Nutritional advice

Objectives:
Taurine plays a pivotal role in regulating glucose and lipid metabolism, blood pressure homeostasis and obesity largely due to its cytoprotective, antioxidant and anti-inflammatory actions. Despite promising data from animal studies in this scenario, the efficacy of taurine supplementation in human studies has been inconsistent. Therefore, this review article has been conducted.

Does taurine supplementation lower blood pressure and improve the lipid profile in patients with liver dysregulation?

Study design:
This review article included 12 RCTs.
Most studies were conducted in patients with liver or metabolic dysregulation (diabetes, hepatitis, fatty liver, obesity, cystic fibrosis, chronic alcoholism and cardiac surgery).
The taurine dosage varied from 0.5 to 6 g/d for 15 days to 6 months.

Results and conclusions:
The investigators found that taurine administration (supplementation) had a significant effect of on systolic blood pressure [WMD = -4.67 mm Hg, 95% CI = -9.10 to -0.25], diastolic blood pressure [WMD = -2.90 mm Hg, 95% CI = -4.29 to -1.52], total cholesterol levels [WMD = -10.87 mg/dL, 95% CI = -16.96 to -4.79] and triglycerides levels [WMD = -13.05 mg/dL, 95% CI = -25.88 to -0.22]. 

The investigators found, however, that taurine administration had no effect on fasting blood glucose [WMD = 0.06 mg/dL], HDL cholesterol [WMD = 0.90 mg/dL], LDL cholesterol [WMD = -6.17 mg/dL], as well as on body mass index [WMD = -0.46 kg/m²] and body weight [WMD = -0.47 kg] as the anthropometric measures.

The investigators concluded that, in patients with liver dysregulation, taurine supplements (0.5 to 6 g/d for 15 days to 6 months) reduce blood pressure and improve the lipid profile by reducing total cholesterol and triglyceride levels.

Original title:
The effects of taurine supplementation on obesity, blood pressure and lipid profile: A meta-analysis of randomized controlled trials by Guan L and Miao P.

Link:
https://pubmed.ncbi.nlm.nih.gov/32871172/

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Find here more information/studies about taurine consumption and lowering blood pressure and cholesterol levels.

The main sources of taurine are animal foods, such as meat, fish and dairy products.

Objectives:
A dietary protein intake (DPI) of between 0.6 and 0.8 g protein per kilogram body weight per day (g/kg/day) is frequently recommended for adults with moderate-to-advanced chronic kidney disease (CKD). However, evidence on whether patients with diabetic kidney disease (DKD) actually benefit from a DPI of ≤ 0.8 g/kg/day and from a low-protein diet (LPD) at CKD stages 1-3 has not been consistent. Therefore, this review article has been conducted.

Do patients with diabetic kidney disease benefit from a dietary protein intake of 0.8 g protein per kilogram body weight per day (g/kg/day)?

Study design:
This review article included 9 RCTs with a total of 506 participants and follow-up periods varying from 4.5 to 60 months.

Results and conclusions:
The investigators found that patients with diabetic kidney disease who consumed 0.8 g protein/kg/day had a significantly reduced decline in glomerular filtration rate (GFR) [MD = 22.31 mL/min/1.73 m², 95% CI = 17.19 to 27.42, p 0.01] and a significant decrease in proteinuria [SMD = -2.26 units, 95% CI = -2.99 to -1.52, p 0.001] versus those on the control diet.

The investigators found the benefits of a low-protein diet to patients with diabetic kidney disease at chronic kidney disease stages 1-3 were a markedly decreased proteinuria [SMD - 0.96 units, 95% CI = -1.81 to -0.11, p = 0.03] and slight but significant decreases in glycated hemoglobin [-0.42%] and cholesterol levels [-0.22 mmol/L].

The investigators concluded that a dietary protein intake of 0.8 g/kg/day is strongly associated with a slow decline in glomerular filtration rate (GFR) and decreases proteinuria in the patients with diabetic kidney disease. Patients with chronic kidney disease (CKD) stages chronic kidney disease 1-3 benefit from a low-protein diet in terms of a marked decrease of proteinuria and slight but significant improvements in lipid and glucose control.  

Original title:
Diabetic Kidney Disease Benefits from Intensive Low-Protein Diet: Updated Systematic Review and Meta-analysis by Li Q, Wen F, [...], Wang W.

Link:
https://pubmed.ncbi.nlm.nih.gov/33150563/

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Find here more information/studies about protein consumption and kidney disease.

For example: you are a patient with diabetic kidney disease, you weigh 70 kg and you want to eat 2200 kcal every day. How should you meet a dietary protein intake of 0.8 g protein per kilogram body weight per day (g/kg/day) in daily life?
Every day you should take maximal 0.8 g protein x 70 kg = 56 g protein. 56 g protein give 56x4 kcal = 224 kcal. 224 kcal is around 10% of 2200 kcal. Thus, you should eat products whose protein content contributes maximum 10% to the total kcal of the product in question, meaning you should eat products with 10 En% protein. These products in the supermarket contain maximum 10 En% protein.

Thus, a dietary protein intake of 0.8 g protein per kilogram body weight per day (g/kg/day) for a person weighing 70 kg on a diet of 2200 kcal, means he/she should eat products with maximum 10 En% protein in daily life.
 

Objectives:
Soy products contain several compounds with anti-inflammatory properties like genistein and daidzein which reported to act through different pathways. However, there are inconsistent results and lack of any comprehensive review regarding randomized controlled trials which assess the effect of soy products on inflammatory markers. Therefore, this review article has been conducted.

Does soy product supplementation reduce levels of inflammatory markers, like CRP, IL-6?

Study design:
This review article included 51 RCTs.

