Nutrition and health

Objectives:
Fish oil supplementation has been shown to be associated with a lower risk of metabolic syndrome and benefit a wide range of chronic diseases, such as cardiovascular disease, type 2 diabetes and several types of cancers. However, the evidence of fish oil supplementation on glucose metabolism and insulin sensitivity is still controversial. Therefore, this review article (meta-analysis) has been conducted.

Does fish oil supplementation improve insulin sensitivity in humans?

Study design:
This review article included a total of 17 RCTs with 672 participants. One of the 17 studies was crossover design and others were parallel design.
The doses of active ingredients of fish oil (n-3 fatty acids) ranged from 1 g/d to 4 g/d. Duration of the interventions was ranged from 4 weeks to 24 weeks.
There was no suggestion of small study effect based on visual inspection of the funnel plot. Results of the Egger’s (p = 0.78) and Begg’s (p = 0.43) tests showed that there was no potential publication bias.

Results and conclusions:
The investigators found pooled analysis showed that fish oil supplementation had no effects on insulin sensitivity overall [SMD = 0.17, 95% CI = -0.15 to 0.48, p = 0.292, I2 = 58.1%, p = 0.001].

The investigators found subgroup analysis showed that fish oil supplementation significantly improved insulin sensitivity among people who were experiencing at least one symptom of metabolic disorders [SMD = 0.53, 95% CI = 0.17 to 0.88, p 0.001].

The investigators found subgroup analysis showed a positive effect of fish oil on insulin sensitivity among the short-term intervention group (12 weeks) rather than the long-term intervention group [SMD = 0.31, 95% CI = 0.01-0.61, p = 0.04].

The investigators found subgroup analysis showed that fish oil had no effects on insulin sensitivity among the healthy people or people with T2DM.

The investigators found there were no significant differences between subgroups of methods of insulin sensitivity and doses of omega-3 polyunsaturated fatty acids (n-3 PUFA) of fish oil supplementation.

The investigators found in sensitivity analysis that summary results did not differ significantly when omitting studies one at a time.

The investigators concluded that fish oil supplementation during 12 weeks improves insulin sensitivity among people who were experiencing at least one symptom of metabolic disorders.

Original title:
Fish oil supplementation and insulin sensitivity: a systematic review and meta-analysis by Gao H, Geng T, [...], Zhao Q.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5496233/

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

 

Objectives:
Randomised controlled trials comparing low- versus high-fat diets on cardiometabolic risk factors in people with overweight or obesity have shown inconsistent results, which may be due to the mixed metabolic status of people with excess adiposity. The role of dietary fat manipulation in modifying cardiometabolic indicators in people with overweight or obese without metabolic disturbance is unclear. Therefore, this review article (meta-analysis) has been conducted.

Does a low-fat diet modify cardiometabolic indicators in people who are overweight (BMI>25) or obese (BMI>30) without metabolic disturbance?

Study design:
This review article included 20 RCTs with 2,106 participants.

Results and conclusions:
The investigators found total cholesterol levels in people who are overweight or obese without metabolic disturbance were significantly lower following low-fat diet compared with high-fat diet [WMD = -7.05 mg/dL, 95% CI = -11.30 to -2.80, p = 0.001].  

The investigators found LDL-cholesterol levels (bad cholesterol) in people who are overweight or obese without metabolic disturbance were significantly lower following low-fat diet compared with high-fat diet [WMD = -4.41 mg/dL, 95% CI = -7.81 to -1.00, p = 0.011].  

The investigators found HDL-cholesterol levels (good cholesterol) in people who are overweight or obese without metabolic disturbance were significantly lower following low-fat diet compared with high-fat diet [WMD = -2.57 mg/dL, 95% CI = -3.85 to -1.28, p 0.001].  

The investigators found TAG levels (blood fat levels) in people who are overweight or obese without metabolic disturbance were significantly higher following low-fat diet compared with high-fat diet [WMD = -11.68 mg/dL, 95% CI = 5.90 to 17.45, p 0.001].  

The investigators concluded a low-fat diet reduces cholesterol and TAG levels in people with overweight or obesity without metabolic disturbances.

Original title:
Effects of low-fat compared with high-fat diet on cardiometabolic indicators in people with overweight and obesity without overt metabolic disturbance: a systematic review and meta-analysis of randomised controlled trials by Lu M, Wan Y, [...], Li D.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29212558

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

A triglyceride (TG, triacylglycerol, TAG or triacylglyceride) is an ester derived from glycerol and three fatty acids. Triglycerides are the main constituents of body fat in humans.

Those with overweight or obesity are advised to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.
The most easy way to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal is to choose meals/products with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.
However, the most practical way to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal is all meals/products that you eat on a daily basis should on average contain maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.

Objectives:
Dietary fiber intake may provide beneficial effects on the components of metabolic syndrome (MetS); however, observational studies reported inconsistent results for the relationship between dietary fiber intake and metabolic syndrome risk. Therefore, this review article (meta-analysis) has been conducted.

Does dietary fiber intake reduce risk of metabolic syndrome?

Study design:
This review article included 11 cross-sectional studies and 3 cohort studies.
There was evidence of publication bias in cross-sectional studies.

Results and conclusions:
The investigators found in cross-sectional studies when comparing the highest with lowest categories of dietary fiber intake, a significantly reduced risk of 33% [OR = 0.67, 95% CI = 0.58-0.78, I2 = 32.4%, p = 0.181] for metabolic syndrome. However, this reduced risk was not significant in cohort studies [pooled RR = 0.86, 95% CI = 0.70-1.06]. Not significant because RR of 1 was found in the 95% CI of 0.70 to 1.06. RR of 1 means no risk/association.

The investigators concluded that a high dietary intake of fiber may reduce risk of metabolic syndrome. May reduce because there was evidence of publication bias in cross-sectional studies and the reduced risk was not significant in cohort studies. Therefore, more prospective cohort studies are needed to further verify the association between dietary fiber intake and the risk of metabolic syndrome.

