Nutritional advice

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

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

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

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

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

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

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

Objectives:
Does magnesium reduce risk of type 2 diabetes?

Study design:
This review article included 35 cohort studies and 26 RCTs (1,168 participants).

Results and conclusions:
The investigators found compared to the lowest magnesium dietary intake, the highest level was associated with a 22% lower risk for type 2 diabetes.

The investigators found the risk for type 2 diabetes was reduced by 6% for each 100mg increment in daily magnesium dietary intake.

The investigators found in 26 RCTs (1,168 participants) that magnesium supplementation significantly reduced:
-the fasting plasma glucose (FPG) level [SMD = -0.32, 95% CI = -0.59 to -0.05];
-2-h oral glucose tolerance test (2-h OGTT) result [SMD = -0.30, 95% CI = -0.58 to -0.02];
-fasting insulin level [SMD = -0.17, 95% CI = -0.30 to -0.04];
-homeostatic model assessment-insulin resistance (HOMA-IR) score [SMD = -0.41, 95% CI = -0.71 to -0.11];
-triglyceride (TG) level;
-systolic blood pressure (SBP) and;
-diastolic blood pressure (DBP).

The investigators found trial sequential analysis (TSA) showed an inverse association, with most benefits of magnesium supplementation on glucose metabolism being stable.

The investigators concluded magnesium dietary intake has an inverse dose-response association with type 2 diabetes incidence and supplementation appears to be advisable in terms of glucose parameters in type 2 diabetes/high-risk individuals.

Original title:
Association of Magnesium Consumption with Type 2 Diabetes and Glucose Metabolism: a Systematic Literature Review and Pooled Study with Trial Sequential Analysis by Zhao B, Deng H, [...], Zhang W.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31758631

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

Objectives:
Do low folate levels and vitamin B12 levels increase risk of depression among the aged people?

Study design:
This review article included both gender data of 11 folate-related (7,949 individuals) and 9 B12-related studies (6,308 individuals) and gender-specific data of 4 folate-related (3,409 individuals) and 3 B12-related studies (1,934 individuals).

Results and conclusions:
The investigators found low folate levels significantly increased risk of depression among the aged people with 23% [OR =1.23, 95% CI =1.07-1.43]. 

The investigators found low vitamin B12 levels significantly increased risk of depression among the aged people with 20% [OR =1.20, 95% CI =1.02-1.42]. 

The investigators found in subgroup analysis low vitamin B12 levels significantly increased risk of depression among the aged women with 33% [OR =1.33, 95% CI =1.02-1.74]. 

The investigators concluded both low folate levels and low vitamin B12 levels increase risk of depression among the aged people.

Original title:
Folate and B12 serum levels in association with depression in the aged: a systematic review and meta-analysis by Petridou ET, Kousoulis AA, [...], Stefanadis C.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/26055921

Additional information of El Mondo:
Find more information/studies on vitamin B12, folate and elderly.
 

Objectives:
Low-potassium diets are recommended to reduce serum potassium (Sk) and prevent complications of chronic kidney disease (CKD), but evidence underpinning this recommendation has not been systematically reviewed and synthesized. Therefore, this review article has been conducted.

Do patients with chronic kidney disease benefit from low-potassium diets?

Study design:
This review article included 7 studies  with 3,489 participants.

Results and conclusions:
The investigators found in very-low-quality studies that restricted (1,295 mg/d) versus unrestricted (1,570 mg/d) dietary potassium lowered serum potassium by 0.22 mEq/L [95% CI = -0.33 to -0.10, I2 = 0%].

The investigators found in very-low-quality studies that lower (1,725 mg/d) versus higher (4,558 mg/d) dietary potassium was not significantly associated with disease progression [HR = 1.14, 95% CI = 0.77 to 1.70, I2 = 57%].

The investigators found in very-low-quality studies that lower (1,670 mg/d), compared with higher (4,414 mg/d) dietary potassium intake was associated with a 40% reduction in mortality hazard [HR = 0.60, 95% CI = 0.40 to 0.89, I2 = 56%].

The investigators concluded very-low-quality evidence supports consensus that dietary potassium restriction reduces serum potassium in normokalemia and is associated with a reduced risk of death in those with chronic kidney disease. However, high-quality randomized controlled trials are needed to confirm these findings.

Original title:
Effect of Dietary Potassium Restriction on Serum Potassium, Disease Progression, and Mortality in Chronic Kidney Disease: A Systematic Review and Meta-Analysis by Morris A, Krishnan N, […], Lycett D.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31734057

Additional information of El Mondo:
Find here more information/studies about potassium and kidney disease.

