Nutrition and health

Objectives:
What are the cardiovascular benefits of indiscriminate supplementation of omega-3 supplementation?

Study design:
This review article included 8 RCTs.

Results and conclusions:
The investigators found omega-3 supplementation significantly resulted in a 8% decrease of the risk of cardiac death, unless the patients are treated by statins.

The investigators found omega-3 supplementation prolonged quality adjusted life years by about a month. Old people gained less, whereas diabetes mellitus type 2 patients and people with history of cardiovascular events gained more.

The investigators concluded omega-3 supplementation decreases risk of cardiac death, unless the patients are treated by statins.

Original title:
The cardiovascular benefits of indiscriminate supplementation of omega-3 fatty acids; meta-analysis and decision-making approach by Leshno M, Goldbourt U, [...], Lichtenberg D.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29171335

Additional information of El Mondo:
Find more information/studies on omega-3 fatty acids and cardiovascular diseases right here.

Objectives:
Beetroot is considered a complementary treatment for hypertension because of its high content of inorganic NO3.

The aim of this meta-analysis (review article) is to clarify several aspects of beetroot juice supplementation on systolic blood pressure (SBP) and diastolic blood pressure (DBP).

Study design:
This review article included 22 RCTs with a total of 47 intervention (n = 650) and 43 control (n = 598) groups.

Results and conclusions:
The investigators found overall, systolic blood pressure [-3.55 mmHg, 95% CI = -4.55 to -2.54 mmHg] and diastolic blood pressure [-1.32 mmHg, 95% CI = -1.97 to -0.68 mmHg] were significantly lower in the beetroot juice-supplemented groups than in the control groups.

The investigators found the mean difference of systolic blood pressure was larger between beetroot juice-supplemented and control groups in the longer than in the shorter (≥14 compared with 14 days) study durations [-5.11 compared with -2.67 mmHg].

The investigators found the mean difference of systolic blood pressure was larger between beetroot juice-supplemented and control groups in the highest compared with the lowest (500 compared with 70 and 140 mL/d] doses of beetroot juice [-4.78 compared with -2.37 mmHg].

The investigators found a positive correlation between beetroot juice doses and the mean differences of blood pressures.

The investigators found a smaller effect size of blood pressures after supplementation with higher NO3 (milligrams per 100 mL beetroot juice).

The investigators found a weak effect size in a meta-analysis of trials that used NO3-depleted beetroot juice as a placebo compared with other interventions [-3.09 compared with -4.51 mmHg for systolic blood pressure and -0.81 compared with -2.01 mmHg for diastolic blood pressure].

The investigators concluded beetroot juice supplementation, particularly 500 mL/d beetroot juice during at least 14 days, reduces blood pressure.

Original title:
The Nitrate-Independent Blood Pressure-Lowering Effect of Beetroot Juice: A Systematic Review and Meta-Analysis by Bahadoran Z, Mirmiran P, […], Ghasemi A.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29141968

Additional information of El Mondo:
Find more information/studies on fruit, hypertension prevention and cardiovascular diseases right here.

Objectives:
What is the relationship of the intake of whole grains, refined grains, vegetables, fruits, nuts, legumes, eggs, dairy, fish, red meat, processed meat and sugar-sweetened beverages (SSBs) and the risk of hypertension?

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

Results and conclusions:
The investigators found in dose-response meta-analysis of 4 studies with 28,069 incident hypertension cases, a significantly reduced risk of 8% [RR = 0.92, 95% CI = 0.87-0.98, I2 = 88%, p 0.0001] for hypertension for 30 g/day whole grains. Significant means that there is an association with a 95% confidence.
The reduced risk was highest (15%) at 90 g/day whole grains.

The investigators found in dose-response meta-analysis of 6 studies, a significantly reduced risk of 3% [RR = 0.97, 95% CI = 0.96-0.99, I2 = 64%, p = 0.02] for hypertension for 100 g/day fruits.
The strongest risk reduction was 7% at 300 g/day fruits.

The investigators found in dose-response meta-analysis of 9 studies with 31,509 incident hypertension cases, a significantly reduced risk of 5% [RR = 0.95, 95% CI = 0.94-0.97, I2 = 0%, p = 0.50] for hypertension for 200 g/day dairy products.
The strongest risk reduction was 15% at 800 g/day dairy products.

The investigators found in dose-response meta-analysis of 7 studies with 97,745 incident hypertension cases, a significantly increased risk of 14% [RR = 1.14, 95% CI = 1.02-1.28, I2 = 88%, p 0.001] for hypertension for 100 g/day red meat.
The increased risk was highest (40%) at 200 g/day red meat.

The investigators found in dose-response meta-analysis of 4 studies, a significantly increased risk of 12% [RR = 1.12, 95% CI = 1.00-1.26, I2 = 82%, p 0.001] for hypertension for 50 g/day processed meat.

The investigators found in dose-response meta-analysis of 4 studies, a significantly increased risk of 7% [RR = 1.07, 95% CI = 1.04-1.10, I2 = 64%, p = 0.04] for hypertension for 250 mL/day sugar-sweetened beverages.
The increased risk was highest (13%) at 450 mL/day sugar-sweetened beverages.

The investigators found compared with nonconsumption, an intake of 2 servings red meat/d [170g, RR = 1.35], 1 serving processed meat/d [35g, RR = 1.07], 1 serving fish/d [100g, RR = 1.08] and 2 servings sugar-sweetened beverages/d [500mL, RR = 1.14 was associated with a 78% increased risk of hypertension. On the other hand, a risk reduction by 44% would be achieved by not consuming these foods (red meat, processed meat, fish and sugar-sweetened beverages).

The investigators concluded a daily dietary intake of 30g whole grains, 100g fruits, 200g dairy products reduce risk of hypertension, whereas a daily dietary intake of 100g red meat, 50g processed meat, and 250mL sugar-sweetened beverages increase risk of hypertension. These findings need to be seen under the light of very-low to low credibility of meta-evidence. However, the findings support the current dietary recommendations in the primary prevention of hypertension.

Original title:
Food Groups and Risk of Hypertension: A Systematic Review and Dose-Response Meta-Analysis of Prospective Studies by Schwingshackl L, Schwedhelm C, […], Boeing H.

