Nutrition and health

Objectives:
With the increasing incidence of osteoporosis, vitamin K and calcium have been linked to bone mineral density (BMD) and undercarboxylated osteocalcin (UcOC) in many studies, but the results of studies of the combined effect of vitamin K and calcium on BMD and UcOC in humans have been inconsistent. Therefore, this review article has been conducted.

Do vitamin K and calcium supplements used in combination increase bone mineral density and decrease undercarboxylated osteocalcin level?

Study design:
This review article included 10 randomized controlled trials (RCTs) with a total of 1,346 patients.

Results and conclusions:
The investigators found that the combination of vitamin K and calcium supplements was significantly associated with a higher lumbar spine bone mineral density [SMD = 0.20, 95% CI = 0.07 to 0.32, I2 = 46.9%, p = 0.049].
However, after applying trim and fill method (where correction was made for publication bias), the results were not statistically significant [estimate = 0.067, 95% CI = -0.044 to 0.178].

The investigators found that vitamin K and calcium supplementation led to a significant decrease in undercarboxylated osteocalcin [SMD = -1.71, 95% CI = - 2.45 to -0.96, I2 = 95.7%, p  0.01].
The results did not change after correcting publication bias [estimate = - 0.947, 95% CI = -1.211 to - 0.687].
The SMD in the sensitivity analysis was -0.82 [95% CI = - 1.10 to -0.55, I2 = 65.4%, p  0.01].

The investigators found in subgroup analysis that the combination of vitamin K2 and calcium supplements was significantly associated with a higher lumbar spine bone mineral density [SMD = 0.30, 95% CI = 0.10 to 0.51, I2 = 0%].

The investigators found in subgroup analysis that the combination of vitamin K and  ≤ 1000 mg/d calcium supplements was significantly associated with a higher lumbar spine bone mineral density [SMD = 0.19, 95% CI = 0.05 to 0.32, I2 = 62.3%].

The investigators found in subgroup analysis that the combination of  ≤100 µg/d vitamin K and calcium supplements was significantly associated with a higher lumbar spine bone mineral density [SMD = 0.40, 95% CI = 0.20 to 0.61, I2 = 49.9%].

The investigators found in subgroup analysis that the combination of vitamin K and calcium supplements during ≤1 year was significantly associated with a higher lumbar spine bone mineral density [SMD = 0.38, 95% CI = 0.19 to 0.57, I2 = 40%].

The investigators concluded that ≤100 µg/d vitamin K2 and ≤1000 mg/d calcium supplements used in combination are associated with a higher lumbar spine bone mineral density and a lower undercarboxylated osteocalcin level.

Original title:
The combined effect of vitamin K and calcium on bone mineral density in humans: a meta-analysis of randomized controlled trials by Hu L, Ji J, [...], Yu B.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8515712/

Additional information of El Mondo:
Find more information/studies on review article/RCTs/publication bias, vitamin K, calcium and increasing bone mineral density right here.

Objectives:
Whether mushroom consumption, which is a rich source of potent antioxidants ergothioneine and glutathione, vitamins and minerals (e.g., selenium & copper), is associated with a lower mortality risk is not well understood. Therefore, this review article (meta-analysis) has been conducted.

Does mushroom consumption reduce all-cause mortality?

Study design:
This review article included 5 prospective cohort studies with a total of 50,787 cases of deaths accrued in 601,893 men and women.

Results and conclusions:
The investigators found in a meta-analysis that mushroom consumption was significantly associated with an 6% decrease of the risk of all-cause mortality [pooled risk ratio = 0.94, 95% CI = 0.91 to 0.98].  

The investigators concluded that a meta-analysis of prospective cohort studies shows mushroom consumption reduces all-cause mortality. These findings can be used to support public health recommendations and increase awareness about the health-promoting effects of mushrooms. Large prospective cohort studies with repeated dietary data measurements are needed to replicate these findings and clarify the potential protective role of mushrooms against premature mortality.

Original title:
Prospective study of dietary mushroom intake and risk of mortality: results from continuous National Health and Nutrition Examination Survey (NHANES) 2003-2014 and a meta-analysis by Ba DM, Gao X, [...], Richie Jr JP.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8454070/

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

Objectives:
Previous meta-analysis studies have indicated inverse associations between some carotenoids and risks of metabolic syndrome, cardiovascular disease, cancer and all-cause mortality. However, the results for associations between carotenoids and type 2 diabetes (T2D) remain inconsistent and no systematic assessment has been done on this topic. Therefore, this review article (meta-analysis) has been conducted.

Do higher dietary intakes and circulating concentrations of carotenoids reduce risk of type 2 diabetes?

Study design:
This review article included 13 studies.

Results and conclusions:
The investigators found for the the highest versus the lowest categories of dietary intake of β-carotene a significantly reduced risk of 22% for type 2 diabetes [pooled RR = 0.78, 95% CI = 0.70 to 0.87, I2 = 13.7%, n = 6].
This significantly reduced risk was also found for total carotenoids (n = 2), α-carotene (n = 4), and lutein/zeaxanthin (n = 4), with pooled RRs ranging from 0.80 to 0.91, whereas no significant associations were observed for β-cryptoxanthin and lycopene.

