Nutritional advice

Objectives:
The morbidity of eczema has increased in the recent years and the methods to prevent or ameliorate its effects are becoming more important. Therefore, this review article has been conducted.

Do vitamin supplements reduce risk of eczema?

Study design:
This review article included 10 RCTs with a total of 456 patients.
The sample sizes ranged from 5 to 57. The studies were published from 2008 to 2018.
5 studies were conducted on atopic dermatitis, 3 studies were conducted on pediatric atopic dermatitis and 2 studies were conducted on winter-related atopic dermatitis.

Results and conclusions:
The investigators found that the SCORAD index or EASI scores significantly decreased in patients given vitamin D3 (cholecalciferol) supplements [mean difference = -5.96, 95% CI = -7.69 to -4.23, I2 = 33%].

The investigators found that the SCORAD index significantly decreased after the topical application of vitamin B12-containing cream [mean difference = -3.19, 95% CI = -4.27 to -2.10, I2 = 0%]. 

The investigators found that the SCORAD index significantly improved after vitamin E supplementation [mean difference = -5.72, 95% CI = -11.41 to -0.03, I2 = 0%]. 

The investigators concluded vitamin D3, B12 and E supplements could be important therapeutics to help manage eczema patients.

Original title:
Assessment of the Effectiveness of Vitamin Supplement in Treating Eczema: A Systematic Review and Meta-Analysis by Zhu Z, Yang Z, [...], Liu H.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6875217/

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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

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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

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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

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Find here more information/studies about omega-3 fatty acids and kidney disease.  
 

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

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Find here more information/studies about selenium, zinc and copper and chronic disease.


 

Objectives:
Systematic inflammation plays a major role in all stages of chronic diseases. Recent evidence suggests that coenzyme Q10 (CoQ10), as an anti-inflammatory agent, has shown beneficial effects on the inflammatory process of various human diseases. However, several trials have examined the effects of coenzyme Q10 on pro-inflammatory cytokines with contrasting results. Therefore, this review article has been conducted.

Does coenzyme Q10 supplementation reduce inflammation in humans?

Study design:
This review article included 9 RCTs with a total of 509 patients (269 in the coenzyme Q10 arm and 240 in the control arm).

Results and conclusions:
The investigators found that oral coenzyme Q10 supplementation (60-500 mg/day for 8-12 weeks) resulted in significant reduction of TNF-α [SMD = -0.44, 95% CI = -0.81 to -0.07 mg/dL, I2 = 66.1%, p  = 0.00] and IL-6 levels [SMD = -0.37, 95% CI = -0.65 to -0.09, I2 = 57.2%, p  = 0.01], respectively.

The investigators found subgroup analyses represented a significant reduction of TNF-α and IL-6 levels in patients with BMI  26.
Due to the small number of studies and patients included in each subgroup, these subgroup analyses need to be interpreted cautiously.

The investigators concluded there is a significant effect of 60-500 mg/day coenzyme Q10 supplements for 8-12 weeks on some of the inflammatory markers among patients with chronic diseases which could attenuate the inflammatory state. However, well-designed studies with a larger sample size are required. Note that the results should be interpreted with caution because of the evidence of heterogeneity and limited number of studies.

Original title:
Can coenzyme Q10 supplementation effectively reduce human tumor necrosis factor-α and interleukin-6 levels in chronic inflammatory diseases? A systematic review and meta-analysis of randomized controlled trials by Vafa M.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31185284

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Objectives:
There is little evidence whether eggs affect inflammation. Therefore, this review article has been conducted.

Does egg consumption increase risk of inflammation?

Study design:
This review article included 8 RCTs assessed high sensitivity c-reactive protein (hs-CRP), 4 RCTs assessed interleukin-6 (IL-6) and 5 RCTs assessed tumor necrosis factor alpha (TNF-α).

