Nutrition and health

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 

Additional information of El Mondo:
Find here more information/studies about chronic disease and L-carnitine.

Objectives:
Although many studies have shown that low zinc status is associated with diabetes, the putative effects of zinc supplementation on glycemic control are inconclusive. Therefore, this review article (meta-analysis) has been conducted.

Does zinc supplementation reduce risk of diabetes mellitus?

Study design:
This review article included 32 RCTs, involving a total of 1,700 participants in 14 countries.

Results and conclusions:
The investigators found overall, compared with their respective control groups, the subjects in the zinc supplementation group had a statistically significant reduction in concentrations of :
-fasting glucose [WMD = -14.15 mg/dL, 95% CI = -17.36 to -10.93 mg/dL];
-2-h postprandial glucose [WMD = -36.85 mg/dL, 95% CI = -62.05 to -11.65 mg/dL];
-fasting insulin [WMD = -1.82 mU/L, 95% CI = -3.10 to -0.54 mU/L];
-homeostasis model assessment for insulin resistance [WMD = -0.73, 95% CI = -1.22 to -0.24]:
-glycated hemoglobin [WMD = -0.55%, 95% CI = -0.84 to -0.27%] and;
-high-sensitivity C-reactive protein [WMD = -1.31 mg/L, 95% CI = -2.05 to -0.56 mg/L].

The investigators found, moreover, subgroup analyses revealed that the effects of zinc supplementation on fasting glucose were significantly influenced by diabetic status and the formulation of the zinc supplement.

The investigators concluded several key glycemic indicators are significantly reduced by zinc supplementation, particularly the fasting glucose in subjects with diabetes and in subjects who received an inorganic zinc supplement. Together, these findings support the notion that zinc supplementation may have clinical potential as an adjunct therapy for preventing or managing diabetes.

Original title:
Zinc supplementation improves glycemic control for diabetes prevention and management: a systematic review and meta-analysis of randomized controlled trials by Wang X, Wu W, [...], Wang F.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31161192

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

Objectives:
Dietary proteins, including those obtained from animal and plant sources, have inconsistently been correlated with type 2 diabetes mellitus (T2DM) risk. Therefore, this review article (meta-analysis) has been conducted.

Does dietary protein intake increase risk of type 2 diabetes mellitus?

Study design:
This review article included 21 cohort studies with a total of 487,956 individuals and 38,350 T2DM cases (persons with type 2 diabetes mellitus).

Results and conclusions:
The investigators found high total dietary protein intake was associated with an increased risk of 10% for type 2 diabetes mellitus [RR = 1.10, p = 0.006] whereas moderate total dietary protein intake was not significantly associated with type 2 diabetes mellitus risk [RR = 1.00,  p = 0.917].  
Not significantly because the calculated p-value of 0.917 was larger than the p-value of 0.05.

The investigators found, moreover, an increased risk of 13% [RR = 1.13, p = 0.013] for type 2 diabetes mellitus was observed with high  dietary animal protein intake whereas moderate animal protein intake had little or no effect on type 2 diabetes mellitus risk [RR = 1.06, p = 0.058].

The investigators found, high dietary intake of plant protein did not affect type 2 diabetes mellitus risk [RR = 0.93, p = 0.074], whereas moderate intake was associated with a reduced risk of 6% for type 2 diabetes mellitus [RR = 0.94, p  0.001].

The investigators concluded high dietary total protein and dietary animal protein intakes are associated with an increased risk of type 2 diabetes mellitus, whereas moderate plant protein intake is associated with a decreased risk of type 2 diabetes mellitus.

Original title:
Dietary protein intake and subsequent risk of type 2 diabetes: a dose-response meta-analysis of prospective cohort studies by Ye J, Yu Q, [...], Wang Y.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30929078

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

A diet with high protein intake is a diet with a minimum of 35 En% protein (En% = energy percentage). These products from the supermarket contain at least 35 En% protein.
35 En% protein means that the amounts of protein contribute 35% to the total calories (kcal) of the diet.
If the diet contains 2000 kcal, 175 grams of protein contribute 35% to this 2000 kcal.
1 gram of protein gives 4 kcal. Thus, 175 grams of protein provide 700 kcal and 700 kcal is 35% of 2000 kcal.

A diet with moderate protein consumption is a diet with 20-25 En% protein. The easiest way to follow a diet with moderate protein consumption is to choose only products/meals that also contain 20-25 En% protein. These products from the supermarket contain 20-25 En% protein.

 

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:
The role of gut microbiota in the management of diabetes has been shown. Several current trials are investigating the effect of probiotics and prebiotics, which are widely used to modulate intestinal microbiota, on inflammatory factors and biomarkers of oxidative stress in diabetic patient. However, their findings are controversial. Therefore, this review article (meta-analysis) has been conducted.

