Nutrition and health

Objectives:
An enhanced risk for cardiovascular disease (CVD) still exists even when patients with type 2 diabetes have tight control on blood sugar. Thus, identification of treatment approaches that address CVD risk factors may be useful for patients beyond the blood sugar management. Although emerging evidence suggests that nuts consumption have beneficial effects on cardiometabolic health, the effects of almond intake in patients with type 2 diabetes are still controversial. Therefore, this review article has been conducted. 

Does almond consumption improve risk factors (cholesterol, triglycerides, fasting plasma glucose, insulin, hemoglobin A1c (HbA1c), body mass index, weight, body fat, systolic and diastolic blood pressure and CRP) of cardiovascular disease in patients with type 2 diabetes?

Study design:
This review article included 9 RCTs.

Results and conclusions:
The investigators found there was a causal relationship between almond dietary intake and a  significant reduction in low-density lipoprotein cholesterol (LDL cholesterol or bad cholesterol) [WMD = -5.28 mg/dL, 95% CI = -9.92 to -0.64, p = 0.026] in patients with type 2 diabetes compared with the control group.
This lowering effect of LDL cholesterol was robust in subgroups with almond consumption >50 g/day and baseline LDL cholesterol level 130 mg/dL.

The investigators found, however, the effect of almond on total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL cholesterol or good cholesterol), fasting plasma glucose, insulin, HbA1c, body mass index, weight, body fat, systolic and diastolic blood pressure and CRP was not significant compared with the control group.

The investigators concluded that a dietary intake of at least 50 g/d almond decreases causally LDL cholesterol (bad cholesterol) but has no favourable effect on other cardiometabolic outcomes in patients with type 2 diabetes. Further high-quality studies are needed to firmly establish the clinical efficacy of the almond.

Original title:
Effects of almond on cardiometabolic outcomes in patients with type 2 diabetes: A systematic review and meta-analysis of randomized controlled trials by Moosavian SP, Rahimlou M, […], Jalili C.

Link:
https://pubmed.ncbi.nlm.nih.gov/35443097/

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

Objectives:
While there is growing research interest in the effects of nutrition and exercise on delaying sarcopenia, the results are inconclusive and there is scarce information on regional patterns. Therefore, this review article has been conducted.

Do protein supplements combined with exercise improve extremity strength in healthy older adults with sarcopenia?

Study design:
This review article included 14 RCTs, involving a total of 888 healthy older adults (>60 years).

4 studies in Asian countries provided data on lower-extremity strength, involving 280 participants (138 in protein supplements + exercise group and 142 in exercise group).
Lower-extremity strength was assessed using knee extension (n = 3) or leg extension (n = 1).
The intervention period of all studies was 12 weeks.
The dosage of protein ranged from 3 g/d to 40 g/d.

Results and conclusions:
The investigators found in 4 studies in Asian countries a significant increase in the lower-extremity strength in the protein supplementation + exercise group compared to the exercise group, with a SMD of 0.24 [95% CI = 0.00 to 0.47, p = 0.048, I2 = 0.0%, p = 0.513].

The investigators concluded that protein supplements (3 g/d to 40 g/d during 12 weeks) combined with exercise (knee extension and leg extension) exerts superior benefit on lower-extremity strength in healthy older adults with sarcopenia in Asian countries, when compared to exercise alone or with a placebo. However, no additional benefits from protein supplementation are observed on upper-extremity strength, muscle mass and physical performance regardless of the regions. More well-designed RCTs with information on baseline and total protein intake for longer follow-up periods are warranted to evaluate the effectiveness of protein supplementation and exercise on the prevention and management of sarcopenia in healthy older adults.

Original title:
Effects of protein supplementation and exercise on delaying sarcopenia in healthy older individuals in Asian and non-Asian countries: A systematic review and meta-analysis by Li L, He Y, […], Liu X.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8808080/

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

Upper extremity is part of the body that includes the arm, wrist and hand.

Lower extremity refers to the part of the body from the hip to the toes.

Sarcopenia is a type of muscle loss (muscle atrophy) that occurs with aging and/or immobility. Sarcopenia can affect people in their 30s and beyond.
 

Objectives:
Epidemiological studies indicate that higher intakes of flavonoids are associated with reduced stroke risk. However, which subtypes play significant roles to protect against stroke remain unclear. Therefore, this review article has been conducted.

Does dietary intake of different flavonoid subclasses (flavanones, flavan-3-ols) reduce risk of stroke?

Study design:
This review article included 10 independent prospective cohort studies with 387,076 participants and 9,564 events (persons with stroke).