Results and conclusions:
The investigators found egg consumption did not affect hs-CRP [WMD = 0.24 mg/L, 95% CI = -0.43 to 0.90, I2 = 53.8%, p = 0.48], IL-6 [WMD = 0.20 pg/mL, 95% CI =  -0.71 to 1.11, I2 = 69.3%, p = 0.50] and TNF-α [WMD = -0.38 pg/mL, 95% CI = -0.87 to 0.10, I2 = 0.00%, p = 0.12] relative to controls.

The investigators concluded that egg consumption has no effect on serum biomarkers of inflammation in adults.

Original title:
Effect of Egg Consumption on Inflammatory Markers: A Systematic Review and Meta-Analysis of Randomized Controlled Clinical Trials by Sajadi Hezaveh Z, Khalighi Sikaroudi M, […], Soltani S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31259415

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Inflammation in human body can be measured by means of biomarkers. These biomarkers are hs-CRP, IL-6 and TNF-α.
 

Objectives:
The prevalence of overweight/obesity in adults is raised to 39%, which is nearly tripled more than 1975. The alteration of the gut microbiome has been widely accepted as one of the main causal factors. Therefore, this review article has been conducted.

Does probiotics supplementation prevent overweight/obesity in adults?

Study design:
This review article included 12 RCTs (11 randomized, double-blinded, controlled trials and 1 randomized, single-blinded, controlled trial) with a total of 821 participants (416 participants were given placebo and 405 participants were given probiotics).

7 RCTs included participants who consumed two or multiple strains of probiotics and 5 RCTs included participants who consumed a single strain of probiotics.
7 RCTs investigated a high dosage of probiotics (>1010 CFU) and 5 RCTs investigated lower dosage of probiotics (1010 CFU).
Probiotics were administered in different forms, including sachet, capsule, powder, kefir, yogurt and fermented milk.
Duration of the probiotics supplementation ranged from 8 to 24 weeks.

There was no significant publication bias.

Results and conclusions:
The investigators found compared with control groups, probiotics supplementation resulted in a significantly reduction in body weight [WMD = -0.55, 95% CI = -0.91 to -0.19 kg, I2 = 64%, p = 0.003].
Subgroup analyses stratified by probiotics dosage, the number of probiotics strains or forms of probiotics showed the effects of probiotics supplementation on body weight were significantly reduced in trials with high dose of probiotics [WMD = -0.58, 95% CI = -0.92 to 0.23 kg], a single strain of probiotics [WMD = -0.49, 95% CI = -0.92 to -0.07 kg] and the capsule or powder of probiotics [WMD = -0.55, 95% CI = -0.84 to -0.26 kg].
Sensitivity analyses revealed that no particular studies significantly affected the summary effects of body weight.

The investigators found compared with control groups, probiotics supplementation resulted in a significantly reduction in BMI [WMD = -0.30, 95% CI = -0.43 to -0.18 kg/m², I2 = 59%, p = 0.006].
Subgroup analyses stratified by probiotics dosage, the number of probiotics strains or forms of probiotics showed the effects of probiotics supplementation on BMI were significantly reduced with the high dose [WMD = -0.29, 95% CI = -0.46 to -0.12 kg/m²] and single strain of probiotics [WMD = -0.36, 95% CI = -0.52 to -0.20 kg/m²].
Sensitivity analyses revealed that no particular studies significantly affected the summary effects of BMI.

The investigators found compared with control groups, probiotics supplementation resulted in a significantly reduction in waist circumference [WMD = -1.20, 95% CI = -2.21 to -0.19 cm, p = 0.02, I2 = 90%, p 0.00001].
Subgroup analyses stratified by probiotics dosage, the number of probiotics strains or forms of probiotics indicated the effects of probiotics supplementation on waist circumference were significantly reduced in trials with high dose of probiotics [WMD = -1.53, 95% CI = -2.64 to -0.41 cm], a single strain of probiotics [WMD = -1.69, 95% CI = -3.04 to -0.33 cm] and the food form of probiotics [WMD = -1.11, 95% CI = -1.64 to -0.59 cm].
Sensitivity analyses revealed that no particular studies significantly affected the summary effects of waist circumference.