Do probiotic and synbiotic supplementation improve biomarkers of inflammation and oxidative stress in diabetic patients?

Study design:
This review article included 16 RCTs (n = 1,060).

Randomized controlled trials (RCTs) reported the effect of probiotics or synbiotics on circulating (serum and plasma) inflammatory marker (hs-CRP) and oxidative stress indicators (malondialdehyde [MDA], glutathione [GSH], nitric oxide [NO] and total antioxidant capacity [TAC]) among patients with diabetes.

The methodological quality varied across these trials.

Results and conclusions:
The investigators found probiotic and synbiotic supplementation significantly decreased hs-CRP level [SMD = -0.38, 95% CI = -0.51 to -0.24, p = 0.000] and the oxidative stress indicator malondialdehyde [SMD = -0.61, 95% CI = -0.89 to -0.32, p = 0.000] in diabetic patients compared to those in subjects receiving placebos.

The investigators found, in addition, probiotic and synbiotic supplementation significantly increased total antioxidant capacity [SMD = 0.31, 95% CI = 0.09 to 0.52, p = 0.006], nitric oxide [SMD = 0.62, 95% CI = 0.25 to 0.99, p = 0.001] and glutathione [SMD = 0.41, 95% CI = 0.26, 0.55, p = 0.000] levels.

The investigators concluded that probiotic and synbiotic supplementation improve biomarkers of inflammation and oxidative stress in diabetic patients. Further studies are needed to develop clinical practice guidelines for the management of inflammation and oxidative stress in these patients.

Original title:
The effect of probiotic and synbiotic supplementation on biomarkers of inflammation and oxidative stress in diabetic patients: A systematic review and meta-analysis of randomized controlled trials by Zheng HJ, Guo J, [...], Wang Y.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30794924

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

Oxidative stress is an imbalance between free radicals and antioxidants in your body. Antioxidants can reduce oxidative stress.
 

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

Additional information of El Mondo:
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:
Various mechanisms link higher total homocysteine to higher insulin resistance and risk of type 2 diabetes (T2D). Folate supplementation is recognized as a way to lower homocysteine. However, randomized controlled trials (RCTs) show inconsistent results on insulin resistance and type 2 diabetes outcomes. Therefore, this review article (meta-analysis) has been conducted.

Does folate supplementation improve insulin resistance and type 2 diabetes outcomes?

Study design:
This review article included 29 RCTs (22,250 participants) that assessed the effect of placebo-controlled folate supplementation alone or in combination with other B vitamins on fasting glucose, insulin, homeostasis model assessment for insulin resistance (HOMA-IR), glycated hemoglobin (HbA1c) or risk of type 2 diabetes.

The meta-analysis was conducted using both random- and fixed-effects models to calculate weighted mean differences (WMDs) or risk ratios with 95% CIs.
Heterogeneity was low in all meta-analyses.

Results and conclusions:
The investigators found when compared with placebo, folate supplementation significantly lowered fasting insulin [WMD = -13.47 pmol/L, 95% CI = -21.41 to -5.53 pmol/L, p 0.001] and HOMA-IR [WMD = -0.57 units, 95% CI = -0.76 to -0.37 units, p 0.0001], but no overall effects were observed for fasting glucose or HbA1c.

The investigators found subgroup analysis showed no signs of effect modification except for change in homocysteine, with the most pronounced effects in trials with a change of >2.5 µmol/L.
Changes in homocysteine after folate supplementation correlated with changes in fasting glucose [β = 0.07, 95% CI = 0.01 to 0.14, p = 0.025] and HbA1c [β = 0.46, 95% CI = 0.06 to 0.85, p = 0.02].

The investigators found only 2 studies examined folate supplementation on risk of type 2 diabetes and they found no change in RR [pooled RR = 0.91, 95% CI = 0.80 to 1.04, p = 0.16].

The investigators concluded that folate supplementation lowers fasting insulin and HOMA-IR. However, folate supplementation does not reduce risk of type 2 diabetes.

Original title:
Effect of folate supplementation on insulin sensitivity and type 2 diabetes: a meta-analysis of randomized controlled trials by Lind MV, Lauritzen L, [...], Eriksen JN.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30615110

Additional information of El Mondo:
Find more information/studies on diabetes and folate (also called folic acid) right here.
 

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

Additional information of El Mondo:
Find here more information/studies about random-effects meta-analysis and magnesium.
 

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

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

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

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

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

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

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

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

Additional information of El Mondo:
Find here more information/studies about coffee consumption and chronic diseases.
 

Objectives:
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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Find here more information/studies about fish consumption, n-3 PUFAs and chronic diseases.
 

Objectives:
Evidence from randomized controlled trials (RCTs) suggests that viscous dietary fiber may offer beneficial effects on glycemic control and, thus, an improved cardiovascular disease risk profile. Therefore, this review article (meta-analysis) has been conducted.

