Nutritional advice

Objectives:
Previous meta-analyses, with some methodological controversies, have assessed the relation between nut consumption and type 2 diabetes (T2D) risk and pointed to contradictory results. Therefore, this review article has been conducted.

Does nut consumption reduce risk of type 2 diabetes?

Study design:
This review article included 5 prospective cohort studies and 3 cross-sectional studies.
The certainty of the evidence using NutriGrade was very low for all the exposures.

Results and conclusions:
The investigators found meta-analyses of cross-sectional studies and prospective cohort studies, comparing the highest with the lowest categories, revealed a nonsignificant association between total nut consumption and type 2 diabetes.
Nonsignificant means that there is no association with a 95% confidence.

The investigators found meta-analyses of prospective cohort studies showed that peanut butter consumption significantly reduced type 2 diabetes incidence with 13% [RR = 0.87, 95% CI = 0.77 to 0.98, I2 = 50.6%, p = 0.16], whereas no association was observed between peanuts or tree nuts and type 2 diabetes.

The investigators found there was no evidence of a linear dose-response or nonlinear dose-response gradient for total nut and peanut consumption in prospective cohort studies.

The investigators concluded peanut butter consumption may reduce type 2 diabetes incidence. May reduce because the certainty of the evidence using NutriGrade was very low.

Original title:
Nut consumption and type 2 diabetes risk: a systematic review and meta-analysis of observational studies by Becerra-Tomás N, Paz-Graniel I, […], Salas-Salvadó J.

Link:
https://pubmed.ncbi.nlm.nih.gov/33471083/

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Objectives:
Peripheral neuropathy (PN) is common in patients with diseases that are in turn associated with deficiency of the B-vitamins, and vitamin treatment has shown mixed results. Therefore, this review article has been conducted.

Does a low vitamin B level increase the risk of peripheral neuropathy?

Study design:
This review article included 46 observational studies and 7 interventional studies.

Results and conclusions:
The investigators found the presence of peripheral neuropathy was significantly associated with lowered B12 levels [1.51, 95% CI = 1.23 to 1.84, n = 34, I2 = 43.3%, p = 0.003].

The investigators found the presence of peripheral neuropathy was significantly associated with elevated methylmalonic acid levels [2.53, 95% CI = 1.39 to 4.60, n = 9, I2 = 63.8%, p = 0.005].

The investigators found the presence of peripheral neuropathy was significantly associated with elevated homocysteine levels [3.48, 95% CI = 2.01 to 6.04, n = 15, I2 = 70.6%, p 0.001].

The investigators found treatment with vitamin B1 was associated with a significant improvement in symptoms of peripheral neuropathy [5.34, 95% CI = 1.87 to 15.19, n = 3, I2 = 64.6%, p = 0.059].

The investigators found B12 treatment (vs. the comparators) showed a non-significant association with symptom improvement [1.36, 95% CI = 0.66 to 2.79, n = 4, I2 = 28.9%].

The investigators found analysis of 7 trials combined showed a non-significant higher odds ratio for improvement under treatment with the B-vitamins [2.58, 95% CI = 0.98 to 6.79, I2 = 80.0%, p 0.001].

The investigators concluded peripheral neuropathy is associated with lowered plasma vitamin B12 and elevated methylmalonic acid and homocysteine levels. Well-designed studies, especially in non-diabetes peripheral neuropathy, are needed.

Original title:
Association between neuropathy and B-vitamins: A systematic review and meta-analysis by Stein J, Geisel J and Obeid R.

Link:
https://pubmed.ncbi.nlm.nih.gov/33619867/

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Find here more information/studies about review article/significant, vitamin B1 y B12 and chronic diseases.

Peripheral neuropathy refers to the conditions that result when nerves that carry messages to and from the brain and spinal cord from and to the rest of the body are damaged or diseased.

Increased methylmalonic acid levels are a sensitive indicator of mild vitamin B12 deficiency.
 

Objectives:
Recent systematic reviews and meta-analyses of randomized, double-blind, placebo-controlled trials (double-blind, placebo-controlled RCTs) have reported controversial findings regarding the associations between calcium supplements on the risk of cardiovascular disease (CVD). Therefore, this review article has been conducted.

Do calcium supplements increase risk of cardiovascular disease (CVD)?

Study design:
This review article included 13 RCTs with 28,935 participants in an intervention group (group with calcium supplements) and 14,243 in a control group (group without calcium supplements).

The mean age of the study participants was 66.3 years (range: 35 to 97 years) and 92.8% of those were women.
Publication bias was not observed.

Results and conclusions:
The investigators found calcium supplements significantly increased the risk of cardiovascular disease with 15% in healthy postmenopausal women [RR = 1.15, 95% CI = 1.06 to 1.25, I2 = 0.0%, n = 14].

The investigators found calcium supplements significantly increased the risk of coronary heart disease with 16% in healthy postmenopausal women [RR = 1.16, 95% CI = 1.05 to 1.28, I2 = 0.0%, n = 9].

The investigators found in the subgroup meta-analysis, dietary calcium intake of 700-1000 mg per day or supplementary calcium intake of 1000 mg per day significantly increased the risk of cardiovascular disease and coronary heart disease.

The investigators concluded that the use of calcium supplements (1000 mg per day) is significantly associated with the increased risk of cardiovascular disease and coronary heart disease by 15%, specifically in postmenopausal women. These findings should be explicitly confirmed by conducting further RCTs with cardiovascular disease outcome measures as well as the incidence of osteoporosis or fractures as the primary endpoints.

Original title:
Calcium Supplements and Risk of Cardiovascular Disease: A Meta-Analysis of Clinical Trials by Myung SK, Kim HB, […], Oh SW.