The investigators found compared with control groups, probiotics supplementation resulted in a significantly reduction in fat mass [WMD = -0.91, 95% CI = -1.19 to -0.63 kg, p 0.00001, I2 = 43%, p = 0.08] and fat percentage [WMD = -0.92, 95% CI = -1.27 to -0.56%, p 0.00001, I2 = 57%, p = 0.04].
Subgroup analyses stratified by probiotics dosage, the number of probiotics strains and forms of probiotics indicated that the effect of probiotics supplementation on fat mass was significantly reduced, showing a greater decrease in fat mass with high dosage probiotics WMD -1.08, 95% CI = -1.21 to -0.95 kg] compared to low dosage probiotics [WMD = -1.00, 95% CI = -1.59 to -0.42 kg], a greater decrease with single strain probiotics [WMD = -1.15, 95% CI = -1.28 to -1.02 kg] compared to multiple strain probiotics [WMD = -0.60, 95% CI = -0.94 to -0.26] kg] and a greater decrease with administration probiotics in the form of food [WMD = -1.13, 95% CI = -1.58 to -0.67 kg] compared to in the forms of capsule or powder [WMD = -1.07, 95% CI = -1.20 to -0.94 kg].
No particular study significantly affected the pooled effect of probiotics on fat mass and fat percentage by sensitivity analyses.

The investigators found compared with control groups, probiotics supplementation significantly improved total cholesterol levels [SMD = -0.43, 95% CI = -0.80 to -0.07, p = 0.02, I2 = 73%, p = 0.001].
Subgroup analyses only stratified by probiotics dosage and the number of probiotics strains indicated the effects of probiotics supplementation on total cholesterol were significantly reduced in trials with single strain probiotics [WMD = -0.61, 95% CI = -1.54 to -0.32], compared to multiple strain probiotics [WMD = -0.39, 95% CI = -0.66 to -0.13].
Sensitivity analyses revealed that no particular studies significantly affected the summary effects of total cholesterol.

The investigators found compared with control groups, probiotics supplementation significantly improved LDL-cholesterol levels [SMD = -0.41, 95% CI = -0.77 to -0.04, p = 0.03, I2 = 73%, p = 0.001].
Subgroup analyses stratified by probiotics dosage and the number of probiotics strains indicated the effects of probiotics supplementation on LDL-cholesterol were significantly reduced in trials with multiple strain probiotics [WMD = -0.33, 95% CI = -0.57 to -0.09]. Sensitivity analyses revealed that no particular studies significantly affected the summary effects of LDL-cholesterol.

The investigators found compared with control groups, probiotics supplementation significantly improved fasting plasma glucose (FPG) [SMD = -0.35, 95% CI = -0.67 to -0.02, p = 0.04, I2 = 64%, p = 0.02].

The investigators found compared with control groups, probiotics supplementation significantly improved insulin [SMD = -0.44, 95% CI = -0.84 to -0.03, p = 0.03, I2 = 76%, p = 0.0008].

The investigators found compared with control groups, probiotics supplementation significantly improved HOMA-IR [SMD = -0.51, 95% CI = -0.96 to -0.05, p = 0.03, I2 = 76%, p = 0.003].

The investigators concluded probiotics supplementation during 8 to 24 weeks reduces the body weight and fat mass and improves some of the lipid and glucose metabolism parameters, although some of the effects were small. Probiotics may become a new potential strategy for the prevention and treatment of overweight/obesity in adult individuals.

Original title:
The Potential Role of Probiotics in Controlling Overweight/Obesity and Associated Metabolic Parameters in Adults: A Systematic Review and Meta-Analysis by Wang ZB, Xin SS, [...], Zhang XD.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6500612/

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Objectives:
Previous studies reported that magnesium deficiency was associated with vascular calcifications, atherosclerosis and cardiovascular disease, which might play an independent pathogenic role in chronic kidney disease (CKD) and end-stage renal disease (ESRD) patients. However, the results of these studies were somewhat underpowered and inconclusive. Therefore, this review article has been conducted.