Results and conclusions:
The investigators found higher intakes of flavanones significantly reduced risk of stroke with 15% [RR = 0.85, 95% CI = 0.78 to 0.93].

The investigators found dose-response analysis showed that 50 mg/day increment of flavanones dietary intake was significantly associated with 11% reduction in stroke risk [RR = 0.89, 95% CI = 0.84 to 0.94].

The investigators found dose-response analysis showed that 200 mg/day increment of flavan-3-ols dietary intake was significantly associated with 14% reduction in stroke risk [RR = 0.86, 95% CI = 0.75 to 0.98].

The investigators found no association with respect to other flavonoid subclasses.

The investigators concluded that both 50 mg/day flavanones and 200 mg/day flavan-3-ols dietary intake reduce stroke risk. The findings of these associations of the present study need to be confirmed in other regions and ethnic origins.

Original title:
A meta-analysis of prospective cohort studies of flavonoid subclasses and stroke risk by Li XQ, Wang C, […], Guo XF.

Link:
https://pubmed.ncbi.nlm.nih.gov/35023220/

Additional information of El Mondo:
Find more information/studies on flavonoid consumption and stroke prevention right here.

Objectives:
Is IL-6 is a candidate marker for severe malaria?

Study design:
This review article included 43 studies.

Most of the included studies were prospective observational studies (19, 44.2%) and the remaining study types included cross-sectional studies (16, 37.2%), case-controlled studies (6, 14%) and randomized controlled trials (RCTs) (2, 4.6%).

The studies enrolled patients with P. falciparum (32, 74.4%), P. vivax (4, 9.3%), P. falciparum/P. vivax (3, 6.98%), P. falciparum/P. knowlesi (1, 2.3%), P. falciparum/P. vivax/P. ovale (1, 2.3%), P. falciparum/P. vivax/mixed infection (1, 2.3%) and P. falciparum/P. vivax/P. ovale/P. malariae (1, 2.3%).

Some studies enrolled children (20, 46.5%), adults (16, 37.2%), all age groups (6, 14%) and not specified (1, 2.3%).

Most of the studies (31, 72.1%) used only microscopy for malaria detection although microscopy/PCR (5, 11.6%), microscopy/rapid diagnostic test (RDT; 5, 11.6%) and microscopy/RDT/PCR (2, 4.65%) were also used.

An ELISA was the most common method used for IL-6 measurements (30, 69.8%), followed by a bead-based assay (13, 30.2%).

Thirty-two studies (74.4%) were high quality, whereas 11 studies were moderate qualities.
Heterogeneity of the effect estimate among the included studies was the main limitation of this analysis.

Results and conclusions:
The investigators found results of the meta-analysis showed that patients with severe malaria had higher mean IL-6 levels than those with non-severe malaria [WMD = 96.63 pg/mL, 95% CI = 0.88 to 19.38 pg/mL, p = 0.04, I2 = 99.9%, 13 studies].

The investigators found that the pooled effect estimate was unchanged after the publication bias was adjusted [WMD = 96.60 pg/mL, 95% CI = 4.32 to 188.89 pg/mL, p = 0.04, 13 studies].

The investigators found results of the meta-analysis showed that patients with uncomplicated malaria had higher mean IL-6 levels than the controls [WMD = 42.86 pg/mL, 95% CI = 30.17 to 55.56 pg/mL, p 0.001, I2 = 100%, 17 studies].

The investigators found results of the meta-analysis showed no differences in the mean levels of IL-6 between patients with uncomplicated malaria and those with asymptomatic malaria [WMD = 42.07 pg/mL, 95% CI = -2.23 pg/mL to -86.37 pg/mL, p = 0.063, I2 = 99.1%, 8 studies] or between patients with asymptomatic malaria and healthy controls [WMD = 1.67 pg/mL, 95% CI = -2.73 pg/mL to -6.07 pg/mL, p = 0.45, I2 = 98.1%, 2 studies].

The investigators found subgroup analysis of continents showed no differences in IL-6 levels between patients with severe malaria and non-severe malaria for studies conducted in Africa and Asia.

The investigators found results of the meta-analysis showed that a higher mean level of IL-6 was observed in patients who died compared with the levels of those who survived [WMD = 1,399.19 pg/mL, 95% CI = 384.16 to  2,414.2 pg/mL, p = 0.007, I2 = 93.1%, 4 studies].

The investigators found meta-regression analyses of continents, malarial complications, parasitemia, age, male percentage, malaria diagnostic methods and IL-6 measurement methods showed that these co-variates did not confound the effect estimate [p > 0.05].