Original title:
Fruit and vegetable consumption and risk of the metabolic syndrome: a meta-analysis by Tian Y, Su L, [...], Jiang X.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29151369

Additional information of El Mondo:
Find more information/studies on publication bias/cohort studies/significant, fiber consumption and overweight right here.  

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Those with metabolic syndrome are advised to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.
The most easy way to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal is to choose meals/products with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.
However, the most practical way to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal is all meals/products that you eat on a daily basis should on average contain maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.

Objectives:
Several epidemiological studies have been performed to evaluate the association of fruit and vegetable consumption with risk of the metabolic syndrome (MetS), but the results remain controversial. Therefore, this review article (meta-analysis) has been conducted.

Does consumption of vegetables or fruit reduce risk of metabolic syndrome?

Study design:
This review article included a total of 9 studies for fruit consumption, 9 studies for vegetable consumption and 7 studies for fruit and vegetable consumption.

There was no evidence of small-study effect (publication bias)

Results and conclusions:
The investigators found a significantly reduced risk of 13% [pooled RR = 0.87, 95% CI = 0.82-0.92, I2 = 46.7%] for metabolic syndrome when comparing the highest fruit consumption versus the lowest consumption.

The investigators found a significantly reduced risk of 15% [pooled RR = 0.85, 95% CI = 0.80-0.91, I2 = 0.0%] for metabolic syndrome when comparing the highest vegetable consumption versus the lowest consumption.

The investigators found a significantly reduced risk of 24% [pooled RR = 0.76, 95% CI = 0.62-0.93, I2 = 83.5%] for metabolic syndrome when comparing the highest fruit and vegetable consumption versus the lowest consumption.

The investigators found in subgroup analyses stratified by continent, the inverse association of fruit consumption [RR = 0.86, 95% CI = 0.77-0.96] and vegetable consumption [RR = 0.86, 95% CI = 0.80-0.92] with risk of metabolic syndrome remained significant in Asia.

The investigators concluded that a high fruit or/and vegetable consumption reduce risk of metabolic syndrome, particularly among Asian. Therefore, people should consume more fruits and vegetables to reduce risk of metabolic syndrome.

Original title:
Fruit and vegetable consumption and risk of the metabolic syndrome: a meta-analysis by Tian Y, Su L, [...], Jiang X.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29151369

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

Find out whether you are overweight or not right here.

Those with metabolic syndrome are advised to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.
The most easy way to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal is to choose meals/products with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.
However, the most practical way to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal is all meals/products that you eat on a daily basis should on average contain maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.

Objectives:
The scientific literature shows conflicting evidence about the relationship between adiposity and bone mass in overweight and obese populations. Therefore, this review article (meta-analysis) has been conducted.

Does a high adipose mass reduce bone mineral density in overweight and obese populations?

Study design:
This review article included a total of 16 studies, comprising 2587 participants and 75 correlation coefficients.

Results and conclusions:
The investigators found strong evidence supported a negative relationship between relative (%) adipose mass and bone mineral density (BMD) in men [R = -0.37, 95% CI = -0.57 to -0.12] and in those aged less than 25 years [R = -0.28, 95% CI = -0.45 to -0.08].

The investigators concluded that a high relative (%) adipose mass reduces bone mineral density in overweight (BMI = 25-30) and obese populations (BMI > 30), particularly in men and those aged less than 25 years. Therefore, to prevent bone loss in overweight and obese populations, nutrition- and exercise-based interventions that focus on a controlled reduction of adipose mass with concomitant preservation of lean mass are recommended.

Original title:
Influence of adipose tissue mass on bone mass in an overweight or obese population: systematic review and meta-analysis by Dolan E, Swinton PA, […], O'Reilly J.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29028271

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

Find out whether you are overweight or not right here.

Those with overweight (BMI = 25-30) or obesity (BMI > 30) are advised to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.
The most easy way to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal is to choose meals/products with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.
However, the most practical way to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal is all meals/products that you eat on a daily basis should on average contain maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.

Strength exercise is the best way to reduce adipose mass while preserving lean mass.

Objectives:
The potential glucose-lowering effects of pomegranate have been reported in animal and observational studies, but intervention studies in humans have generated mixed results. Therefore, this review article (meta-analysis) has been conducted.

What are the effects of pomegranate supplementation on measures of glucose control, insulin levels and insulin sensitivity in humans?

Study design:
This review article included 16 RCTs with 538 subjects. 14 trials adopted parallel study designs and the 2 remaining trials used crossover designs.
The total number of subjects included in each study ranged from 14 to 74 subjects.
The mean age of participants in each trial ranged from 30 to 70 years, with differing age ranges in most studies.
11 studies used pomegranate juice as a supplement (the dosage ranged from 120 to 500 ml/day).
2 studies used pomegranate seed oil as treatments (the dosage ranged from 400 to 2000 mg/day).
3 studies utilized pomegranate extract as the intervention (the dosage ranged from 710 to 1420 mg/day).  
The duration of the pomegranate intervention varied from 1 to 12 weeks (median: 5.5 weeks).

Overall, significant heterogeneity was detected for FBI and HOMA-IR, but subgroup analysis could not identify factors significantly influencing these parameters.
No significant publication bias was found.

Results and conclusions:
The investigators found that pomegranate did not significantly affect the measures of:
-FBG (fasting blood glucose) [WMD = -0.6 mg/dL, 95% CI = -2.79 to 1.58, p = 0.59, I2 = 0%];
-FBI (fasting blood insulin) [WMD = 0.29 μIU/mL, 95% CI = -1.16 to 1.75, p = 0.70, I2 = 60.4%];
-HOMA-IR (homeostatic model assessment of insulin resistance) [WMD = -0.04, 95% CI = -0.53 to 0.46, p = 0.88, I2 = 59.8%] or;
-HbA1c (glycated haemoglobin) [WMD = -0.11%, 95% CI = -0.39 to 0.18, p = 0.46, I2 = 0%].
These results were robust in sensitivity analysis.

The investigators found meta-regression analysis showed that the factor (dose of pomegranate juice supplementation) was not associated with the treatment effects on FBG level [coefficient = -0.006, 95% CI = -0.023 to 0.011, p = 0.46].