The investigators found for the the highest versus the lowest categories of circulating concentration of β-carotene a significantly reduced risk of 40% for type 2 diabetes [pooled RR = 0.60, 95% CI = 0.46 to 0.78, I2 = 56.2%, n = 7].
This significantly reduced risk was also found for total carotenoids (n = 3), lycopene (n = 4), and lutein (n = 2), with pooled RRs ranging from 0.63 to 0.85, whereas no significant association was found for circulating concentrations of α-carotene and zeaxanthin when comparing extreme categories.

The investigators found dose-response analysis indicated that nonlinear relations were observed for circulating concentrations of α-carotene, β-carotene, lutein and total carotenoids [all p-nonlinearity 0.05], but not for other carotenoids or dietary exposures.

The investigators concluded that higher dietary intakes and circulating concentrations of total carotenoids, especially β-carotene, are associated with a lower risk of type 2 diabetes. More studies are needed to confirm the causality and explore the role of foods rich in carotenoids in prevention of type 2 diabetes.

Original title:
Dietary Intake and Circulating Concentrations of Carotenoids and Risk of Type 2 Diabetes: A Dose-Response Meta-Analysis of Prospective Observational Studies by Jiang YW, Sun ZH, [...], Pan A.

Link:
https://pubmed.ncbi.nlm.nih.gov/33979433/

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

Objectives:
Does fruits and vegetables (FVs) consumption reduce risk of frailty?

Study design:
This review article included 10 cohort studies and 4 cross-sectional studies with 18,616 subjects with frailty and 101,969 controls (persons without frailty).

Based on the NutriGrade score, the quality of evidence for a protective effect of fruits and vegetables consumption on frailty was "moderate".

Results and conclusions:
The investigators found in 7 cohort studies for the highest versus lowest category of fruits and vegetables consumption a significantly reduced risk of 35% for frailty [RR = 0.65, 95% CI = 0.50 to 0.84, I2 = 81%].

The investigators found that every 200g per day increment in fruits and vegetables consumption was significantly associated with a 14% lower risk of frailty.
The risk of frailty decreased linearly up to fruits and vegetables consumption of 700 g/d, with flattening the curve at higher intake.

The investigators found that pooled analysis regarding fruits and vegetables separately did not indicate a significant association with the risk of frailty.

The investigators concluded that 200-700 g/d fruits and vegetables consumption decreases risk of frailty. Further large-scale prospective cohort studies are needed to reach more confident conclusions.

Original title:
Fruit and vegetable intake and risk of frailty: A systematic review and dose response meta-analysis by Ghoreishy SM, Asoudeh F, […], Mohammadi H.

Link:
https://pubmed.ncbi.nlm.nih.gov/34534684/

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

Objectives:
Findings on the link between dietary intakes of monounsaturated fatty acids (MUFA) and risk of mortality are conflicting. Therefore, this review article has been conducted.

Does monounsaturated fatty acids dietary intake reduce risk of mortality?

Study design:
This review article included 17 prospective cohort studies with a total of 1022,321 participants aged ≥ 20 years, of which 191,283 all-cause deaths, 55,437 cardiovascular diseases (CVD) deaths and 64,448 cancer deaths.

Results and conclusions:
The investigators found combining 15 effect sizes from 11 studies, monounsaturated fatty acids dietary intake was significantly associated with a reduced risk of 6% for all-cause mortality [RR = 0.94, 95% CI = 0.90 to 0.98, I2 = 55.5%, p = 0.005].
Significantly because RR of 1 was not found in the 95% CI of 0.90 to 0.98. RR of 1 means no risk/association.

The investigators found based on 17 effect sizes from 11 studies, no significant association between monounsaturated fatty acids dietary intake and risk of cardiovascular diseases mortality [RR = 0.95, 95% CI = 0.89 to 1.01, I2 =37.0%, p = 0.06].
No significant means that there is no association with a 95% confidence.

The investigators found when combining 10 effect sizes from 6 studies, monounsaturated fatty acids dietary intake was not significantly associated with cancer mortality [RR = 0.99, 95% CI = 0.96 to 1.03, I2 = 13.3%, p = 0.32].  
Not significantly because RR of 1 was found in the 95% CI of 0.96 to 1.03. RR of 1 means no risk/association.

The investigators found an additional 5% of energy (5 En%) from monounsaturated fatty acids was significantly associated with a 3% reduced risk of all-cause mortality [RR = 0.97, 95% CI = 0.96 to 0.98], but not with cardiovascular diseases [RR = 0.98, 95% CI = 0.95 to 1.01] and cancer mortality [RR = 0.99, 95% CI = 0.97 to 1.01].

The investigators concluded that monounsaturated fatty acids dietary intake reduces risk of all-cause mortality.

Original title:
Dietary intakes of monounsaturated fatty acids and risk of mortality from all causes, cardiovascular disease and cancer: A systematic review and dose-response meta-analysis of prospective cohort studies by Lotfi K, Salari-Moghaddam A, […], Esmaillzadeh A.

