% of breast cancer cases attributed to genetic inheritance, prevention efforts have focused on modifiable risk factors. Physical activity plays a role in reducing breast cancer risk; however, the interaction between physical activity and other modifiable risk factors, such as obesity, has received little attention. Therefore, this review article (meta-analysis) has been conducted.

What is the relationship between physical activity and breast cancer and how it may be modified by body mass index (BMI)?

Study design:
This review article included 18 cohort and 11 case-control studies.

Results and conclusions:
The investigators found overall, a significant reduction of 15% for breast cancer risk in postmenopausal women with a BMI 25 kg/m² for high versus low levels of physical activity [RR = 0.85, 95% CI = 0.79-0.92]. 

The investigators found overall, a significant reduction of 13% for breast cancer risk in postmenopausal women with a BMI ≥25 kg/m² for high versus low levels of physical activity for women [RR = 0.87, 95% CI = 0.81-0.93]. 

The investigators found overall, a non-significant reduction of 7% for breast cancer risk in postmenopausal women with a BMI ≥30 kg/m² for high versus low levels of physical activity for women [RR = 0.93, 95% CI = 0.76-1.13]. 

The investigators found, however, physical activity was not associated with a significant reduction in risk of breast cancer in premenopausal women in any BMI group.

The investigators concluded high levels of physical activity reduce risk of breast cancer in postmenopausal women with a BMI until 30. Since the included studies used diverse methods for assessment of physical activity and categories of BMI, results should be interpreted with caution and additional work is needed.

Original title:
Does obesity modify the relationship between physical activity and breast cancer risk? by Neil-Sztramko SE, Boyle T, […], Campbell KL.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28803384

Additional information of El Mondo:
Find more information/studies on breast cancer, BMI and physical activity right here.