Does viscous dietary fiber supplementation improve glycemic control in type 2 diabetes?

Study design:
This review article included 28 RCTs of ≥3 weeks in duration that assessed the effects of viscous fiber on markers of glycemic control in type 2 diabetes with a total of 1,394 participants.

Results and conclusions:
The investigators found that viscous fiber at a median dose of ∼13.1 g/day significantly reduced HbA1c in type 2 diabetes [MD = -0.58%, 95% CI = -0.88 to -0.28, p = 0.0002] compared with control and in addition to standard of care.

The investigators found that viscous fiber at a median dose of ∼13.1 g/day significantly reduced fasting blood glucose in type 2 diabetes [MD = -0.82 mmol/L, 95% CI = -1.32 to -0.31, p = 0.001] compared with control and in addition to standard of care. 

The investigators found that viscous fiber at a median dose of ∼13.1 g/day significantly reduced HOMA-insulin resistance in type 2 diabetes [MD = -1.89, 95% CI = -3.45 to -0.33, p = 0.02] compared with control and in addition to standard of care.

The investigators found the certainty of evidence was graded moderate for HbA1c, fasting glucose, fasting insulin and HOMA-IR and low for fructosamine.

The investigators concluded that 13.1 g/day viscous fiber supplements improve conventional markers of glycemic control beyond usual care and should be considered in the management of type 2 diabetes.

Original title:
Should Viscous Fiber Supplements Be Considered in Diabetes Control? Results From a Systematic Review and Meta-analysis of Randomized Controlled Trials by Jovanovski E, Khayyat R, […], Vuksan V.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30617143

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

Study design:
This review article included 8 studies.

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

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

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

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

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

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

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

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Find here more information/studies about vitamin D and chronic diseases.
 

Objectives:
Diabetes prevention is a public health priority. Vitamin D supplementation may help prevent the development of diabetes in persons at increased risk. Therefore, this review article has been conducted.

Does vitamin D supplementation reduce risk of type 2 diabetes?

Study design:
This review article included 28 RCTs with 3,848 participants.

The sample size varied from 23 to 511.
The mean age of participants ranged from 26 years to 71 years.
The duration of follow-up across studies ranged from 2 months to 5 years, with a median follow-up of 22 weeks [interquartile range (IQR): 14 to 48 weeks], a duration long enough to detect changes in measured outcomes.

The average vitamin D supplementation dose of 88 µg/d (3500 IU/d).
All included trials measured the effect of vitamin D supplementation on serum 25(OH)D concentrations.

Results and conclusions:
The investigators found overall, serum 25(OH)D concentrations in the treated arms (vitamin D-supplemented groups) significantly improved by 45.1 nmol/L [95% CI = 41.3 to 48.9, p 0.001, I2 = 97.4%].

The investigators found compared with the control group, vitamin D supplementation significantly reduced HbA1c level by -0.48% [95% CI = -0.79 to -0.18, p = 0.002, I2 = 92.1%].
However, after adjusting the effect size for potential publication bias using the “trim and fill” method, 4 potentially missing studies were imputed in the funnel plot and the effect size increased from -0.48% [95% CI = -0.79 to -0.18] to -0.71% [95% CI = -1.02 to -0.39].

The investigators found compared with the control group, vitamin D supplementation significantly reduced fasting plasma glucose level by -0.46 mmol/L [95% CI = -0.74 to -0.19, p = 0.001, I2 = 92.4%].  
However, after adjusting the effect size for potential publication bias using the “trim and fill” method, 6 potentially missing studies were imputed in the funnel plot and the effect size increased -0.46 mmol/L [95% CI = -0.74 to ­0.19] to -0.72 mmol/L [95% CI =-1.02 to -0.42].

The investigators found compared with the control group, vitamin D supplementation significantly reduced HOMA-IR level by -0.39 [95% CI = -0.68 to -0.11, p = 0.007, I2 = 91.3%].
However, after adjusting the effect size for potential publication bias using the “trim and fill” method, 5 potentially missing studies were imputed in the funnel plot and the effect size increased from -0.39 [95% CI = -0.68 to -0.11] to -0.62 [95% CI = -0.92 to -0.32].

The investigators found in subgroup analysis both HbA1c and HOMA-IR showed a greater reduction over time among overweight/obese individuals compared with prediabetics [HbA1c = -0.98 ± 0.45 vs -0.29 ± 0.14, p = 0.1 and HOMA-IR = -0.62 ± 0.23 vs -0.07 ± 0.16, p = 0.05].

The investigators found in subgroup analysis vitamin D supplementation significantly decreased HbA1c [p = 0.05], fasting plasma glucose level [p = 0.05] and HOMA-IR [p = 0.1] to a greater extent when serum 25(OH)D concentration achieved was above 86 nmol/L.