Link:
https://pubmed.ncbi.nlm.nih.gov/34560281/

Additional information of El Mondo:
Find more information/studies on fatty acids, cardiovascular disease and elderly right here.

Objectives:
Although current guidelines recommend reduction of salt intake in patients with diabetes, the benefits of reducing salt intake in people with type 2 diabetes mellitus (T2DM) lack clear evidence. Therefore, this review articles has been conducted.

Does dietary sodium restriction causally reduce blood pressure in patients with type 2 diabetes mellitus (T2DM)?

Study design:
This review article included 8 RCTs with 10 trials (7 cross-over and 3 parallel designs).
No publication bias was found from Begg's and Egger's tests.

Results and conclusions:
The investigators found compared with ordinary sodium intake, dietary sodium restriction significantly decreased 24-hour urine sodium level [WMD = -38.430 mmol/24h, 95% CI = -41.665 mmol/24h to -35.194 mmol/24h].

The investigators found dietary sodium restriction significantly lowered systolic blood pressure [WMD = -5.574 mm Hg, 95% CI = -8.314 to -2.834 mm Hg, I2 = 0.0%] and diastolic blood pressure [WMD = -1.675 mm Hg, 95% CI = -3.199 to -0.150 mm Hg, I2 = 0.0%].

The investigators concluded that dietary sodium restriction causally reduces systolic blood pressure and diastolic blood pressure in patients with type 2 diabetes mellitus (T2DM).

Original title:
Effect of dietary sodium restriction on blood pressure in type 2 diabetes: A meta-analysis of randomized controlled trials by Ren Y, Liqiang Qin L, […], Ma Y.

Link:
https://pubmed.ncbi.nlm.nih.gov/33838996/

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

Salt consists of sodium and chloride. So a dietary sodium restriction means a reduction in dietary salt intake.

A diet with dietary salt restriction is a diet with maximum 0.2 grams of salt per 100 kcal.

The easiest way to follow this diet is to choose only products/meals with maximum 0.2 grams of salt per 100 kcal. These products from the supermarket contain maximum 0.2 grams of salt per 100 kcal.

However, the most practical way to follow this diet is, all your daily consumed products/meals should contain on average maximum 0.2 grams of salt per 100 kcal.
To do this, use the 7-points nutritional profile app to see if your daily diet contains maximum 0.2 grams of salt per 100 kcal.

Objectives:
Evidence regarding associations between potato consumption and type 2 diabetes (T2D) and gestational diabetes mellitus (GDM) risks is accumulating. Therefore, this review article has been conducted.

Does a high potato intake increase type 2 diabetes and gestational diabetes mellitus (diabetes mellitus during pregnancy) risk?

Study design:
This review article included 19 studies (13 for type 2 diabetes and 6 for gestational diabetes mellitus) with a total of 21,357 type 2 diabetes cases among 323,475 participants and 1,516 gestational diabetes mellitus cases among 29,288 pregnancies.

Results and conclusions:
The investigators found meta-analysis showed a significantly increased risk of 19% [RR = 1.19, 95% CI = 1.06 to 1.34] for type 2 diabetes for total potato intakes among Western populations.

The investigators found meta-analysis showed a significantly increased risk of 8% [RR = 1.08, 95% CI = 1.00 to 1.16] for type 2 diabetes for baked/boiled/mashed potato intakes among Western populations.

The investigators found meta-analysis showed a significantly increased risk of 33% [RR = 1.33, 95% CI = 1.03 to 1.70] for type 2 diabetes for French fries/fried potato intakes among Western populations.

The investigators found dose-response meta-analysis demonstrated a significantly increased type 2 diabetes risk by 10% [95% CI = 1.07 to 1.14, p for trend 0.001], 2% [95% CI = 1.00 to 1.04, p for trend = 0.02] and 34% [95% CI = 1.24 to 1.46, p for trend 0.001] among Western populations for each 80 g/day (serving) increment in total potato, unfried potato and fried potato intakes, respectively.

The investigators found dose-response meta-analysis demonstrated a significantly increased gestational diabetes mellitus risk by 22% [95% CI = 1.06 to 1.42, p for trend 0.007] among Western populations for each 80 g/day (serving) increment in total potato intakes.

The investigators found dose-response meta-analysis demonstrated a significantly increased gestational diabetes mellitus risk by 26% [95% CI = 1.07 to 1.48, p for trend = 0.006] among Western populations for each 80 g/day (serving) increment in unfried potato intakes.

The investigators concluded that higher potato intake (at least 80g per day) is associated with higher type 2 diabetes risk among Western populations. The positive relationship presents a significant dose-response manner. Wisely controlled potato consumption may confer potential glucometabolic benefits.

Original title:
Dietary potato intake and risks of type 2 diabetes and gestational diabetes mellitus by Guo F, Zhang Q, [...], Ma L.

Link:
https://pubmed.ncbi.nlm.nih.gov/34130021/

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

Objectives:
Does vitamin C supplementation improve triglyceride and cholesterol levels in patients with type 2 diabetes mellitus?

Study design:
This review article included 15 studies with 872 participants.