The investigators found no significant difference in the FBG-lowering effect between trials that were conducted in subjects with cardiovascular disease risk [WMD = 0.30 mg/dL, 95% CI = -2.36 to 2.97, p = 0.82] and those that were conducted in healthy individuals [WMD = -2.53 mg/dL, 95% CI = -6.36 to 1.30, p = 0.19].

The investigators found no statistically significant differences in the pooled effects of pomegranate on FBG in the subgroups stratified by study designs, intervention durations, types of intervention, baseline BMI and baseline FBG levels (FBG levels at the beginning of the studie).

The investigators concluded pomegranate supplements have no favourable effect on improvements in glucose and insulin metabolism. The current evidence suggests that daily pomegranate supplementation is not recommended as a potential therapeutic strategy in glycemic management. Further large-scale RCTs with longer duration are required to confirm these results.

Original title:
Lack of efficacy of pomegranate supplementation for glucose management, insulin levels and sensitivity: evidence from a systematic review and meta-analysis by Huang H, Liao D, […], Zhu Y.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5629805/

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

Objectives:
The prevalence of metabolic syndrome (MetS) has been greatly increased, worldwide. In recent years, investigators have proposed that sodium might contribute to the development of metabolic syndrome; however, the published data were conflicting. Therefore, this review article (meta-analysis) has been conducted.

Does sodium contribute to the development of metabolic syndrome?

Study design:
This review article included 17 observational studies with 66,274 participants.

Results and conclusions:
The investigators found that subjects with metabolic syndrome had significantly higher levels of sodium compared to healthy controls [Hedges' g = 0.21, 95% CI = 0.12-0.29, I2 = 68.6%]. Subgroup analyses revealed that the difference was significant when the sodium status was assessed using urinary sodium levels.

The investigators found that random effects meta-regression analysis also revealed that body sodium level increases with the number of metabolic syndrome components.

The investigators found that participants with highest dietary/urinary or serum sodium levels had a significantly 37% higher chance of developing metabolic syndrome when compared with participants with the lowest sodium levels [OR = 1.37, 95% CI = 1.31-1.42, I2 = 86.9%].

The investigators concluded that higher sodium input into the body is directly associated with the likelihood of metabolic syndrome. Prospective cohort studies and well-designed randomized clinical trials considering the effect of sodium restricted diets on the risk of metabolic syndrome as an outcome are necessary to represent the causal association.

Original title:
Sodium status and the metabolic syndrome: A systematic review and meta-analysis of observational studies by Soltani S, Kolahdouz Mohammadi R, […], Salehi-Abargouei A.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28846446

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

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Those with metabolic syndrome are advised to select the following food items.

Sodium is part of table salt or sodium choride.

High-sodium or high-salt products are products with more than 0.3 gram salt per 100 kcal. These products are rich in salt.
A high-salt diet is a diet with many products with more than 0.3 gram salt per 100 kcal.

Objectives:
Do patients with type 2 diabetes benefit from a low carbohydrate diet?

Study design:
This review article included a total of 9 RCTs with 734 patients with type 2 diabetes.

Results and conclusions:
The investigators found that low carbohydrate diet significantly reduced HbA1c level [WMD = -0.44, 95% CI = -0.61 to -0.26, p= 0.00] of patients with type 2 diabetes.

The investigators found that low carbohydrate diet significantly reduced triglycerides concentration [WMD = -0.33, 95% CI = -0.45 to -0.21, p = 0.00] of patients with type 2 diabetes.

The investigators found that low carbohydrate diet significantly increased HDL cholesterol concentration (WMD = 0.07, 95% CI = 0.03 to 0.11, p = 0.00] of patients with type 2 diabetes.

The investigators found that low carbohydrate diet was not associated with decreased level of total cholesterol and LDL cholesterol.

The investigators found subgroup analyses showed that short term intervention of low carbohydrate diet was effective for weight loss [WMD = -1.18, 95% CI = -2.32 to -0.04, p = 0.04] in patients with type 2 diabetes.

The investigators concluded there is a beneficial effect of low carbohydrate diet intervention on glucose control in patients with type 2 diabetes. The low carbohydrate diet intervention also has a positive effect on triglycerides and HDL cholesterol concentrations, but without significant effect on long term weight loss.

Original title:
Efficacy of low carbohydrate diet for type 2 diabetes mellitus management: A systematic review and meta-analysis of randomized controlled trials by Meng Y, Bai H, […], Chen L.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28750216

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

A low carbohydrate diet is a diet that is largely made up of meals/products with 20-40 En% carbohydrate. Practically, this means that all meals/products that you eat on a daily basis should on average contain 20-40 En% carbohydrate.
20-40 En% carbohydrate means that the total amounts of carbohydrate make up for a 20-40% of the total kcal of the diet. Check here which products contain 20-40 En% carbohydrate.

Objectives:
The relationships between metabolic syndrome (MetS) and risk of incident stroke are inconsistent. Therefore, this review article (meta-analysis) has been conducted.

Does metabolic syndrome increase risk of stroke?

Study design:
This review article included a total of 16 prospective cohort studies, including 116,496 participants who were initially free of cardiovascular diseases.

Results and conclusions:
The investigators found comparing the persons without metabolic syndrome, those with metabolic syndrome had a significantly higher risk of 70% for incident stroke [pooled relative risk (RR) = 1.70, 95% CI = 1.49-1.95]. Significant means that there is an association with a 95% confidence.

The investigators found in subgroup analyses that women with metabolic syndrome had a significantly higher risk of 83% for incident stroke [pooled relative risk (RR) = 1.83, 95% CI = 1.31-2.56]. Significant because RR of 1 was not found in the 95% CI of 1.31 to 2.56. RR of 1 means no risk/association.

The investigators found in subgroup analyses that men with metabolic syndrome had a significantly higher risk of 47% for incident stroke [pooled relative risk (RR) = 1.47, 95% CI = 1.22-1.78].