Objectives:
Observational evidence suggests higher nut consumption is associated with better glycemic control. However, it is unclear if this association is causal. Therefore, this review article has been conducted.

Is there a causal relationship between consumption of tree nuts or peanuts and reduced risk of type 2 diabetes?

Study design:
This review article included a total of 40 RCTs with 2,832 unique participants, with a median duration of 3 months (range: 1-12 months).

Results and conclusions:
The investigators found overall consumption of tree nuts or peanuts had a favourable effect on HOMA-IR values [WMD = -0.23, 95% CI = -0.40 to -0.06, I2 = 51.7%] and fasting insulin levels [WMD = -0.40 μIU/mL, 95% CI = -0.73 to -0.07 μIU/mL, I2 = 49.4%].

The investigators found, however, there was no significant effect of nut consumption on fasting blood glucose levels [WMD = -0.52 mg/dL, 95% CI = -1.43 to 0.38 mg/dL, I2 = 53.4%] or HbA1c [WMD = 0.02%, 95% CI = -0.01% to 0.04%, I2 = 51.0%].

The investigators concluded consumption of peanuts or tree nuts decreases HOMA-IR and fasting insulin levels. These findings suggest that nut consumption may improve insulin sensitivity. In the future, well-designed clinical trials are required to elucidate the mechanisms that account for these observed effects.

Original title:
The effect of nuts on markers of glycemic control: a systematic review and meta-analysis of randomized controlled trials by Tindall AM, Johnston EA, […], Petersen KS.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30722007

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

Objectives:
Parkinson's disease (PD) is the most common neurodegenerative disease after Alzheimer's dementia. Whereas the exact etiology of Parkinson's disease remains unknown, risk of developing Parkinson's disease seems to be related to a combination of genetic and environmental factors. This also includes abnormal exposure to trace elements of nutritional and toxicological interest. Therefore, this review article has been conducted.

Is there a relationship between exposure to trace elements and Parkinson’s disease risk?

Study design:
This review article included 56 case-control studies reporting data for selenium (cases/controls: 588/721), copper (2,190/2,522), iron (2,956/3,469) and zinc (1,798/1,913) contents in cerebrospinal fluid (CSF) and blood.

Results and conclusions:
The investigators found patients with Parkinson's disease had significantly higher levels of selenium in cerebrospinal fluid compared with controls [+51.6%, WMD = 5.49, 95% CI = 2.82 to 8.15], while levels in serum were similar [-0.2%, WMD = -0.22, 95% CI = -8.05 to 7.62].

The investigators found patients with Parkinson's disease had non-significantly higher levels of copper in cerebrospinal fluid compared with controls [+4.5%, WMD = 1.87, 95% CI = -3.59 to 7.33] and non-significantly lower levels of copper in serum [WMD = -42.79, 95% CI = -134.35 to 48.76].

The investigators found patients with Parkinson's disease had significantly higher levels of iron in cerebrospinal fluid compared with controls [+9.5%, WMD = 9.92, 1.23 to 18.61] and significantly lower levels of iron both in serum/plasma [-5.7%, WMD = -58.19, 95% CI = -106.49 to -9.89] and whole blood [-10.8%, WMD = -95.69, 95% CI = -157.73 to -33.65].

The investigators found patients with Parkinson's disease had significantly lower levels of zinc in cerebrospinal fluid compared with controls [-10.8%, WMD = -7.34, 95% CI = -14.82 to -0.14] and significantly lower levels of zinc in serum/plasma [-7.5%, WMD = -79.93, 95% CI = -143.80 to -16.06].

The investigators found a longer duration of the disease tends to be associated with overall lower trace element levels in either cerebrospinal fluid or blood.

The investigators concluded higher levels of both selenium and iron in cerebrospinal fluid increase Parkinson's disease, while higher levels of zinc in cerebrospinal fluid decrease Parkinson's disease.

Original title:
Selenium and Other Trace Elements in the Etiology of Parkinson's Disease: A Systematic Review and Meta-Analysis of Case-Control Studies by Adani G, Filippini T, […], Vinceti M.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31454800

Additional information of El Mondo:
Find here more information/studies about iron, zinc, selenium and chronic disease
 

Objectives:
Does omega-3 fatty acids supplementation improve serum levels of inflammatory biomarkers (C-reactive protein [CRP], high-sensitivity CRP [hs-CRP], tumor necrosis factor-alpha, interleukin-6) and albumin in patients on hemodialysis?