Link:
https://pubmed.ncbi.nlm.nih.gov/33530332/

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Objectives:
Does a low-carbohydrate diet (LCD) causally increase adiponectin concentration in adults?

Study design:
This review article included 11 RCTs with 534 participants in low-carbohydrate diet group and 513 participants in control group (group without a low-carbohydrate diet).
Proportion of carbohydrate from calorie was from 4 to 34% (4-34 En%).
Time of the follow-up varied between studies and ranged from 6 to 152 weeks.
Meta-regression analysis revealed that age [β = 0.04, p = 0.15], baseline BMI [β= -0.15, p = 0.15], time of follow-up [β = 0.01, p = 0.17], energy percentage of carbohydrates [β = 0.004, p = 0.90], energy percentage of protein [β = -0.12, p = 0.08], energy percentage of fat [β = 0.20, p = 0.61] and baseline adiponectin [β = 0.001, p = 0.97] are not sources of heterogeneity

Results and conclusions:
The investigators found low-carbohydrate diet significantly increased adiponectin concentration [0.02 µg/mL, 95% CI = 0.01 to 0.03, p 0.001].

The investigators found dose-response analysis indicated a nonlinear association between the percentage of carbohydrate and change in adiponectin level from baseline [p = 0.04].

The investigators found in subgroup analysis based on the proportion of carbohydrate from calorie, there was a significant increase in adiponectin concentration in studies that prescribed 30% of calorie from carbohydrates [0.12 µg/mL, 95% CI = 0.07 to 0.18].
In contrast, diets which consisted ≥30% of carbohydrates had no significant effect on adiponectin [0.50 µg/mL, 95% CI = -0.46 to 1.48].

The investigators concluded that a diet with 30% of calorie from carbohydrates (diet with 30 En% carbohydrates) causally increases adiponectin concentration in adults.

Original title:
Effect of low-carbohydrate diet on adiponectin level in adults: a systematic review and dose-response meta-analysis of randomized controlled trials by Shemirani F, Golzarand M, […], Mahmoudi M.

Link:
https://pubmed.ncbi.nlm.nih.gov/33455438/

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The most easy way to follow a diet with maximum 30% of calorie from carbohydrates (diet with 30 En% carbohydrates) is to choose only meals/products with maximum 30 En% carbohydrates. Check here which products contain maximum 30 En% carbohydrates. However, the most practical way to follow a diet with maximum 30 En% carbohydrates is, all meals/products that you eat on a daily basis should on average contain maximum 30 En% carbohydrates.
30 En% carbohydrates means that the total amounts of carbohydrates make up for a 30% of the total kcal of the diet.

Adiponectin is a protein hormone produced and secreted exclusively by adipocytes (fat cells) that regulates the metabolism of lipids and glucose. Adiponectin influences the body's response to insulin. Adiponectin also has antiinflammatory effects on the cells lining the walls of blood vessels.
 

Objectives:
Vitamin D deficiency during pregnancy or infancy is associated with adverse growth in children. No systematic review has been conducted to summarize available evidence on the effect of vitamin D supplementation in pregnancy and infancy on growth and body composition in children. Therefore, this review article has been conducted.

Does vitamin D supplementation during pregnancy or infancy increase adiposity (severe or morbid overweight) risk in childhood?

Study design:
This review article included 12 RCTs with a total of 4,583 participants.
The doses of vitamin D in the intervention group (group with vitamin D supplements) were 60,000 IU/4 weeks (1,500 mcg/4 weeks) or 60,000 IU/8 weeks and in the control group (group without vitamin D supplements) was 400 IU/day.

Results and conclusions:
The investigators found vitamin D supplementation during pregnancy was associated with higher triceps skinfold thickness (mm) [MD = 0.33, 95% CI = 0.12 to 0.54, I2 = 34%] in neonates.

The investigators found vitamin D supplementation during pregnancy or infancy was associated with significantly increased length for age z-score in infants at 1 year of age [MD = 0.29, 95% CI = 0.03 to 0.54, I2 = 0%].

The investigators found vitamin D supplementation during pregnancy or infancy was associated with lower body mass index (BMI) (kg/m²) [MD = -0.19, 95% CI = -0.34 to -0.04, I2 = 0%] and body mass index z-score (BMIZ) [MD = -0.12, 95% CI = -0.21 to -0.04, I2 = 0%] in offspring at 3-6 years of age.

The investigators found vitamin D supplementation during early life was not observed to be associated with children’s bone, lean or fat mass.

The investigators concluded vitamin D supplementation during pregnancy or infancy is associated with reduced adiposity (severe or morbid overweight) in childhood. Future large well-designed double blinded RCTs are needed to assess the effectiveness of vitamin D supplementation in early life on children’s bone health, lean mass and adiposity.

Original title:
Effect of Vitamin D Supplementation in Early Life on Children's Growth and Body Composition: A Systematic Review and Meta-Analysis of Randomized Controlled Trials by Ma K, Wei SQ, [...], Wen SW.

Link:
https://www.mdpi.com/2072-6643/13/2/524/htm

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Objectives:
Fish oil has been shown to reduce the risk of metabolic disorders. However, the effects of fish oil intervention on glucose metabolism and insulin sensitivity are still controversial, especially in children. Therefore, this review article has been conducted.

Do fish oil supplements (EPA + DHA) improve insulin sensitivity in children?

Study design:
This review article included 13 RCTs with 567 children in placebo group (group without fish oil supplements) and 565 in fish oil group (intervention group).

No heterogeneity was found for the pooled and subgroup analyses.

Results and conclusions:
The investigators found compared with the placebo group, fish oil intervention had beneficial effects on insulin sensitivity in the pooled analysis [WMD = -0.219, 95% CI = -0.392 to -0.046, p = 0.013].