Results and conclusions:
The investigators found, findings from 15 studies indicated that vitamin C supplementation significantly decreased triglyceride (TG) levels [WMD= -16.48 mg/dL, 95% CI = -31.89 to -1.08, p 0.001] and total cholesterol (TC) levels [WMD = -13.00 mg/dL, 95% CI = -23.10 to -2.91, p 0.001] in patients with type 2 diabetes mellitus.

The investigators found, however, vitamin C supplementation failed to improve LDL (bad cholesterol) and HDL cholesterol (good cholesterol) levels. 

The investigators found the meta-regression analysis suggested that lipid profile improvement was affected by duration of vitamin C treatment.

The investigators found dose-response analysis showed that vitamin C supplementation changed LDL cholesterol significantly based on vitamin C dose.

The investigators concluded that vitamin C supplementation improves lipid profile via decreases in triglyceride and total cholesterol levels in patients with type 2 diabetes mellitus. It appears that vitamin C supplementation is more beneficial to lipid profile in long-term vs. short term interventions.

Original title:
Does vitamin C supplementation exert profitable effects on serum lipid profile in patients with type 2 diabetes? A systematic review and dose-response meta-analysis by Namkhah Z, Ashtary-Larky D, […], Asbaghi O.

Link:
https://pubmed.ncbi.nlm.nih.gov/33984490/

Additional information of El Mondo:
Find more information/studies on vitamine C, cholesterol and diabetes right here.

Objectives:
Does spirulina supplementation improve glycemic related markers (like, fasting blood glucose, post prandial blood sugar and HbA1c levels) and lipid profile (like, triglyceride and cholesterol levels) among type 2 diabetes patients?

Study design:
This review article included 8 RCTs (9 arms).

Results and conclusions:
The investigators found, spirulina supplementation significantly reduced fasting blood glucose levels [-17.88 mg/dL, 95% CI = -26.99 to -8.78, I2 = 25%] among type 2 diabetes patients.

The investigators found, spirulina supplementation significantly reduced triglyceride levels [-30.99 mg/dL, 95% CI = -45.20 to -16.77, I2 = 50%] among type 2 diabetes patients.

The investigators found, spirulina supplementation significantly reduced total cholesterol levels [-18.47 mg/dL, 95% CI = -33.54 to -3.39, I2 = 73%] among type 2 diabetes patients.

The investigators found, spirulina supplementation significantly reduced LDL cholesterol (bad cholesterol) levels [-20.04 mg/dL, 95% CI = -34.06 to -6.02, I2 = 75%] among type 2 diabetes patients.

The investigators found, spirulina supplementation significantly reduced VLDL cholesterol levels [-6.96 mg/dL, 95% CI = -9.71 to -4.22, I2 = 33%] among type 2 diabetes patients.

The investigators found, spirulina supplementation significantly increased HDL cholesterol (good cholesterol) levels among type 2 diabetes patients.

The investigators found no significant effect on HbA1C or post prandial blood sugar among type 2 diabetes patients following spirulina supplementation.

The investigators concluded that spirulina supplementation has beneficial effects on fasting blood glucose and blood lipid profiles among type 2 diabetes patients.

Original title:
The effect of spirulina on type 2 diabetes: a systematic review and meta-analysis by Hatami E, Ghalishourani SS, […], Mansour-Ghanaei F.

Link:
https://pubmed.ncbi.nlm.nih.gov/34178867/

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

Objectives:
Does grapes/grape products supplementation improve glycemic indices (like HOMA-IR, Hb1Ac and fasting insulin level) in adults or in other words, does eating grapes or grape products causally improve glycemic indices in adults?

Study design:
This review article included 29 RCTs with a total of 1,297 participants.

Results and conclusions:
The investigators found, overall, the grapes/grape products supplementation significantly reduced homeostatic model assessment of insulin resistance (HOMA-IR) [WMD = -0.54, 95% CI = -0.91 to -0.17, p = 0.004] in adults.   
Significantly because the calculated p-value of = 0.004 was less than the p-value of 0.05.

The investigators found, however, the grapes/grape products supplementation did not affect fasting insulin levels [WMD = -0.90 μIU/mL, 95% CI = -1.04 to 2.84, p = 0.362] and hemoglobin A1c (Hb1Ac) percentage [WMD = 0.00%, 95% CI = -0.10 to 0.11, p = 0.916] in the main analyses.
Did not affect because the calculated p-value of 0.916 was larger than the p-value of 0.05.

The investigators concluded that the grapes/grape products supplementation reduces homeostatic model assessment of insulin resistance (HOMA-IR) in adults. Further, large-scale RCTs with longer duration are required to confirm these results.

Original title:
The effect of grapes/grape products on glycemic response: A systematic review and meta-analysis of randomized controlled trials by Moodi V, Abedi S, […], Miraghajani M.

Link:
https://pubmed.ncbi.nlm.nih.gov/33893683/

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

Homeostatic model assessment of insulin resistance (HOMA-IR) is a method for assessing β-cell function and insulin resistance (IR) from basal (fasting) glucose and insulin or C-peptide concentrations. HOMA-IR is an indicator of insulin resistance in diabetic patients. The higher the value, the more resistant you are to insulin. Diabetic patients often have a high HOMA-IR value.