Link:
http://advances.nutrition.org/content/8/6/793.long

Additional information of El Mondo:
Find more information/studies on different food groups, hypertension prevention and cardiovascular diseases right here.

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

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

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

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

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

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

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

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

Additional information of El Mondo:
Find more information/studies on chronic disease and protein right here.
A protein intake of 0.8 g/kg/day usually corresponds to a diet with 11 En% protein.
A protein intake of 0.4 g/kg/day usually corresponds to a diet with 5.5 En% protein.
A diet with 5.5 En% protein is a diet with a lot of products with 5.5 En% protein. Check here which products contain 5.5 En% protein.
 

Objectives:
Previous meta‐analyses on meat intake and risk of stroke did not report the effect of white meat (poultry meat, excluding fish) and did not examine stroke incidence and mortality separately. Therefore, this review article (meta-analysis) has been conducted.

What is the relationship of total (red and processed meat), red (unprocessed or fresh red meat) and processed (processed red meat) meat consumption along with white meat on risk of stroke incidence and mortality disease risk?

Study design:
This review article included 15 prospective cohort studies (254,742 participants with 9,522 stroke incidents and 487,150 participants with 12,999 cases of stroke mortality). The follow-up duration varied from 5.5 to 26 years.

There was no significant publication bias based on the Egger test except that the evaluation of total meat with stroke incidence reached the significance threshold.

The average score for study quality assessed by the Newcastle‐Ottawa Scale was 7.29 (range 7-8) for studies on meat consumption and stroke incidence and 6.87 (range 6-8) for those on stroke mortality.

Results and conclusions:
The investigators found that a high total meat (red and processed meat) consumption resulted in a significantly higher risk of 18% [pooled relative risk = 1.18, 95% CI = 1.09-1.28, I2 = 0%] for total stroke incidence. Significantly means that there is an association with a 95% confidence.

The investigators found that a high red meat consumption resulted in a significantly higher risk of 11% [pooled relative risk = 1.11, 95% CI = 1.03-1.20, I2 = 0%] for total stroke incidence.

The investigators found that a high processed meat consumption resulted in a significantly higher risk of 17% [pooled relative risk = 1.17, 95% CI = 1.08-1.25, I2 = 0%] for total stroke incidence.

The investigators found that a high white meat consumption resulted in a significantly lower risk of 13% [pooled relative risk = 0.87, 95% CI = 0.78-0.97, I2 = 0%] for total stroke incidence.

The investigators found, however, no significant associations between consumption of total [RR = 0.97, 95% CI = 0.85-1.11, I2 = 0%] or red meat [RR = 0.87, 95% CI = 0.64-1.18, I2 = 70.9%] and stroke mortality. No significant associations because RR of 1 was found in the 95% CI of 0.64 to 1.18. RR of 1 means no risk/association.

The investigators found that a high total meat consumption was associated with an increased risk of 41% for hemorrhagic stroke [RR = 1.41, 95% CI = 1.08-1.84, I2 = 0%], but no significant association was found between a high total meat consumption and ischemic stroke [RR = 1.16, 95% CI = 0.94-1.43, I2 = 40.6%].

The investigators found a positive association between total meat consumption and stroke incidence, regardless of sex, number of cases and follow‐up duration.

The investigators found when stratified by adjustment variables, studies that adjusted for family history of myocardial infarction, fruit and vegetable intake and use of aspirin showed a statistically significant relationship between total meat intake and risk of stroke compared with other studies that did not include those as adjustment variables.

The investigators found that a high red meat consumption was associated with an increased risk of 24% for ischemic stroke [RR = 1.24, 95% CI = 1.05-1.46, I2 = 17.7%], but no significant association was found between a high red meat consumption and hemorrhagic stroke [RR = 1.11, 95% CI = 0.89-1.38, I2 = 0%].

The investigators found that a high processed meat consumption was linked to neither ischemic [RR = 1.10, 95% CI = 0.96-1.27, I2 = 11.4%] nor hemorrhagic stroke [RR = 1.19, 95% CI = 0.95-1.49, I2 = 8.10%].

The investigators concluded that higher consumption of red or processed meat is associated with an increase in the risk of stroke, while higher intake of white meat is related to a reduction in stroke incidence. Therefore, recommendations for replacing proportions of red and processed meat to white meat for the prevention of stroke may be considered in clinical practice.

Original title:
Role of Total, Red, Processed, and White Meat Consumption in Stroke Incidence and Mortality: A Systematic Review and Meta-Analysis of Prospective Cohort Studies by Kim K, Hyeon J, […], Park SM.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5634267/

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

Objectives:
Dietary fiber intake, especially viscous soluble fiber, has been established as a means to reduce cardiometabolic risk factors. Whether this is true for blood pressure remains controversial. Therefore, this review article (meta-analysis) has been conducted.

Does viscous soluble fiber supplementation reduce cardiovascular disease risk?

Study design:
This review article included 22 (n = 1430) and 21 RCTs (N = 1343) for systolic blood pressure (SBP) and diastolic blood pressure (DBP), respectively.

5 types of viscous fiber supplementation were β-glucan from oats and barley, guar gum, konjac, pectin and psyllium.

Results and conclusions:
The investigators found viscous soluble fiber supplementation significantly reduced systolic blood pressure [MD = -1.59 mmHg, 95% CI = -2.72 to -0.46, I2 = 72%, p 0.01] and diastolic blood pressure [MD = -0.39 mmHg, 95% CI = -0.76 to -0.01, I2 = 67%, p 0.01] at a median dose of 8.7 g/day (1.45-30 g/day) over a median follow-up of 7-weeks.

The investigators found within the five fiber types, systolic blood pressure reductions were observed only for supplementation using psyllium fiber [MD = -2.39 mmHg, 95% CI = -4.62 to -0.17].

The investigators concluded 8.7 g/day viscous soluble fiber supplementation, particularly psyllium fiber during 7 weeks reduces systolic blood pressure (SBP) and diastolic blood pressure (DBP). Therefore, inclusion of viscous fiber to habitual diets may have additional value in reducing cardiovascular risk via improvement in blood pressure.