Does hypomagnesemia (a low blood magnesium concentration) increase risk of mortality in patients with chronic kidney disease and end-stage renal disease?

Study design:
This review article included 20 studies involving 200,934 participants.

Results and conclusions:
The investigators found hypomagnesemia significantly increased risk of all-cause mortality in patients with chronic kidney disease and end-stage renal disease with 32% [multivariable adjusted HR = 1.32, 95% CI = 1.19-1.47, p 0.00001]. 

The investigators found, on the contrary, hypermagnesemia (a high blood magnesium concentration) significantly decreased risk of all-cause mortality in patients with chronic kidney disease and end-stage renal disease with 14% [HR = 0.86, 95% CI = 0.79-0.94, p = 0.001] (per unit increase).

The investigators found, moreover, hypermagnesemia significantly decreased risk of cardiovascular mortality in patients with chronic kidney disease and end-stage renal disease with 29% [adjusted HR = 0.71, 95% CI = 0.53-0.97, p = 0.03]. 

The investigators found subgroup analysis showed that hypomagnesemia significantly increased all-cause mortality in hemodialysis patients with 29% [HR = 1.29, 95% CI = 1.12-1.50, p = 0.0005].

The investigators concluded hypomagnesemia (a low blood magnesium concentration) increases cardiovascular and all-cause mortality in patients with chronic kidney disease and end-stage renal disease. Further studies evaluating benefits of magnesium correction in chronic kidney disease and dialysis patients with hypomagnesemia should be performed.

Original title:
Serum magnesium, mortality, and cardiovascular disease in chronic kidney disease and end-stage renal disease patients: a systematic review and meta-analysis by Xiong J, He T, […], Zhao J.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30888644

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Normal values of serum magnesium are considered those between 0.7 and 1.0 mmol/L.
Hypomagnesemia has a serum magnesium concentration of 0.7 mmol/L.
Blood magnesium concentration can be increased by eating magnesium-rich foods and/or taking magnesium supplements.

Objectives:
Insulin resistance, dyslipidemia and increased systemic inflammation are important risk factors for chronic kidney disease (CKD). Hence, vitamin D administration might be an appropriate approach to decrease the complications of chronic kidney disease. Therefore, this review article has been conducted.

Have vitamin D supplements beneficial effects on people with chronic kidney disease?

Study design:
This review article included 17 RCTs.

Results and conclusions:
The investigators found pooling findings from 5 RCTs revealed a significant reduction in fasting glucose among people with chronic kidney disease [WMD = -18.87, 95% CI = -23.16 to -14.58] following the administration of vitamin D.

The investigators found pooling findings from 3 RCTs revealed a significant reduction in homeostatic model assessment of insulin resistance (HOMA-IR) among people with chronic kidney disease [WMD = -2.30, 95% CI = -2.88 to -1.72] following the administration of vitamin D.

The investigators found pooling findings from 6 RCTs revealed a significant reduction in triglycerides among people with chronic kidney disease [WMD = -32.52, 95% CI = -57.57 to -7.47] following the administration of vitamin D or treatment.

The investigators found pooling findings from 5 RCTs revealed a significant reduction in total cholesterol concentrations among people with chronic kidney disease [WMD = -7.93, 95% CI = -13.03 to -2.83] following the administration of vitamin D or treatment.

The investigators found there was no effect on insulin, HbA1c, LDL and HDL cholesterol and CRP levels among people with chronic kidney disease following the administration of vitamin D or treatment.

The investigators concluded there are beneficial effects of vitamin D supplementation or treatment on improving fasting glucose, HOMA-IR, triglycerides and total cholesterol levels among patients with chronic kidney disease.