These beneficial effects were also found in subgroup analyses, when the fish oil intervention period was short-term (≤6 months) low dose (eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) dose 1.5 g/day) and high ratio (eicosapentaenoic acid to docosahexaenoic acid ≥1).

The investigators concluded fish oil supplements, especially 1.5 g/day EPA + DHA during 6 months, improve insulin sensitivity in children.

Original title:
Effect of Fish Oil on Insulin Sensitivity in Children: A Systematic Review and Meta-Analysis of Randomized, Controlled Trials by Hou M, Zhou W, [...], Lv H.

Link:
https://pubmed.ncbi.nlm.nih.gov/33388274/

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Objectives:
Does type 1 diabetes mellitus (T1DM) decrease bone mineral density (BMD) in children and adolescents?

Study design:
This review article included 9 cross-sectional studies with a total of 1,522 children and adolescents.

Funnel plot and the Egger test did not reveal significant publication bias.

Results and conclusions:
The investigators found a significant decrease in bone mineral density Z-score in the whole body [pooled WMD = -0.47, 95% CI = -0.92 to -0.02, I2 = 80.2%] and lumbar spine [pooled WMD = -0.41, 95% CI = -0.69 to -0.12, I2 = 80.3%] in children and adolescents with type 1 diabetes mellitus, which was consistent in published studies from Asia and South America, but inconsistent in the North America and Europe.
Sensitivity analyses did not modify these findings.

The investigators found, importantly, the differences in bone mineral density Z-scores were independent of age, level of glucose control (HbA1c) and prepubertal stage.

The investigators concluded type 1 diabetes mellitus (T1DM) decreases bone mineral density (BMD) Z-scores in the whole body and lumbar spine in children and adolescents.

Original title:
Association between type 1 diabetes mellitus and reduced bone mineral density in children: a meta-analysis by Zhu Q, J Xu J, […], Shi J.

Link:
https://pubmed.ncbi.nlm.nih.gov/33404757/  

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Objectives:
Is there a causal relationship between dairy products or calcium supplements and the reduction in fat mass and BMI among overweight or obese adults?

Study design:
This review article included 10 and 14 RCTs with ≥ 12 weeks interventions of calcium supplements and dairy products among overweight (BMI>25) or obese (BMI>30) adults aged ≥18.

Results and conclusions:
The investigators found that dairy products significantly reduced fat mass among overweight or obese adults [SMD = -0.40, 95% CI = -0.77 to -0.02].
This reduction was also significant in the analysis of RCTs with low risk of bias scores.

The investigators found that dairy products significantly reduced BMI among overweight or obese adults [SMD = -0.46 kg/m², 95% CI = -0.67 to -0.26].
This reduction was also significant in the analysis of RCTs with low risk of bias scores.

The investigators found that calcium supplements significantly reduced fat mass among overweight or obese adults [SMD = -0.15, 95% CI = -0.28 to -0.02].
However, this reduction was not significant in the analysis of RCTs with low risk of bias scores.

The investigators concluded there is a causal relationship between dairy products without distinction of fat percentage and the reduction in fat mass and BMI among overweight or obese adults.

Original title:
Meta-analysis of randomized controlled trials on calcium supplements and dairy products for changes in body weight and obesity indices by Hong JY, Lee JS, [...], Kim MK.

Link:
https://pubmed.ncbi.nlm.nih.gov/33292017/

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Objectives:
Type 1 diabetes mellitus (T1DM) causes the irreversible destruction of pancreatic beta cells. The Bacillus Calmette-Guerin (BCG) vaccine can modulate the immune response and decelerate disease progression. Therefore, this review article has been conducted.

Do patients with type 1 diabetes mellitus benefit from the Bacillus Calmette-Guerin (BCG) vaccine?

Study design:
This review article included 4 RCTs. The sample sizes ranged from 6 to 94, with a total of 198 subjects. The mean age of the examinees ranged from 10.1 to 36.0 years and the follow-up duration ranged from 1 to 8 years.

Results and conclusions:
The investigators found the pooled meta-analysis demonstrated no significant difference in HbA1c levels [MD = -0.12, 95% CI = -0.53 to 0.30, I2 = 56%] or fasting C-peptide levels [MD = -0.15, 95% CI = -0.35 to 0.06, I2 = 0%] in the BCG intervention group as compared with that in the placebo group.
The results remained unchanged after removing each study in the sensitivity analysis.

The investigators concluded there is no robust evidence to support the use of the Bacillus Calmette-Guerin (BCG) vaccine for the treatment of type 1 diabetes mellitus although the HbA1c levels tend to improve. Additional RCTs to assess the long-term effects of the Bacillus Calmette-Guerin (BCG) vaccine on glycemic control are warranted.

Original title:
Therapeutic Effects of BCG Vaccination on Type 1 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomized Controlled Trials by Chang YC, Lin CJ, […], Hsu HY.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7139880/

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Objectives:
Does pistachio supplementation reduce obesity risk?

Study design:
This review article included 11 randomized controlled trials (RCTs) with 1,593 subjects.

The assigned pistachio intake was below 50 g/d in 3 studies.
Intervention times were shorter than 12 weeks in 4 studies.
There was no significant publication bias.

Results and conclusions:
The investigators found compared to the control diet group, the pistachio supplementation regimen significantly decreased BMI [-0.18 kg/m², 95% CI = -0.26 to -0.11 kg/m², p 0.001, I2 = 29.8%, p = 0.180].

The investigators found compared to the control diet group, the pistachio supplementation regimen did not significantly change waist circumference [net change = 0.76 cm, 95% CI = -0.11 to 1.63 cm, p = 0.087, I2 = 7.0%, p = 0.340].