Study design:
This review article included 8 RCTs comprising 371 patients on hemodialysis.

Results and conclusions:
The investigators found omega-3 supplementation significantly decreased serum levels of CRP in patients on hemodialysis [SMD = -1.95 mg/dL, 95% CI = -3.09 to -0.80] and hs-CRP [SMD = -2.09, 95% CI = -3.62 to -0.56].

The investigators found, however, omega-3 supplementation did not significantly improved albumin [SMD = 0.91, 95% CI = -0.78 to 2.59], tumor necrosis factor-alpha [SMD = -1.51, 95% CI = -3.24 to 0.22] and interleukin-6 levels [SMD = 0.72, 95% CI = -0.56 to 1.99] in patients on hemodialysis.

The investigators concluded omega-3 supplementation leads to a significant decrease in serum levels of CRP and hs-CRP in patients on hemodialysis.

Original title:
The Effect of Omega-3 Supplementation on Serum Levels of Inflammatory Biomarkers and Albumin in Hemodialysis Patients: A Systematic Review and Meta-analysis by Dezfouli M, Moeinzadeh F, [...], Feizi A.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31420233

Additional information of El Mondo:
Find here more information/studies about omega-3 fatty acids and kidney disease.  
 

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

Study design:
This review article included 48 RCTs.

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

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

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

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

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

Additional information of El Mondo:
Find more information/studies on fruits, meta-analysis and cholesterol right here.
 

Objectives:
Findings from observational studies and clinical trials on the associations between vitamin E and dementia remain controversial. Therefore, this review article has been conducted.

Do low vitamin E levels increase risk of Alzheimer's disease (AD) or age-related cognitive deficits and mild cognitive impairment (MCI)?

Study design:
This review article included 31 studies.

Results and conclusions:
The investigators found individuals with Alzheimer's disease had lower circulatory concentrations of α-tocopherol (vitamin E) compared with healthy controls [SMD = -0.97, 95% CI = -1.27 to -0.68, p  0.00001].

The investigators found individuals with age-related cognitive deficits had lower circulatory concentrations of α-tocopherol (vitamin E) compared with healthy controls [SMD = -0.72, 95% CI = -1.12 to -0.32, p  0.0005].

The investigators found individuals with mild cognitive impairment had lower circulatory concentrations of α-tocopherol (vitamin E) compared with healthy controls [SMD = -0.72, 95% CI = -1.12 to -0.32, p  0.0005].

The investigators found levels of β-, γ- and δ-tocopherols did not significantly differ between groups of Alzheimer's disease and age-related cognitive deficits compared to controls.

The investigators concluded that lower α-tocopherol (vitamin E) levels have a strong association with Alzheimer's disease and mild cognitive impairment supporting evidence for the role of diet and vitamin E in Alzheimer's disease risk and age-related cognitive decline.

Original title:
A meta-analysis of peripheral tocopherol levels in age-related cognitive decline and Alzheimer's disease by Ashley S, Bradburn S and Murgatroyd C.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31661399

Additional information of El Mondo:
Find more information/studies on vitamin E and elderly.
 

Objectives:
Does iron-fortified flour increase iron status?

Study design:
This review article included 94 trials.
The main target groups were women, children and infants/toddlers.
The effects of different types of iron-fortified flour (wheat, maize, rice, soy and beans) on iron status were examined.

Results and conclusions:
The investigators found a random effects analysis of before-after studies showed that iron-fortified flour led to significant increases of mean haemoglobin level [3.360 g/L, 95% CI = 0.980 to 5.730] and mean serum ferritin level [4.518 µg/L, 95% CI = 2.367 to 6.669].

The investigators found a random effects analysis of before-after studies showed that iron-fortified flour led to significant decreases of anaemia [-6.7%, 95% CI = -9.8% to -3.6%] and iron deficiency (ID) [-10.4%, 95% CI = -14.3% to -6.5%].

The investigators found a random effects analysis of before-after studies showed that iron-fortified flour had no significant effect on iron deficiency anaemia (IDA).

The investigators found a random effects analysis of controlled trials indicated that iron-fortified flour led to significant increases of mean haemoglobin level [2.630 g/L, 95% CI = 1.310 to 3.950] and mean ferritin level [8.544 µg/L, 95% CI = 6.767 to 10.320].

The investigators found a random effects analysis of controlled trials indicated that iron-fortified flour led to significant decreases of anaemia [-8.1%, 95% CI = -11.7% to -4.4%], iron deficiency [-12.0%, 95% CI = -18.9% to -5.1%] and iron deficiency anaemia [-20.9%, 95% CI = -38.4% to -3.4%].