The investigators concluded significantly increased levels of IL-6 are observed in patients with severe malaria compared with those in patients with non-severe malaria, which indicates that IL-6 is a candidate marker for severe malaria. In addition, IL-6 might be a candidate marker for malaria infection and therefore could be used to differentiate malaria infection from other febrile diseases. Therefore, it is recommended that future studies should investigate the sensitivity and specificity of increased IL-6 levels to determine the effectiveness of measuring IL-6 levels to detect malaria infection and monitor malaria severity to improve the efficiency of malaria diagnosis and management.

Original title:
Increased interleukin-6 levels associated with malaria infection and disease severity: a systematic review and meta-analysis by Wilairatana P, Mala W, […], Kotepui M.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8993930/

Additional information of El Mondo:
Find more information/studies on food fortification/malnutrition and malaria right here.

Objectives:
Oat supplementation interventions (OSIs) may have a beneficial effect on cardiovascular disease (CVD) risk. However, dietary background can modulate such effect. Therefore, this review article has been conducted.

Does dietary oat supplementation lower levels of blood lipids (cholesterol, triglycerides) and improve anthropometric parameters (glucose level, body mass index, weight, blood pressure, waist circumference) among participants with predominantly mild metabolic disturbances?

Study design:
This review article included 74 RCTs with a total of 4,937 predominantly hypercholesterolemic, obese subjects, with mild metabolic disturbances. Of these, 59 RCTs contributed to the meta-analyses.

The majority of included RCTs (81.1%) had some concerns for risk of bias.

Results and conclusions:
The investigators found oat supplementation (as oat, oat beta-glucan-rich extracts or avenanthramides), compared to control arms without oats, significantly improved levels of:
-total cholesterol (TC) [WMD = -0.42 mmol/L, 95% CI = -0.61 to -0.22];
-LDL cholesterol [WMD = -0.29 mmol/L, 95% CI = -0.37 to -0.20];
-glucose [WMD = -0.25 nmol/L, 95% CI = -0.36 to -0.14];
-body mass index [WMD = -0.13 kg/m², 95% CI = -0.26 to -0.01];
-weight [WMD = -0.94 kg, 95% CI = -1.84 to -0.05] and;
-waist circumference [WMD = -1.06 cm, 95% CI = -1.85 to -0.27].

The investigators found RCTs on inflammation and/or oxidative stress markers were scarce and with inconsistent findings.

The investigators found RCTs comparing an oat supplementation intervention to heterogeneous interventions (e.g., wheat, eggs, rice, etc.), showed lowered levels of glycated haemoglobin, diastolic blood pressure, HDL cholesterol and apolipoprotein B.

The investigators concluded dietary oat supplementation (as oat, oat beta-glucan-rich extracts or avenanthramides) may lower levels of blood lipids and improve anthropometric parameters among obese participants with predominantly mild metabolic disturbances, regardless of dietary background or control. May lower because the majority of included RCTs had some concerns for risk of bias. Therefore, further high-quality trials are warranted to establish the role of oat supplementation intervention on blood pressure, glucose homeostasis and inflammation markers.

Original title:
Effect of oat supplementation interventions on cardiovascular disease risk markers: a systematic review and meta-analysis of randomized controlled trials by Llanaj E, Dejanovic GM, […], Muka T.

Link:
https://pubmed.ncbi.nlm.nih.gov/34977959/

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

These products are suitable for persons with cardiovascular diseases.

Objectives:
Is there an association between dietary diversity (DDiv) and growth outcomes (stunting, wasting and underweight) in children aged 5 years?

Study design:
This review article included 70 cross-sectional studies, 4 longitudinal cohort studies, 5 case-control studies and 2 randomized controlled trials.

Of the studies, 45 focused on infants and 36 on children aged 5 years.
The reviewed articles had good quality and low risk of bias (scores >6).

Results and conclusions:
The investigators found in infants, low dietary diversity was significantly associated with stunting, wasting and being underweight [79%, 57% and 68% of the studies, respectively].

The investigators found among children aged 5 years, the association was observed in 75%, 56% and 57% of the studies, respectively, for stunting, wasting and underweight.

The investigators concluded the findings indicate an association between low dietary diversity (DDiv) of infants and children aged 5 years with stunting. However, this association remains uncertain with wasting and being underweight.

Original title:
Association of Dietary Diversity With Growth Outcomes in Infants and Children Aged Under 5 Years: A Systematic Review by Gol RM, Kheirouri S and Alizadeh M.

Link:
https://pubmed.ncbi.nlm.nih.gov/35000681/

Additional information of El Mondo:
Find more information/studies on food fortification/malnutrition right here.

Objectives:
Evidence associating diet with the incidence of renal cell carcinoma (RCC) is inconclusive. Therefore, this umbrella review article has been conducted.