Objectives:
Despite growing evidence that type 2 diabetes is associated with dementia, the question of whether intensive glucose control can prevent or arrest cognitive decline remains unanswered. Therefore, this review articles (meta-analysis) has been conducted.

Does intensive glucose control slow down cognitive decline in persons with type 2 diabetes?

Study design:
This review article included 5 cohort studies with 16,584 participants.
The mean follow-up duration ranged from 3.5 to 10 years.
The mean age of participants in the studies included in the current meta-analysis was 65.6 years at the initiation of the studies and the proportion of women was 40.8%.
All quality assessment scores fell in the range of 8 or 9, indicating high quality.
There was no publication bias.

Results and conclusions:
The investigators found a significantly poorer decline in cognitive function in the intensive glucose control group [β = -0.03, 95% CI = -0.05 to -0.02] than in the conventional glucose control group.

The investigators found, subgroup analysis showed a significant difference in the change in cognitive performance in composite cognitive function [β = -0.03, 95% CI = -0.05 to -0.01] and memory [β = -0.13, 95% CI = -0.25 to -0.02].

The investigators concluded that intensive glucose control in persons with type 2 diabetes slows down cognitive decline, especially the decline in composite and memory function. The impact of intensive glucose control on the brain structural abnormalities and risk of dementia needs further rigorously designed studies to validate these findings. Also, replicating and validating these findings is warranted.

Original title:
Impact of Intensive Glucose Control on Brain Health: Meta-Analysis of Cumulative Data from 16,584 Patients with Type 2 Diabetes Mellitus by Tang X, Cardoso MA, […], Simó R.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7947088/

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

Objectives:
Does chromium supplementation improve lipid profile (serum levels of triglyceride and cholesterol) in patients with type 2 diabetes mellitus (T2DM)?

Study design:
This review article included  24 RCTs (with 28 effect sizes).

Results and conclusions:
The investigators found that chromium supplementation resulted in a significant decrease in serum levels of triglyceride (TG) in patients with type 2 diabetes mellitus [MD = -6.54 mg/dL, 95 % CI = -13.08 to -0.00, p = 0.050].
Significant means that there is an association with a 95% confidence.

The investigators found that chromium supplementation resulted in a significant decrease in serum levels of total cholesterol (TC) in patients with type 2 diabetes mellitus [WMD = -7.77 mg/dL, 95 % CI = -11.35 to -4.18, p 0.001].

The investigators found that chromium supplementation significantly increased high-density lipoprotein cholesterol (HDL cholesterol or good cholesterol) in patients with type 2 diabetes mellitus [WMD = 2.23 mg/dL, 95 % CI = 0.07 to 4.40, p = 0.043] level.

The investigators found, however, chromium supplementation did not have significant effects on low-density lipoprotein cholesterol (LDL cholesterol or bad cholesterol) in patients with type 2 diabetes mellitus [WMD = -8.54 mg/dL, 95 % CI = -19.58 to 2.49, p = 0.129] level.

The investigators concluded that chromium supplementation decreases serum levels of triglyceride (TG) and total cholesterol (TC) and increases HDL cholesterol (good cholesterol) levels in patients with type 2 diabetes mellitus. It should be noted that the lipid-lowering properties of chromium supplementation are small and may not reach clinical importance.

Original title:
Effects of chromium supplementation on lipid profile in patients with type 2 diabetes: A systematic review and dose-response meta-analysis of randomized controlled trials by Asbaghi O, Naeini F, […], Naeini AA.

Link:
https://pubmed.ncbi.nlm.nih.gov/33813266/

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

Objectives:
Magnesium supplementation is often purported to improve sleep; however, as both an over-the-counter sleep aid and a complementary and alternative medicine, there is limited evidence to support this assertion. Therefore, this review article (meta-analysis) has been conducted.

Does magnesium supplementation improve sleep in older adults with insomnia?

Study design:
This review article included 3 randomized control trials (RCTs), comparing oral magnesium to placebo in 151 older adults in 3 countries.

All 3 RCTs were at moderate-to-high risk of bias and outcomes were supported by low to very low quality of evidence.

Daily elemental magnesium intake ranged from 320 mg to 729 mg taken 2 to 3 times per day using 2 formulations (magnesium oxide and magnesium citrate tablets).
Duration of follow-up for outcome assessment ranged from 20 days to 8 weeks.

Results and conclusions:
The investigators found pooled analysis showed that post-intervention sleep onset latency time was significantly 17.36 min less [95% CI = -27.27 to -7.44, p = 0.0006] after magnesium supplementation compared to placebo.
Significantly because the calculated p-value of = 0.0006 was less than the p-value of 0.05.

The investigators found pooled analysis showed that total sleep time improved by 16.06 min in the magnesium supplementation group but was statistically insignificant [95% CI = - 5.99 to 38.12, p = 0.15].
Insignificant because the calculated p-value of 0.15 was larger than the p-value of 0.05.

The investigators concluded that RCT evidence may support oral magnesium supplements (less than 1 g quantities given up to 3 times a day) for insomnia symptoms in older adults. May support because all 3 RCTs are at moderate-to-high risk of bias and outcomes are supported by low to very low quality of evidence.