The investigators found compared to the control diet group, the pistachio supplementation regimen had no effect on body weight [net change = 0.22 kg, 95% CI = -0.50 to 0.07 kg, p = 0.141, I2 = 0.0%, p = 0.962].

The investigators concluded compared to a controlled dietary intake, an adequate amount of pistachio supplementation lowers BMI without increasing body weight, which supports the view that pistachio consumption is beneficial for human health.

Original title:
The relationship between pistachio (Pistacia vera L) intake and adiposity: A systematic review and meta-analysis of randomized controlled trials by Xia K, Yang T, […], Chen XZ.

Link:
https://journals.lww.com/md-journal/Fulltext/2020/08210/The_relationship_between_pistachio__Pistacia_vera.7.aspx

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Objectives:
Does fish consumption reduce risk of coronary heart disease (CHD), stroke and all-cause mortality in patients with type 2 diabetes (T2D)?

Study design:
This review article included 9 prospective cohort studies with 57,394 diabetic patients.

Results and conclusions:
The investigators found for the highest compared with the lowest category of fish consumption, a significantly reduced risk of 14% [relative risk = 0.86, 95% CI = 0.76 to 0.96, I2 = 50%, n = 8] for all-cause mortality in patients with type 2 diabetes.

The investigators found for the highest compared with the lowest category of fish consumption, a significantly reduced risk of 39% [relative risk = 0.61, 95% CI = 0.29 to 0.93, I2 = 68%, n = 3] for coronary heart disease in patients with type 2 diabetes.

The investigators found there was a monotonic inverse association, with a nadir at fish consumption of approximately 2-3 servings/week, in both analyses.

The investigators concluded 2-3 servings/week of fish consumption reduce risk of all-cause mortality and coronary heart disease in patients with type 2 diabetes.

Original title:
Fish consumption and the risk of cardiovascular disease and mortality in patients with type 2 diabetes: a dose-response meta-analysis of prospective cohort studies by Jayedi A, Soltani S, […], Shab-Bidar S.

Link:
https://pubmed.ncbi.nlm.nih.gov/32410513/

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Objectives:
There are numerous trials reported the effect of alpha-lipoic acid (ALA) on obesity measurements; while no summarised dose-response meta-analysis is available to address the effects of dose and duration of ALA supplementation on obesity measurements. Therefore, this review article has been conducted.

Does alpha-lipoic acid supplementation improve obesity measurements including weight, body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR) and fat mass (FM)?

Study design:
This review article included 18, 21 and 8 RCTs of ALA-weight, ALA-BMI, ALA-WC, respectively.

Results and conclusions:
The investigators found in two-class meta-analysis, alpha-lipoic acid supplementation significantly reduced weight [WMD = -2.29 kg, 95% CI = -2.98 to -1.60, p 0.01] and BMI [WMD = -0.49 g/m², 95% CI = -0.83 to -0.15, p = 0.005] but had no effect on waist circumference [WMD = -2.57 cm, 95% CI = -8.91 to 3.76, p = 0.426].

The investigators found while the dose-response meta-analysis revealed that the duration of alpha-lipoic acid supplementation was a significant factor affecting waist circumference reduction [p non-linearity = 0.047].
While no evidence of departure from linearity was observed for other variables; moreover, subgrouping also revealed that gender could be an important factor affecting the alpha-lipoic acid impact on waist circumference, which was significant among women [WMD = -4.099, 95%CI = -7.837 to -0.361, p = 0.032].

The investigators concluded that alpha-lipoic acid supplementation reduces BMI, weight in a two-class meta-analysis without evidence of departure from linearity in terms of dose or duration. While the association of alpha-lipoic acid supplementation on waist circumference is dependent to the duration of the study. Although further trials evaluating the other obesity measurements specially central obesity will be helpful to infer a more reliable result.

Original title:
Alpha-lipoic acid supplementation significantly reduces the risk of obesity in an updated systematic review and dose response meta-analysis of randomised placebo-controlled clinical trials by Vajdi M and Farhangi MA.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32091656

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Objectives:
Does niacin (vitamin B3) supplementation improve lipid profiles and glycemic control in patients with type 2 diabetes mellitus?

Study design:
This review article included 8 RCTs comprised a total of 2,110 patients with type 2 diabetes mellitus.
Studies published ranged from 1990 to 2016 and 15 to 1,053 patients were included in each individual trial.

The follow-up duration ranged from 8.0 weeks to 12.0 months.

The study quality was assessed using the Jadad scale. 4 studies had 3 scores and the remaining 4 studies had 2 scores.

There was no significant publication bias.

Results and conclusions:
The investigators found patients’ niacin supplementation was associated with lower levels of total cholesterol [WMD = -0.28, 95% CI = -0.44 to -0.12, p =  0.001], triglyceride [WMD = -0.37, 95% CI = -0.52 to -0.21, p   0 .001] and low-density lipoprotein cholesterol (bad cholesterol) [WMD = -0.42, 95% CI = -0.50 to -0.34, p    0.001].

The investigators found, moreover, the level of high-density lipoprotein cholesterol (good cholesterol) was significantly increased when niacin supplementation [WMD = 0.33, 95% CI = 0.21 to 0.44, p 0 .001] was provided.

The investigators found, however, niacin supplementation produced no significant effects on plasma glucose [WMD = 0.18, 95% CI = -0.14 to 0.50, p = 0 .275] and hemoglobin A1c (HbA1c) levels [WMD = 0.39, 95% CI = -0.15 to 0.94, p = 0 .158].

The investigators concluded that niacin (vitamin B3) supplementation improves lipid profiles, including total cholesterol, LDL and HDL cholesterol without affecting the glycemic levels for patients with type 2 diabetes mellitus. Additional large-scale RCTs should be conducted to evaluate the long-term effectiveness of niacin supplementation.