What is the association between diet and renal cell carcinoma incidence?

Study design:
This umbrella review article included 22 meta-analyses with a total of 502 individual studies and 64 summary hazard ratios (HRs) for renal cell carcinoma incidence: dietary patterns or dietary quality indices (n = 6), foods (n = 13), beverages (n = 4), alcohol (n = 7), macronutrients (n =15) and micronutrients (n =19).

No meta-analyses had high methodological quality.

59% of these 502 individual studies were cohort studies (n = 298), 39% were case-control studies (n = 196) and 2% were pooled studies (n = 8).

Sixty (94%) exposures in the included meta-analyses had more than 1,000 cases or 20,000 participants.

Results and conclusions:
The investigators found no dietary factors showed convincing or highly suggestive evidence of association with renal cell carcinoma incidence in the overall analysis.

The investigators found in the overall analysis that dietary intake of vegetables significantly reduced risk of renal cell carcinoma with 26% [summary HR = 0.74, 95% = 0.63 to 0.86, suggestive evidence].

The investigators found in the overall analysis that dietary intake of vitamin C significantly reduced risk of renal cell carcinoma with 23% [summary HR = 0.77, 95% = 0.66 to 0.90, suggestive evidence].

The investigators found in the overall analysis that moderate drinking significantly reduced risk of renal cell carcinoma with 23% [summary HR = 0.77, 95% = 0.70 to 0.84, convincing evidence] in Europe and North America.

The investigators found in the overall analysis that dietary intake cruciferous vegetables significantly reduced risk of renal cell carcinoma with 22% [summary HR = 0.78, 95% = 0.70 to 0.86, highly suggestive evidence] in North America.

The investigators concluded dietary intake of vegetables and vitamin C could reduce renal cell carcinoma risk. Moderate drinking might be beneficial for Europeans and North Americans and cruciferous vegetables might be beneficial to North Americans, but the results should be interpreted with caution because no meta-analyses had high methodological quality. More researches are needed in the future.

Original title:
The role of diet in renal cell carcinoma incidence: an umbrella review of meta-analyses of observational studies by Liao Z, Fang Z, […], Luo Z.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8812002/

Additional information of El Mondo:
Find more information/studies on cancer, vegetables, vitamin C right here.

An umbrella review article is a scientific article which only includes meta-analyses (also called review articles). The results found in an umbrella review article are more reliable than found in an individual review article.

One swallow does not make a summer. A famous Dutch saying that could not be any more obvious. Just because one single scientific study about a certain topic makes certain claims, it does not necessarily mean it is true. On the other hand, a review article (a collection of scientific studies on a certain topic) of randomized, placebo-controlled double blind clinical trials (RCTs) will answer the following question:
"Do taking dietary supplements make sense?" Yes for a positive conclusion and no for a negative conclusion.

One swallow does not make a summer. A famous Dutch saying that could not be any more obvious. Just because one single scientific study about a certain topic makes certain claims, it does not necessarily mean it is true. On the other hand, a review article (a collection of scientific studies on a certain topic) of (prospective) cohort studies or case-control studies will answer the following question:
"Should I change my diet?".

Objectives:
There is currently a lack of high-quality research on the best dietary recommendations for patients with early glaucoma or at high risk for glaucoma. Therefore, this review article has been conducted.

Does a high dietary vitamin intake reduce risk of glaucoma?

Study design:
This review article included 8 cohort studies, with a total of 262,189 patients.

There was no publication bias.

Results and conclusions:
The investigators found that high-dose dietary intake of vitamins A was significantly associated with a 27% low risk of glaucoma [OR = 0.63, 95% CI = 0.53 to 0.76 , p 001, I2 = 49%].

The investigators found that high-dose dietary intake of vitamins B (a combination of B1, B2, B3, B6 and B12) was significantly associated with a 29% low risk of glaucoma [OR = 0.71, 95% CI = 0.64 to 0.80, p 0.001, I2 = 29%].

The investigators found no association between high-dose dietary intake of vitamins C, D or E and lower risk of glaucoma.

The investigators concluded that high-dose dietary intake of vitamins A and B, but not vitamins C, D or E, is associated with a low prevalence of glaucoma. Overall, middle-aged and elderly people or patients with early glaucoma should consume vitamin-rich foods rich or take additional vitamin supplements.

Original title:
Vitamin intake and glaucoma risk: A systematic review and meta-analysis by Han FF and Fu XX.             

Link:
https://www.sciencedirect.com/science/article/pii/S0181551222000419?via%3Dihub

Additional information of El Mondo:
Find here more information/studies about chronic diseases, vitamin A and B.
 