The investigators found in subgroup analyses that those with metabolic syndrome had a significantly higher risk of 112% for ischemic stroke [pooled relative risk (RR) = 2.12, 95% CI = 1.46-3.08].

The investigators found in subgroup analyses that those with metabolic syndrome had a non-significantly higher risk of 48% for hemorrhagic stroke [pooled relative risk (RR) = 1.48, 95% CI = 0.98-2.24].

The investigators concluded metabolic syndrome increases risk of stroke, particularly among women and those with ischemic stroke.

Original title:
Metabolic syndrome and stroke: A meta-analysis of prospective cohort studies by Li X, Li X, […], Gao Q.

Link:
http://www.sciencedirect.com/science/article/pii/S0967586816311079

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

Find out whether you are overweight or not right here.

Those with metabolic syndrome are advised to select the following food items.

Objectives:
Polyunsaturated fats (PUFAs) have been shown to reduce type 2 diabetes (T2DM) risk and improve insulin responsiveness in T2DM subjects, but whether the plant sources of omega-3 PUFA (alpha-linolenic acid [ALA]) have an effect on glycemic control requires further investigation. Therefore, this review article (meta-analysis) has been conducted.

Does alpha-linolenic acid dietary intake reduce diabetes risk?

Study design:
This review article included a total of 8 RCTs involving 212 participants with type 2 diabetes.
5 trials (62.5%) were parallel designs and 3 (37.5%) were crossover designs.
Participants were generally middle-aged (median age  =  54 years, range  =  47-64 years) and overweight or obese (median BMI  =  30.7, range  =  28.0-33.2).
Overall, participants had controlled diabetes (median HbA1c = 6.8%, median FBG = 7.95 mmol/L) and the majority of studies indicated the use of hypoglycemic drugs or other medications, although all studies excluded the use of insulin therapy.
The dose of ALA ranged from 1.5 to 7.4 g/day with a median assigned dose of 4.4, 5.4 and 5.4 g/day of ALA for trials that reported HbA1c, FBG and FBI, respectively.
The median duration of the treatment was 3 months, ranging from 2 to 12 months.
7 studies (87.5%) were considered high quality (MQS ≥8).

Results and conclusions:
The investigators found compared to a control diet, a median dose of 4.4 g/day of alpha-linolenic acid intake for a median duration of 3 months did not affect HbA1c (%) of patients with type 2 diabetes [MD =  -0.01, 95% = -0.32 to 0.31, p  =  0.96].

The investigators found compared to a control diet, a median alpha-linolenic acid dose of 5.4 g/day did not lower fasting blood glucose (FBG) of patients with type 2 diabetes [MD  = 0 .07, 95% CI = -0.61 to 0.76, p  = 0 .84] or fasting blood insulin (FBI) of patients with type 2 diabetes [MD  =  7.03, 95% CI = -5.84 to 19.89, p  = 0 .28].

The investigators found summary effect estimates were generally compromised by considerable and unexplained heterogeneity [I2 ≥ 75%].

The investigators found in the subgroup analysis of continuous predictors, a reduction in HbA1c (%) and FBG (mmol/L) was significantly associated with an increased intake of ALA.

The investigators found further adjustment for publication bias using Duval and Tweedie's trim-and-fill analysis provided an adjusted, significant MD of 0.25 [95% CI = -0.38 to -0.12, 0.001) for HbA1c (%).

The investigators concluded alpha-linolenic acid-enriched diet with a median alpha-linolenic acid dose of 4.4 g/day during 3 months has no effects on HbA1c, FBG or FBI in patients with type 2 diabetes. The scarce number of existing RCTs and the presence of heterogeneity in the meta-analysis limit the ability to make firm conclusions about alpha-linolenic acid in type 2 diabetes management. The potential for alpha-linolenic acid to have dose-dependent effects warrants further research in this area.

Original title:
The effect of alpha-linolenic acid on glycemic control in individuals with type 2 diabetes: A systematic review and meta-analysis of randomized controlled clinical trials by Jovanovski E1, Li D, […], Vuksan V.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5457843/

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

4.4 g/day alpha-linolenic acid can be achieved by taking 1 to 2 tablespoons of flax or salba-chia seeds or about 12 whole walnuts per day.

 

Objectives:
The associations between n-3 polyunsaturated fatty acids (PUFAs) and metabolic syndrome (MetS) risk have demonstrated inconsistent results. Therefore, this review article (meta-analysis) has been conducted.

Do higher circulating n-3 PUFA levels associate with a lower metabolic syndrome risk?

Study design:
This review article included a total of 7 case-control studies and 20 cross-sectional studies.
There was no publication bias.
Results and conclusions:
The investigators found a higher plasma/serum n-3 PUFAs was associated with a lower metabolic syndrome risk of 37% [pooled OR = 0.63, 95% CI = 0.49-0.81, I2 = 72.4%].

The investigators found the plasma/serum n-3 PUFAs in controls was significantly higher than cases [WMD = 0.24, 95% CI = 0.04-0.43], especially docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA).

The investigators found, however, no significant association between dietary intake of n-3 PUFAs or fish and metabolic syndrome risk.

The investigators found in sensitivity analysis by omitting one study at a time and re-calculated the remaining data, that exclusion of anyone study did not substantially influence the pooled effects.

The investigators concluded a higher circulating n-3 PUFAs is associated with a lower metabolic syndrome risk. The circulating n-3 PUFAs can be regarded as biomarkers indicating metabolic syndrome risk, especially DPA and DHA. The evidence of this review article will have important public implications in preventing metabolic syndrome through supplemental long-chain n-3 PUFAs of marine-origin. Furthermore, added RCTs and epidemiological studies with large sample-size are warranted to confirm these findings.

Original title:
n-3 Polyunsaturated Fatty Acids and Metabolic Syndrome Risk: A Meta-Analysis by Guo XF, Li X, […], Li D.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5537818/

Additional information of El Mondo:
Find more information/studies on overweight and n-3 PUFA right here.  
Docosapentaenoic acid (DPA) is a dietary omega-3 fatty acid mainly found in fish, fish oil, seal oil and red meat.