Original title:
The effects of vitamin D treatment on glycemic control, serum lipid profiles, and C-reactive protein in patients with chronic kidney disease: a systematic review and meta-analysis of randomized controlled trials by Milajerdi A, Ostadmohammadi V, […], Asemi Z.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31338797

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Objectives:
Does dietary intake of n-3 PUFAs (such as DHA, EPA, DPA and ALA) or fish consumption improve lung function?

Study design:
This review article included 9 cohort studies from the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium (n = 37,077 black and white participants).

In each cohort and each ancestry, separately, associations of dietary n-3 PUFA/fish intake with lung function were estimated in linear regression models.
Fixed-effects meta-analysis was used to generate summarized effect estimates across the cohorts and ancestries.

The lung function was measured by the forced expiratory volume in 1 second (FEV1) and the forced vital capacity (FVC).

Results and conclusions:
The investigators found dietary DPA, DHA, EPA and fish intake significantly improved forced expiratory volume in one second (FEV1) and forced vital capacity (FVC).
However, dietary α-linolenic acid (ALA) had little to no association with these lung function parameters.

The investigators found associations were similar for black and white participants and consistent in direction and magnitude across most cohort studies.

The investigators found for all participants, 1 standard deviation (SD) higher dietary intake of DPA (∼30 mg/d), DHA (∼200 mg/d) and EPA (∼150 mg/d) were associated with 12-16 mL higher FEV1 and 10-15 mL higher FVC.
The effect estimates for fish consumption were in the same direction but smaller in magnitude.

The investigators found ∼200 mg/d DHA and ∼150 mg/d EPA were associated with 28-32 mL higher FEV1 and 24-25 mL higher FVC in current smokers.

The investigators found ∼200 mg/d DHA and ∼150 mg/d EPA were associated with 17-21 mL higher FEV1 and 7-12 mL higher FVC in former smokers.

The investigators found ∼200 mg/d DHA and ∼150 mg/d EPA had little to no association with FEV1 and FVC in never smokers.

The investigators concluded that dietary ∼200 mg/d DHA, ∼30 mg/d DPA and ∼150 mg/d EPA and fish intake are associated with higher lung function, especially among current and former smokers.

Original title:
Positive Associations of Dietary Marine Omega-3 Polyunsaturated Fatty Acids with Lung Function: A Meta-analysis (P18-087-19) by Patchen B, Xu J, […], Cassano P.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6579416/  

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DHA, DPA and EPA are found in fish.

 

Objectives:
Whether exercise can improve cardiovascular health in kidney transplant recipients (KTRs) is unclear. Therefore, this review article (meta-analysis) has been conducted.

Does exercise improve cardiovascular health in kidney transplant recipients?

Study design:
This review article included 12 RCTs (trials) in the review and 11 RCTs for further qualitative analysis.
Most trials provided a 30-60 minutes exercise session for 2-4 times per week.
In terms of the total intervention period, most trials ranged from 10 weeks to 6 months.

Results and conclusions:
The investigators found in 5 trials with a total of 199 participants that exercise had no effects on either systolic [MD = 1.67, 95% CI = -2.17 to 5.51, p = 0.39] or diastolic blood pressure [MD = 0.65, 95% CI = -4.02 to 5.32, p = 0.78].

The investigators found in 3 trials with a total of 261 participants that exercise had no significant benefits in overall lipid profile [MD = 0.03, 95% CI = -0.09 to 0.15, p = 0.62].
In subgroup analysis, total cholesterol [p = 0.15], LDL cholesterol [p = 0.83] and triglyceride [p = 0.82] were not ameliorated by exercise.

The investigators found in 2 trials with 22 subjects in the exercise group and 28 controls that a 12 months of resistance training or regimens of aerobic or resistance training for 12 weeks was not associated with an improvement in kidney function [MD = 2.60, 95% CI = -12.88 to 13.09, p = 0.74].