Results and conclusions:
The investigators found soy product supplementation significantly reduced CRP levels [MD = -0.27 mg/L, 95% CI = -0.51 to -0.02, p = 0.028] but it did not affect IL-6 [MD = 0.0 pg/mL, 95% CI = -0.06 to 0.06, p = 0.970] and TNF-α [MD = -0.04 pg/mL, 95% CI = -0.11 to 0.03, p = 0.252].

The investigators found subgroup analysis showed that soy supplementation had a significant impact on decreasing IL-6 and TNF-α levels when studies had a long-term intervention (≥12 weeks) and used low dose isoflavone (100 mg/day).

The investigators concluded there is a significant reduction in CRP levels after soy product supplementation.

Original title:
The effects of soy supplementation on inflammatory biomarkers: A systematic review and meta-analysis of randomized controlled trials by Asbaghi O, Yaghubi E, […], Ghaedi E.

Link:
https://pubmed.ncbi.nlm.nih.gov/32979840/

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Objectives:
There is some inconclusive evidence for the role of fish consumption in susceptibility to multiple sclerosis (MS). Therefore, this review article has been conducted.

Does fish consumption reduce multiple sclerosis (MS)?

Study design:
This review article included 6 observational studies.

Results and conclusions:
The investigators found that the consumption of fish (at least 0.5 servings of fish per week) significantly decreased the risk of multiple sclerosis with 23% [OR = 0.77, 95% CI = 0.64 to 0.92, p-value = 0.004, I2 = 54.7%] compared with controls.

The investigators concluded that dietary intake of at least 0.5 servings of fish per week during adolescence and after reduce the risk of multiple sclerosis; however, further studies are required to prove this preventive effect.

Original title:
Dietary fish intake and the risk of multiple sclerosis: a systematic review and meta-analysis of observational studies by Rezaeizadeh H, Mohammadpour Z, […], Homayon IA.

Link:
https://pubmed.ncbi.nlm.nih.gov/32787642/

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Objectives:
The relationship between dietary pattern and the risk of chronic obstructive pulmonary disease (COPD) has been described; however, the exclusive role of dietary factors remains controversial. Therefore, this review article has been conducted.

Does a dietary intake of fruits and vegetables, dietary fiber, fish, n-3 or n-6 fatty acids and antioxidant vitamins reduce risk of COPD in adults?

Study design:
This review article included 10 cohort, 6 case-control and 20 cross-sectional studies.

To assess usual dietary intake, 28 studies had used food frequency questionnaires (FFQ), of which 2 studies had used FFQ and a 24-hour recall, 3 studies had used the crosscheck dietary method, 1 study had assessed with only 24-hour recall and 1 study had used weighted household food records.

Results and conclusions:
The investigators found a significantly reduced risk of 26% [relative risk = 0.74, 95% CI = 0.65 to 0.85] for COPD for the highest fruit intake group compared with the lowest intake group.
This significantly reduced risk was 29% in cohort studies [RR = 0.71, 95% CI = 0.63 to 0.79, I2 = 0.0%].

The investigators found a significantly reduced risk of 47% [relative risk = 0.53, 95% CI = 0.39 to 0.74, I2 = 0.0%, p = 0.65] for COPD mortality for the highest fruit intake group compared with the lowest intake group.

The investigators found a significantly reduced risk of 35% [relative risk = 0.65, 95% CI = 0.55 to 0.78] for COPD for the highest dietary fiber intake group compared with the lowest intake group.
This significantly reduced risk was 39% in cohort studies [RR = 0.61, 95% CI = 0.54 to 0.68, I2 = 0.0%, p = 0.9].

The investigators found a significantly reduced risk of 29% [relative risk = 0.71, 95% CI = 0.58 to 0.85] for COPD for the highest fish intake group compared with the lowest intake group.

The investigators found a significantly reduced risk of 11% [relative risk = 0.89, 95% CI = 0.76 to 0.99] for COPD for the highest vitamin C dietary intake group compared with the lowest intake group.

The investigators found no association between the risk of COPD and the intake of vegetables, n-3 fatty acids, vitamin E and β-carotene.

The investigators concluded that a higher dietary intake of fruit, dietary fiber, fish and vitamine C reduce the risk of COPD in adults.

Original title:
Dietary Factors and Risk of Chronic Obstructive Pulmonary Disease: A Systemic Review and Meta-Analysis by Seyedrezazadeh E, Moghaddam MP, […], Kolahdooz F.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7309892/

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Find here more information/studies about fruit, dietary fiber, fish and vitamine C.

Objectives:
Vitamin D deficiency has been related to the risk of sepsis. However, previous studies showed inconsistent results regarding the association between serum 25-hydroxyvitamin D (25 (OH)D) and mortality risk in septic patients. Therefore, this review article has been conducted.

Does a low serum 25-hydroxyvitamin D (vitamin D level in blood) increase mortality risk in septic patients?

Study design:
This review article included 8 follow-up studies (4 were prospective and the other 4 were retrospective) with 1,736 septic patients.

The sample sizes of the included studies varied from 57 to 610.
The mean ages of the patients included in each study ranged from 57 to 75 years and the proportions of male patients varied from 43% to 71%.

Optimal vitamin D level, vitamin D insufficiency, vitamin D deficiency and severe vitamin D deficiency are defined as serum 25 (OH)D > 30 ng/mL, 21-29 ng/mL and  20 ng/mL, 10 ng/mL, respectively.

There was no publication bias.

Results and conclusions:
The investigators found meta-analysis with a random-effect model showed that septic patients with lower serum 25 (OH)D ( 30 ng/ml) at admission was associated with a significantly increased mortality risk of 93% [adjusted RR = 1.93, 95% CI = 1.41 to 2.63, p  0.001, I2 = 63%, p = 0.003].
Sensitivity analysis by excluding one study at a time did not significantly change the results.