Find out whether you are overweight or not right here.

Objectives:
Have flaxseed supplementation positive effects on body composition?

Study design:
This review article included a total of 45 RCTs.

Results and conclusions:
The investigators found a significant reduction in body weight [WMD = -0.99 kg, 95% CI = -1.67 to -0.31, p = 0.004], BMI [WMD = -0.30 kg m², 95% CI = -0.53 to -0.08, p = 0.008] and waist circumference [WMD = -0.80 cm, 95% CI = -1.40 to -0.20, p = 0.008] following flaxseed supplementation.

The investigators found subgroup analyses showed that using whole flaxseed in doses ≥30 g/d, longer-term interventions (≥12 weeks) and studies including participants with higher BMI (≥ 27 kg/m²) had positive effects on body composition.

The investigators concluded whole flaxseed supplementation in doses ≥30 g/d during ≥12 weeks has positive effects on body composition in overweight and obese participants (=participants with BMI ≥ 25 kg/m²).

Original title:
The effect of flaxseed supplementation on body weight and body composition: a systematic review and meta-analysis of 45 randomized placebo-controlled trials by Mohammadi-Sartang M, Mazloom Z, […], Totosy de Zepetnek JO.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28635182

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

Find out whether you are overweight or not right here.

Objectives:
Have flaxseed supplementation positive effects on body composition?

Study design:
This review article included a total of 45 RCTs.

Results and conclusions:
The investigators found a significant reduction in body weight [WMD = -0.99 kg, 95% CI = -1.67 to -0.31, p = 0.004], BMI [WMD = -0.30 kg m², 95% CI = -0.53 to -0.08, p = 0.008] and waist circumference [WMD = -0.80 cm, 95% CI = -1.40 to -0.20, p = 0.008] following flaxseed supplementation.

The investigators found subgroup analyses showed that using whole flaxseed in doses ≥30 g/d, longer-term interventions (≥12 weeks) and studies including participants with higher BMI (≥ 27 kg/m²) had positive effects on body composition.

The investigators concluded whole flaxseed supplementation in doses ≥30 g/d during ≥12 weeks has positive effects on body composition in overweight and obese participants (=participants with BMI ≥ 25 kg/m²).

Original title:
The effect of flaxseed supplementation on body weight and body composition: a systematic review and meta-analysis of 45 randomized placebo-controlled trials by Mohammadi-Sartang M, Mazloom Z, […], Totosy de Zepetnek JO.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28635182

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

Find out whether you are overweight or not right here.

Objectives:
It has been unclear whether supplemental probiotics therapy improves clinical outcomes in type 2 diabetic patients. Therefore, this meta-analysis (systematic review) has been conducted.

Do probiotics supplements improve clinical outcomes in type 2 diabetic patients?

Study design:
This review article included 12 RCTs involving 684 type 2 diabetic patients.

Results and conclusions:
The investigators found a significant decreased glucose level in the probiotics group [pooled standardized mean difference = -0.18 mg/dL, 95% CI = -0.35 to -0.01, p = 0.04, I2 = 64%, p = 0.004] compared to the control group.

The investigators found a significant reduction in HbA1c in the probiotics group [pooled standardized mean difference = -0.38%, 95% CI = -0.62 to -0.14, p = 0.002, I2 = 0%, p = 0.72] compared to the control group.

The investigators found a significant reduction in fasting insulin level in the probiotics group [pooled standardized mean difference = -0.38, 95% CI = -0.59 to -0.18, p = 0.003, I2 = 0%, p = 0.81] compared to the control group.

The investigators found a significant reduced HOMA-IR level in the probiotics group [pooled standardized mean difference = -0.99, 95% CI = -1.52 to -0.4, p = 0.0002, I2 = 86%, p 0.00001] compared to the control group.

The investigators found a significant reduced CRP level in the probiotics group [pooled standardized mean difference = -1.34 mg/L, 95% CI = -1.76 to -0.92, p 0.00001, I2 = 90%, p 0.00001] compared to the control group.

The investigators found a non-significant reduction in both triglyceride levels [SMD = -0.23, 95% CI = -0.48 to 0.02, p = 0.07, I2 = 52%, p = 0.03] and cholesterol levels [total cholesterol: SMD = -0.18, 95% CI = -0.42 to 0.06, p = 0.14, I2 = 47%, p = 0.05 and LDL-cholesterol: SMD = -0.03, 95% CI = -0.20 to 0.14, p = 0.73, I2 = 3%, p = 0.41] in the probiotics group compared to the control group.

The investigators concluded that probiotics supplementation is associated with significant improvement in HbA1c and fasting insulin in type 2 diabetes patients. These results may provide evidence for encouraging use of probiotics in patients with type 2 diabetes mellitus. However, more randomized placebo-controlled trials with larger sample sizes are warranted to confirm these findings.

Original title:
Effect of Probiotics on Glucose and Lipid Metabolism in Type 2 Diabetes Mellitus: A Meta-Analysis of 12 Randomized Controlled Trials by Yao K, Zeng L, [...], Zou X.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5491138/

Additional information of El Mondo:
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Objectives:
Do overweight and obese adults benefit from n-3 PUFA supplements?

Study design:
This review article included a total of 11 RCTs involving 617 participants.

Results and conclusions:
The investigators found a statistically non-significant difference in weight loss between n-3 PUFA supplements and placebo [WMD = 0.00, 95% CI = -0.42 to 0.43, p = 0.99].

The investigators found n-3 PUFA supplements was superior to placebo in reducing serum triglyceride levels [Std MD = -0.59, 95% CI = -0.93 to -0.25, p = 0.0007].

The investigators found a significant reduction in waist circumference for n-3 PUFA group [WMD = -0.53, 95% CI = -0.90 to -0.16, p = 0.005].

The investigators found no significant differences in body mass index, total serum levels of cholesterol, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol and fasting glucose levels between n-3 PUFA supplements and placebo.

The investigators concluded that n-3 PUFA supplements reduce waist circumference and triglyceride levels in overweight and obese adults. However, large-scale, well-designed RCTs are needed to further address this issue.