Original title:
The effect of viscous soluble fiber on blood pressure: A systematic review and meta-analysis of randomized controlled trials by Khan K, Jovanovski E, […], Vuksan V.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29153856

Additional information of El Mondo:
Find more information/studies on fiber consumption, hypertension and cardiovascular diseases right here.

Objectives:
Elevated cholesterol has been linked to cardiovascular disease in adults and preclinical markers of atherosclerosis in children, thus reducing saturated (SFA) and trans-fatty acids (TFA) intake from an early age may help to reduce cholesterol and the risk of cardiovascular disease later in life. The World Health Organization (WHO) is currently updating its guidance on SFA and TFA intake in adults and children. Therefore, this review article (meta-analysis) has been conducted.

Does a diet with low saturated fatty acids reduce cholesterol and blood pressure in children and adolescents between 2 to 19 years of age?

Study design:
This review article included 8 RCTs (5 trials had a duration of 1 year and 3 had a duration of ≥ 1year with a total of 2,430 individual children and adolescents between 2 to 19 years of age) and 3 cohort studies.

Minimum duration was 13 days for RCTs and one year for cohort studies.

Saturated fatty acids intake was assessed using 24hr dietary recalls in 4 trials, 3-day diet records in 3 trials and food frequency questionnaires and/or checklists in 2 trials.

No trials were identified meeting the inclusion criteria for trans-fatty acids.

Publication bias was not assessed as the number of trials found was not sufficient to conduct funnel plot analyses for any outcome measure.

Results and conclusions:
The investigators found compared with control diets, there was a highly statistically significant effect of reduced saturated fatty acids intake on total cholesterol [MD = -0.16 mmol/L, 95% CI = -0.25 to -0.07, I2 = 64%], LDL cholesterol [MD = -0.13 mmol/L, 95% CI = -0.22 to -0.03, I2 = 77%] and diastolic blood pressure [MD = -1.45 mmol/L, 95% CI = -2.34 to -0.56].
The effects on cholesterol were greatest among those in which saturated fatty acids was replaced primarily with PUFA or MUFA and when the intervention group achieved a reduction in saturated fatty acids to below 10% of total energy intake.

The investigators found subgroup analysis of the effect of the initial lipid status of the participants showed a significantly different effect of saturated fatty acids reduction on total cholesterol [p = 0.05] between trials involving normolipidaemic/mixed status children [MD -0.21 mmol/L, 95% CI = -0.31 to -0.12] vs hyperlipidaemic children [MD = -0.08 mmol/L, 95% CI = -0.15 to -0.01].

The investigators found subgroup analysis of the effect of the initial lipid status of the participants showed the reduction in LDL cholesterol (bad cholesterol) was greater among the trials conducted in normolipidaemic/mixed status [MD -0.21 mmol/L, 95% CI = -0.30 to -0.13] vs hyperlipidaemic children [MD = -0.02 mmol/L, 95% CI = -0.14 to -0.11].

The investigators found there were no significant associations observed for HDL cholesterol (good cholesterol), triglycerides or apolipoproteins A1 or B.

The investigators found there were no significant associations observed between reduced saturated fatty acids intake and weight, height, body mass index (BMI) or waist circumference.

The investigators found there was no evidence of adverse effects of reducing saturated fatty acids intake in children on micronutrient intakes, cognitive development or sexual maturation in the small number of trials reporting these outcomes.  

The investigators concluded a diet with low saturated fatty acids reduces total cholesterol, LDL cholesterol and diastolic blood pressure in children and adolescents between 2 to 19 years of age without evidence of adverse effects on growth and development. The greatest effect on cholesterol occurred when saturated fatty acids was replaced with PUFA or a mixture of PUFA/MUFA and when saturated fatty acids intake was less than 10% of total energy intake. Therefore, dietary guidelines for children and adolescents should continue to recommend diets low in saturated fat.

Original title:
Health effects of saturated and trans-fatty acid intake in children and adolescents: Systematic review and meta-analysis by Morenga L and Montez JM.

Link:
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0186672

Additional information of El Mondo:
Find more information/studies on fat consumption, body mass index, hypertension, cholesterol and cardiovascular diseases right here.  

A diet with saturated fatty acids intake less than 10% of total energy intake is a diet with less than 10 En% saturated fat.
A diet with less than 10 En% saturated fat is a diet that is largely made up of meals/products with less than 10 En% saturated fat. Practically, this means that all meals/products that you eat on a daily basis should on average contain less than 10 En% saturated fat. Check here which products contain less than 10 En% saturated fat.

Objectives:
Despite growing evidence for food-based dietary patterns' potential to reduce cardiovascular disease risk, knowledge about the amounts of food associated with the greatest change in risk of specific cardiovascular outcomes and about the quality of meta-evidence is limited. Therefore, this review article (meta-analysis) has been conducted.

Which food-based dietary patterns reduce risk of cardiovascular diseases, such as coronary heart disease (CHD), stroke and heart failure (HF)?

Study design:
This review article included 123 prospective cohort studies.

Results and conclusions:
The investigators found whole grains significantly reduced risk of coronary heart disease with 5% [RR = 0.95, 95% CI = 0.92-0.98]. Significantly means that there is an association with a 95% confidence.

The investigators found whole grains significantly reduced risk of heart failure with 4% [RR = 0.96, 95% CI = 0.95-0.97]. Significantly because RR of 1 was not found in the 95% CI of 0.95 to 0.97. RR of 1 means no risk/association.

The investigators found vegetables significantly reduced risk of coronary heart disease with 3% [RR = 0.97, 95% CI = 0.96-0.99]. Significantly means it can be said with a 95% confidence that a intake of vegetables really decreased the risk of getting coronary heart disease with 3%.  

The investigators found fruits significantly reduced risk of coronary heart disease with 6% [RR = 0.94, 95% CI = 0.90-0.97].

The investigators found vegetables significantly reduced risk of stroke with 8% [RR = 0.92, 95% CI = 0.86-0.98].

The investigators found fruits significantly reduced risk of stroke with 10% [RR = 0.90, 95% CI = 0.84-0.97].