The investigators found subgroup analyses according to the severity of vitamin D deficiency showed that patients with severe vitamin D deficiency ( 10 ng/mL) was significantly associated with a 92% higher mortality risk [adjusted RR = 1.92, 95% CI = 1.09 to 2.55, p  0.001].
But the associations were not significant for vitamin D insufficiency (25 (OH)D = 20-30 ng/mL) or deficiency (25 (OH)D = 10-20 ng/mL).

The investigators found further analyses showed that the association between lower serum 25(OH) D and higher mortality risk were consistent in studies applied different diagnostic criteria for sepsis (SIRS, Sepsis-2.0 or Sepsis-3.0), short-term (within 1 month) and long-term studies (3-12 months) and in prospective and retrospective studies.

The investigators concluded that severe vitamin D deficiency ( 10 ng/mL) is independently associated with increased mortality in patients with sepsis. Large-scale prospective studies are needed to validate these findings.

Original title:
Serum 25-Hydroxyvitamin D and the risk of mortality in adult patients with Sepsis: a meta-analysis by Li Y and Ding S.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7057612/

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Objectives:
Multiple sclerosis (MS) is a demyelinating and disabling inflammatory disease of the central nervous system. Multiple sclerosis is triggered by complex environmental factors which mostly affect genetically the susceptible young people. Emerging data has suggested that changes of homocysteine (Hcy), vitamin B12 and folate serum levels may be associated with multiple sclerosis. However, previous findings are not always consistent. Therefore, this review aricle has been conducted.

Does a low serum homocysteine, vitamin B12 or folate level increase risk of multiple sclerosis?

Study design:
This review article included 21 original studies with 1,738 multiple sclerosis patients and 1,424 controls (patients without multiple sclerosis). There were 17 studies for measuring homocysteine, 16 studies for measuring vitamin B12 and 13 studies for measuring folate in patients with multiple sclerosis, respectively.

Results and conclusions:
The investigators found patients with multiple sclerosis (MS) had higher serum levels of homocysteine [SMD = 0.64, 95% CI = 0.33 to 0.95, p 0.0001] compared with control groups.

The investigators found no significant differences of SMD for vitamin B12 [SMD = -0.08, 95% CI = -0.35 to 0.20, p = 0.58] or folate [SMD = 0.07, 95% CI = -0.14 to 0.28, p = 0.52] between MS and controls.

The investigators found subgroup analysis demonstrated that there was statistically significant difference for homocysteine between relapsing-remitting MS (RRMS) patients and controls with a SMD of 0.67 [95% CI = 0.21 to 1.13, p = 0.004].

However, no significant difference of homocysteine serum levels between secondary progressive MS patients or primary progressive MS patients and controls.

The investigators found no significant difference of homocysteine levels in females [SMD = 0.22, 95% CI = -0.16 to 0.60, p = 0.25] or males [SMD = 0.56, 95% CI = -0.13 to 1.26, p = 0.11] between MS patients and controls.

The investigators concluded higher serum levels of homocysteine increase risk of multiple sclerosis (MS), especially for relapsing-remitting MS (RRMS) patients. Functional studies are required to assess the effects of homocysteine on patients with MS at the molecular level.

Original title:
Serum levels of Homocysteine, Vitamin B12 and Folate in Patients with Multiple Sclerosis: an Updated Meta-Analysis by Li X, Yuan J, [...], Hu W.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7085269/

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Find here more information/studies about lowering serum levels of homocysteine.

Objectives:
Physical exercise may offer multiple benefits to patients with chronic kidney disease (CKD). However, it was not traditionally recommended because of the possibility of impairing renal function and increasing proteinuria. Therefore, this review aricle has been conducted.

Does low-intensity physical exercise offer benefits to patients with chronic kidney disease?

Study design:
This review article included 21 RCTs with a intervention of at least 12 weeks and 927 patients.

The frequency of low-intensity physical exercise in 14 studies was 3 times per week during 30 minutes.

Results and conclusions:
The investigators found no differences in glomerular filtration rate or proteinuria between the intervention group (group with low-intensity physical exercise) and the control group (group without low-intensity physical exercise) [SMD = -0.3, p = 0.81 and SMD = 26.6, p = 0.82].

The investigators found positive effects on peak oxygen consumption [SMD = 2.5, p 0.001], functional capacity [SMD = 56.6, p 0.001], upper limb strength [SMD = 6.8, p 0.001] and haemoglobin [SMD = 0.3, p = 0.003] for the intervention group.

The investigators found an improvement on the quality of life, using the KDQOL-36 survey [SMD = 3.56, p = 0.02] and the SF-36 survey [SMD = 6.66, p = 0.02] for the intervention group.

The investigators concluded low-intensity physical exercise routinely has no negative impact on renal function. On the contrary, it improves aerobic and functional capacity, impacting positively on the quality of life.

Original title:
Impact of physical exercise in patients with chronic kidney disease: Sistematic review and meta-analysis by Villanego F, Naranjo J, […], Mazuecos A.

Link:
https://reader.elsevier.com/reader/sd/pii/S0211699520300266?token=62CEB2BCF50CE23B396565B5DC989F795AEEB75C666C74AA410FD2172DB39F90DBBB5D72BF3B4347C0C8AD2FEF8B0110

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

Low-intensity physical exercises are a casual walk, a stretch session, a beginners' yoga class or tai chi.

Objectives:
Is there a causal relationship between dietary anthocyanins and reduced levels of systemic and vascular inflammation?