The investigators found in subgroup analysis vitamin D supplementation for less than 6 months provided a larger effect size on HbA1c in comparison with long durations [-0.75 ± 0.33 vs -0.25 ± 0.11, p = 0.1].

The investigators found in subgroup analysis HbA1c showed greater improvement in populations with a mean age younger than 45 years in comparison with older populations [-1.15 ± 0.6 vs -0.30 ± 0.1, p = 0.05].

The investigators found in subgroup analysis greater reductions were found within HbA1c and fasting plasma glucose levels when baseline (at the beginning of the study) mean serum 25(OH)D concentration was ≥50 nmol/L, whereas the lowering effect was significantly less in the subgroup with baseline mean 25(OH)D 50 nmol/L [HbA1c = -0.79 ± 0.25 vs -0.14 ± 0.13, p = 0.04 and fasting plasma glucose level = -0.69 ± 0.21 vs -0.11 ± 0.10, p = 0.05].

The investigators concluded 88 µg/d vitamin D supplementation during 22 weeks improves glycemic measures and insulin sensitivity and may be useful as part of a preventive strategy for type 2 diabetes, particularly among overweight/obese individuals younger than 45 years.

Original title:
Vitamin D Supplementation, Glycemic Control, and Insulin Resistance in Prediabetics: A Meta-Analysis by Mirhosseini N, Vatanparast H, [...], Kimball SM.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6016617/

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

HbA1c, FPG, HOMA-IR and plasma glucose after 2-hour oral glucose tolerance test (2HPG) are different parameters associated with (pre)diabetes.

 

Objectives:
Is there an association between dietary factors and the risk of gout and hyperuricemia?
 
Study design:
This review article included 10 prospective cohort studies (the follow-up duration ranged from 6 years to 26 year) and 9 cross-sectional studies.

Based on the Newcastle-Ottawa Scale (NOS), the quality assessment of included studies yielded a mean NOS score of 7.1, suggesting the presence of high methodologic quality.

Results and conclusions:
The investigators found in meta-analysis that the risk of getting gout significantly increased with:
29% [OR = 1.29, 95% CI = 1.16-1.44] for dietary red meat intake;
31% [OR = 1.31, 95% CI = 1.01-1.68] for dietary seafoods intake;
158% [OR = 2.58, 95% CI = 1.81-3.66] for dietary alcohol intake;
114% [OR = 2.14, 95% CI = 1.65-2.78] for dietary fructose intake.

The investigators found in meta-analysis that the risk of getting gout significantly decreased with:
44% [OR = 0.56, 95% CI = 0.44-0.70] for dietary dairy products intake;
15% [OR = 0.85, 95% CI = 0.76-0.96] for dietary soy foods intake;
14% [OR = 0.86, 95% CI = 0.75-0.98] for dietary high-purine vegetables intake;
53% [OR = 0.47, 95% CI = 0.37-0.59] for dietary coffee intake.

The investigators found in meta-analysis that the risk of getting hyperuricemia (an excess of uric acid in the blood) significantly increased with:
24% [OR = 1.24, 95% CI = 1.04-1.48] for dietary red meat intake;
47% [OR = 1.47, 95% CI = 1.16-1.86] for dietary seafoods intake;
106% [OR = 2.06, 95% CI = 1.60-2.67] for dietary alcohol intake;
85% [OR = 1.85, 95% CI = 1.66-2.07] for dietary fructose intake.

The investigators found in meta-analysis that the risk of getting hyperuricemia (an excess of uric acid in the blood) significantly decreased with:
50% [OR = 0.50, 95% CI = 0.37-0.66] for dietary dairy products intake;
30% [OR = 0.70, 95% CI = 0.56-0.88] for dietary soy foods intake.

The investigators found in meta-analysis that the risk of getting hyperuricemia (an excess of uric acid in the blood) non-significantly increase with:
10% [OR = 1.10, 95% CI = 0.88-1.39] for dietary high-purine vegetables intake.

The investigators found in meta-analysis that the risk of getting hyperuricemia (an excess of uric acid in the blood) non-significantly decreased with 24% [OR = 0.76, 95% CI = 0.55-1.06] for dietary coffee intake in men.
Non-significantly because OR of 1 was found in the 95% CI of 0.55 to 1.06. OR of 1 means no risk/association.

The investigators found in meta-analysis that the risk of getting hyperuricemia (an excess of uric acid in the blood) significantly increased with 58% [OR = 1.58, 95% CI = 1.16-2.16] for dietary coffee intake in women.
Significant because OR of 1 was not found in the 95% CI of 1.16 to 2.16. OR of 1 means no risk/association.