The investigators found nuts non-significantly reduced risk of coronary heart disease with 33% [RR = 0.67, 95% CI = 0.43-1.05]. Non-significantly means that there is no association with a 95% confidence.

The investigators found fish consumption significantly reduced risk of stroke with 14% [RR = 0.86, 95% CI = 0.75-0.99].

The investigators found fish consumption significantly reduced risk of heart failure with 20% [RR = 0.80, 95% CI = 0.67-0.95].

The investigators found egg significantly increased risk of heart failure with 16% [RR = 1.16, 95% CI = 1.03-1.31].

The investigators found red meat significantly increased risk of coronary heart disease with 15% [RR = 1.15, 95% CI = 1.08-1.23].

The investigators found red meat significantly increased risk of stroke with 12% [RR = 1.12, 95% CI = 1.06-1.17].

The investigators found red meat significantly increased risk of heart failure with 8% [RR = 1.08, 95% CI = 1.02-1.14].

The investigators found processed meat significantly increased risk of coronary heart disease with 27% [RR = 1.27, 95% CI = 1.09-1.49].

The investigators found processed meat significantly increased risk of stroke with 17% [RR = 1.17, 95% CI = 1.02-1.34].

The investigators found processed meat significantly increased risk of heart failure with 12% [RR = 1.12, 95% CI = 1.05-1.19].

The investigators found sugar-sweetened beverages significantly increased risk of coronary heart disease with 17% [RR = 1.17, 95% CI = 1.11-1.23].

The investigators found sugar-sweetened beverages significantly increased risk of heart failure with 7% [RR = 1.07, 95% CI = 1.02-1.12].

The investigators found sugar-sweetened beverages significantly increased risk of stroke with 8% [RR = 1.08, 95% CI = 1.05-1.12].

The investigators found there were clear indications for non-linear dose-response relationships between whole grains, fruit, nuts, dairy and red meat and coronary heart disease.

The investigators concluded there is a relationship between food-based dietary patterns and risk of cardiovascular diseases, with an increased risk for consumption of eggs, red meat, processed meat and sugar-sweetened beverages and a decreased risk for consumption of whole grains, vegetables, fruit and fish.

Original title:
Food groups and risk of coronary heart disease, stroke and heart failure: A systematic review and dose-response meta-analysis of prospective studies by Bechthold A, Boeing H, […], Schwingshackl L.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29039970

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

Objectives:
The therapeutic efficacy of coenzyme Q10 on patients with cardiac failure remains controversial. Therefore, this review article (meta-analysis) has been conducted.

Do patients with heart failure benefit from coenzyme Q10 supplements?

Study design:
This review article included a total of 14 RCTs with 1064 patients in coenzyme Q10 (treatment) group and 1085 patients in placebo (control) group.

Egger’s test results showed no significant evidence of publication bias in either endpoint.

Results and conclusions:
The investigators found compared with placebo, coenzyme Q10 supplementation significantly decreased mortality risk with 31% [RR = 0.69, 95% CI = 0.50 to 0.95, p = 0.02, I2 = 0%].

The investigators found a greater improvement in exercise capacity was established in patients who used coenzyme Q10 than in those who used placebo [SMD = 0.62, 95% CI = 0.02 to 0.30, p = 0.04, I2 = 54%].

The investigators found patients who used coenzyme Q10 and placebo associated with similar left heart ejection fraction [SMD = 0.14, 95% CI = -0.08 to 0.37, p = 0.22, I2 = 54%].

The investigators found no significant difference between coenzyme Q10 and placebo for NYHA classification [SMD = -0.70, 95% CI = -1.92 to 0.51, p = 0.26, I2 = 89%].

The investigators concluded in patients with heart failure, the administration of coenzyme Q10 results in lower mortality and improved exercise capacity compared with the effects of placebo treatment.

Original title:
Efficacy of coenzyme Q10 in patients with cardiac failure: a meta-analysis of clinical trials by Lei L and Liu Y.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5525208/

Additional information of El Mondo:
Find more information/studies on coenzyme Q10 and cardiovascular diseases right here. 

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

Do EPA and DHA supplements reduce risk of cardiovascular diseases?

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

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

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

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

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

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

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

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

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

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

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

Additional information of El Mondo:
Find more information/studies on EPA and DHA, cholesterol and cardiovascular diseases right here. 

Objectives:
Several previous meta-analyses show a consistent inverse association between nut consumption and all-cause mortality, but the associations with cause-specific mortality remain uncertain. Therefore, this meta-analysis (review article) has been conducted.

Does nut consumption reduce all-cause and cause-specific mortality?

Study design:
This review article included 18 prospective cohort studies with 81,034 deaths.

Results and conclusions:
The investigators found random-effects meta-analysis of 18 studies with 81,034 deaths showed a significant reduced risk of 19% [summary RR = 0.81, 95% CI = 0.78-0.84] for all-cause mortality for high compared with low nut consumption. This significant reduced risk was broadly consistent within subgroups according to various study and population characteristics and within sensitivity analyses that took into account potential confounders.

The investigators found random-effects meta-analysis of 17 studies with 20,381 deaths showed a significant reduced risk of 25% [summary RR = 0.75, 95% CI = 0.71-0.79] for cardiovascular mortality for high compared with low nut consumption. This significant reduced risk was broadly consistent within subgroups according to various study and population characteristics and within sensitivity analyses that took into account potential confounders.

The investigators found random-effects meta-analysis of 14 studies with 10,438 deaths showed a significant reduced risk of 27% [summary RR = 0.73, 95% CI = 0.67-0.80] for coronary heart disease mortality for high compared with low nut consumption. This significant reduced risk was broadly consistent within subgroups according to various study and population characteristics and within sensitivity analyses that took into account potential confounders.

The investigators found random-effects meta-analysis of 13 studies with 4,850 deaths showed a significant reduced risk of 18% [summary RR = 0.82, 95% CI = 0.73-0.91] for stroke mortality for high compared with low nut consumption. This significant reduced risk was broadly consistent within subgroups according to various study and population characteristics and within sensitivity analyses that took into account potential confounders.