Study design:
This review article included 32 RCTs.

Results and conclusions:
The investigators found that dietary anthocyanins significantly decreased levels of C-reactive protein (CRP) [-0.33 mg/L, 95% CI = -0.55 to -0.11, p = 0.00], interleukin-6 (IL-6) [-0.41 ρg/mL, 95% CI = -0.70 to -0.13, p = 0.004], tumor necrosis factor-alpha (TNF-α) [-0.64 ρg/mL, 95% CI = -1.18 to -0.09, p = 0.023], intercellular adhesion molecule-1 [-52.4 ng/mL, 95% CI = -85.7 to -19.1, p = 0.002] and vascular adhesion molecule-1 (VCAM-1)  [-49.6 ng/mL, 95% CI = -72.7 to -26.5, p  0.001]. 

The investigators found that dietary anthocyanins significantly increased adiponectin level [0.75 μg/mL, 95% CI = 0.23 to 1.26, p = 0.004].

The investigators found subgroup analyses showed that administration of higher doses of anthocyanins (>300 mg/day) significantly decreased levels of CRP, IL-6, TNF-α and VCAM-1.

The investigators concluded that >300 mg/day dietary anthocyanins reduce the levels of systemic and vascular inflammation in the subjects.

Original title:
Impact of dietary anthocyanins on systemic and vascular inflammation: Systematic review and meta-analysis on randomised clinical trials by Fallah AA, Sarmast E, […], Jafari T.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31669599

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Inflammation in the body can be measured by the following biomarker; the pro-inflammatory cytokines. The pro-inflammatory cytokines are the C-reactive protein (CRP), IL-1, interleukin-6 (IL-6), IL-8, MCP-1, the vascular adhesion molecule-1 (VCAM-1) and tumor necrosis factor alpha (TNF-α).

Objectives:
Is there a causal relationship between intake of pomegranate and decreased risk of getting inflammation in adults?

Study design:
This review article included 16 randomized controlled trials (RCTs) involving 572 subjects.

Results and conclusions:
The investigators found when compared to placebo, that pomegranate supplementation significantly reduced hs-CRP levels [WMD = -6.57 mg/L, 95% CI = -10.04 to -3.10, p = 0.000].

The investigators found when compared to placebo, that pomegranate supplementation significantly reduced IL-6 levels [WMD = -1.68 pg/mL, 95% CI = -3.52 to -0.157, p = 0.000].

The investigators found when compared to placebo, that pomegranate supplementation significantly reduced TNF-α levels [WMD = -2.37 pg/mL, 95% CI = -3.67 to -1.07, p = 0.00].

The investigators found no association between pomegranate supplementation and CRP levels [WMD = 2.19 mg/dL, 95% CI = -3.28 to 7.67, p = 0.61], E-selectin levels [WMD = 8.42 ng/mL, 95% CI = -22.9 to 39.8, p = 0.599], ICAM levels [WMD = -17.38 ng/mL, 95% CI = -53.43 to 18.66, p = 0.107], VCAM levels [WMD = -69.32 ng/mL, 95% CI = -229.26 to 90.61, p = 0.396] or MDA levels [WMD = 0.031 μmol/L, 95% CI = -1.56 to 0.218, p = 0.746].

The investigators concluded pomegranate supplementation reduces hs-CRP levels, IL-6 levels and TNF-α levels in adults.

Original title:
The effects of pomegranate supplementation on biomarkers of inflammation and endothelial dysfunction: A meta-analysis and systematic review by Wang P, Zhang Q, [...], Yao G.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32147056

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Find here more information/studies about fruit and chronic diseases.

Inflammation in humans can be measured by biomarkers, such as highly sensitive C-reactive protein (hs-CRP), interleukin-6 (IL-6) and the tumor necrosis factor alpha (TNF-α).

Inflammation in humans can lower the resistance. A low resistance makes the body susceptible to diseases.
 

Objectives:
The activity of hepatitis B virus (HBV) as a risk factor for the incidence and progression of chronic kidney disease (CKD) has not been clarified. Therefore, this review article has been conducted.

Does hepatitis B virus infection increase risk of chronic kidney disease?

Study design:
This review article included 33 studies with a total of 7,849,849 patients.

Results and conclusions:
The investigators found in 11 cohort studies with 1,056,645 patients, that a positive HBV serologic status (hepatitis B virus infection) significantly increased risk of incidence of chronic kidney disease with 40% [adjusted HR = 1.40, 95% CI = 1.16 to 1.69, p 0.001, I2 = 49.5%, p 0.0001].

The investigators found in 10 cross-sectional studies with 3,222,545 patients, no relationship between hepatitis B virus infection and prevalence of chronic kidney disease [adjusted OR = 1.04, 95% CI = 0.90 to 1.218, p = 0.5].

The investigators found meta-regression analysis reported a relationship between positive HBsAg status and incidence of chronic kidney disease in the general population [p 0.015].

The investigators concluded hepatitis B virus infection increases risk of developing of chronic kidney disease in the adult general population. Studies aimed to understand the mechanisms responsible of such association are underway.

Original title:
HBV infection is a risk factor for chronic kidney disease: Systematic review and meta-analysis by Fabrizi F, Cerutti R, […], Messa P.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32037008

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Find here more information/studies about kidney disease.
 

Objectives:
Lead is a known risk factor for amyotrophic lateral sclerosis (ALS). However, the results of studies exploring the relationship between lead exposure and the occurrence of ALS are inconsistent. Therefore, this review article has been conducted.

Does a high lead exposure increase risk of ALS?

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

Results and conclusions:
The investigators found a high lead exposure significantly increased risk of ALS with 28% [OR = 1.28, 95% CI = 1.02 to 1.63].
Subgroup and sensitivity analyses showed stable results.