Original title:
Efficacy of Omega-3 Polyunsaturated Fatty Acids Supplementation in Managing Overweight and Obesity: A Meta-Analysis of Randomized Clinical Trials by Zhang YY, Liu W, […], Tian HM.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28112774

Additional information of El Mondo:
Find more information/studies on overweight, n-3 PUFA and cholesterol right here.  

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Objectives:
The effects of green tea on lipid metabolism were inconsistent. Therefore, this review article (meta-analysis) has been conducted.

Have tea consumption beneficial effects on lipid metabolism?

Study design:
This review article included 21 RCTs studying 1,704 overweight or obese subjects.

Results and conclusions:
The investigators found that green tea consumption significantly decreased plasma total cholesterol with 3.38 mg/dL [WMD = -3.38 mg/dL, 95% CI = -6.42 to -0.33 mg/dL] in overweight or obese people.

The investigators found that green tea consumption significantly decreased plasma LDL cholesterol (bad cholesterol) with 5.29 mg/dL [WMD = -5.29 mg/dL,95% CI = -7.92 to -2.66 mg/dL] in overweight or obese people.

The investigators found that green tea consumption, however, showed no effect on plasma triglyceride and HDL cholesterol levels (good cholesterol) in overweight or obese people with a relatively high heterogeneity.

The investigators concluded that drinking green tea lowers plasma total cholesterol and LDL cholesterol levels in overweight or obese people. Nevertheless, green tea's effect on plasma triglyceride and HDL cholesterol levels must be further evaluated by additional high-quality and large-scale RCTs.

Original title:
Effects of green tea on lipid metabolism in overweight or obese people: A meta-analysis of randomized controlled trials by Fen Y, Hui D, [...], Fu Er L.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28636182

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

Objectives:
What is the relationship between intake of 12 major food groups and risk of type 2 diabetes (T2D)?

Study design:
This review article included prospective cohort studies.
The 12 major food groups are whole grains, refined grains, vegetables, fruits, nuts, legumes, eggs, dairy, fish, red meat, processed meat and sugar-sweetened beverages (SSB).

The meta-evidence was graded "low" for legumes and nuts; "moderate" for refined grains, vegetables, fruit, eggs, dairy and fish; and "high" for processed meat, red meat, whole grains and sugar-sweetened beverages.

Results and conclusions:
The investigators found 6 out of the 12 food-groups showed a significant relation with risk of type 2 diabetes; 3 of them a decrease of risk with increasing consumption (whole grains, fruits and dairy) and 3 an increase of risk with increasing consumption (red meat, processed meat and sugar-sweetened beverages) in the linear dose-response meta-analysis.

The investigators found evidence of a non-linear relationship between fruits, vegetables, processed meat, whole grains and sugar-sweetened beverages and type 2 diabetes risk.

The investigators found optimal consumption of risk-decreasing foods resulted in a 42% reduction and consumption of risk-increasing foods was associated with a threefold type 2 diabetes risk, compared to non-consumption.

The meta-evidence was graded "low" for legumes and nuts; "moderate" for refined grains, vegetables, fruit, eggs, dairy and fish; and "high" for processed meat, red meat, whole grains, and sugar-sweetened beverages. Among the investigated food groups, selecting specific optimal intakes can lead to a considerable change in risk of type 2 diabetes.

The investigators concluded that a higher consumption of whole grains, fruits and dairy products reduces type 2 diabetes risk, while a higher consumption of red meat, processed meat and sugar-sweetened beverages increases type 2 diabetes risk.

Original title:
Food groups and risk of type 2 diabetes mellitus: a systematic review and meta-analysis of prospective studies by Schwingshackl L, Hoffmann G, […], Boeing H.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28397016

Additional information of El Mondo:
Find more information/studies on consumption of meat, fruit, dairy products and nuts and type 2 diabetes right here.

Objectives:
Olive oil (OO) as food is composed mainly of fatty acids and bioactive compounds depending from the extraction method. Both had been discussed as health promoting with still open questions. Therefore, this meta-analysis (systematic review) has been conducted.

Does olive oil intake reduce risk of type 2 diabetes?

Study design:
This review article included 4 cohort studies including 15,784 type 2 diabetes cases and 29 intervention trials.

Results and conclusions:
The investigators found the highest olive oil intake category showed a 16% reduced risk of type 2 diabetes [RR = 0.84, 95% CI = 0.77, 0.92) compared with the lowest. The reduced risk was significant.

The investigators found evidence for a nonlinear relationship between olive oil intake and the reduced risk of type 2 diabetes.

The investigators found in patients with type 2 diabetes that olive oil supplementation resulted in a significantly more pronounced reduction in HbA1c [MD = -0.27%, 95% CI = -0.37 to -0.17] and fasting plasma glucose [MD = -0.44 mmol/L, 95% CI = -0.66 to -0.22] as compared with the control groups.

The investigators concluded that the intake of olive oil is beneficial for the prevention and management of type 2 diabetes. This conclusion regards olive oil as food and might not been valid for single components comprising this food.

Original title:
Olive oil in the prevention and management of type 2 diabetes mellitus: a systematic review and meta-analysis of cohort studies and intervention trials by Schwingshackl L, Lampousi AM, […], Boeing H1.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28394365

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

Objectives:
Epidemiological studies have presented inconsistent evidence of the correlation between a fish-oriented dietary intake (FDI) and the risk of cognitive decline. Therefore, this meta-analysis (review article) has been conducted.

Does a fish-oriented dietary intake reduce risk of cognitive decline?

Study design:
This review article included 9 cohort studies containing 28,754 subjects.
Limited evidence involving heterogeneity was found within subgroups or across studies.

Results and conclusions:
The investigators found when comparing the highest versus lowest categories of fish consumption a significant reduced risk of 20% [RR = 0.80, 95% CI = 0.65-0.97] for dementia of Alzheimer type (DAT).