Original title:
Oral magnesium supplementation for insomnia in older adults: a Systematic Review & Meta-Analysis by Mah J and Pitre T.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8053283/

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

Magnesium oxide contains 60% elemental magnesium and magnesium citrate contains 16% elemental magnesium.
So if you want to get 320 mg elemental magnesium from magnesium supplements, you have to take 534 mg magnesium oxide supplements or 2000 mg magnesium citrate.

Objectives:
Lifestyle interventions are an important and viable approach for preventing cognitive deficits. However, the results of studies on alcohol, coffee and tea consumption in relation to cognitive decline have been divergent, likely due to confounds from dose-response effects. Therefore, this review article (meta-analysis) has been conducted.

Does alcohol, coffee or tea consumption reduce the risk of cognitive deficits (such as dementia or Alzheimer's disease)?

Study design:
This review article included 29 prospective cohort studies from America, Japan, China and some European countries (131,777 participants for alcohol, 333,843 participants for coffee and 20,411 participants for tea).

The NOS score was 8.

Results and conclusions:
The investigators found dose-response relationships showed that compared to non-drinkers, low consumption (11 g/day) of alcohol significantly reduced the risk of cognitive deficits or only dementias, but there was no significant effect of heavier drinking (>11 g/day).

The investigators found dose-response relationships showed that compared to non-drinkers, low consumption of coffee significantly reduced the risk of any cognitive deficit (2.8 cups/day) or dementia (2.3 cups/day).
However, coffee drinking was not a significant protective factor for cognitive deficits in groups of average age 60 years.

The investigators found dose-response relationships showed that compared to non-drinkers, every cup of green tea per day significantly reduced risk of cognitive deficits with 6% [relative risk = 0.94, 95% CI = 0.92 to 0.97].  

The investigators concluded that light consumption of alcohol (11 g/day) and coffee (2.8 cups/day) reduces risk of cognitive deficits. Cognitive benefits of green tea consumption increases with the daily consumption.

Original title:
Alcohol, coffee and tea intake and the risk of cognitive deficits: a dose-response meta-analysis by Ran LS, Liu WH, […], Wang W.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8061189/

Additional information of El Mondo:
Find more information/studies on alcohol, coffee and tea consumption and dementia right here.

Objectives:
Does L-arginine supplementation improve biomarkers (fasting blood sugar, insulin, HbA1c and HOMA-IR values) of glycemic control in adults?

Study design:
This review article included 12 randomised clinical trials (RCTs).

Results and conclusions:
The investigators found L-arginine supplementation had no significant effect on serum fasting blood sugar (FBS) [weighted mean difference (WMD) = -3.38 mg/dL, 95% CI = -6.79 to 0.04, p = 0.53], serum insulin [WMD = -0.12 Hedges' g, 95% CI = -0.33 to 0.09, p = 0.27], glycated haemoglobin A1c (HbA1c) [WMD = -0.04%, 95% CI = -0.25 to 0.17, p = 0.71] and homeostasis model assessment for insulin resistance (HOMA-IR) [WMD = -0.48, 95% CI = -1.15 to 0.19, p = 0.15].
No significant because the calculated p-value of 0.15 was larger than the p-value of 0.05.

The investigators concluded although several animal studies have proposed that L-arginine supplementation might improve blood glucose control, the present review article could not confirm this benefit in humans.

Original title:
Effects of L-arginine supplementation on biomarkers of glycemic control: a systematic review and meta-analysis of randomised clinical trials by Karimi E, Hatami E, […], Askari G.

Link:
https://pubmed.ncbi.nlm.nih.gov/33426939/

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

Arginine is classified as a semiessential or conditionally essential amino acid, depending on the developmental stage and health status of the individual, that helps the body build protein. L-arginine is also found in most protein-rich foods, including fish, red meat, poultry, soy, whole grains, beans and dairy products.
 

Objectives:
Does garlic supplementation reduce adiponectin and leptin serum levels?

Study design:
This review article included 5 RCTs.

Results and conclusions:
The investigators found that garlic supplementation did not significantly affect adiponectin [Hedges's = 0.20, 95% CI = -0.06 to 0.47, p = 0.12] and leptin [Hedges's = 0.08, 95% CI = -0.26 to 0.41, p = 0.65] concentrations in comparison with placebo.

The investigators found, however, in the subgroup analysis, significantly increased serum adiponectin level was seen following garlic supplementation in trials with a mean age of participants ˂30 years [Hedges's = 0.44, 95% CI = 0.01 to 0.87, p = 0.04], the doses ˂1.5 g/day [Hedges's = 0.38, 95% CI = 0.02 to 0.71, p = 0.04] and trials with duration ≥8 weeks [Hedges's = 0.48, 95% CI = 0.08 to 0.89, p = 0.02].

The investigators concluded that ˂1.5 g/day garlic supplementation during ≥8 weeks reduces adiponectin level among participants ˂30 years.

Original title:
Systematic review and meta-analysis of randomized, controlled trials on the effects of garlic supplementation on serum adiponectin and leptin levels by Shekarchizadeh-Esfahani P, Hassani B, […], Soraya N.