The investigators concluded a high lead exposure increases risk of ALS.

Original title:
Population-based study of environmental/occupational lead exposure and amyotrophic lateral sclerosis: a systematic review and meta-analysis by Meng E, Mao Y, […], Jin W.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31578652

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Objectives:
Many studies have been reported that dietary meat intake may be associated with the risk of asthma in children, but the results are inconsistent. Therefore, this review article has been conducted.

Does dietary meat intake increase asthma in children?

Study design:
This review article included a total of 9 articles.

No publication bias was detected.

Results and conclusions:
The investigators found dietary meat intake 3 or more times per week compared with never/occasionally intake had no significant association with asthma risk among children [OR = 1.27, 95% CI  =  0.80-2.01, p =  0.308].
Not significant because OR of 1 was found in the 95% CI of 0.80 to 2.01. OR of 1 means no risk/association.

The investigators found, similarly, daily dietary intake of meat did not affect the risk of asthma in children when compared with never/occasionally intake [OR  =  1.13, 95% CI  =  0.93-1.37, p  =  0.234].

The investigators concluded dietary meat intake is not a risk factor for asthma in children. Due to some limitations that exist in this review article, more studies are needed to further assess the association between dietary meat intake and asthma risk in children.

Original title:
Dietary meat intake and risk of asthma in children: evidence from a meta-analysis by Zhang D, Cao L, [...], Wang Z.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31895767

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Objectives:
Women have a 50% risk of urinary tract infection (UTI) over their lifetime and 20-30% experience a subsequent urinary tract infection recurrence. Cranberry (Vaccinium spp.) has been advocated for treatment of urinary tract infection; however, its efficacy is controversial. Therefore, this review article (meta-analysis) has been conducted.

Does cranberry reduce the risk of urinary tract infection recurrence in healthy women?

Study design:
This review article included 7 RCTs conducted in healthy nonpregnant women aged ≥18 years with a history of urinary tract infection (n = 1498 participants).
Risk of bias indicated that 2 studies had high loss to follow-up or selective outcome reporting. Overall, the studies were relatively small, with only 2 having >300 participants.

Results and conclusions:
The investigators found that cranberry significantly reduced the risk of urinary tract infection by 26% [pooled risk ratio = 0.74, 95% CI = 0.55-0.98, I2 = 54%].

The investigators concluded that cranberry may be effective in preventing urinary tract infection recurrence in generally healthy women. May be effective because the studies were relatively small, with only 2 having >300 participants. Therefore, larger high-quality studies are needed to confirm these findings.

Original title:
Cranberry Reduces the Risk of Urinary Tract Infection Recurrence in Otherwise Healthy Women: A Systematic Review and Meta-Analysis by Zhuxuan Fu, DeAnn Liska, […], Mei Chung.

Link:
http://jn.nutrition.org/content/147/12/2282.abstract

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Objectives:
Epidemiological studies have provided controversial evidence between beverage consumption and the risk of ulcerative colitis (UC). Therefore, this review article (meta-analysis) has been conducted.

Is there a relationship between beverage consumption and risk of ulcerative colitis?

Study design:
This review article included 13 case-control studies and 3 prospective cohort studies, with a total of 3,689 cases (subjects with ulcerative colitis) and 335,339 controls (subjects without ulcerative colitis).

Egger test detected no significant publication bias.

Results and conclusions:
The investigators found high intake of soft drinks versus low intake, significantly increased risk of ulcerative colitis with 69% [pooled RR = 1.69, 95% CI = 1.24-2.30, I2  =  12.9%, p  = 0 .332].
In subgroup analysis, no substantial changes of the primary result were found between subgroups.

The investigators found high tea consumption versus low consumption, significantly decreased risk of ulcerative colitis with 31% [pooled RR = 0.69, 95% CI = 0.58-0.83, I2  =  0.0%, p  = 0 .697].
In subgroup analysis, no substantial changes of the primary result were found between subgroups.

The investigators found no significant association between alcohol [pooled RR = 1.08, 95% CI = 0.66-1.51] or coffee consumption [pooled RR = 0.58, 95% CI = 0.33-1.05, I2  =  87.5%, p    0.001] and risk of ulcerative colitis. No significant association because RR of 1 was found in the 95% CI of 0.66 to 1.51. RR of 1 means no risk/association.

The investigators concluded high consumption of soft drinks increases the risk of ulcerative colitis, while high tea consumption decreases the risk.

Original title:
Beverage consumption and risk of ulcerative colitis. Systematic review and meta-analysis of epidemiological studies by Nie JY and Zhao Q.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5728934/

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Objectives:
The role of omega-3 polyunsaturated fatty acids (omega-3 or n-3 PUFAs) in the pathogenesis and treatment of children and adolescents with attention deficit hyperactivity disorder (ADHD) is unclear. Therefore, this review article (meta-analysis) has been conducted.

Do children and adolescents with attention deficit hyperactivity disorder (ADHD) benefit from n-3 PUFA supplementation?

Study design:
This review article included 7 RCTs and 7 case-control studies.

Results and conclusions:
The investigators found in 7 RCTs (n = 534 randomised youth with ADHD) n-3 PUFAs supplementation significantly improved ADHD clinical symptom scores [g = 0.38, p 0.0001].

The investigators found in 3 RCTs (n = 214 randomised youth with ADHD) n-3 PUFAs supplementation significantly improved cognitive measures associated with attention [g = 1.09, p = 0.001].