The investigators found random-effects meta-analysis of 11 studies with 21,353 deaths showed a significant reduced risk of 13% [summary RR = 0.87, 95% CI = 0.80-0.93] for cancer mortality for high compared with low nut consumption. This significant reduced risk was broadly consistent within subgroups according to various study and population characteristics and within sensitivity analyses that took into account potential confounders.

The investigators found peanut (5 studies) and tree nut (3 studies) consumption were similarly associated with mortality risks.

The investigators found dose-response analyses suggested evidence for nonlinear associations between nut consumption and mortality [p-nonlinearity 0.001 for all outcomes except cancer mortality], with mortality risk levelling off at the consumption of about 3 servings per week (12g/day).

The investigators concluded that nut consumption is associated with reduced all-cause and cause-specific mortality, with the strongest reduction for coronary heart disease (CHD) mortality. Both tree nuts and peanuts lower mortality and most of the survival benefits could be achieved at a relative low level of nut consumption (up to 12g/day).

Original title:
Nut consumption in relation to all-cause and cause-specific mortality: a meta-analysis 18 prospective studies by Chen GC, Zhang R, [...], Qin LQ.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28875220

Additional information of El Mondo:
Find more information/studies on nut consumption, cancer, cardiovascular disease and stroke right here.
 

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

Does resveratrol supplementation reduce risk of non-communicable diseases?

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

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

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

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

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

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

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

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

Additional information of El Mondo:
Find more information/studies on flavonoids, cholesterol, blood pressure, diabetes and chronic diseases right here.

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

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

Objectives:
Anthocyanins are of interest due to their anti-oxidative and vasodilatory properties. Earlier reviews have shown that berries and other anthocyanin rich foods or extracts can improve vascular health. However, the effect of anthocyanins on vascular function has not yet been reviewed. Therefore, this review article (meta-analysis) has been conducted.

Does anthocyanin supplementation improve vascular function?

Study design:
This review article included 29 RCTs (15 were parallel and 14 were crossover designs).
Anthocyanin intakes ranged from 1 to 724 mg/day.
Most studies (n = 19) involved participants in the middle to older age group (mean age ≥ 40 years).
The number of participants that completed each study ranged from 10 to 146.
Intervention durations ranged from 1 h to 6 h in the acute studies and one week to six months in the chronic studies.

There was no publication bias.

Results and conclusions:
The investigators found compared to placebo-control, acute anthocyanin supplementation (1-8 h post consumption of anthocyanin doses between 7 and 724 mg) significantly improved FMD [SMD = 3.92%, 95% CI = 1.47 to 6.38, p = 0.002, I2 = 91.8%].
No improvements were observed in PAT-RHI [SMD = 0.08, 95% CI = -0.34 to 0.50, p = 0.71, I2 = 0%].
Collectively, (i.e., the pooling of studies using FMD and/or PAT-RHI) anthocyanins may improve vascular reactivity [overall SMD = 2.41, 95% CI = 0.91 to 3.91, p = 0.002, I2 = 92.6%].

The investigators found compared to placebo-control, acute anthocyanin supplementation (1-8 h post consumption of anthocyanin doses between 7 and 724 mg) also significantly improved arterial stiffness, using PWV [SMD = -1.27 m/s, 95% CI = -1.96 to -0.58, p = 0.000, I2 = 17.9%].

The investigators found pulse wave velocity was improved following acute anthocyanin supplementation only [SMD = -1.27 m/s, 95% CI = -1.96 to -0.58, p = 0.000, I2 = 17.8%]. 

The investigators found compared to placebo-control, chronic anthocyanin supplementation (one week to six months and used anthocyanin doses of 12 to 320 mg/day) significantly improved FMD [SMD = 0.84%, 95% CI = 0.55 to 1.12, p = 0.000, I2 = 62.5%].
Collectively (i.e., the pooling of studies using FMD and/or PAT-RHI), chronic anthocyanin supplementation may improve vascular reactivity [overall SMD = 0.77, 95% CI = 0.37 to 1.16, p = 0.000, I2 = 85.3%].

The investigators concluded that both acute and chronic anthocyanin supplementation improve vascular health, particularly with respect to vascular reactivity measured by FMD. However, more research is required to determine the optimal dosage and the long-term effects of anthocyanin consumption.

Original title:
The Effect of Anthocyanin-Rich Foods or Extracts on Vascular Function in Adults: A Systematic Review and Meta-Analysis of Randomised Controlled Trials by Fairlie-Jones L, Davison K, […], Hill AM.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5579701/

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

Objectives:
Although epidemiological studies have examined the role of chocolate in preventing cardiometabolic disease, the results remain inconsistent. Therefore, this review article (meta-analysis) has been conducted.

Does chocolate consumption reduce risk of coronary heart disease (CHD), stroke and diabetes?

Study design:
This review article included 14 prospective cohort studies, with 508,705 participants from six countries and 7,267 coronary heart disease (CHD) cases, 8,197 stroke cases and 13,271 diabetes cases.
The follow-up duration of the studies ranged from 5 to 16 years.
One serving was defined as 30g of chocolate.
The majority of chocolate consumed in the included studies was milk or dark chocolate.

Results and conclusions:
The investigators found in 6 cohort studies for the highest versus lowest intake of chocolate a significant reduced risk of 10% for coronary heart disease [pooled RR = 0.90, 95% CI = 0.82-0.97, I2 = 24.3%, p = 0.25]. Leave-one-out sensitivity analysis had no significant influence on the pooled results.

The investigators found regarding CHD subtype, a significant reduced risk of 14% [RR = 0.86, 95% CI = 0.77-0.96] for myocardial infarction.

The investigators found for studies with follow-up duration of 10 years a significant reduced risk of 28% for coronary heart disease [RR = 0.72, 95% CI = 0.57-0.92].

The investigators found for studies with follow-up duration of ≥10 years a significant reduced risk of 8% for coronary heart disease [RR = 0.92, 95% CI = 0.86-0.99].

The investigators found in dose-response meta-analysis of 5 studies a curvilinear association between chocolate consumption and risk of coronary heart disease [p for nonlinearity = 0.006].