The investigators concluded flour fortification with iron is an effective public health strategy that improves iron status of populations worldwide.

Original title:
Systematic review and meta-analysis of the effect of iron-fortified flour on iron status of populations worldwide by Sadighi J, Nedjat S2 and Rostami R.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31486352

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

Objectives:
The incidence of type 2 diabetes mellitus (DM) has increased in the US over the last several years. The consumption of low-fat dairy foods has been linked with decreasing the risk of diabetes mellitus but studies have yet to show a clear correlation. Therefore, this review article has been conducted.

Is there a causal relationship between consumption of low-fat dairy foods and reduced risk of type 2 diabetes?

Study design:
This review article included 30 RCTs.
The total sample size was 2,900 with >50% female participants, but the distribution varied greatly across different studies.
The mean age of subjects ranged from 18-63 years.
The funnel plots for all 3 outcomes (HOMA-IR, waist circumference and body weight) did not suggest significant publication bias.

Results and conclusions:
The investigators found (794 individuals) comparing high intake to the control group, consumption of low-fat dairy foods significantly reduced the HOMA-IR values [MD = -1.21, 95% CI = -1.74 to -0.67, p 0.00001, I2 = 92%].

The investigators found (1,348 individuals) comparing high intake to the control group, consumption of low-fat dairy foods significantly reduced waist circumference [MD = -1.09 cm, 95% CI = -1.68 to -0.58, p 0.00001, I2 = 94%].

The investigators found for body weight (2,362 individuals), the low-fat dairy foods intervention group weighed 0.42 kg less than the control group [p 0.00001, I2 = 92%].

The investigators found limiting to studies that were assessed to have low risk of bias did not significantly change the point estimates or heterogeneity statistics (Q or I2) for all 3 outcomes.
Similarly excluding studies with a physical activity component did not significantly alter point estimates or heterogeneity statistics for all 3 outcomes.

The investigators concluded low-fat dairy products have a beneficial effect on HOMA-IR, waist circumference and body weight. This could impact dietary recommendations to reduce type 2 diabetes risk.

Original title:
The Effects of Dairy Intake on Insulin Resistance: A Systematic Review and Meta-Analysis of Randomized Clinical Trials by Sochol KM, Johns TS, […], Melamed ML.

Link:
https://www.mdpi.com/2072-6643/11/9/2237/htm

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

Objectives:
Creatine supplements are intended to improve performance, but there are indications that it can overwhelm liver and kidney functions, reduce the quality of life and increase mortality. Therefore, this review article has been conducted.

Does creatine supplementation increase risk of renal damage?

Study design:
This review article included 15 studies in the qualitative analysis and 6 studies in the quantitative analysis.

Results and conclusions:
The investigators found creatine supplementation did not significantly increase serum creatinine levels [standardized mean difference = 0.48, 95% CI = 0.24-0.73, p = 0.001, I2 = 22%].

The investigators found creatine supplementation did not significantly increase plasma urea values [standardized mean difference = 1.10, 95% CI = 0.34-1.85, p = 0.004, I2 = 28%].
The investigators concluded that creatine supplementation does not induce renal damage in the studied amounts and durations.

Original title:
Effects of Creatine Supplementation on Renal Function: A Systematic Review and Meta-Analysis by de Souza ESA, Pertille A, […], de Oliveira JJ.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31375416

Additional information of El Mondo:
Find here more information/studies on kidney disease and creatine.

Objectives:
Serum uric acid (SUA) accounts for about 50% of extracellular antioxidant activity, suggesting that hyperuricemia (an abnormally high level of uric acid in the blood) may have a protective role in diseases characterized by high levels of oxidative stress, such as osteoporosis. Therefore, this review article has been conducted.

Does a high serum uric acid level (also called hyperuricemia) increase bone mineral density (BMD)?

Study design:
This review article included 19 cross-sectional studies with a total of 55,859 participants.

Results and conclusions:
The investigators found in 6 studies that subjects with higher serum uric acid levels had significantly higher bone mineral density values for the spine [SMD = 0.29, 95% CI = 0.22-0.35, I2 = 47%].
Simple correlation analyses substantially confirmed this finding.

The investigators found in 7 studies that subjects with higher serum uric acid levels had significantly higher bone mineral density values for total hip [SMD = 0.29, 95% CI = 0.24-0.34, I2 = 33%].
Simple correlation analyses substantially confirmed this finding.