Original title:
Effectiveness of niacin supplementation for patients with type 2 diabetes: A meta-analysis of randomized controlled trials by Xiang D, Zhang Q and Wang YT.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7373507/

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Objectives:
Type 2 diabetes mellitus is a chronic disease that occurs among the general population. The insulin-lowering and homeostasis model assessment of insulin resistance-improving effects of inulin are unconfirmed. Therefore, this review article has been conducted.

Do inulin supplements improve HOMA-IR, fasting plasma glucose and HbA1c in patients with type 2 diabetes mellitus?

Study design:
This review article included 9 RCTs with a total of 661 participants.

The duration of the interventions ranged from 6 weeks to 12 weeks and the dosage of inulin supplementation ranged from 8.4 g to 10 g per day.

Results and conclusions:
The investigators found inulin supplementation significantly improved fasting plasma glucose [SMD = -0.55, 95% CI = -0.73 to -0.36, p = 0.0], HOMA-IR [SMD = -0.81, 95% CI = -1.59 to -0.03, p = 0.042] and HbA1c [SMD = -0.69, 95% CI = -0.92 to -0.46, p = 0.0] in patients with type 2 diabetes mellitus.

The investigators found, further subgroup analyses revealed a significant role of inulin supplementation for treatment durations ≥8 weeks [p = 0.038 for insulin, p = 0.002 for HOMA-IR, p = 0.032 for fasting plasma glucose, p = 0 for HbA1c] in patients with type 2 diabetes mellitus.

The investigators concluded that daily 8.4-10 grams of inulin supplements for at least 8 weeks improve HOMA-IR, fasting plasma glucose and HbA1c in patients with type 2 diabetes mellitus.

Original title:
Efficacy of inulin supplementation in improving insulin control, HbA1c and HOMA-IR in patients with type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials by Zhang W, Tang Y, […], Hu H.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7263925/

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Inulin is a type of fiber that's found in certain plant foods. Chicory root is the main source of inulin in supplement form.

Objectives:
Antioxidant status is considered as important factor in the pathogenesis (the manner of development of a disease) of vitiligo. However, there are controversial findings about serum status of antioxidants in vitiligo patients. Therefore, this review article has been conducted.

Is there a relationship between serum antioxidant level (e.g. vitamin C, E, zinc and selenium) and risk of vitiligo?

Study design:
This review article included 11 studies including 570 vitiligo cases and 580 controls (people without vitiligo).

Serum vitamin A and copper level in vitiligo patients were only evaluated in single studies and not included in meta-analysis.

Results and conclusions:
The investigators found based on fixed effect model, there were no statistical difference between two groups regarding serum vitamin C levels [OR = 1.17, 95% CI = 0.74 to 1.84, p = 0.495] and serum vitamin E levels [OR = 0.61, 95% CI = 0.30 to 1.25, p = 0.180].

The investigators found in sensitivity analysis, higher serum zinc levels significantly decreased risk of vitiligo with 71% [OR = 0.29, 95% CI = 0.15 to 0.54, p 0.001].

The investigators found in sensitivity analysis, higher serum selenium level significantly increased risk of vitiligo with 331% [OR = 4.31, 95% CI = 2.72 to 6.81, p 0.001].

The investigators concluded that higher serum selenium and lower zinc level increase risk of vitiligo. Potential mechanism associated with preventive effects of zinc and the depigmentation effect of selenium should be more elucidated in further studies.

Original title:
Serum Level of Antioxidant Vitamins and Minerals in Patients With Vitiligo, a Systematic Review and Meta-Analysis by Huo J, Liu T, [...], Wang R.

Link:
https://pubmed.ncbi.nlm.nih.gov/32593085/

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Vitiligo is a long-term condition where pale white patches develop on the skin. It's caused by the lack of melanin, which is the pigment in skin. Vitiligo can affect any area of skin, but it commonly happens on the face, neck and hands and in skin creases.

Objectives:
Does barberry (Berberis vulgaris L.) supplementation improve glycemic markers including fasting blood sugar (FBS) concentrations, insulin levels, homeostatic model assessment for insulin resistance (HOMA-IR) and glycosylated hemoglobin (HbA1c) percentage?

Study design:
This review article included 7 RCTs, comprising 452 participants.

Results and conclusions:
The investigators found the meta-analysis revealed that barberry supplementation significantly reduced insulin levels [Hedges’s = -0.67, 95% CI = -1.31 to -0.03, p = 0.04, I2 = 73.3%].
However, no significant positive effect was observed for fasting blood sugar levels [WMD = -8.06 mg/dL, 95% CI = -20.46 to 4.33, p = 0.23, I2 = 96.1%], HbA1c percentage [WMD = -0.83%, 95% CI = -2.33 to 0.67, p = 0.27, I2 = 88.3%] and HOMA-IR index [WMD = -0.55, 95% CI = -1.60 to 0.50, p = 0.30, I2 = 99.4%].

The investigators concluded barberry supplementation improves insulin levels.

Original title:
The Effect of Barberry (Berberis Vulgaris L.) on Glycemic Indices: A Systematic Review and Meta-Analysis of Randomized Controlled Trials by Safari Z, Farrokhzad A, […], Askari G.

Link:
https://www.sciencedirect.com/science/article/abs/pii/S0965229920302235?via%3Dihub

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Objectives:
Does coenzyme Q10 supplementation reduce body weight and body mass index (BMI) of patients in randomized controlled clinical trial studies (RCTs)?

Study design:
This review article included 17 RCTs.