The investigators found children and adolescents with ADHD had lower levels of DHA [7 case-control studies, n = 412, g = -0.76, p = 0.0002], EPA (7 case-control studies, n = 468, g = -0.38, p = 0.0008] and total n-3 PUFAs [6 case-control studies, n = 396, g = -0.58, p = 0.0001].

The investigators concluded there is evidence that n-3 PUFAs supplementation monotherapy improves clinical symptoms and cognitive performances in children and adolescents with ADHD and that these youth have a deficiency in n-3 PUFAs levels. These findings provide further support to the rationale for using n-3 PUFAs as a treatment option for ADHD.

Original title:
Omega-3 Polyunsaturated Fatty Acids in Youths with Attention Deficit Hyperactivity Disorder (ADHD): A Systematic Review and Meta-Analysis of Clinical Trials and Biological Studies by Chang JC, Su KP, [...], Pariante CM.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28741625

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Find more information/studies on chronic disease, n-3 PUFA right here.
EPA and DHA are n-3 PUFA.

Objectives:
Recent data pose the question whether conservative management of chronic kidney disease (CKD) by means of a low-protein diet can be a safe and effective means to avoid or defer transition to dialysis therapy without causing protein-energy wasting or cachexia. Therefore, this review article (meta-analysis) has been conducted.

Do subjects with chronic kidney disease benefit from a low-protein diet?

Study design:
This review article included 16 controlled trials of low-protein diet in chronic kidney disease that met the stringent qualification criteria including having 30 or more participants.

Results and conclusions:
The investigators found compared with diets with protein intake of >0.8 g/kg/day, diets with restricted protein intake (0.8 g/kg/day) were associated with higher serum bicarbonate levels, lower phosphorus levels, lower azotemia, lower rates of progression to end-stage renal disease and a trend towards lower rates of all-cause death.

The investigators found compared with diets with protein intake of >0.8 g/kg/day, very-low-protein diets (protein intake 0.4 g/kg/day) were associated with greater preservation of kidney function and reduction in the rate of progression to end-stage renal disease.

The investigators found safety and adherence to a low-protein diet was not inferior to a normal protein diet and there was no difference in the rate of malnutrition or protein-energy wasting.

The investigators concluded a low-protein diet, particularly protein intake 0.4 g/kg/day, appears to enhance the conservative management of non-dialysis-dependent chronic kidney disease and may be considered as a potential option for chronic kidney disease patients who wish to avoid or defer dialysis initiation and to slow down the progression of chronic kidney disease, while the risk of protein-energy wasting and cachexia remains minimal.
 
Original title:
Low-protein diet for conservative management of chronic kidney disease: a systematic review and meta-analysis of controlled trials by Rhee CM, Ahmadi SF, [...], Kalantar-Zadeh K.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29094800

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A protein intake of 0.8 g/kg/day usually corresponds to a diet with 11 En% protein.
A protein intake of 0.4 g/kg/day usually corresponds to a diet with 5.5 En% protein.
A diet with 5.5 En% protein is a diet with a lot of products with 5.5 En% protein. Check here which products contain 5.5 En% protein.
 

Objectives:
Over 200 clinical trials have examined the effect of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplements on risk factors associated with cardiovascular disease. However, an updated analysis of the evidence is lacking. Therefore, this review article (meta-analysis) has been conducted.

Do EPA and DHA supplements reduce risk of cardiovascular diseases?

Study design:
This review article included 171 RCTs with acceptable quality (Jadad score ≥3).

Results and conclusions:
The investigators found compared to placebo-control, EPA and DHA supplements produced significant reductions of triglycerides of 0.368 mmol/L [95% CI = -0.427 to -0.309].
The triglyceride-lowering effect was dose-dependent.

The investigators found compared to placebo-control, EPA and DHA supplements produced significant reductions of systolic blood pressure of 2.195 mmHg [95% CI = -3.172 to -1.217].

The investigators found compared to placebo-control, EPA and DHA supplements produced significant reductions of diastolic blood pressure of 1.08 mmHg [95% CI = -1.716 to -0.444].

The investigators found compared to placebo-control, EPA and DHA supplements produced significant reductions of heart rate of 1.37 bpm [95% CI = -2.41 to -0.325].

The investigators found compared to placebo-control, EPA and DHA supplements produced significant reductions of C-reactive protein of 0.343 mg/L [95% CI = -0.454 to -0.232].

The investigators found compared to placebo-control, EPA and DHA supplements produced a significant increase of LDL cholesterol (bad cholesterol) [mean difference = 0.150 mmol/L, 95% CI = 0.058 to 0.243].

The investigators found compared to placebo-control, EPA and DHA supplements produced a significant increase of HDL cholesterol (good cholesterol) [mean difference = 0.039 mmol/L, 95% CI = 0.024-0.054].

The investigators concluded EPA and DHA supplements have lipid-lowering, hypotensive, anti-arrhythmic and anti-inflammatory effects.

Original title:
Eicosapentaenoic acid and docosahexaenoic acid containing supplements modulate risk factors for cardiovascular disease: a meta-analysis of randomised placebo-control human clinical trials by AbuMweis S, Jew S, […], Agraib L.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28675488

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

Does resveratrol supplementation reduce risk of non-communicable diseases?

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

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

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

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

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

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

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

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

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

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

Objectives:
Promising experimental studies suggest that quercetin has potential anti-inflammatory effects. However, the results of current clinical trials on quercetin's effects on the C-reactive protein (CRP), a sensitive inflammatory biomarker, are ambiguous. Therefore, this review article (meta-analysis) has been conducted.

Does quercetin supplementation reduce CRP levels?

Study design:
This review article included 7 RCTs with 10 treatment arms.

Results and conclusions:
The investigators found a significant reduction of circulating CRP levels [WMD = -0.33 mg/L, 95% CI = -0.50 to -0.15, p 0.001] following quercetin supplementation.