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 6% for coronary heart disease for 1 serving (30g) chocolate per week [RR = 0.94, 95 CI = 0.90-0.99].   

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 9% for coronary heart disease for 3 servings (90g) chocolate per week [RR = 0.91, 95 CI = 0.85-0.97].   

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 11% for coronary heart disease for 7 servings (210g) chocolate per week [RR = 0.89, 95 CI = 0.83-0.95].   

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 12% for coronary heart disease for 10 servings (300g) chocolate per week [RR = 0.88, 95 CI = 0.81-0.95].   

The investigators found in 8 reports from 7 studies for the highest versus lowest level of chocolate consumption a significant reduced risk of 16% for stroke [pooled RR = 0.84, 95% CI = 0.78-0.90, I2 = 0%, p = 0.49]. The pooled risk of total stroke was not obviously modified in the sensitivity analysis by excluding one study at a time
Egger’s test suggested the presence of publication bias [p = 0.008]. However, after introducing the “trim and fill” method to adjust this bias, the overall risk estimate remained significant in favor of chocolate intake [RR = 0.86, 95% CI = 0.79-0.92].

The investigators found with regard to stroke subtypes, a significant reduced risk of 13% [RR = 0.87, 95% CI = 0.78-0.96] for cerebral infarction and a significant reduced risk of 17% [RR = 0.83, 95% CI = 0.71-0.97] for hemorrhagic stroke.

The investigators found in the stratified analysis by gender, a significant reduced risk of 13% of total stroke for male [RR = 0.87, 95% CI = 0.79-0.97] and a significant reduced risk of 16% of total stroke for female [RR = 0.84, 95% CI = 0.74-0.94].

The investigators found a significant reduced risk of 44% for studies with follow-up durations of 10 years [RR = 0.56, 95% CI = 0.37-0.85].

The investigators found a significant reduced risk of 15% for studies with follow-up durations of ≥10 years [RR = 0.85, 95% CI = 0.79-0.91].

The investigators found in 7 reports from 6 studies a nonlinear correlation between chocolate intake and risk of stroke [p for nonlinearity = 0.001].

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 9% for stroke for 1 serving chocolate per week [RR = 0.91, 95% CI = 0.86-0.97].   

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 13% for stroke for 3 servings chocolate per week [RR = 0.87, 95% CI = 0.81-0.94].   

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 15% for stroke for 7 servings chocolate per week [RR = 0.85, 95% CI = 0.76-0.93].   

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 17% for stroke for 10 servings chocolate per week [RR = 0.83, 95% CI = 0.72-0.94].   

The investigators found in 4 studies using “trim and fill” method, for the highest versus lowest intake of chocolate, a non-significant reduced risk of 8% for diabetes [pooled RR = 0.92, 95% CI = 0.78-1.08].

The investigators found in stratified analysis by sex, a significant reduced risk of 21% [RR = 0.79, 95% CI = 0.65-0.96] for men and a non-significant reduced risk of 8% [RR = 0.92, 95% CI = 0.72-1.17] for women.
Similarly, the risks of diabetes were not different between subsets of studies with follow-up durations of below or over 10 years [p for interaction = 0.51].

The investigators found in dose-response meta-analysis of 6 reports, a curvilinear association between chocolate intake and risk of diabetes [p for nonlinearity 0.001].

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 20% for diabetes for 1 serving chocolate per week [RR = 0.80, 95% CI = 0.71-0.91]. Significant means that there is an association with a 95% confidence.

The investigators found in dose-response meta-analysis, compared with no intake, a significant reduced risk of 24% for diabetes for 3 servings chocolate per week [RR = 0.76, 95% CI = 0.63-0.91]. Significant because RR of 1 was not found in the 95% CI of 0.63 to 0.91. RR of 1 means no risk/association.

The investigators found in dose-response meta-analysis, compared with no intake, a non-significant reduced risk of 17% for diabetes for 7 servings chocolate per week [RR = 0.83, 95% CI = 0.67-1.03]. Non-significant means it cannot be said with a 95% confidence that 7 servings chocolate per week really decreased the risk of diabetes with 17%.

The investigators found in dose-response meta-analysis, compared with no intake, a non-significant reduced risk of 11% for diabetes for 10 servings chocolate per week [RR = 0.89, 95% CI = 0.69-1.16].   

The investigators found in general, the dose-response pattern was J-shaped and the peak reduction in diabetes risk occurred at an intake of 2 servings/week [RR = 0.75, 95% CI = 0.63-0.89], with no protective effects observed when consuming chocolate > 6 servings/week.

The investigators concluded that chocolate consumption confers reduced risks of coronary heart disease, stroke and diabetes. Consuming chocolate in moderation (1-6 servings/week or 30-180g) may be optimal for the prevention of these burdensome diseases. However, additional large prospective studies are required to confirm the observed benefits of chocolate in populations with different characteristics and to establish the optimum frequency of chocolate intake for preventing cardiometabolic disease.

Original title:
Chocolate Consumption and Risk of Coronary Heart Disease, Stroke, and Diabetes: A Meta-Analysis of Prospective Studies by Yuan S, Li X, […], Lu J.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5537803/

Additional information of El Mondo:
Find more information/studies on chocolate, diabetes and cardiovascular diseases right here.

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

Does quercetin supplementation reduce CRP levels?

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

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

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

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

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

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

Additional information of El Mondo:
Find more information/studies on chronic disease and flavonoids right here. Quercetin is a flavonoid.

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

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

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

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

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

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

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

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

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

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

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

Objectives:
The clinical benefits of perioperative antioxidant vitamin therapy in cardiac patients remain controversial. Therefore, this review article (meta-analysis) has been conducted.

Do patients undergoing cardiac surgery benefit from perioperative antioxidant vitamin therapy?

Study design:
This review article included 12 RCTs with 1584 cardiac patients.

Results and conclusions:
The investigators found compared with placebo or no antioxidant vitamin therapy that administration of antioxidant vitamin therapy resulted in a significant reduction:
-in postoperative atrial fibrillation (POAF) [RR = 0.55, 95% CI = 0.42 to 0.73, p  0.0001];
-duration of hospital stay [MD = -0.68, 95% CI = -0.98 to -0.39, p  0.00001];
-intensive care unit length of stay [MD = -0.21, 95% CI = -0.30 to -0.12, p  0.00001] and;      
-intubation time [MD = -2.41, 95% CI = -3.83 to -0.98, p = 0.001].