The investigators found that aerobic training, resistance training or the combination during 12 weeks to 12 months was not associated with an improvement on body weight [MD = -2.02, 95% CI = -8.24 to 4.20, p = 0.52, n = 3] or BMI [MD = 0.12, 95% CI = -1.52 to 1.77, p = 0.88, n = 4].

The investigators found in 2 trials with a total of 64 participants that a 12-week exercise showed a consistent improvement in small arterial stiffness [MD = -1.14, 95% CI = -2.19 to -0.08, p = 0.03].

The investigators found in 5 trials with a total of 202 participants that aerobic training, resistance training or combined method over the course of 12 weeks to 12 months had a significant improvement in exercise capacity (VO₂ peak) [MD = 2.25, 95% CI = 0.54 to 3.69, p = 0.01]. 

The investigators found exercise improved quality of life in different aspects, with significant enhancement in social functioning [MD = 16.76, 95% CI = 2.16 to 31.37, p = 0.02] and overall QOL scores [MD = 12.87, 95% CI = 6.80 to 18.94, p 0.01].

The investigators concluded exercise intervention in kidney transplant recipients improves arterial stiffness and it also improves exercise tolerance and quality of life. Additional long-term RCTs examining a greater number of patients are needed to understand the effects of exercise on cardiovascular health in kidney transplant recipients.

Original title:
Effects of exercise training on cardiovascular risk factors in kidney transplant recipients: a systematic review and meta-analysis by Chen G, Liu Gao L and Li X.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6534232/

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Objectives:
The role of fruit and vegetables (FVs) consumption in decreasing gallstone disease risk remains contradictory.Therefore, this review article has been conducted.

Does fruit or vegetables consumption reduce risk of gallstone disease?

Study design:
This review article included 1 cross-sectional study, 1 case-control studie and 9 cohort studies, covering approximately 33,983 patients with gallstone disease and 1,53,3752 participants.

Results and conclusions:
The investigators found in a pooled analysis, vegetables consumption was significantly related to a decreased gallstone disease risk of 17% [RR  =  0.83, 95% CI = 0.74-0.94, I2  =  91.1%]. This reduced gallstone disease risk was solid in most subgroup analysis.

The investigators found in a pooled analysis, fruits consumption was significantly related to a decreased gallstone disease risk of 12% [RR  =  0.88, 95% CI = 0.83-0.92, I2  =  0.01%].  
This reduced gallstone disease risk was solid in most subgroup analysis.

The investigators found nonlinear dose-response analysis indicated that gallstone risk was reduced by 4% [RR  =  0.96, 95% CI = 0.93-0.98, p =0.001] for every 200 g per day increment in vegetables consumption.

The investigators found nonlinear dose-response analysis indicated that gallstone risk was reduced by 3% [RR  =  0.97, 95% CI = 0.96-0.98, p =0.001] for every 200 g per day increment in fruits consumption.

The investigators concluded that vegetables and fruits consumption, particularly 200g fruits or 200g vegetables per day is correlated with a reduced risk of gallstone disease.

Original title:
Fruits and vegetables consumption and the risk of gallstone diasease: A systematic review and meta-analysis by Zhang JW, Xiong JP, [...], Zhao HT.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31305451

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Objectives:
Has L-carnitine supplementation positive effects on inflammatory mediators including C-reactive protein (CRP), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6)?

Study design:
This review article included 13 RCTs.

Results and conclusions:
The investigators found L-carnitine supplementation was significantly associated with lower levels of CRP in comparison to controls [WMD = -1.23 mg/L, 95% CI = -1.73 to -0.72 mg/dL, p  0.0001].
This reduced effect was greatest during an intervention of more than 12 weeks.

The investigators found L-carnitine supplementation was also significantly associated with lower levels of IL-6 in comparison to controls [WMD = -0.85 pg/dL, 95% CI = -1.38 to -0.32 pg/dL, p = 0.002].
This reduced effect was greatest during an intervention of more than 12 weeks.