The investigators concluded that the risk of hyperuricemia and gout is positively correlated with the dietary intake of red meat, seafoods, alcohol or fructose and negatively with dairy products or soy foods. High-purine vegetables show no association with hyperuricemia, but negative association with gout. Coffee intake is negatively associated with gout risk, whereas it is positively associated with hyperuricemia risk in women.

Original title:
Dietary factors and risk of gout and hyperuricemia: a meta-analysis and systematic review by Li R, Yu K and Li C.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30485934

Additional information of El Mondo:
Find more information/studies on food groups and chronic diseases right here.

Objectives:
Postherpetic neuralgia (PHN) is the most distressful complication of herpes zoster. Postherpetic neuralgia results in an impaired quality of life and higher healthcare utilization. Vitamin B12 has been proven to be effective in pain relief for various conditions. Therefore, this review article has been conducted.

Do postherpetic neuralgia patients benefit from vitamin B12 supplementation?

Study design:
This review article included 4 RCTs (published between 2013 and 2016) including 383 participants.

Results and conclusions:
The investigators found compared with the placebo group, the vitamin B12 group exhibited a significant decrease in the Numeric Rating Scale score, with a mean difference of -4.01 [95% CI = -4.70 to -3.33].

The investigators found compared with the placebo group, vitamin B12 administration improved the quality of life of postherpetic neuralgia patients with moderate quality evidence and significantly decreased the number of patients using analgesics.

The investigators concluded that vitamin B12 appears to be an attractive complementary therapy for postherpetic neuralgia patients. However, further investigation is needed before conclusive recommendations can be made.

Original title:
Vitamin B12 for herpetic neuralgia: A meta-analysis of randomised controlled trials by Wang JY, Wu YH, [...], Lu PH.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30477853

Additional information of El Mondo:
Find more information/studies on vitamin B12 and chronic diseases right here.

Postherpetic neuralgia (PHN) is a nerve pain (neuralgia) that persists after a shingles rash has cleared. Postherpetic neuralgia is caused by the chickenpox (varicella-zoster) virus.
 

Objectives:
Does magnesium supplementation reduce C-reactive protein concentrations in humans?

Study design:
This review article included 8 RCTs (2004-2014) with 349 participants.

The mean age of participants ranged from 18 to 85 years.
The range of duration of the supplementation intervention across studies was from 8 h to 6.5 months.
The consumed range of magnesium dose in these studies was from 320 to 1500 mg/day. The baseline level (at the start of the study) of the CRP varied between the studies from 0.42 mg/dL as minimum to 9.4 mg/dL as maximum.

Results and conclusions:
The investigators found magnesium supplementation significantly reduced serum CRP levels [WMD = -1.33 mg/dL, 95% CI = -2.63 to -0.02, p 0.001, I2 = 29.1%, p 0.123] across all studies.
In leave-one-out sensitivity analyses, the pooled effect estimates remained similar across all studies for CRP levels [WMD = -1.33 mg/dL, 95% CI = -2.63 to -0.02].

The investigators found after adjustment of the effect size for potential publication bias using the “trim and fill” correction, no potentially missing studies were imputed in the funnel plot [WMD = -1.33 mg/dL, 95% CI = -2.63 to -0.02]. The “fail-safe N” test showed that 146 studies would be needed to bring the WMD down to a non-significant [p > 0.05] value.

The investigators found in random-effects meta-regression changes in serum CRP levels were independent of the dosage of magnesium [slope = -0.004, 95% CI = -0.03 to 0.02, p = 0.720, and duration [slope = -0.06, 95% CI = -0.37 to 0.24, p = 0.681] of supplementation.

The investigators found in 4 RCTs that subjects with a baseline CRP of ≥ 2 mg/dL had more significant reduction in the serum CRP level [WMD = -2.95 mg/dL, 95% CI = -3.35 to -2.25, p 0.001, I2 = 1.1%, p = 0.952] compared with subjects with a baseline CRP of 2 mg/dL [WMD = -0.23 mg/dL, 95% CI = -0.195 to -0.326, p 0.001, I2 = 1.3% p = 0.923].

The investigators found magnesium supplementation non-significantly reduced IL-6 levels [WMD = -0.16 pg/dL, 95% CI = -3.52 to 3.26, p = 0.236, I2 = 2.3%, p = 0.802] across all studies.

The investigators found magnesium supplementation significantly increased TNF-α levels [WMD = 1.97 pg/dL, 95% CI = 1.12 to 2.82, p = 0.043, I2 = 2.1%, p = 0.869] across all studies.

The investigators found magnesium supplementation non-significantly decreased fasting blood glucose (FBG) levels [WMD = -0.61 mg/dL, 95% CI = -2.72 to 1.48, p = 0.182, I2 = 6.1%, p = 0.742] across all studies.

The investigators found magnesium supplementation non-significantly decreased systolic blood pressure levels [WMD = -0.93 mmHg, 95% CI = -3.03 to 1.20, p = 0.293, I2 = 3.6%, p = 0.526] across all studies.