The investigators also found a trend towards a decrease in postoperative complications [RR = 0.72, 95% CI = 0.48-1.08, p = 0.11] and duration of postoperative atrial fibrillation [MD = -1.950, 95% CI = -3.28 to 0.29, p = 0.10].

The investigators concluded that perioperative antioxidant vitamin therapy in patients undergoing cardiac surgery reduces the incidence of postoperative atrial fibrillation, duration of hospital stay, intensive care unit length of stay and intubation time.

Original title:
The clinical benefits of perioperative antioxidant vitamin therapy in patients undergoing cardiac surgery: a meta-analysis by Geng J, Qian J, […], Shen Z.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28645181

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

Objectives:
Studies implicate choline and betaine metabolite trimethylamine N-oxide (TMAO) in cardiovascular disease (CVD). Therefore, this review article (meta-analysis) has been conducted.

Is there an association between choline and betaine dietary intake and cardiovascular disease?

Study design:
This review article included a total of 6 prospective cohort studies comprising 18,076 incident cardiovascular disease events, 5,343 cardiovascular disease deaths among 184,010 participants.

There was no evidence for heterogeneity among studies.
Only 2 studies provided data on phosphatidylcholine and cardiovascular disease mortality.

Results and conclusions:
The investigators found in random effects meta-analysis, incident cardiovascular disease was not associated with choline [RR = 1.00, 95% CI = 0.98-1.02] or betaine [RR = 0.99, 95% CI = 0.98-1.01] dietary intake.
Results did not vary by study outcome (incident coronary heart disease, stroke, total cardiovascular disease).

The investigators found random effects meta-analysis did not support an association between choline and cardiovascular disease mortality [RR = 1.09, 95% CI = 0.89-1.35], but one study supported a positive association and there was significant heterogeneity [I2 = 84%, p 0.001].

The investigators concluded that there is no association between dietary choline/betaine intake with incident cardiovascular disease, but further research into choline and cardiovascular disease mortality are needed.

Original title:
Dietary Choline and Betaine and Risk of CVD: A Systematic Review and Meta-Analysis of Prospective Studies by Meyer KA and Shea JW.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28686188

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

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

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

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

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

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

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

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

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

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

Objectives:
Controversy exists on the association between alcohol consumption and risk of heart failure (HF). Therefore, this review article (meta-analysis) has been conducted.

Is there an association between alcohol consumption and risk of heart failure?

Study design:
This review article included a total of 13 prospective cohort studies, with 13,738 heart failure cases among 355,804 participants.

Results and conclusions:
The investigators found light alcohol drinking (0.1-7 drinks/week) significantly reduced risk of heart failure with 14% [RR = 0.86, 95% CI = 0.81-0.90]. However, there was no statistically significant association between moderate (7.1-14 drinks/week), high (14.1-28 drinks/week), or heavy (>28 drinks/week) alcohol consumption and heart failure risk.

The investigators found former drinking significantly increased risk of heart failure with 22% [RR = 1.22, 95% CI = 1.11-1.33] compared with never or occasional drinking.

The investigators concluded that light alcohol drinking (0.1-7 drinks/week) is associated with a lower risk of heart failure, while former drinking is associated with a higher risk of heart failure.

Original title:
Alcohol consumption and risk of heart failure: Meta-analysis of 13 prospective studies by Susanna C. Larsson, […], Alicja Wolk

Link:
http://www.sciencedirect.com/science/article/pii/S0261561417301681

Additional information of El Mondo:
Find more information/studies on alcohol consumption and cardiovascular diseases right here.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Additional information of El Mondo:
Find more information/studies on fat, protein, carbohydrate and fiber right here.

 

Objectives:
Low glycaemic index (GI) diets are beneficial in the management of hyperglycemia. Cardiovascular diseases are the major cause of mortality in diabetes therefore it is important to understand the effects of GI on blood lipids. Therefore, this review article has been conducted.

Does a low GI diet lower the cholesterol levels?

Study design:
This review article included 28 RCTs comparing low with high GI diets over at least 4 weeks. These 28 RCTs contained 1272 participants with studies ranged from 6 to 155 participants, one was powered on blood lipids and 3 had adequate allocation concealment.

Results and conclusions:
The investigators found that compared to high GI diet low GI diet significantly reduced total cholesterol by 0.13 mmol/L [95% CI = -0.22 to -0.04, p = 0.004, 27 trials, 1441 participants]. Significantly means, it can be said with 95% confidence that low GI diet really lowered the total cholesterol levels with 0.13 mmol/L.

The investigators found that compared to high GI diet low GI diet significantly reduced LDL-cholesterol by 0.16 mmol/L [95% CI = -0.24 to -0.08, p 0.0001, 23 studies, 1281 participants]. Significantly, because the p-value was less than 0.05.

The investigators found subgroup analyses suggested that reductions in LDL-cholesterol were greatest in studies of shortest duration and greatest magnitude of GI reduction. Furthermore, lipid improvements appeared greatest and most reliable when the low GI intervention was accompanied by an increase in dietary fiber.

The investigators found sensitivity analyses, removing studies without adequate allocation concealment, lost statistical significance but retained suggested mean falls of 0.10 mmol/L in both.

The investigators found no effects on HDL-cholesterol [MD = -0.03 mmol/L, 95% CI = -0.06 to 0.00, I2 = 0%], or triglycerides [MD was 0.01 mmol/L, 95% CI = -0.06 to 0.08, I2 = 0%].

The researchers concluded that low GI diets reduce total and LDL-cholesterol (bad cholesterol) but had no effect on HDL-cholesterol (good cholesterol) or triglycerides.

Original title:
Low glycemic index diets and blood lipids: A systematic review and meta-analysis of randomized controlled trials by Goff LM, Cowland DE, [...], Frost GS.