The investigators found in subgroup analysis, a significant reducing effect in trials with ≥500 mg/day dosage [WMD = -0.34 mg/L, 95% CI = -0.52 to -0.16, p ≤ 0.001] and in those with CRP 3 mg/L [WMD = -0.34 mg/L, 95% CI = -0.51 to -0.18, p ≤ 0.001].

The investigators found in meta-regression, no association between changes in CRP concentrations, dose of supplementation and CRP baseline values.

The investigators concluded quercetin supplementation reduces circulating C-reactive protein levels; especially at doses above 500 mg/day and in patients with CRP 3 mg/L.
 
Original title:
Effects of supplementation with quercetin on plasma C-reactive protein concentrations: a systematic review and meta-analysis of randomized controlled trials by Mohammadi-Sartang M, Mazloom Z, […], Firoozi D.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28537580

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Objectives:
Previous studies have demonstrated that asthma might be associated with an increase in cardiovascular disease (CVD) and death. However, this relationship differs by gender. Therefore, this review article (meta-analysis) has been conducted.

Is asthma associate with an increase risk in cardiovascular disease and death among men and women?

Study design:
This review article included 4 retrospective cohort studies and 6 prospective cohort studies. The length of follow-up ranged from 4.5 to 27 years. The sample sizes of the cohorts ranged from 1,233 to 151,620 (a total of 406,426).

There was no evidence of publication bias [Begg’s, p = 1.000 and Egger’s linear regression, p = 0.150].

Results and conclusions:
The investigators found overall, subjects with asthma experienced a significant increased risk of 33% for cardiovascular disease events [RR = 1.33, 95% CI = 1.15-1.53, p 0.0001, I2 = 88%, p 0.00001]. These findings remained consistent after sensitivity analysis by omitting one study each time.

The investigators found in subgroup analyses that women with asthma had a significantly higher risk of cardiovascular disease as compared to the reference group [RR = 1.55, 95% CI = 1.20-2.00, p = 0.0007, I2 = 84%], whereas no significant association was found in men [RR = 1.20, I2 = 83%, 95% CI = 0.92-1.56, p = 0.17]. However, the combined RR value was 1.36, 95% CI = 1.15-1.62, p = 0.0003]. These findings remained consistent after sensitivity analysis by omitting one study each time.
To further explore the interaction between gender and asthma on cardiovascular disease risk, the “test for subgroup differences” were examined and gave a p = 0.17, which suggested that the influence of gender on the association between asthma and cardiovascular disease risk was not statistically significant. Therefore, it cannot confirm or refute a significant difference in the incidence of cardiovascular disease between male and female asthmatic patients.

The investigators found asthma was associated with an increased risk of 36% of all-cause mortality in a random effects model as compared to reference subjects without asthma [RR = 1.36, 95% CI = 1.01-1.83, p = 0.05, I2 = 62%, p = 0.05]. These findings remained consistent after sensitivity analysis by omitting one study each time.

The investigators concluded there is an association between asthma and an increased risk of cardiovascular disease and all-cause mortality and women with asthma have a higher risk of cardiovascular disease than men with asthma. These findings indicate a need for early detection and intervention during general outpatient visits in asthmatics who may have potential cardiovascular disease complications or mortality.

Original title:
Asthma and risk of cardiovascular disease or all-cause mortality: a meta-analysis by Xu M, Xu J and Yang X.

Link:
http://www.annsaudimed.net/index.php/vol37/vol37iss2/1109.html

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Objectives:
Iron deficiency is a prevalent nutritional disease and fatigue is a common complaint in the general and patient population, however, the association between iron deficiency without anaemia (IDNA) and fatigue is unclear. Therefore, this review article (meta-analysis) has been conducted.

Does improving iron status decrease fatigue in patients with iron deficiency without anaemia?

Study design:
This review article included a total of 6 RCTs and 6 cross-sectional studies.

Results and conclusions:
The investigators found in the meta-analysis of 6 RCTs, a significant therapeutic effect of iron supplements in fatigue patients with iron deficiency without anaemia [pooled effect size = 0.33, 95% CI = 0.17 to 0.48, I2 = 0.0%, p 0.0001]. A sensitivity analysis found that the overall results (i.e. significant association) were robust.

The investigators found in the meta-analysis of 6 cross-sectional studies, a non-significant therapeutic effect of iron supplements in fatigue patients with iron deficiency without anaemia [pooled effect size = 0.10, 95% CI = -0.11 to 0.31, I2 = 57.4%, p = 0.362]. A sensitivity analysis found that the overall results (i.e. no significant association) were not robust, however, removal of one study made the outcomes significant.

The investigators concluded improving iron status decreases fatigue in patients with iron deficiency without anaemia. However, further research is necessary to identify diagnostic criteria for selecting fatigue patients who might benefit from iron therapy and to assess the prevalence of patients with iron deficiency without anaemia in the general population.

Original title:
Iron deficiency without anaemia is a potential cause of fatigue: meta-analyses of randomised controlled trials and cross-sectional studies by Yokoi K and Konomi A.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28625177

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Objectives:
Dietary intake is potentially associated with the onset of Crohn’s disease (CD), but evidence from epidemiological studies has remained unclear. Therefore, this review article (meta-analysis) has been conducted.

Is there a positive association between fat, carbohydrate or protein intake and the risk of Crohn’s disease?

Study design:
This review article included 4 case-control studies with a total of 311 Crohn’s disease cases and 660 controls and 5 prospective cohort studies with a total of 238,887 participants and 482 Crohn’s disease cases.