The investigators found magnesium supplementation non-significantly decreased diastolic blood pressure levels [WMD = -0.30 mmHg, 95% CI = -2.80 to 2.19, p = 0.639, I2 = 3.8%, p = 0.489] across all studies.

The investigators found magnesium supplementation non-significantly increased BMI levels [WMD = 0.27 kg/m², 95% CI = -0.59 to 1.15, p = 0.542, I2 = 2.0%, p = 0.906] across all studies.  

The investigators concluded that 320 to 1500 mg/day magnesium supplementation decreases serum CRP levels, especially with the baseline values ≥ 2 mg/dL. To provide more conclusive results and clarify the mechanistic pathways, RCTs with a larger sample size and a long-term follow-up period are warranted.

Original title:
Effect of magnesium supplements on serum C-reactive protein: a systematic review and meta-analysis by Mazidi M, Rezaie P and Banach M.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6040119/

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

Objectives:
High potato intake has been suggested as a risk factor for the development of type 2 diabetes. Therefore, this review article has been conducted.

Does potato intake increase risk of type 2 diabetes?

Study design:
This review article included 6 prospective cohort studies with a total of 4,545,230 person-year of follow-up and 17,758 diabetes cases.

Results and conclusions:
The investigators found for every increment of 1 serving/day of total potato consumption a significantly increased risk of 20% [HR = 1.20, 95% CI = 1.13 to 1.127, p 0.001, I2 = 27.1%, p for heterogeneity = 0.23] for type 2 diabetes both in men en women.

The investigators found for 2 servings/day of total potato consumption a significantly increased risk of 44% [HR = 1.44, 95% CI = 1.28 to 1.63] for type 2 diabetes both in men en women.

The investigators found for 3 servings/day of total potato consumption a significantly increased risk of 74% [HR = 1.74, 95% CI = 1.45 to 2.09] for type 2 diabetes both in men en women.

The investigators found significant evidence of a non-linear association between total potato consumption and risk of type 2 diabetes [X2 = 17.5, p for linearity 0.001].

The investigators concluded that long-term high consumption of potato (each serving a day increase) is strongly associated with increased risk of type 2 diabetes. These findings suggest that diet-health policy may be of importance in the prevention of diabetes.

Original title:
Potato consumption and risk of type 2 diabetes: A dose-response meta-analysis of cohort studies by Bidel Z, Teymoori F, […], Nazarzadeh M.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30144898

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

According to the USDA Dietary Guidelines a serving of potato is 1 cup diced, mashed or baked or 1 medium boiled potato.

 

Objectives:
Dietary salt reduction in the general population lowers blood pressure and cardiovascular risk. Despite being widely recommended, there is limited evidence as to whether this is applicable to individuals with end-stage renal disease (ESRD) receiving dialysis. Therefore, this review article has been conducted.

Study design:
This review article included 4 RCTs (91 participants), of which 3 were crossover trials and 1 was a parallel study.
Participants were 18 years and over; a reduction in salt intake of at least 1 g/day over 1 week and no concomitant interventions during the study.
The primary outcome was change in systolic and diastolic blood pressure.

Results and conclusions:
The investigators found dietary salt reduction was associated with an 8.4 mmHg [95% CI = 4.8-12.0, Ι2 = 0%] reduction in systolic blood pressure and a 4.4 mmHg [95% CI = 2.2-6.6, Ι2 = 0%] reduction in diastolic blood pressure.

The investigators concluded that a reduction in salt intake of at least 1 g/day over 1 week reduces blood pressure among individuals with end-stage renal disease (ESRD) receiving dialysis.

Original title:
The effect of dietary salt on blood pressure in individuals receiving chronic dialysis: a systematic review and meta-analysis of randomised controlled trials by Cole NI, Swift PA, […], Suckling RJ.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30413764

Additional information of El Mondo:
Find more information/studies on lowering blood pressure, salt intake and chronic disease right here.
 

Objectives:
The association between coffee consumption and the circulating level of adiponectin and leptin has been evaluated in several epidemiological studies with conflicting results. Therefore, this review article has been conducted.

Is there an association between coffee consumption and the circulating level of adiponectin and leptin in humans?

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

Results and conclusions:
The investigators found when compared the highest versus the lowest coffee intake category, coffee consumption was associated with a higher circulating adiponectin level [SMD = 0.11, 95% CI = 0.06 to 0.17, p 0.001].

The investigators found in subgroup analysis when compared the highest versus the lowest coffee intake category, coffee consumption was associated with a higher circulating adiponectin level in women [SMD = 0.11, 95% CI = 0.02 to 0.20, p = 0.01], but not in men [SMD = 0.03, 95% CI = -0.08 to 0.14, p = 0.59].