Link:
http://www.sciencedirect.com/science/article/pii/S0939475312001524

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

High LDL-cholesterol levels and high triglyceride levels increase the risk of getting cardiovascular diseases whereas high HDL-cholesterol levels decrease the risk of getting cardiovascular diseases.

A low GI diet is a diet with a GI value of 55 or lower.

Objectives:
Recent evidence has suggested that flavonoid and lignan intake may be associated with decreased risk of chronic and degenerative diseases. Therefore, this review article (meta-analysis) has been conducted.

Does dietary flavonoid intake reduce risk of all-cause and cardiovascular disease mortality?

Study design:
This review article included 22 prospective cohort studies.

Results and conclusions:
The investigators found when compared with lower consumption, high consumption of total flavonoids was associated with a significant decreased risk of 26% for all-cause mortality [risk ratio = 0.74, 95% CI = 0.55-0.99].

The investigators found a 100-mg/day increment in dietary total flavonoids intake led to a (linear) decreased risk of 6% and 4% of all-cause and cardiovascular disease mortality, respectively.

The investigators found among flavonoid classes, significant results were obtained for intakes of flavonols, flavones, flavanones, anthocyanidins and proanthocyanidins.

The investigators found limited evidence was available on lignans intake and all-cause mortality.

The investigators concluded that higher dietary flavonoids intakes - at least 100-mg/day of flavonols, flavones, flavanones, anthocyanidins or proanthocyanidins - are associated with decreased risk of all-cause and cardiovascular disease mortality.

Original title:
Dietary Flavonoid and Lignan Intake and Mortality in Prospective Cohort Studies: Systematic Review and Dose-Response Meta-Analysis by Grosso G, Micek A, […], Giovannucci EL.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28472215

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

Objectives:
The association between elevated serum phosphorus concentration and cardiovascular or all-cause mortality yielded conflicting results. Therefore, this review article (meta-analysis) has been conducted.

Does an elevated serum phosphorus concentration increase cardiovascular and all-cause mortality in the general population?

Study design:
This review article included 6 prospective cohort studies involving 120,269 subjects.

Results and conclusions:
The investigators found when compared the highest with the reference concentration of serum phosphorus, a significant increased risk of 36% for cardiovascular mortality [pooled RR = 1.36, 95% CI = 1.07-1.72]. Significant because RR of 1 was not found in the 95% CI of 1.07 to 1.72. RR of 1 means no risk/association.

The investigators found when compared the highest with the reference concentration of serum phosphorus, a significant increased risk of 33% for all-cause mortality [pooled RR = 1.33, 95% CI = 1.15-1.58]. Significant means that there is an association with a 95% confidence.

The investigators found stratified analyses revealed that elevated serum phosphorus significantly increased all-cause mortality risk with 33% among men [RR 1.33, 95% CI = 1.11-1.60], but not in women [RR = 1.09, 95% CI = 0.89-1.33].

The investigators concluded elevated serum phosphorus concentration is independently associated with excessive risk of cardiovascular and all-cause mortality in the general population without chronic kidney disease. Serum phosphorus on all-cause mortality risk appears to be pronounced in men but exhibits no clear effect on women. However, gender difference of elevated serum phosphorus on mortality risk should be verified by more prospective cohort studies.

Original title:
Serum phosphorus, cardiovascular and all-cause mortality in the general population: A meta-analysis by Bai W, Li J and Liu J.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/27475981

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

Objectives:
Increased dietary potassium intake is thought to be associated with low blood pressure (BP). Whether potassium supplementation may be used as an antihypertensive agent is a question that should be answered. Therefore, this review article (meta-analysis) has been conducted.

Does potassium supplementation reduce blood pressure among patients with essential hypertension (SBP ≥140 mmHg and DBP ≥90 mmHg)?

Study design:
This review article included 23 trials (9 parallel and 14 crossover randomized placebo-controlled clinical trials with a minimum of 4 weeks of therapy to ensure that the intervention had sufficient time to produce an effect) involving 1,213 patients with essential hypertension (SBP ≥140 mmHg and DBP ≥90 mmHg).

The result of meta-regression revealed that the association between potassium dosage, follow-up period and mean age were not statistically significant; therefore they did not play an important role in the heterogeneity across studies.

There was no publication bias.

Results and conclusions:
The investigators found that potassium supplementation significantly reduced systolic blood pressure (SBP) of patients with essential hypertension with 4.25 mmHg [95% CI = -5.96 to -2.53, I2 = 41%].

The investigators found that potassium supplementation significantly reduced diastolic blood pressure (DBP) of patients with essential hypertension with 2.53 mmHg [95% CI = -4.05 to -1.02, I2 = 65%].

The investigators found in 8 RCTs when compared to baseline, the mean changes in systolic blood of patients with essential hypertension was -8.89 mmHg [95% CI = -13.67 to -4.11] significantly higher in the intervention group (group taking potassium supplements) than the control group. 

The investigators found in 8 RCTs when compared to baseline, the mean changes in diastolic blood pressure of patients with essential hypertension was -6.42 mmHg [95% CI = -10.99 to -1.84] significantly higher in the intervention group (group taking potassium supplements) than the control group. 

The investigators found in subgroup analysis that the mean difference in systolic blood of patients with essential hypertension was -2.64 mmHg [95% CI = -5.25 to -0.03] in America, -4.56 mmHg [95% CI = -6.51 to -2.62) in Europe and -5.21 mmHg [95% CI = -9.63 to -0.79] in Asia.

The investigators found a dose-response relationship between potassium intake and reduction in systolic and diastolic blood pressure (low-dose (50 mmol/day), moderate-dose (50-99 mmol/day) and high-dose (≥100 mmol/day)).

The investigators concluded that potassium supplementation for at least 4 weeks reduces blood pressure of patients with essential hypertension and therefore, can be recommended as an adjuvant antihypertensive agent for patients with essential hypertension (SBP ≥140 mmHg and DBP ≥90 mmHg).

Original title:
Oral potassium supplementation for management of essential hypertension: A meta-analysis of randomized controlled trials by Poorolajal J, Zeraati F, […], Maleki A.

Link:
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0174967

Additional information of El Mondo:
Find more information/studies on hypertension and potassium right here.