The investigators found the dose-response synthesized data indicated that a 100-g/week increase in fish intake reduced the risk of dementia of Alzheimer type by an additional 12% [RR = 0.88, 95% CI = 0.79-0.99].

The investigators found that the reduced risk of dementia of all causes (DAC) and mild cognitive impairment (MCI) was non-significant.

The investigators concluded that a higher intake of fish, at least 100-g/week is correlated with a reduced risk of dementia of Alzheimer type.

Original title:
An exploration of the role of a fish-oriented diet in cognitive decline: a systematic review of the literature by Zeng LF, Cao Y, […], Wang NS.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28418899

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

Objectives:
Nutrition therapy is an integral part of self-management education in patients with type 2 diabetes. Carbohydrates with a low glycemic index are recommended, but the ideal amount of carbohydrate in the diet is unclear. Therefore, this meta-analysis (systematic review) has been conducted.

Has carbohydrate restriction (below 45 En% carbohydrate) beneficial effects on glycemic control in type 2 diabetes?

Study design:
This review article included 10 RCTs. In total, 1,376 subjects with type 2 diabetes were included in this analysis. Forty-nine percent were male and the average age was 58 years. The majority were obese; mean BMI ranged from 26 kg/m² in an Asian population to 37 kg/m² in an American population.

The duration of the intervention varied from 3 to 24 months.

The average predefined targets for the assigned carbohydrate restriction were 25 En% (range 14-40 En%). The average reported intake was 30 En% (range 14-45 En%) after 3 or 6 months of intervention and 38 En% (range 27-45 En%) at 1 year (5 trials).

Results and conclusions:
The investigators found following a carbohydrate diet of 30 En% (range 14-45 En%) during 3 to 6 months significantly reduced HbA1c level of patients with type 2 diabetes with 0.34% [95% CI = 0.06 to 0.63] compared with a diet of 45-60 En% carbohydrate (high-carbohydrate diet).
Owing to heterogeneity, however, the quality of the evidence for this is only moderate. However, at 1 year or later, HbA1c level (seven trials included) was similar in the two groups.

The investigators found the greater the carbohydrate restriction, the greater the glucose-lowering effect [R = -0.85, p 0.01].

The investigators found the effect of the 2 types of diet on BMI/body weight, LDL cholesterol, QoL and attrition rate was similar throughout interventions.

The investigators concluded that carbohydrate restriction (below 45 En% carbohydrate) has a greater effect on glycemic control in type 2 diabetes than an high-carbohydrate diet in the short term. The magnitude of the effect was correlated to the carbohydrate intake, the greater the restriction, the greater glucose lowering, a relationship that has not been demonstrated earlier. However, in the long term, the glucose-lowering effect of high-carbohydrate diet (HCD) and low-carbohydrate diets (LCD) was similar.

Original title:
Systematic review and meta-analysis of dietary carbohydrate restriction in patients with type 2 diabetes by Snorgaard O, Poulsen GM, [...], Astrup A.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5337734/

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

Objectives:
Controversy persists regarding the effect of mixtures of conjugated linoleic acids (c9,t11- and t12,c10-CLA) in fasting blood glucose (FBG) and waist circumference (WC) in humans. Therefore, this review article (meta-analysis) has been conducted.

Does CLA reduce fasting blood glucose (FBG) and waist circumference (WC) in humans?

Study design:
This review article included 32 randomized clinical trials.

Results and conclusions:
The investigators found subgroup analysis showed that taking CLA supplement did not significantly influence fasting blood glucose [SMD = 0.075 mg/dL, 95% CI = -0.099 to 0.249, p = 0.399].

The investigators found subgroup analysis showed that taking CLA supplement reduced non-significantly waist circumference with 0.149cm [SMD = -0.149cm, 95% CI = -0.522 to 0.225, p = 0.435].

The investigators found foods enriched in CLA also showed no significant effect on fasting blood glucose [SMD = 0.126 mg/dL, 95% CI = -0.100 to 0.352, p = 0.274].

The investigators found foods enriched in CLA also showed no significant effect on waist circumference [SMD = -0.233cm, 95% CI = -0.625 to 0.159, p = 0.244].

The investigators concluded that c9,t11- and t12,c10-CLA administered as a supplement or used to enrich foods does not reduce fasting blood glucose (FBG) and waist circumference (WC) in humans.

Original title:
Effect of conjugated linoleic acid as a supplement or enrichment in foods on blood glucose and waist circumference in humans: A meta-analysis by Rahbar AR, Ostvar A, […], Rahbar A.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28176632

Additional information of El Mondo:
Find more information/studies on overweight and fat consumption right here.
Overweight people often have higher fasting blood glucose (FBG) and greater waist circumference (WC).

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Conjugated linoleic acids (CLA) are a family of isomers of linoleic acid found mostly in meat and dairy products derived from ruminants. An average daily diet supplies 15-174mg of conjugated linoleic acid.

Chemical structures of CLA.

Objectives:
Randomised controlled trials (RCTs) have observed contrasting results on the effects of vitamin C on circulating biomarkers of glycaemic and insulin regulation. Therefore, this meta-analysis (systematic review) has been conducted.

Has vitamin C supplementation a favorable effect on circulating biomarkers of glycaemic and insulin regulation?

Study design:
This review article included 22 RCTs with 937 participants.

Results and conclusions:
The investigators found overall, vitamin C supplementation did not modify glucose, HbA1c and insulin concentrations.

The investigators found, however, subgroup analyses showed that vitamin C supplementation significantly reduced glucose concentrations with 0.44 mmol/L [95% CI = -0.81 to -0.07, p =0.01] in patients with type 2 diabetes and in interventions with a duration greater than 30 days [-0.53%, 95% CI = -0.79 to -0.10, p = 0.02].

The investigators found vitamin C administration had greater effects on fasting [-13.63 pmol/L, 95% CI = -22.73 to -4.54, p 0.01] compared to postprandial insulin concentration. However, meta-regression analyses showed that age was a modifier of the effect of vitamin C on insulin concentration.

The investigators found the effect size of vitamin C supplementation was associated with baseline BMI and plasma glucose levels and with the duration of the intervention.