Results and conclusions:
The investigators found results of random-effect size meta-analysis showed that supplementation with coenzyme Q10 had no significant decreasing effects on body weight [WMD = 0.28 kg, 95% CI = -0.91 to 1.47, p = 0.64] and BMI [WMD = -0.03, 95% CI = -0.4 to 0.34, p = 0.86] of study participants.
No significant because the calculated p-value of 0.64 was larger than the p-value of 0.05.
Subgroup analysis revealed that dosage of Q10 and trial duration could not differ the results of Q10 supplementation.

The investigators concluded that coenzyme Q10 supplementation has no decreasing effects on body weight and BMI.

Original title:
Effect of Q10 supplementation on body weight and body mass index: A systematic review and meta-analysis of randomized controlled clinical trials by Saboori S, Rad EY, […], Falahi E.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31336462

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Find more information/studies on RCTs/subgroup analysis, coenzyme Q10 and obesity/overweight right here.

Objectives:
A low insulin-like growth factor 1 (IGF-1) level is known to be associated with many disorders. Several studies have shown that soy consumption may influence IGF-1, but the findings remain inconclusive. Therefore, this review article (meta-analysis) has been conducted.

Does soy consumption increase insulin-like growth factor 1 (IGF-1) level?

Study design:
This review article included 8 clinical trials.

Results and conclusions:
The investigators found, overall, a significant increment in plasma IGF-1 was observed following soy intervention [WMD = 13.5 ng/mL, 95% CI = 5.2 to 21.8, I2 = 97%].

The investigators found, subgroup analyses demonstrated a significantly greater increase in IGF-1, when soy was administered at a dosage of ≤40 g/day [WMD = 11.7 ng/mL, 95% CI = 10.9 to 12.6, I2 = 98%] and when the intervention duration was 12 weeks [WMD = 26.6 ng/mL, 95% CI = 9.1 to 44.1, I2 = 0.0%].

The investigators found, in addition, soy intervention resulted in a greater increase in IGF-1 among non-healthy subjects [WMD = 36 ng/mL, 95% CI = 32.7 to 39.4, I2 = 84%] than healthy subjects [WMD = 9.8 ng/mL, 95% CI = 8.9 to 10.7, I2 = 90%].

The investigators concluded ≤40 grams of soy consumption per day during 12 weeks increase the IGF-1 level.

Original title:
The Effect of Soy Intervention on Insulin-Like Growth Factor 1 Levels: A Meta-Analysis of Clinical Trials by Jiawei Zeng J, Feng Y, […], Chen X.

Link:
https://pubmed.ncbi.nlm.nih.gov/32072706/

Additional information of El Mondo:
Find more information/studies on subgroup analysis/significant and soja consumption right here.

Objectives:
Does high magnesium dietary intake reduce risk of type 2 diabetes and stroke?

Study design:
This review article included 53 prospective cohort studies with a total of 1,912,634 participants and 76,678 cases (persons with type 2 diabetes or stroke).

Participants were predominately middle aged at baseline (at the beginning of the studies), with a mean magnesium intake of 370 mg/day for the highest category and 232 mg/day for the lowest category.

The mean duration of all eligible studies was 10.7 years.

Results and conclusions:
The investigators found, when comparing the highest category of magnesium dietary intake (370 mg/day) to the lowest (232 mg/day), a significantly reduced risk of 22% [RR = 0.78, 95% CI = 0.75 to 0.81, p 0.001, I2 = 35.6%, p = 0.021] for type 2 diabetes.

The investigators found, when comparing the highest category of magnesium dietary intake (370 mg/day) to the lowest (232 mg/day), a significantly reduced risk of 11% [RR = 0.89, 95% CI = 0.83 to 0.94, p 0.001, I2 = 0%, p = 0.529] for total stroke.

The investigators found, when comparing the highest category of magnesium dietary intake (370 mg/day) to the lowest (232 mg/day), a significantly reduced risk of 12% [RR = 0.88, 95% CI = 0.81 to 0.95, p = 0.001, I2 = 16.9%, p = 0.265] for ischaemic stroke.

The investigators found in studies adjusted for cereal fiber dietary intake, a significantly reduced risk of 21% [RR = 0.79, 95% CI = 0.73 to 0.85, p 0.001] for type 2 diabetes.

The investigators found in studies adjusted for calcium dietary intake, a significantly reduced risk of 11% [RR = 0.89, 95% CI = 0.80 to 0.99, p = 0.040] for total stroke.

The investigators found in stratified analyses by characteristics of the population and study design, a significantly reduced risk of 9% [RR = 0.91, 95% CI = 0.83 to 0.99] for total stroke among female.

The investigators found in stratified analyses by characteristics of the population and study design, a significantly reduced risk of 11% [RR = 0.89, 95% CI = 0.79 to 1.00] for ischaemic stroke among female.

The investigators found in stratified analyses by characteristics of the population and study design, a significantly reduced risk of 11% [RR = 0.89, 95% CI = 0.82 to 0.96] for total stroke among individuals with BMI ≥25 kg/m².

The investigators found in stratified analyses by characteristics of the population and study design, a significantly reduced risk of 12% [RR = 0.88, 95% CI = 0.81 to 0.96] for ischaemic stroke among individuals with BMI ≥25 kg/m².

The investigators found in stratified analyses by characteristics of the population and study design, a significantly reduced risk of 11% [RR = 0.89, 95% CI = 0.83 to 0.95] for total stroke among studies wtith ≥12-year follow-up.

The investigators found in stratified analyses by characteristics of the population and study design, a significantly reduced risk of 12% [RR = 0.88, 95% CI = 0.81 to 0.95] for ischaemic stroke among studies wtith ≥12-year follow-up.

The investigators found for every 100 mg/day increment of magnesium dietary intake, a significantly reduced risk of 6% [RR = 0.94, 95% CI = 0.93 to 0.95] for type 2 diabetes.