The investigators found L-carnitine supplementation was also significantly associated with lower levels of TNF-α in comparison to controls [WMD = -0.37 pg/dL, 95% CI = -0.68 to -0.06 pg/dL, p = 0.018].
This reduced effect was greatest during an intervention of more than 12 weeks.

The investigators concluded that L-carnitine supplementation reduces levels of inflammatory mediators, especially in studies with a duration of more than 12 weeks. Further studies with different doses and intervention durations and separately in men and women are necessary.

Original title:
The effect of L-carnitine on inflammatory mediators: a systematic review and meta-analysis of randomized clinical trials by Haghighatdoost F, Jabbari M and Hariri M.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30915521 

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Objectives:
Plasma creatinine has been described as a prognostic biomarker for Amyotrophic Lateral Sclerosis (ALS), but with conflicting results in the literature. Therefore, this review article (meta-analysis) has been conducted.

Does a high plasma creatinine concentration reduce risk of ALS?

Study design:
This review article included 14 distinct cohorts (19 studies).

The overall quality of the studies was low mainly due to potential attrition bias and several studies did not report analyzable results raising concern regarding a potential reporting bias.

Results and conclusions:
The investigators found for baseline plasma creatinine, mortality risk was 28% lower when creatinine was higher than 88.4 µmol/L [HR = 0.72, 95% CI = 0.58 to 0.88, p = 0.0003] and was 25% lower if creatinine was above versus below the median [HR = 0.75, 95% CI = 0.63 to 0.89, p = 0.0008].

The investigators found a significant positive correlation between plasma creatinine at baseline and functional score and between creatinine decline and functional score decline [p  0.0001 for both].

The investigators found, however, a negative correlation between plasma creatinine and functional score decline [p = 0.033].

The investigators concluded plasma creatinine seems to be a promising prognostic biomarker for ALS. However, new studies with sound methodology and standardized criteria for the evaluation of ALS progression should be conducted to validate plasma creatinine as a clinical biomarker for ALS prognosis.

Original title:
Plasma creatinine and amyotrophic lateral sclerosis prognosis: a systematic review and meta-analysis by Lanznaster D, Bejan-Angoulvant T, […], Blasco H.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30961401

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Objectives:
A high intake of dietary fibre has been associated with a reduced risk of diverticular disease in several studies. However, the dose-response relationship between fibre intake and diverticular disease risk has varied and the available studies have not been summarised in a meta-analysis yet. Therefore, this review article (meta-analysis) has been conducted.

Is there a dose-response relationship between fibre intake and reduced risk of diverticular disease?

Study design:
This review article included 5 prospective cohort studies with 19,282 cases (persons with a diverticular disease) and 865,829 participants.

There was no evidence of publication bias with Egger's test, p = 0.58.

Results and conclusions:
The investigators found every 10 g/day increase of dietary fibre intake significantly reduced risk of diverticular disease with 26% [summary RR = 0.74, 95% CI = 0.71-0.78, I2 = 0%]. This significantly reduced risk persisted in subgroup and sensitivity analyses.

The investigators found no evidence of a nonlinear association between dietary fibre intake and diverticular disease risk [p nonlinearity = 0.35].

The investigators found compared to 7.5 g/day, 20 g/day of dietary fibre intake significantly reduced risk of diverticular disease with 23%.

The investigators found compared to 7.5 g/day, 30 g/day of dietary fibre intake significantly reduced risk of diverticular disease with 41%.

The investigators found compared to 7.5 g/day, 40 g/day of dietary fibre intake significantly reduced risk of diverticular disease with 58%.

The investigators found every 10 g/day increase of dietary cereal fibre intake significantly reduced risk of diverticular disease with 26% [summary RR = 0.74, 95% CI = 0.67-0.81, I2 = 60%, n = 4].

The investigators found every 10 g/day increase of dietary fruit fibre intake significantly reduced risk of diverticular disease with 44% [summary RR = 0.56, 95% CI = 0.37-0.84, I2 = 73%, n = 2].