The investigators concluded vitamin C supplementation has greater reduction in glucose concentrations in patients with type 2 diabetes, older individuals and with more prolonged supplementation (greater than 30 days). Personalized interventions with vitamin C may represent a feasible future strategy to enhance benefits and efficacy of interventions. Nevertheless, results need to be interpreted cautiously due to limitations in the primary studies.

Original title:
Effects of vitamin C supplementation on glycaemic control: a systematic review and meta-analysis of randomised controlled trials by Ashor AW, Werner AD, […], Siervo M.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28294172

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

Objectives:
Does magnesium supplementation reduce risk of cardiovascular disease among diabetic subjects?

Study design:
This review article included RCTs.

Results and conclusions:
The investigators found magnesium supplementation significantly improved fasting plasma glucose with 4.641 mg/dL [WMD = -4.641 mg/dL, 95% CI = -7.602 to -1.680, p = 0.002]. A more beneficial effect of magnesium supplementation was observed in diabetic subjects with hypomagnesaemia.

The investigators found magnesium supplementation significantly improved high-density lipoprotein (HDL or good cholesterol) with 3.197 mg/dL [WMD = 3.197 mg/dL, 95% CI = 1.455 to 4.938, p 0.001]. A more beneficial effect of magnesium supplementation was observed in diabetic subjects with hypomagnesaemia.

The investigators found magnesium supplementation significantly improved low-density lipoprotein (LDL or bad cholesterol) with 10.668 mg/dL [WMD = -10.668 mg/dL, 95% CI = -19.108 to -2.228, p = 0.013]. A more beneficial effect of magnesium supplementation was observed in diabetic subjects with hypomagnesaemia.

The investigators found magnesium supplementation significantly improved plasma triglycerides with 15.323 mg/dL [WMD = -15.323 mg/dL, 95% CI = -28.821 to -1.826, p = 0.026]. A more beneficial effect of magnesium supplementation was observed in diabetic subjects with hypomagnesaemia.

The investigators found magnesium supplementation significantly improved systolic blood pressure with 3.056 mmHg [WMD = 3.056 mmHg, 95% CI = -5.509 to -0.603, p = 0.015]. A more beneficial effect of magnesium supplementation was observed in diabetic subjects with hypomagnesaemia.

The investigators concluded magnesium supplementation has a favourable effect on risk factors of cardiovascular diseases. Although future large RCTs are needed for making robust guidelines for clinical practice.

Original title:
Effect of magnesium supplementation on type 2 diabetes associated cardiovascular risk factors: a systematic review and meta-analysis by Verma H and Garg R.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28150351

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Objectives:
The conclusions from epidemiological studies are controversial between apple and pear consumption and type 2 diabetes mellitus (T2DM) risk. Therefore, this meta-analysis (systematic review) has been conducted.

Study design:
This review article included a total of 5 independent prospective cohort studies with 14,120 T2DM incident cases among 228,315 participants.

Results and conclusions:
The investigators found consumption of apples and pears was associated with 18% reduction in type 2 diabetes mellitus risk [multivariate-adjusted relative risk = 0.82, 95% CI = 0.75-0.88, I2 = 0.00%] when comparing the highest versus lowest category.

The investigators found dose-response analysis showed that one serving per week increment of apple and pear consumption was associated with a 3% [95% CI = 0.96-0.98, p for trend 0.001] reduction in type 2 diabetes mellitus risk.

The investigators concluded a higher consumption of apples and pears; at least one serving per week reduces type 2 diabetes mellitus risk.

Original title:
Apple and pear consumption and type 2 diabetes mellitus risk: a meta-analysis of prospective cohort studies by Guo XF, Yang B, […], Li D.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28186516

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

The standard serving size is a 1/2 cup of sliced fruit. A medium pear produces approximately 1 cup of fruit; so an average medium pear equals two fruit servings.
1 small apple = 1 serving.
 

Objectives:
The association between serum folate and vitamin B12 levels and the risk of diabetic peripheral neuropathy (DPN) remains unclear. Therefore, this review article (meta-analysis) has been conducted.

Do reduced serum levels of folate and vitamin B12 increase peripheral neuropathy risk among patients with type 2 diabetes?

Study design:
This review article included 16 studies of serum folate levels (1190 patients with diabetic peripheral neuropathy and 1501 patients without diabetic peripheral neuropathy) and 18 studies of serum vitamin B12 levels (1239 patients with diabetic peripheral neuropathy and 1562 patients without diabetic peripheral neuropathy) in patients with type 2 diabetes mellitus (T2DM).

Results and conclusions:
The investigators found reduced serum levels of folate in patients with type 2 diabetes and diabetic peripheral neuropathy compared with patients with type 2 diabetes but without diabetic peripheral neuropathy [WMD = -1.64, 95% CI = -2.46 to -0.81].
A subgroup analysis confirmed this association in the Chinese population, but not in the Caucasian and mixed populations.

The investigators found reduced serum levels of vitamin B12 in patients with type 2 diabetes and diabetic peripheral neuropathy compared with patients with type 2 diabetes but without diabetic peripheral neuropathy [WMD = -70.86, 95% CI = -101.55 to -40.17].
A subgroup analysis confirmed this association in the Chinese population, but not in the Caucasian and mixed populations.

The investigators concluded reduced serum levels of folate and vitamin B12 increase peripheral neuropathy risk among patients with type 2 diabetes. These findings support the need for further controlled studies in defined patient populations and the importance of monitoring serum folate and vitamin B12 levels in patients with type 2 diabetes.

Original title:
Serum folate, vitamin B12 levels and diabetic peripheral neuropathy in type 2 diabetes: A meta-analysis by Wang D, Zhai JX and Liu DW.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28081987

Additional information of El Mondo:
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Diabetic peripheral neuropathy is a long-term complication of diabetes. Exposure to high blood glucose levels over an extended period of time causes damage to the peripheral nerves; the nerves that go to the arms, hands, legs and feet. It is one of many complications associated with diabetes, with nearly 60 percent of diabetics having some form of nerve damage.