The investigators found in 6 studies that subjects with higher serum uric acid levels had significantly higher bone mineral density values for femoral neck [SMD = 0.25, 95% CI = 0.16-0.34, I2 = 71%].
Simple correlation analyses substantially confirmed this finding.

The investigators found in 3 studies that an increase of one standard deviation in serum uric acid levels significantly reduced risk of new fractures with 17% [HR = 0.83, 95% CI = 0.74-0.92, I2 = 0%].

The investigators found no significant differences between men and women, although data about women were limited.

The investigators concluded a high serum uric acid level is independently associated with higher bone mineral density values and a lower risk of fractures, supporting a protective role for uric acid in bone metabolism disorders.

Original title:
Hyperuricemia protects against low bone mineral density, osteoporosis and fractures: a systematic review and meta-analysis by Veronese N, Carraro S, […], Cereda E.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/27636234

Additional information of El Mondo:
Find more information/studies on elderly.
 

Objectives:
National immunization schedules in many countries recommend HPV vaccination for females until the age of 26 years and thus substantial numbers with reproductive age may be exposed to HPV vaccines. Therefore, this review article has been conducted.

Do inadvertent HPV vaccine exposures in the periconceptional period or during pregnancy increase risk of adverse pregnancy outcomes (spontaneous abortion, stillbirth, small for sestational age, preterm birth and birth defects)?

Study design:
This review article included 8 studies.

Results and conclusions:
The investigators found compared with the unexposed pregnancies, HPV vaccine exposed pregnancies were associated with no higher risk for:
-spontaneous abortion [RR = 0.99, 95% CI = 0.90 to 1.08];
-stillbirth (RR =1.16, 95% CI = 0.71 to 1.90];
-small for gestational age [RR = 0.96, 95% CI = 0.86 to 1.07];
-preterm birth [RR = 1.04 [95% CI = 0.91 to 1.18];
-birth defects [RR = 1.18, 95% CI = 0.97 to 1.43].

The investigators concluded inadvertent bivalent/quadrivalent HPV vaccination during pregnancy is not associated with significantly greater risks of adverse pregnancy outcomes.

Original title:
Pregnancy Outcomes After Human Papillomavirus Vaccination in Periconceptional Period or During Pregnancy: A Systematic Review and Meta-analysis by Wang A, Liu C, […], Huang Y.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31486334

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

Objectives:
In recent years, cardiovascular diseases (CVDs) have become a focus topic and global concern. There have been mixed reports on the relationship between whole grain or cereal fiber intake and the risk of type 2 diabetes. Therefore, this review article has been conducted.

Does grain or cereal fiber dietary intake reduce risk of type 2 diabetes?

Study design:
This review article included 7 cohort studies and 1 case-control study with a total of 434,903 participants and 14,728 cases of type 2 diabetes.
The average follow-up was 12.6 years.
There was no publication bias.

Results and conclusions:
The investigators found whole grain or cereal fiber dietary intake was associated with a reduced risk of 26% [combined RR = 0.74, 95% CI = 0.67 to 0.82, I2 = 56.8%, p = 0.06] for type 2 diabetes.
This reduced risk was 38% [pooled RR = 0.68, 95% CI = 0.64-0.73, I2 = 0.0%, p = 0.452] in sensitivity analysis.

The investigators found whole grain or cereal fiber dietary intake was associated with a reduced risk of 32% [combined RR = 0.68, 95% CI = 0.49 to 0.88] for type 2 diabetes among males.

The investigators found whole grain or cereal fiber dietary intake was associated with a reduced risk of 26% [combined RR = 0.74, 95% CI = 0.64 to 0.77] for type 2 diabetes among females.

The investigators concluded that increased whole grain and cereal fiber dietary intake reduce risk of type 2 diabetes.

Original title:
Whole grain and cereal fiber intake and the risk of type 2 diabetes: a meta-analysis by Wang Y, Duan Y, […], Jin Y.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6627783/

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

Objectives:
The results of epidemiological studies on the relationship between fruit and vegetable intake and lung cancer risk were inconsistent among participants with different smoking status. Therefore, this review article has been conducted.

Do dietary intakes of fruit and vegetables reduce risk of lung cancer?

Study design:
This review article included a total of 12 prospective cohort studies.
The duration of follow-up ranged from 4 to 12.9 years.
No publication bias was found.

Results and conclusions:
The investigators found for dietary consumption of fruit a significantly reduced risk of 14% [summary RR = 0.86, 95% CI = 0.78 to 0.94, I2 = 0.0%, p = 0.642] for lung cancer among current smokers.