The investigators found when compared the highest versus the lowest coffee intake category, coffee consumption was associated with a lower circulating leptin level [SMD = -0.19, 95% CI = -0.28 to -0.10, p 0.001].

The investigators concluded that coffee consumption is associated with a higher circulating level of adiponectin in women and a lower circulating level of leptin. However, more well-designed prospective cohort studies and randomised controlled trials are needed to further elaborate the concerned issues.

Original title:
Associations of coffee consumption with circulating level of adiponectin and leptin. A meta-analysis of observational studies by Zhang Y and Zhang DZ.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29513118

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

Adiponectin is a unique adipokine, which is specifically and abundantly expressed in adipose tissues and improves insulin resistance. Having insulin resistance may increase the risk of type 2 diabetes and metabolic syndrome.

Objectives:
Several studies have been published about the effect of garlic on lipid profile and blood glucose in diabetic patients. Which, the results mostly contradict with each other. Therefore, this review article has been conducted.

Does garlic improve lipid profile and blood glucose in diabetic patients?

Study design:
This review article included 33 articles with a total of 1,273 individuals, with a mean of 39 samples per study.

Results and conclusions:
The investigators found the concentration of serum total cholesterol significantly decreased wih 16.87 mg/dL [95% CI = -21.01 to -12.73, p = 0.001] in the garlic group when compared with the placebo group.

The investigators found the concentration of serum LDL cholesterol (bad cholesterol) significantly decreased with 9.65 mg/dL [95% CI = -15.07 to -4.23, p = 0.001] in the garlic group when compared with the placebo group.

The investigators found the concentration of serum triglycerides significantly decreased with 12.44 mg/dL [95% CI = -18.19 to -6.69, p = 0.001] in the garlic group when compared with the placebo group.

The investigators found the concentration of serum HDL cholesterol (good cholesterol) significantly increased with 3.19 mg/dL [95% CI = 1.85 to 4.53, p = 0.001] in the garlic group when compared with the placebo group.

The investigators found the concentration of serum fasting blood sugar significantly decreased with 10.90 mg/dL [95% CI = -16.40 to -5.40, p = 0.001] in the garlic group when compared with the placebo group.

The investigators found the concentration of serum HbA1c significantly decreased with 0.60 mg/dL [95% CI = -0.98 to -0.22, p = 0.001] in the garlic group when compared with the placebo group.

The investigators concluded that garlic improves lipid profile as well as glucose parameters and can be therapeutically effective in patients suffering from cardiovascular diseases and diabetes.

Original title:
The effect of garlic on lipid profile and glucose parameters in diabetic patients: A systematic review and meta-analysis by Shabani E, Sayemiri K and Mohammadpour M.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30049636

Additional information of El Mondo:
Find more information/studies on diabetes, cholesterol, meta-analyses/heterogeneity and garlic right here.

 

Objectives:
Inflammation is associated with an increased risk of a range of chronic diseases. A diet high in fruit and vegetables may help to reduce inflammation, as fruit and vegetables are rich sources of antioxidants and other biologically active substances, which may improve immune function. Therefore, this meta-analysis (systematic review) has been conducted.

Does fruit or vegetables intake reduce inflammation and improve immune function?

Study design:
This review article included 71 clinical trials and 12 were observational studies (n = 10 cross-sectional studies and n = 2 cohort studies).

Results and conclusions:
The investigators found among observational studies (n = 10 studies) an inverse association between intakes of fruit or vegetables and inflammatory biomarkers.

The investigators found the majority of the intervention studies (n = 48 studies) reported beneficial effects of fruit or vegetable intake on ≥1 biomarker of systemic or airway inflammation.

The investigators found a meta-analysis of included studies showed that fruit or vegetable intake significantly decreased circulating levels of C-reactive protein and tumor necrosis factor-α [p 0.05] and significantly increased the γδ-T cell population [p 0.05].

The investigators concluded that higher intakes of fruit and vegetables lead to both a reduction in proinflammatory mediators and an enhanced immune cell profile.

Original title:
Effects of fruit and vegetable consumption on inflammatory biomarkers and immune cell populations: a systematic literature review and meta-analysis by Hosseini B, Berthon BS, […], Wood LG.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29931038

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

The level of C-reactive protein (CRP), which can be measured in your blood, increases when there's inflammation in your body.

Tumour necrosis factor-alpha (TNF-alpha) is recognized as an important mediator in many cytokine-dependent inflammatory events.

 

Objectives:
Although glucosamine and chondroitin sulfate have showed beneficial effects on joint tissues in osteoarthritis (OA), their therapeutic use in the clinical setting is still debatable. Therefore, this meta-analysis (systematic review) has been conducted.

Do glucosamine and chondroitin sulfate supplements relieve pain of knee osteoarthritis?

Study design:
This review article included RCTs.