Objectives:
There is some evidence regarding the positive effects of ginger supplementation on metabolic profile in patients with type 2 diabetes (T2DM). However, they are conflicting and therefore, this review article has been conducted. 

Does ginger supplementation improve metabolic profile (FBS, HbA1c, TC, TG, LDL, HDL, SBP and DBP) in patients with type 2 diabetes?

Study design:
This review article included 10 RCTs.

Results and conclusions:
The investigators found pooled meta-analysis showed a significant reduction in fasting blood sugar (FBS) level following ginger supplementation by polling 8 effect sizes [WMD = -18.81, 95% CI = -28.70 to -8.92, I2 = 77.4%].

The investigators found pooled meta-analysis showed a significant reduction in HbA1c level following ginger supplementation by polling 7 effect sizes [WMD = -0.57, 95% CI = -0.93 to -0.20, I2 = 88.6%].

The investigators found pooled meta-analysis showed a significant reduction in systolic blood pressure (SBP) following ginger supplementation by polling 5 effect sizes [WMD = -4.20, 95% CI = -7.64 to -0.77, I2 = 97%].

The investigators found pooled meta-analysis showed a significant reduction in diastolic blood pressure (DBP) following ginger supplementation by polling 5 effect sizes [WMD = -1.61, 95% CI = -3.04 to -0.18, I2 = 93.2%].

The investigators found pooled meta-analysis showed ginger supplementation had no significant influence on lipid profile involving triglyceride (TG), total cholesterol (TC), LDL cholesterol and HDL cholesterol.

The investigators concluded supplementation with ginger reduces fasting blood sugar, HbA1c, systolic blood pressure and diastolic blood pressure in patients with type 2 diabetes. Further large RCTs are required to shed light on this issue.

Original title:
The effect of ginger supplementation on metabolic profiles in patients with type 2 diabetes mellitus: A systematic review and meta-analysis of randomized controlled trials by Ebrahimzadeh A, Ebrahimzadeh A, […], Milajerdi A.

Link:
https://pubmed.ncbi.nlm.nih.gov/35031435/

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

Objectives:
Does a high serum vitamin D level reduce risk of latent tuberculosis infection?

Study design:
This review article included 2 case-control studies and 3 cohort studies with a total of 1,516 subjects, comprising 117 latent tuberculosis infection (LTBI) patients.
Diagnosis of LTBI in all studies was based upon QFN-GIT, IGRAs and/or TST.
2 case-control and 3 cohort studies were considered as high quality.

Between-studies heterogeneity varied from none to small for the meta-analyses with I2 values ranging from 64.5 to 75.7%. However, sensitivity analysis and visual inspection of funnel plots for checking asymmetry and publication bias weren’t done because only 2 articles were included in association of vitamin D and the risk of LTBI and 3 in association of vitamin D and the incidence of LTBI.

Results and conclusions:
The investigators found in a pooled analysis of 2 case-control studies with 41 LTBI cases and 142 control subjects, that relatively high serum vitamin D level was not significantly associated with a decreased risk of latent tuberculosis infection [OR = 0.51, 95% CI = 0.05 to 5.65, p = 0.58, I2 = 64.5%].
Not significantly because the calculated p-value of 0.58 was larger than the p-value of 0.05.

The investigators found in a pooled analysis of 3 cohort studies involving 1,333 participants, that relatively high serum vitamin D levels did not reduce the incidence of latent tuberculosis infection [RR = 0.56, 95% CI = 0.19 to 1.67, p = 0.300, I2 = 75.7%].

The investigators concluded that serum vitamin D levels are not associated with incidence of latent tuberculosis infection and relatively high serum vitamin D level is not a protective factor for latent tuberculosis infection. Further RCTs are needed to verify whether sufficient vitamin D levels and vitamin D supplementation prevents latent tuberculosis infection.

Original title:
Vitamin D and the risk of latent tuberculosis infection: a systematic review and meta-analysis by Cao Y, Wang X, […], Du J.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8772077/

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

Objectives:
Does a high olive oil consumption reduce cancer risk?

Study design:
This review article included 37 case-control studies with 17,369 cases (persons with cancer) and 28,294 controls (persons without cancer) and 8 cohort studies with 12,461 incident cases among 929,771 subjects (participants).

Significant publication bias was detected via Egger’s test in the analysis on overall cancer risk [p 0.001], breast cancer [p = 0.013] and gastrointestinal cancer risk [p = 0.048].

Results and conclusions:
The investigators found in pooled analysis of case-control and cohort studies that highest olive oil consumption was significantly associated with a 31% lower risk of any cancer [pooled RR = 0.69, 95% CI = 0.62 to 0.77].  
Significantly means that there is an association with a 95% confidence.