Significant means that there is an association with a 95% confidence.

The investigators found for dietary consumption of fruit a significantly reduced risk of 9% [summary RR = 0.91, 95% CI = 0.84 to 0.99, I2 = 0.0%, p = 0.653] for lung cancer among former smokers.
Significant because RR of 1 was not found in the 95% CI of 0.84 to 0.99. RR of 1 means no risk/association.

The investigators found stratified analysis showed that dietary consumption of fruit significantly reduced risk of lung cancer with 23% [RR = 0.77, 95% CI = 0.62 to 0.96] in current smoking subjects from Europe.

The investigators found in linear dose-response analysis that an increase of 100 grams of fruit intake per day was associated with a 5% reduction [RR = 0.95, 95% CI = 0.93 to 0.97, p for trend 0.001] in current smokers.

The investigators found in linear dose-response analysis that an increase of 100 grams of fruit intake per day was associated with a 5% reduction [RR = 0.95, 95% CI = 0.93 to 0.99, p for trend = 0.001] in former smokers.

The investigators found for dietary consumption of vegetables a significantly reduced risk of 13% [summary RR = 0.87, 95% CI = 0.78 to 0.97, I2 = 25.4%, p = 0.226] for lung cancer among current smokers.

The investigators found in linear dose-response analysis that an increase of 100 grams of vegetable intake per day was associated with a 3% lower risk of lung cancer in current smokers [95% CI = 0.96 to 1.00, p for trend = 0.057]. 

The investigators concluded that fruit consumption, at least 100g per day decreases lung cancer risk among current smokers and former smokers, while vegetables consumption, at least 100g per day decreases lung cancer risk of current smokers. These findings may have considerable public health significance for the prevention of lung cancer through dietary interventions.

Original title:
The Associations of Fruit and Vegetable Intake with Lung Cancer Risk in Participants with Different Smoking Status: A Meta-Analysis of Prospective Cohort Studies by Wang C, Yang T, [...], Li D.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6723574/

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

 

Objectives:
Findings of epidemiological studies regarding the association between carrot consumption and lung cancer risk remain inconsistent. Therefore, this review article has been conducted.

Do dietary intakes of carrot reduce risk of lung cancer?

Study design:
This review article included a total of 17 case-control studies and 1 prospective cohort study, involving 202,969 individuals and 5,517 patients with lung cancer.

Results and conclusions:
The investigators found in 18 studies a significantly reduced risk of 42% [pooled OR = 0.58, 95% CI = 0.45 to 0.74] for lung cancer by comparing the highest category with the lowest category of carrot consumption.
Exclusion of any single study did not materially alter the pooled OR.

The investigators found based on subgroup analyses for the types of lung cancer a significantly reduced risk of 66% [pooled OR = 0.34, 95% CI = 0.15 to 0.79] for the lung cancer adenocarcinoma by comparing the highest category with the lowest category of carrot consumption.

The investigators found based on subgroup analyses for the types of lung cancer a significantly reduced risk of 39% [OR = 0.61, 95% CI = 0.46 to 0.81] for mixed types of lung cancer by comparing the highest category with the lowest category of carrot consumption.

The investigators concluded that carrot consumption decreases the risk of lung cancer, especially for adenocarcinoma.

Original title:
Is carrot consumption associated with a decreased risk of lung cancer? A meta-analysis of observational studies by Xu H, Jiang H, […], Lu Z.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31552816

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

 

Objectives:
Malaria causes a reduction in haemoglobin that is compounded by primaquine, particularly in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency.

The aim of this review article is to determine the relative contributions to red cell loss of malaria and primaquine in patients with uncomplicated Plasmodium vivax.

Study design:
This review article included 29 studies with a total of 3,421 patients (1,692 (49.5%) with normal glucose-6-phosphate dehydrogenase status, 1,701 (49.7%) with unknown status and 28 (0.8%) deficient or borderline individuals).

Patients were followed for 28 days in 14 studies (n = 1,841), 29 to 42 days in 7 studies (n = 388) and more than 42 days in 8 studies (n = 1,192).

The majority of patients were male (64.6%, 2,211/3,421).
The median age of patients was 19 years (inter-quartile range (IQR) 9-32), with 1,314 (38.4%) patients younger than 15 years.