Link:
https://pubmed.ncbi.nlm.nih.gov/33792129/

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Adiponectin is a fat-derived hormone that appears to play a crucial role in protecting against insulin resistance/diabetes and atherosclerosis (atherosclerosis is the dominant cause of cardiovascular disease (CVD)). Decreased adiponectin levels are thought to play a central role in the development of obesity, cardiovascular disease and type 2 diabetes in humans.

Objectives:
Do magnesium intakes reduce risk of all-cause, cancer and cardiovascular disease (CVD) mortality?

Study design:
This review article included 19 prospective cohort studies with a total of 1,168,756 participants (52,378 deaths from all causes (all-cause mortality), 23,478 from cardiovascular disease (CVD) and 11,408 from cancer).
The follow-up period was 3.5 to 32 years.

Results and conclusions:
The investigators found dietary magnesium intake was significantly associated with a lower risk of 13% for all-cause mortality [pooled effect size (ES) = 0.87, 95% CI = 0.79 to 0.97, p = 0.009, I2 = 70.7%, p 0.001].

The investigators found dietary magnesium intake was significantly associated with a lower risk of 20% for cancer mortality [pooled ES = 0.80, 95% CI = 0.67 to 0.97, p = 0.023, I2 = 55.7%, p = 0.027].

The investigators found for supplemental and total magnesium intakes, no significant associations with risks of all-cause, cardiovascular disease and cancer mortality.

The investigators found, however, linear dose-response meta-analysis indicated that each additional intake of 100 mg/d of dietary magnesium was significantly associated with a 6% and 5% reduced risk of all-cause and cancer mortality, respectively.

The investigators concluded that higher intake of dietary magnesium (at least 100 mg/d of dietary magnesium) is associated with a reduced risk of all-cause and cancer mortality, but not cardiovascular disease mortality. Supplemental and total magnesium intakes are not associated with the risk of all-cause, cardiovascular disease and cancer mortality. These findings indicate that consumption of magnesium from dietary sources may be beneficial in reducing all-cause and cancer mortality and thus have practical importance for public health.  

Original title:
Total, Dietary, and Supplemental Magnesium Intakes and Risk of All-Cause, Cardiovascular, and Cancer Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies by Bagheri A, Naghshi S, […], Esmaillzadeh A.

Link:
https://pubmed.ncbi.nlm.nih.gov/33684200/

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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:
Previous population studies on the associations between dietary fatty acids (FAs), plasma FAs levels and the risk of age-related macular degeneration (AMD) have yielded inconclusive results. Therefore, this review article (meta-analysis) has been conducted.

Do higher dietary fatty acids (EPA and DHA) intakes or higher plasma fatty acids levels reduce risk of age-related macular degeneration?

Study design:
This review article included 11 prospective cohort studies with 167,581 participants. During the follow-up periods (ranging from 3 to 28 years), 6,318 cases of age-related macular degeneration were recorded.

Results and conclusions:
The investigators found that each 1 g/day increment of dietary intake of docosahexaenoic acid (DHA) and eicosatetraenoic acid (EPA) combined significantly reduced risk of early age-related macular degeneration with 33% [RR = 0.67, 95% CI = 0.51 to 0.88].
Significantly means that there is an association with a 95% confidence.

The investigators found that each 1 g/day increment of dietary intake of docosahexaenoic acid (DHA) significantly reduced risk of early age-related macular degeneration with 50% [RR = 0.50, 95% CI = 0.32 to 0.78].
Significantly means it can be said with a 95% confidence that each 1 g/day increment of dietary intake of docosahexaenoic acid (DHA) really reduces risk of early age-related macular degeneration with 50%.

The investigators found that each 1 g/day increment of dietary intake of eicosatetraenoic acid (EPA) significantly reduced risk of early age-related macular degeneration with 60% [RR = 0.40, 95% CI = 0.18 to 0.87].
Significantly because RR of 1 was not found in the 95% CI of 0.18 to 0.87. RR of 1 means no risk/association.

The investigators found that higher plasma docosahexaenoic acid (DHA) levels significantly reduced risk of advanced age-related macular degeneration with 28% [RR = 0.72, 95% CI = 0.55 to 0.95].

The investigators found that higher plasma eicosatetraenoic acid (EPA) levels significantly reduced risk of advanced age-related macular degeneration with 43% [RR = 0.57, 95% CI = 0.40 to 0.81].

The investigators concluded that 1 g/day of dietary intake DHA and 1 g/day of dietary intake EPA and higher plasma DHA and EPA levels are associated with a reduced risk of age-related macular degeneration.

Original title:
Dietary fatty acid intake, plasma fatty acid levels, and the risk of age-related macular degeneration (AMD): a dose-response meta-analysis of prospective cohort studies by Zhong Y, Wang K, [...], Yao K.

Link:
https://pubmed.ncbi.nlm.nih.gov/33469697/

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A high plasma EPA and DHA content can be obtained by eating a lot of oily fish and/or by taking EPA and DHA supplements (fish oil supplements).
Oily fish contains more EPA and DHA than non-oily fish.