The Egger’s test detected no obvious publication bias in fiber (p = 0.708), while there were not enough studies to conduct the analyses for carbohydrate, fat and protein.

Results and conclusions:
The investigators found no evidence of a non-linear relationship between total carbohydrate intake and Crohn’s disease risk [p for non-linearity = 0.376].

The investigators found no association between 10 g increment/day of total carbohydrate intake and Crohn’s disease risk [RR = 0.991, 95% CI = 0.978-1.004, I2 = 0.0%, p = 0.439]. No association because RR of 1 was found in the 95% CI of 0.978 to 1.004. RR of 1 means no risk/association.

The investigators found no evidence of a non-linear relationship between total fat intake and Crohn’s disease risk [p for non-linearity = 0.281].

The investigators found no association between 10 g increment/day of total fat intake and Crohn’s disease risk [RR = 1.018, 95% CI = 0.969-1.069, I2 = 44.6%, p = 0.125].

The investigators found no evidence of a non-linear relationship between total protein intake and Crohn’s disease risk [p for non-linearity = 0.163].

The investigators found no association between 10 g increment/day of total protein intake and Crohn’s disease risk [RR = 1.029, 95% CI = 0.955-1.109, I2 = 54.7%, p = 0.085].

The investigators found a non-linear relationship between fiber dietary intake and Crohn’s disease risk [p for non-linearity = 0.019].

The investigators found a significant reduced risk of 14.7% for Crohn’s disease for per 10 g increment/day of fiber [RR = 0.853, 95% CI = 0.762-0.955]. However, the protective role of fiber dietary intake in the development of Crohn’s disease was gone after adjustment for the risk factor smoking [RR for per 10 g increment/day = 0.890, 95% CI = 0.776-1.020].

The investigators found a non-linear relationship between sucrose intake and Crohn’s disease risk [p for non-linearity = 0.023].

The investigators found a significant increased risk of 8.8% for Crohn’s disease for per 10 g increment/day of sucrose [RR = 1.088, 95% CI = 1.020-1.160, I2 = 0.0%, p = 0.39]. Significant means it can be said with a 95% confidence that each 10 g increment/day of sucrose really increased the risk of Crohn’s disease. 

The investigators concluded there is a lack of association between total carbohydrate, fat or protein intake and the risk of Crohn’s disease, while high fiber dietary intake might decrease the risk but the association was influenced by study design and smoking adjustment. High sucrose intake might increase the risk of Crohn’s disease. However, large-scale prospective designed studies are needed to confirm these findings.

Original title:
Macronutrient Intake and Risk of Crohn’s Disease: Systematic Review and Dose–Response Meta-Analysis of Epidemiological Studies by Zeng L, Hu S, [...], Tan Y.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5452230/

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Objectives:
C-reactive protein (CRP) has been proposed as a risk marker and risk factor of cardiovascular disease. There have been a number of clinical reports suggesting that supplementation with L-carnitine can modulate systemic inflammation and lower circulating CRP concentrations, but the results have not been consistent. Therefore, this review article (meta-analysis) has been conducted.

Does supplementation with L-carnitine reduce circulating CRP concentrations?

Study design:
This review article included 6 RCTs comprising 541 cases and 546 controls.
3 studies were conducted in diabetic or prediabetic patients, 2 studies in hemodialysis patients and 1 study in patients with non-alcoholic steatohepatitis.
Duration of L-carnitine supplementation ranged between 8 to 48 weeks.
Dosage of L-carnitine ranged between 1-2 g/day in all the included trials.

Results and conclusions:
The investigators found in random effect analysis a statistically significant pooled effect size [net change = -0.39 mg/L, 95% CI = -0.62 to -0.16, p = 0.001, I2 = 44%, p = 0.11] for the impact of L-carnitine supplementation among 541 cases and 546 controls. This effect size estimate was found to be robust and remained unaffected by the removal of each single study.

The investigators concluded the present meta-analysis support the clinically relevant benefit of L-carnitine supplementation (1-2 g/day) in lowering the circulating levels of CRP. Conducting future, large-scale, randomized clinical trials is warranted in homogenous populations to verify the findings of this meta-analysis.

Original title:
Effect of L-carnitine Supplementation on Circulating C-reactive Protein Levels: A Systematic Review and Meta-Analysis by Sahebkar A.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4922328/

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Higher circulating levels of CRP increase inflammation.
 

Objectives:
Is there a causal association between low serum vitamin D concentrations, increased body mass index (BMI) and pediatric-onset multiple sclerosis (MS) using genetic risk scores (GRS)?

Study design:
This review article included participants of non-Hispanic white individuals recruited from over 15 sites across the United States (n = 394 cases, 10,875 controls) and Sweden (n = 175 cases, 5,376 controls; total n = 16,820).

Results and conclusions:
The investigators found meta-analysis findings demonstrated that a vitamin D GRS associated with increasing levels of 25(OH)D in serum significantly decreased risk of pediatric-onset MS with 28% [OR =  0.72, 95% CI = 0.55-0.94, p = 0.02] after controlling for sex, genetic ancestry, HLA-DRB1*15:01 and over 100 non-human leukocyte antigen MS risk variants.

The investigators also found that a higher BMI GRS significant increased risk of pediatric-onset MS with 17% [OR = 1.17, 95% CI = 1.05-1.30, p = 0.01] after adjusting for covariates.

The investigators found estimates for each GRS were unchanged when considered together in a multivariable model.

The investigators concluded evidence supporting independent and causal effects of decreased vitamin D levels and increased BMI on susceptibility to pediatric-onset MS.

Original title:
Evidence for a causal relationship between low vitamin D, high BMI, and pediatric-onset MS by Gianfrancesco MA, Stridh P, […], Waubant E.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28356466

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