Results and conclusions:
The investigators found of 1,975 patients treated with chloroquine alone, the mean haemoglobin fell from 12.22 g/dL [95% CI = 11.93 to 12.50] on day 0 to a nadir of 11.64 g/dL [95% CI = 11.36 to 11.93] on day 2, before rising to 12.88 g/dL [95% CI = 12.60 to 13.17] on day 42.

The investigators found in comparison to chloroquine alone, the mean haemoglobin in 1,446 patients treated with chloroquine plus primaquine was -0.13 g/dL [95% CI = - 0.27 to 0.01] lower at day of nadir [p = 0.072], but 0.49 g/dL [95% CI = 0.28 to 0.69] higher by day 42 [p  0.001].

The investigators found on day 42, patients with recurrent parasitaemia had a mean haemoglobin concentration -0.72 g/dL [95% CI = -0.90 to -0.54] lower than patients without recurrence [p  0.001].

The investigators found 7 days after starting primaquine, G6PD normal patients had a 0.3% (1/389) risk of clinically significant haemolysis [fall in haemoglobin > 25% to  7 g/dL] and a 1% (4/389) risk of a fall in haemoglobin > 5 g/dL.

The investigators concluded primaquine has the potential to reduce malaria-related anaemia at day 42 and beyond by preventing recurrent parasitaemia. Its widespread implementation will require accurate diagnosis of glucose-6-phosphate dehydrogenase deficiency to reduce the risk of drug-induced haemolysis in vulnerable individuals.

Original title:
The haematological consequences of Plasmodium vivax malaria after chloroquine treatment with and without primaquine: a WorldWide Antimalarial Resistance Network systematic review and individual patient data meta-analysis by Commons RJ, Simpson JA, […], Price RN.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6670141/

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

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

Study design:
This review article included 9 RCTs.

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

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

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

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

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

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

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

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

Study design:
This review article included 5 RCTs.

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

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

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

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

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

Objectives:
Measles is an important cause of death in children, despite the availability of safe and cost-saving measles-containing vaccines (MCVs). The first MCV dose (MCV1) is recommended at 9 months of age in countries with ongoing measles transmission and at 12 months in countries with low risk of measles.

The aim of this review article is to assess the benefits and risks of MCV1 in infants younger than 9 months.

Study design:
This review article included 56 studies (randomised and quasi-randomised controlled trials, outbreak investigations cohort and case-control studies).

No differences in the risk of adverse events after MCV1 administration were found between infants younger than 9 months and those aged 9 months of older.

Overall, the quality of evidence ranged from moderate to very low.

Results and conclusions:
The investigators found the proportion of infants who seroconverted increased from 50% [95% CI = 29-71] for those vaccinated with MCV1 at 4 months of age to 85% [95% CI = 69-97] for those were vaccinated at 8 months.

The investigators found the pooled geometric mean titre ratio for infants aged 4-8 months vaccinated with MCV1 compared with infants vaccinated with MCV1 at age 9 months or older was 0.46 [95% CI = 0.33-0.66, I2 = 99.9%, p 0.0001].

The investigators found only one study reported on avidity and suggested that there was lower avidity and a shorter duration of immunity following MCV1 administration at 6 months of age than at 9 months of age [p = 0.0016] or 12 months of age [p 0.001].
No effect of age at MCV1 administration on cellular immunity was found.

The investigators found one study reported that vaccine efficacy against laboratory-confirmed measles virus infection was 94% [95% CI = 74-98] in infants vaccinated with MCV1 at 4.5 months of age.

The investigators found the pooled vaccine effectiveness of MCV1 in infants younger than 9 months against measles was 58% [95% CI = 9-80, I2 = 84.9%, p 0.0001].

The investigators found the pooled vaccine effectiveness estimate from within-study comparisons of infants younger than 9 months vaccinated with MCV1 were 51% [95% CI = 44 to 83, I2 = 92.3%, p 0.0001] and for those aged 9 months and older at vaccination it was 83% [95% CI = 76-88, I2 = 93.8%, p 0.0001].  

The investigators concluded MCV1 administered to infants younger than 9 months induces a good immune response, whereby the proportion of infants seroconverted increases with increased age at vaccination. A large proportion of infants receiving MCV1 before 9 months of age are protected and the vaccine is safe, although higher antibody titres and vaccine effectiveness are found when MCV1 is administered at older ages. Recommending MCV1 administration to infants younger than 9 months for those at high risk of measles is an important step towards reducing measles-related mortality and morbidity.