Early age-related macular degeneration: most people do not experience adverse symptoms or vision loss in the early stage of age-related macular degeneration, but night vision problems are often reported. Though no pigmentary abnormalities are apparent upon examination, medium-sized drusen (>63 μm and ≤125 μm) are present.

Objectives:
Previous studies on the association between alcohol intake and risk of fracture have reached conflicting findings. Therefore, this review article has been conducted.

Does alcohol consumption increase risk of fractures?

Study design:
This review article included 38 prospective cohort studies with a total sample size of 5,053,117 participants and 169,560 cases of fracture.

Results and conclusions:
The investigators found in a random-effects meta-analysis, that alcohol consumption significantly increased risk of total fractures with 35% [RR = 1.35, 95% CI = 1.01 to 1.81] and any fractures with 24% [RR= 1.24, 95% CI = 1.11 to 1.38].
Significant because RR of 1 was not found in the 95% CI of 1.01 to 1.81. RR of 1 means no risk/association.

The investigators found, however, no significant association between alcohol intake and risk of hip fractures [RR = 1.19, 95% CI = 0.96 to 1.48], osteoporotic fractures [RR = 2.01, 95% CI = 0.76 to 5.34], vertebral fractures [RR = 0.98, 95% CI = 0.68 to 1.40] and wrist fractures [RR = 0.99, 95% CI = 0.85 to 1.16].
No significant because RR of 1 was found in the 95% CI of 0.85 to 1.06. RR of 1 means no risk/association.

The investigators concluded that alcohol consumption is positively associated with risk of total fractures and any fractures.

Original title:
A systematic review and meta-analysis of prospective cohort studies on the association between alcohol intake and risk of fracture by Asoudeh F, Salari-Moghaddam A, […], Esmaillzadeh A.

Link:
https://pubmed.ncbi.nlm.nih.gov/33596741/

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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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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 evidence suggests that diet can modify the risk of future cognitive impairment and dementia. A biologically plausible rationale and initial clinical data indicate that the antioxidant activities of dietary carotenoids may assist the preservation of cognitive function. Therefore, this review article has been conducted.

Does carotenoid supplementation improve cognitive performance among healthy adults?

Study design:
This review article included 9 RCTs, involving 2,228 subjects in the treated group (group with carotenoid supplementation) and 2,174 subjects in control group (group without carotenoid supplementation).
The age of all participants varied from 45 to 78 years.
The majority of clinical trials assessed the effect of xanthophylls such as lutein, zeaxanthin, and astaxanthin, whereas only 1 study determined the effects of β-carotene.
The duration of carotenoid supplementation ranged from 2 weeks to 12 months.
The dosage of carotenoids administered in the studies ranged from 0.5 mg/d to 50 mg/d.
There was no evidence of publication bias.

Results and conclusions:
The investigators found results of the pooled meta-analysis showed a significant effect of carotenoid intervention on cognitive outcomes [Hedge's g = 0.14, 95% CI = 0.08 to 0.20, p 0.0001, I2 = 0.00%].
The sensitivity analysis did not change the overall findings obtained from the primary analysis.

The investigators concluded that these results highlight the potential role of carotenoids (0.5 mg/d to 50 mg/d) in the protection of mental functions even in subjects (healthy participants aged 45-78 years) without cognitive impairment. This is particularly important because the population is aging and preservation of cognitive function is crucial for individual autonomy and quality of life, even in non-demented subjects. Further well-powered and long-term trials are required to determine treatment duration, type of carotenoid and optimal dosage.

Original title:
Carotenoids and Cognitive Outcomes: A Meta-Analysis of Randomized Intervention Trials by Davinelli S, Ali S, […], Corbi G.

Link:
https://www.mdpi.com/2076-3921/10/2/223/htm

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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:
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:
Increasing macular pigment optical density (MPOD) as a result of increased macular concentration of lutein and zeaxanthin may reduce the risk of age-related macular degeneration (AMD). Therefore, this review article has been conducted.

Have daily egg consumption beneficial effects on macular pigment optical density and serum lutein levels?

Study design:
This review article included 5 RCTs with a total of 296 participants.
There was no heterogeneity between studies.

Results and conclusions:
The investigators found that egg consumption significantly increased macular pigment optical density [WMD = +0.037, 95% CI = 0.004 to 0.069, p = 0.027] and serum lutein levels [WMD = +0.150 μmol/L, 95% CI = 0.037 to 0.263, p = 0.009].

The investigators found subgroup analyses showed that egg consumption had a larger effect on macular pigment optical density in studies with a parallel design and increased serum lutein levels to a greater extent in a healthy population.

The investigators concluded daily egg consumption have beneficial effects on macular pigment optical density and serum lutein level is inversely associated with reduced age-related macular degeneration progression. Further clinical trials are required to confirm the results of this review article.

Original title:
A positive effect of egg consumption on macular pigment and healthy vision: a systematic review and meta-analysis of clinical trials by Sikaroudi MK, Saraf-Bank S, […], Soltani S.

Link:
https://pubmed.ncbi.nlm.nih.gov/33491232/

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