The investigators found every 10 g/day increase of dietary vegetable fibre intake non-significantly reduced risk of diverticular disease with 20% [summary RR = 0.80, 95% CI = 0.45-0.1.44, I2 = 87%, n = 2].

The investigators concluded that 10-40 g/day dietary fiber intake, particularly cereal and fruit fibre reduces risk of diverticular disease. However, further studies are needed on fibre types and risk of diverticular disease and diverticulitis.

Original title:
Dietary fibre intake and the risk of diverticular disease: a systematic review and meta-analysis of prospective studies by Aune D, Sen A, […], Riboli E.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31037341

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Find here more information/studies about chronic disease and fibre intake.

40 grams of fiber per day corresponds to a diet with 2 grams of fiber per 100 kcal. The easiest way to follow a diet with 2 grams of fiber per 100 kcal is to choose only products/meals with 2 grams of fiber per 100 kcal. Check here which products/meals provide 2 grams of fiber per 100 kcal.

Diverticular disease is the general name for a common condition that causes small bulges (diverticula) or sacs to form in the wall of the large intestine (colon). Although these sacs can form anywhere in the colon, they are most common in the sigmoid colon (part of the large intestine closest to the rectum). The recent literature does not identify diverticular disease as a long-term risk factor for colorectal cancer.
 

Objectives:
Anemia is one of the major complications in predialysis patients with chronic kidney disease (CKD). A clearer cognition of the prognostic impact of hemoglobin (Hb) or hematocrit (Hct) target on the outcomes of predialysis patients with CKD is significant. Therefore, this review article (meta-analysis) has been conducted.

Does higher hemoglobin levels decrease transfusion risk in predialysis patients with CKD?

Study design:
This review article included 13 RCTs involving 7,606 patients.

Results and conclusions:
The investigators found compared to lower hemoglobin levels, predialysis patients with chronic kidney disease with higher hemoglobin levels had a significantly lower risk of 49% for transfusion [risk ratio = 0.59, 95% CI = 0.52 to 0.67, p 0.00001].

The investigators found, however, no significant difference in all-cause mortality [RR = 1.10, 95% CI = 0.98 to 1.23, p = 0.11], stroke [RR = 1.32, 95% CI = 0.82 to 2.10, p = 0.25] and treatment of renal replacement including hemodialysis, peritoneal dialysis and renal transplant [RR = 1.08, 95% CI = 0.95 to 1.22, p = 0.23] between the higher hemoglobin group and the lower one.

The investigators concluded higher hemoglobin levels when treating predialysis patients with chronic kidney disease decrease the risk of transfusion without increasing the risk of death, stroke and treatment of renal replacement.

Original title:
Therapeutic targets for the anemia of predialysis chronic kidney disease: a meta-analysis of randomized, controlled trials by Liu H, Ye Y, […], Liu X.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30755495

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Objectives:
Current research suggests conflicting evidence surrounding the association between serum magnesium levels and the diagnosis of attention deficit hyperactivity disorder (ADHD). Therefore, this review article (meta-analysis) has been conducted.

Does serum magnesium deficiency increase risk of ADHD?

Study design:
This review article included 7 observational studies, which reported the mean and standard deviation (SD) of magnesium concentration in both ADHD and control groups.

Results and conclusions:
The investigators found random-effects meta-analysis showed that subjects with ADHD had 0.105 mmol/L [95% CI = -0.188 to -0.022, p 0.013, I2 = 96.2%, p = 0.0103] lower serum magnesium levels compared with to their healthy controls.

The investigators concluded this meta-analysis supports the theory that an inverse relationship between serum magnesium deficiency and ADHD exists. High heterogeneity amongst the included studies suggests that there is a residual need for observational and community-based studies to further investigate this issue.

Original title:
Magnesium status and attention deficit hyperactivity disorder (ADHD): A meta-analysis by Effatpanah M, Rezaei M, […], Hashemi R.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30807974

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Study design:
This review article included 8 studies.

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

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

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

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

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

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

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

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