The investigators found subgroup analyses showed that the protective effect of high olive oil consumption in terms of cancer risk was also significant in case-control studies [37 study arms, RR = 0.65, 95% CI = 0.57 to 0.74] but not in cohort studies [8 study arms, RR = 0.90, 95% CI = 0.77 to 1.05].
Furthermore, the protective association was also found in a multivariate analysis [32 study arms, RR = 0.72, 95% CI = 0.65 to 0.81], a high study quality analysis [RR = 0.72, 95% CI = 0.64 to 0.81], Mediterranean participants [RR = 0.69, 95% CI = 0.60 to 0.79] and non-Mediterranean participants [RR = 0.49, 95% CI = 0.34 to 0.71].

The investigators found in pooled analysis of case-control and cohort studies that highest olive oil consumption was significantly associated with a 33% lower risk of breast cancer [pooled RR = 0.67, 95% CI = 0.52 to 0.86].  
Significantly because RR of 1 was not found in the 95% CI of 0.52 to 0.86. RR of 1 means no risk/association.

The investigators found subgroup analyses showed that the beneficial effect was reproducible in case-control studies [RR = 0.63, 95% CI = 0.45 to 0.87] but not in cohort studies.
Furthermore, high olive oil consumption was linked to a reduced breast cancer risk in Mediterranean [RR = 0.67, 95% CI = 0.49 to 0.92] and non-Mediterranean populations [RR = 0.25, 95% CI = 0.07 to 0.89].

The investigators found in pooled analysis of case-control and cohort studies that highest olive oil consumption was significantly associated with a 23% lower risk of gastrointestinal cancer [pooled RR = 0.77, 95% CI = 0.66 to 0.89].  
Subgroup analyses showed an inverse relationship between highest olive oil consumption and risk for esophageal cancer [RR = 0.47, 95%CI = 0.24 to 0.93] and pancreatic cancer [RR = 0.58, 95% CI = 0.35 to 0.97].
Furthermore, significant effects were also found in case-control studies [RR = 0.72, 95% CI = 0.61 to 0.85), studies within the Mediterranean area [RR = 0.77, 95% CI = 0.67 to 0.88], multivariate analyses [RR = 0.76, 95% CI = 0.63 to 0.90] and high quality studies [RR = 0.73, 95% CI = 0.62 to 0.86].

The investigators found in pooled analysis of case-control and cohort studies that highest olive oil consumption was significantly associated with a 26% lower risk of upper aerodigestive cancer [pooled RR = 0.74, 95% CI = 0.60 to 0.91].  
Subgroup analyses showed results remained significant for case-control studies [RR = 0.74, 95% CI = 0.60 to 0.91], multivariate analyses [RR = 0.75, 95% CI = 0.66 to 0.86] and studies of high quality [RR = 0.68, 95% CI = 0.52 to 0.89].

The investigators found in pooled analysis of case-control studies that highest olive oil consumption was significantly associated with a 54% lower risk of urinary tract cancer [pooled RR = 0.46, 95% CI = 0.29 to 0.72].  
Subgroup analyses showed results remained significant for studies of high quality [RR = 0.46, 95% CI = 0.32 to 0.66].

The investigators concluded highest versus lowest olive oil consumption is associated with 31% lower cancer risk, especially for breast, overall gastrointestinal, upper aerodigestive and urinary tract cancer. Additional prospective cohort studies on various cancer types, especially in non-Mediterranean regions, as well as large randomized trials, seem desirable in order to provide further insight into the role of olive oil in preventing cancer.

Original title:
Olive oil intake and cancer risk: A systematic review and meta-analysis by Markellos C, Ourailidou ME, […], Psaltopoulout T.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8751986/

Additional information of El Mondo:
Find more information/studies on cancer, olive oil consumption right here.

The conclusions in scientific studies are even more reliable when they are also found in cohort studies, multivariate analyzes (studies where adjustments were made for multiple confounding factors) and high-quality studies.
 

Objectives:
Severe hypertension in pregnancy is a hypertensive crisis that requires urgent and intensive care due to its high maternal and fetal mortality. However, there is still a conflict of opinion on the recommendations of antihypertensive therapy.

What are the optimal blood pressure (BP) levels to prevent severe hypertension in pregnant women with nonsevere hypertension?

Study design:
This review article included 40 RCTs with 6,355 patients.