The investigators found for every 100 mg/day increment of magnesium dietary intake, a significantly reduced risk of 2% [RR = 0.98, 95% CI = 0.97 to 0.99] for total stroke.

The investigators found for every 100 mg/day increment of magnesium dietary intake, a significantly reduced risk of 2% [RR = 0.98, 95% CI = 0.97 to 0.99] for ischaemic stroke.

The investigators concluded magnesium dietary intake has a substantial inverse association with type 2 diabetes and (total/ ischaemic) stroke. Furthermore, female, participants with obesity (BMI ≥ 25 kg/m²) and with a longer follow-up period (≥12 years) obtain greater benefit from magnesium intake with a lower risk of total and ischaemic stroke incidence. Overall, these findings support the guidelines to address the role of magnesium dietary intake in early prevention strategies to combat type 2 diabetes and stroke. However, additional RCTs are needed in the future to validate the causality.

Original title:
Association of magnesium intake with type 2 diabetes and total stroke: an updated systematic review and meta-analysis by Zhao B, Zeng L, [...], Zhang W.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7103847/

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

Objectives:
Is there an association between total meat, red meat, processed meat, poultry and fish intake and risk of type 2 diabetes (T2D)?

Study design:
This review article included 28 prospective cohort studies.

Results and conclusions:
The investigators found when compared with the lowest category, the highest category of total meat intake, significantly increased risk of type 2 diabetes with 33% [summary relative risk = 1.33, 95% CI = 1.16 to 1.52].
Significantly means that there is an association with a 95% confidence.

The investigators found when compared with the lowest category, the highest category of red meat intake, significantly increased risk of type 2 diabetes with 22% [summary relative risk = 1.22, 95% CI = 1.16 to 1.28].
Significantly because summary relative risk of 1 was not found in the 95% CI of 1.16 to 1.28. Summary relative risk of 1 means no risk/association.

The investigators found when compared with the lowest category, the highest category of processed meat intake, significantly increased risk of type 2 diabetes with 25% [summary relative risk = 1.25, 95% CI = 1.13 to 1.37].
Significantly means it can be said with a 95% confidence that the highest category of processed meat intake really increased risk of type 2 diabetes with 25%.

The investigators found no association between highest category of poultry intake and risk of type 2 diabetes [summary relative risk = 1.00, 95% CI = 0.93 to 1.07].
No association because summary relative risk of 1 was found in the 95% CI of 0.93 to 1.07. Summary relative risk of 1 means no risk/association.

The investigators found no association between highest category of fish intake and risk of type 2 diabetes [summary relative risk = 1.01, 95% CI = 0.93 to 1.10].

The investigators found in the dose-response analysis, each additional 100g/day of total and red meat and 50g/day of processed meat, were found to be associated with a 36% [95% CI = 1.23 to 1.49], 31% [95% CI = 1.19 to 1.45] and 46% [95% CI = 1.26 to 1.69] increased risk of type 2 diabetes, respectively.

The investigators found, in addition, there was evidence of a non-linear dose-response association between processed meat and type 2 diabetes [p = 0.004], with the risk increasing by 30% with increasing intakes up to 30g/day.

The investigators concluded 100g/day of total meat, 100g/day red meat and 50g/day of processed meat, increase risk of type 2 diabetes.

Original title:
Meat and fish intake and type 2 diabetes: dose-response meta-analysis of prospective cohort studies by Yang X, Li Y, […], Li L.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32302686

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

Objectives:
Results regarding the association between fish intake and risk of metabolic syndrome (MetS) are ambiguous. Therefore, this review article has been conducted.

Does fish consumption reduce risk of metabolic syndrome?

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

Results and conclusions:
The investigators found fish consumption significantly reduced risk of metabolic syndrome with 20% [OR = 0.80, 95% CI = 0.66 to 0.96, p = 0.017, I2 = 62.9%] in cohort studies.
However, this reduced risk was not significant in cross-sectional studies [OR = 0.80, 95% CI = 0.70 to 1.02, p = 0.085, I2 = 50.1%].
Significantly because OR of 1 was not found in the 95% CI of 0.6 to 0.96. OR of 1 means no risk/association.

The investigators found a significant non-linear association between fish intake levels and risk of metabolic syndrome [p for non-linearity = 0.010].

The investigators concluded that fish consumption reduces risk of metabolic syndrome when combining data from prospective cohort studies. Further studies are needed to confirm such an effect.

Original title:
A systematic review and meta-analysis of the association between fish consumption and risk of metabolic syndrome by Karimi G, Heidari Z, [...], Haghighatdoost F.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32127332

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

Objectives:
Is there a causal relationship between psyllium (a dietary fiber) consumption and improvements of risk factors of diabetes?

Study design:
This review article included 9 RCTs with 395 participants.

Results and conclusions:
The investigators found psyllium consumption significantly reduced triglycerides levels with 19.18 mg/dL [WMD = -19.18 mg/dL, 95% CI = -31.76 to -6.60, I2 = 98%].

The investigators found psyllium consumption significantly reduced low-density lipoprotein cholesterol levels with 8.96 mg/dL [WMD = -8.96 mg/dL, 95% CI = -13.39 to -4.52, I2 = 97%].

The investigators found psyllium consumption significantly reduced fasting blood sugar levels with 8.96 mg/dL [WMD = -31.71 mg/dL, 95% CI = -50.04 to -13.38, I2 = 97%].

The investigators found psyllium consumption significantly reduced hemoglobin A1c levels with 0.91% [WMD = -0.91%, 95% CI = -1.31 to -0.51, I2 = 99%].

The investigators found no significant change in high-density lipoprotein, body mass index, cholesterol and weight following psyllium consumption.