Original title:
Immunogenicity, effectiveness, and safety of measles vaccination in infants younger than 9 months: a systematic review and meta-analysis by Nic Lochlainn LM, de Gier B, [...], Hahné SJM.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31548079

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

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

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

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

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

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

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

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

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

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

Objectives:
Vaccinating infants with a first dose of measles-containing vaccine (MCV1) before 9 months of age in high-risk settings has the potential to reduce measles-related morbidity and mortality. However, there is concern that early vaccination might blunt the immune response to subsequent measles vaccine doses. Therefore, this review article (meta-analysis) has been conducted. 

Does measles-containing vaccine (MCV1) administration to infants younger than 9 months reduce immune responses to subsequent MCV doses?

Study design:
This review article included 13 studies.

Overall, the quality of evidence was moderate to very low.

Results and conclusions:
The investigators found from 13 studies, the pooled proportion of infants seropositive after two measles-containing vaccine doses, with MCV1 administered before 9 months of age, was 98% [95% CI = 96-99, I2 = 79.8%, p 0.0001], which was not significantly different from seropositivity after a two-dose MCV schedule starting later [p = 0.087].

The investigators found only 1 of 4 studies found geometric mean titres after MCV2 administration to be significantly lower when MCV1 was administered before 9 months of age than at 9 months of age or later.

The investigators found there was insufficient evidence to determine an effect of age at MCV1 administration on antibody avidity.

The investigators found the pooled vaccine effectiveness estimate derived from 2 studies of a two-dose MCV schedule with MCV1 vaccination before 9 months of age was 95% [95% CI = 89-100, I2 = 12.6%, p = 0.29].

The investigators found 7 studies reporting on measles virus-specific cellular immune responses found that T-cell responses and T-cell memory were sustained, irrespective of the age of MCV1 administration.

The investigators concluded administering MCV1 to infants younger than 9 months followed by additional MCV doses results in high seropositivity, vaccine effectiveness and T-cell responses, which are independent of the age at MCV1, supporting the vaccination of very young infants in high-risk settings. However, there is some evidence that MCV1 administered to infants younger than 9 months results in lower antibody titres after one or two subsequent doses of MCV than when measles vaccination is started at age 9 months or older. Therefore, the clinical and public-health relevance of this immunity blunting effect are uncertain.

Original title:
Effect of measles vaccination in infants younger than 9 months on the immune response to subsequent measles vaccine doses: a systematic review and meta-analysis by Nic Lochlainn LM, de Gier B, [...], Hahné SJM.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31548081

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

Objectives:
Environmental risk factors regrading rheumatoid arthritis (RA) have not been explored extensively. Selenium (Se), zinc (Zn) and copper (Cu) nutrients were reported to associate with rheumatoid arthritis, but the results were inconsistent. Therefore, this review article has been conducted.

Is there a relationship between serum selenium, zinc and copper levels and rheumatoid arthritis risk?

Study design:
This review article included 41 studies.

Results and conclusions:
The investigators found meta-analysis of 16 studies involving 806 rheumatoid arthritis patients and 959 health controls showed that serum selenium levels [SMD = -1.04, 95% CI = -1.58 to -0.50] were significantly decreased in rheumatoid arthritis patients.

The investigators found meta-analysis of 23 studies involving 1,398 rheumatoid arthritis patients and 1,299 health controls showed that serum zinc levels [SMD = -1.20, 95% CI = -1.74 to -0.67] were significantly decreased in rheumatoid arthritis patients.

The investigators found meta-analysis of 26 studies involving 1,723 rheumatoid arthritis patients and 1,451 health controls showed that serum copper levels [SMD = 1.26, 95% CI = 0.63 to 1.89] were significantly increased in rheumatoid arthritis patients.

The investigators found meta-regression reported that steroid use was positively related to serum level of selenium in rheumatoid arthritis [β = 0.041, 95% CI = 0.002 to 0.079].

The investigators found differences in serum selenium, zinc and copper between rheumatoid arthritis patients and controls were all related with the geographical distribution.

The investigators concluded patients with rheumatoid arthritis have significant decreased serum selenium and zinc levels and increased serum copper levels than health controls, suggesting potential roles of selenium, zinc and copper in the pathogenesis of rheumatoid arthritis. Patients and rheumatologist should give enough attention to the monitor of these elements during follow up.

Original title:
Common trace metals in rheumatoid arthritis: A systematic review and meta-analysis by Ma Y, Zhang X, […], Pan F.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31442958

Additional information of El Mondo:
Find here more information/studies about selenium, zinc and copper and chronic disease.


 

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

Does L-carnitine supplementation reduce blood pressure?

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

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

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

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

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

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

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

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

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