Results and conclusions:
The investigators found blood pressure lowering treatment significantly lowered risk of severe hypertension with 54% [RR = 0.46, 95% CI = 0.37 to 0.56], preeclampsia with 18% [RR = 0.82, 95% CI = 0.69 to 0.98], severe preeclampsia with 62% [RR = 0.38, 95% CI = 0.17 to 0.84], placental abruption with 48% [RR = 0.52, 95% CI = 0.32 to 0.86] and preterm birth with 19% [37 weeks: RR = 0.81, 95% CI = 0.71 to 0.93], while the risk of small for gestational age infants was significantly increased with 25% [RR = 1.25, 95% CI = 1.02 to 1.54].

The investigators found an achieved systolic blood pressure (SBP) of 130 mmHg significantly reduced the risk of severe hypertension to nearly one-third compared with a systolic blood pressure of ≥140 mmHg, with a significant interaction of the blood pressure levels achieved with BP-lowering therapy.

The investigators found there was no significant interaction between the subtypes of hypertensive disorders of pregnancy and blood pressure lowering treatment, except for placental abruption.

The investigators concluded blood pressure lowering treatment aimed at a systolic blood pressure 130 mmHg and accompanied by the careful monitoring of fetal growth should be recommended to prevent severe hypertension in pregnant women with nonsevere hypertension.

Original title:
Optimal blood pressure target to prevent severe hypertension in pregnancy: A systematic review and meta-analysis by Abe M, Arima H, […], Mukoyama M.

Link:
https://pubmed.ncbi.nlm.nih.gov/35136186/

Additional information of El Mondo:
Find more information/studies on food fortification/malnutrition and pregnancy right here.

Objectives:
Does a higher intake of dietary antioxidants (like vitamin C and E, β-carotene, zinc, anthocyanins, lutein) reduce risk of Parkinson's disease (PD)?

Study design:
This review article included 6 prospective cohort studies and 2 nested case-control studies (448,737 participants with 4,654 persons with Parkinson's disease) and 6 case-control studies (1,948 persons without Parkinson's disease and 1, 273 persons with Parkinson's disease).

Results and conclusions:
The investigators found comparded to the lowest dietary vitamine E intake, that the highest dietary vitamine E intake significantly reduced risk of Parkinson's disease with 16% [pooled RR = 0.84, 95% CI = 0.71 to 0.99, n = 7 cohort studies].
Significantly means that there is an association with a 95% confidence.

The investigators found compared to the lowest dietary anthocyanins intake, that the highest dietary anthocyanins intake significantly reduced risk of Parkinson's disease with 24% [pooled RR = 0.76, 95% CI = 0.61 to 0.96, n = 2 cohort studies].
Significantly because pooled RR of 1 was not found in the 95% CI of 0.61 to 0.96. RR of 1 means no risk/association.

The investigators found compared to the lowest dietary lutein intake, that the highest dietary lutein intake significantly increased risk of Parkinson's disease with 86% [pooled RR = 1.86, 95% CI = 1.20 to 2.88, n = 3 case-control studies].

The investigators found in dose-response meta-analyses that every increment of dietary vitamin C intake with 50 mg/d significantly reduced risk of Parkinson's disease with 6% [RR = 0.94, 95% CI = 0.88 to 0.99, n = 6].

The investigators found in dose-response meta-analyses that every increment of dietary vitamin E intake with 5 mg/d significantly reduced risk of Parkinson's disease with 16% [RR = 0.84, 95% CI = 0.70 to 0.99, n = 7].

The investigators found in dose-response meta-analyses that every increment of dietary β-carotene intake with 2 mg/d significantly reduced risk of Parkinson's disease with 6% [RR = 0.94, 95% CI = 0.89 to 0.99, n = 6].

The investigators found in dose-response meta-analyses that every increment of dietary zinc intake with 1 mg/d significantly reduced risk of Parkinson's disease with 35% [RR = 0.65, 95% CI = 0.49 to 0.86, n = 1].

The investigators concluded that higher intake of antioxidant-rich foods reduces risk of Parkinson's disease. Future, well-designed prospective studies are needed to validate the present findings.

Original title:
Dietary Antioxidants and Risk of Parkinson's Disease: A Systematic Review and Dose-response Meta-analysis of Observational Studies by Talebi S, Ghoreishy SM, […], Mohammadi H.

Link:
https://pubmed.ncbi.nlm.nih.gov/35030236/

Additional information of El Mondo:
Find here more information/studies about RCTs/significant and antioxidants.
 

Objectives:
Does postoperative coffee or caffeine consumption causally reduce risk of postoperative ileus (POI) in patients undergoing elective colorectal surgery?

Study design:
This review article included 4 RCTs with 312 subjects.

Results and conclusions:
The investigators found postoperative coffee or caffeine consumption significantly decreased the time to first bowel movement [MD = -10.36 h, 95% CI = -14.61 to -6.11], shortened the length of hospital stay [MD = -0.95 days, 95% CI = -1.57 to -0.34] and was significantly  associated with a 36%-decreased risk of the use of any laxatives after the procedure [RR = 0.64, 95% CI = 0.44 to 0.92].