The investigators concluded there is a significant reduction in triglycerides, low-density lipoprotein cholesterol (bad cholesterol), fasting blood sugar and hemoglobin A1c levels following psyllium consumption among diabetic patients.

Original title:
The effect of psyllium consumption on weight, body mass index, lipid profile, and glucose metabolism in diabetic patients: A systematic review and dose-response meta-analysis of randomized controlled trials by Xiao Z, Chen H, [...], Wei Y.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31919936

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

Psyllium is a form of fiber made from the husks of the Plantago ovata plant’s seeds. The psyllium husk is a naturally occurring source of soluble fiber.
Psyllium is commonly found in cereals, dietary supplements and is also added to some foods including baked products such as breads, cereal bars and rice/grain cakes.
 

Objectives:
Genistein (4',5,7-trihydroxyisoflavone) is a phytoestrogen with potential health benefits in the prevention of cardiovascular disease. However, the evidence regarding its effects on hypertension has not been conclusive. Therefore, this review article has been conducted.

Do genistein supplements reduce blood pressure?

Study design:
This review article included 4 RCTs (4 treatment arms).

Results and conclusions:
The investigators found genistein supplements did not show any significant reduction of systolic blood pressure [WMD = -5.32 mmHg, 95% CI = -14.59 to 3.96] and diastolic blood pressure [WMD = -2.06 mmHg, 95% CI = -6.41 to 2.28] compared to that of the placebo group.

The investigators found, however, subgroup analysis by intervention duration showed that more than 6 months genistein supplementation in metabolic syndrome patients significantly decreased systolic blood pressure [WMD = -13.73 mmHg, 95% CI = -18.10 to -9.37] and diastolic blood pressure [WMD = -5.18 mmHg, 95% CI = -6.62 to -3.74].

The investigators concluded genistein supplementation of more than 6 months reduces blood pressure among metabolic syndrome patients.

Original title:
Effects of genistein on blood pressure: A systematic review and meta-analysis by Hemati N, Asis M, […], Abdollahi M.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31955737

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

Objectives:
Previous findings on the associations of legume and soy intake with the risk of type 2 diabetes are conflicting. Therefore, this review article (meta-analysis) has been conducted.

Does legume or soy dietary intake reduce risk of type 2 diabetes?

Study design:
This review article included 15 unique cohort studies with a total of 565,810 individuals and 32,093 incident cases (persons with type 2 diabetes).

Overall quality of evidence was rated as moderate for total legumes and low for total soy and soy subtypes.

Results and conclusions:
The investigators found no association between total legumes dietary intake and risk of type 2 diabetes [summary RR = 0.95, 95% CI = 0.79 to 1.14, I2 = 84.8%].
No association because RR of 1 was found in the 95% CI of 0.79 to 1.14. RR of 1 means no risk/association.

The investigators found no association between total soy dietary intake and risk of type 2 diabetes [summary RR = 0.83, 95% CI = 0.68 to 1.01, I2 = 90.8%].

The investigators found no association between soy milk dietary intake and risk of type 2 diabetes [summary RR = 0.89, 95% CI = 0.71 to 1.11, I2 = 91.7%].

The investigators found tofu dietary intake significantly reduced risk of type 2 diabetes with 8% [summary RR = 0.92, 95% CI = 0.84 to 0.99].
Significantly because RR of 1 was not found in the 95% CI of 0.84 to 0.99. RR of 1 means no risk/association.

The investigators found soy protein dietary intake significantly reduced risk of type 2 diabetes with 16% [summary RR = 0.84, 95% CI = 0.75 to 0.95].

The investigators found soy isoflavones dietary intake significantly reduced risk of type 2 diabetes with 12% [summary RR = 0.88, 95% CI = 0.81 to 0.96].

The investigators found in dose-response analysis, significant linear inverse associations for tofu, soy protein and soy isoflavones [all p 0.05].

The investigators concluded dietary intakes of tofu, soy protein and soy isoflavones reduce incident type 2 diabetes. These findings support recommendations to increase intakes of certain soy products for the prevention of type 2 diabetes. However, the overall quality of evidence was low and more high-quality evidence from prospective studies is needed.

Original title:
Legume and soy intake and risk of type 2 diabetes: a systematic review and meta-analysis of prospective cohort studies by Tang J, Wan Y, […], Feng F.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31915830

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

Objectives:
The relationship between serum copper (Cu) level and overweight/obesity remains controversial. Therefore, this review article (meta-analysis) has been conducted.

Does a high serum copper level increase overweight/obesity risk?

Study design:
This review article included 21 articles.

Results and conclusions:
The investigators found compared with controls, serum copper level was significantly higher in obese children [SMD = 0.74, 95% CI = 0.16 to 1.32] and in obese adults [SMD = 0.39, 95% CI = 0.02 to 0.76].

The investigators found no significant difference in serum copper level between overweight and control groups in children [SMD = 1.52, 95% CI = -0.07 to 3.12] and in adults [SMD = 0.16, 95% CI = -0.06 to 0.38].

The investigators found subgroup analysis revealed a higher serum copper level in obese children [SMD = 0.90, 95% CI = 0.36 to 1.45] and obese adults [SMD = 0.47, 95% CI = 0.05 to 0.88] compared with healthy weight controls.

The investigators found the SMD differed significantly between obese children diagnosed by weight-for-height and controls [SMD = 1.56, 95% CI = 0.57 to 2.55] and there was a significant difference of serum copper level between obese adults diagnosed by BMI (WHO) and controls [SMD = 0.54, 95% CI = 0.08 to 1.01].

The investigators concluded that a higher serum copper level increases risk of obesity in children and adults and these findings need to be further confirmed.

Original title:
The Relationship Between Serum Copper and Overweight/Obesity: a Meta-analysis by Gu K, Li X, […], Jiang X.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31300957

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