The pain of knee osteoarthritis was measured using the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC) and/or the Visual Analog Scale (VAS).

Results and conclusions:
The investigators found that glucosamine supplements significantly reduced pain of knee osteoarthritis (expressed as Visual Analog Scale (VAS) [WMD = - 7.41 mm, 95% CI = - 14.31 to - 0.51, p = 0.04].
Significant means that there is an association with a 95% confidence.

The investigators found that chondroitin supplements significantly reduced pain of knee osteoarthritis (expressed as Visual Analog Scale (VAS) [WMD = - 8.35 mm, 95% CI = - 11.84 to - 4.85, p  0.00001].
Significant because the found p-value of 0.00001 is less than 0.05.

The investigators found that the combination of glucosamine and chondroitin supplements non-significantly reduced pain of knee osteoarthritis (expressed as Visual Analog Scale (VAS) [WMD = - 0.28 mm, 95% CI = - 8.87 to 8.32, p = 0.95].
Non-significantly because the found p-value of 0.95 is greater than 0.05.

The investigators found that none of the glucosamine, chondroitin supplements or their combination had a significant positive effect on the total WOMAC index and its subscores.

The investigators concluded that oral supplementation with glucosamine or chondroitin sulfate reduces pain in knee osteoarthritis. However, there is no additional effect using both therapeutic agents in combination for the management of symptomatic knee osteoarthritis.

Original title:
Effect of glucosamine and chondroitin sulfate in symptomatic knee osteoarthritis: a systematic review and meta-analysis of randomized placebo-controlled trials by Simental-Mendía M, Sánchez-García A, […], Simental-Mendía LE.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29947998

Additional information of El Mondo:
Find more information/studies on chronic disease right here.

 

Objectives:
The purpose of this review article is to review previously published meta-analyses on the effectiveness of dietary fiber on type 2 diabetes.

Study design:
This umbrella review article included 16 meta-analyses.

Results and conclusions:
The investigators found in the meta-analyses when comparing highest versus lowest dietary fiber intake, a statistically significant reduced risk of 15 to 19% [RR = 0.81-0.85] for type 2 diabetes. However, statistically significant heterogeneity was observed in all of these meta-analyses.

The investigators found in the meta-analyses when comparing highest versus lowest dietary cereal fibers, a statistically significant reduced risk of 13 to 33% [RR = 0.67-0.87] for type 2 diabetes. However, statistically significant heterogeneity was observed in all of these meta-analyses.

The investigators found in the meta-analyses of supplementation studies using β-glucan or psyllium fibers on type 2 diabetic participants, statistically significant reductions were identified in both fasting blood glucose concentrations and glycosylated hemoglobin percentages.

The investigators concluded that those consuming the highest amounts of dietary fiber, especially cereal fiber, may benefit from a reduction in the incidence of developing type 2 diabetes. May benefit because statistically significant heterogeneity was observed in all of these meta-analyses.
There also appears to be a small reduction in fasting blood glucose concentration, as well as a small reduction in glycosylated hemoglobin percentage for individuals with type 2 diabetes who add β-glucan or psyllium to their daily dietary intake.

Original title:
Dietary Fiber Intake and Type 2 Diabetes Mellitus: An Umbrella Review of Meta-analyses by McRae MP.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29628808

Additional information of El Mondo:
Find more information/studies on diabetes, meta-analyses/heterogeneity and dietary fiber right here.

 

Objectives:
The association between dietary protein intake and type 2 diabetes risk has been inconsistent in the previous epidemiological studies. Therefore, this review article (meta-analysis) has been conducted.

Is there an association between dietary protein intake and type 2 diabetes risk?

Study design:
This review article included 10 prospective cohort studies with a total of 34,221 type 2 diabetes cases.
No publication bias was detected.

Results and conclusions:
The investigators found after adjustment of potential confounders, a 5% of energy (5 En%) increment from dietary total protein intake was related to a significantly 9% [95 CI = 1.04-1.13, I2 = 42.0%] higher risk of type 2 diabetes. The results were robust in sensitivity analysis.

The investigators found after adjustment of potential confounders, a 5% of energy (5 En%) increment from dietary animal protein intake was related to a significantly 12% [95 CI = 1.08-1.17, I2 = 14.0%] higher risk of type 2 diabetes. The results were robust in sensitivity analysis.

The investigators found after adjustment of potential confounders, a significant U-shaped curve was observed for plant protein intake with the most risk reduction at about 6% of energy from plant protein intake [p nonlinearity = 0.001]. The results were robust in sensitivity analysis.

The investigators concluded that the consumption of protein, particularly animal protein increases risk of type 2 diabetes.

Original title:
Dietary protein intake and risk of type 2 diabetes: a dose-response meta-analysis of prospective studies by Zhao LG, Zhang QL, [...], Xiang YB.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29858629

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