The investigators found the time to first flatus, time to tolerance of solid food, risk of any postoperative complication, postoperative reinsertion of a nasogastric (NG) tube and anastomotic leakage showed no statistical differences between groups.

The investigators concluded postoperative coffee or caffeine consumption causally improves bowel movement and decreases the duration of hospital stay in patients undergoing elective colorectal surgery. This method is safe and can prevent or treat postoperative ileus (POI).

Original title:
The effect of coffee/caffeine on postoperative ileus following elective colorectal surgery: a meta-analysis of randomized controlled trials by Yang TW, Wang CT, […], Tsai MC.

Link:
https://pubmed.ncbi.nlm.nih.gov/34993568/

Additional information of El Mondo:
Find more information/studies on caffeine and cancer right here.

Postoperative ileus is a prolonged absence of bowel function after surgical procedures, usually abdominal surgery.

Objectives:
What is the safety of dihydroartemisinin-piperaquine (DHA-PQ) compared to artemether-lumefantrine (AL) for the treatment of uncomplicated P. falciparum malaria among children in Africa?

Study design:
This review article included 18 studies involving 10,498 African children with uncomplicated P. falciparum malaria.

A target dose (range) of 4 (2-10) mg/kg bw per day dihydroartemisinin and 18 (16-27) mg/kg bw per day piperaquine given once a day for 3 days for children weighing ≥25 kg.
The target doses and ranges for children weighing 25 kg are 4 (2.5-10) mg/kg bw per day dihydroartemisinin and 24 (20-32) mg/kg bw per day piperaquine once a day for 3 days.

Results and conclusions:
The investigators found, compared to AL, DHA-PQ significantly increased frequency of early vomiting with 126% [RR = 2.26, 95% CI = 1.46 to 3.50, I2 = 0%, participants = 7,796, studies = 10, high quality of evidence].

The investigators found, compared to AL, DHA-PQ significantly increased frequency of cough with 6% [RR = 1.06, 95% CI = 1.01 to 1.11, I2 = 0%, participants = 8,013, studies = 13, high quality of evidence].

The investigators found, compared to AL, DHA-PQ significantly increased frequency of diarrhoea with 16% [RR = 1.16, 95% CI = 1.03 to 1.31, I2 = 8%, participants = 6,841, studies = 11, high quality of evidence].

The investigators concluded that both drugs are well tolerated by children. There are comparable occurrences of adverse events in both treatment arms. But, early vomiting, diarrhoea and cough are common and more frequent in African children who are treated with the DHA-PQ than that of AL (high quality of evidence). All serious adverse events are consistent with malaria symptoms and judged to be unrelated to study medication. More studies comparing AL with DHA-PQ are needed to determine the comparative safety of these drugs.

Original title:
Safety of dihydroartemisinin-piperaquine versus artemether-lumefantrine for the treatment of uncomplicated Plasmodium falciparum malaria among children in Africa: a systematic review and meta-analysis of randomized control trials by Assefa DG, Zeleke ED, […], Makonnen E.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8725395/

Additional information of El Mondo:
Find more information/studies on food fortification/malnutrition and malaria right here.

Objectives:
Systematic reviews of case-control studies evaluating the relationship between dietary salt intake and gastric cancer showed a positive association, however a quantitative analysis of longitudinal cohort studies is lacking. Therefore, this review article has been conducted.

Does a high salt intake increase gastric cancer risk?

Study design:
This review article contained 10 cohort studies with 268,718 participants, of which 1,474 gastric cancer events and a follow-up of 6-15 years.

Meta-regression analyses did not detect specific sources of heterogeneity.

There was no evidence of publication bias.

Results and conclusions:
The investigators found for high vs low salt intake a significantly increased risk of 68% for gastric cancer [RR = 1.68, 95% CI = 1.17 to 2.41, p = 0.005].

The investigators found for moderate vs low salt intake a significant increased risk of 41% for gastric cancer [RR = 1.41, 95% CI = 1.03 to 1.93, p = 0.032].

The investigators found the association was stronger in the Japanese population and higher consumption of selected salt-rich foods was also associated with greater risk.

The investigators concluded high salt intake is directly associated with an increased risk of gastric cancer in prospective population studies, with progressively increasing risk across consumption levels.

Original title:
Habitual salt intake and risk of gastric cancer: A meta-analysis of prospective studies by D’Elia L, Rossi G, […], Strazzullo P.

Link:
http://www.clinicalnutritionjournal.com/article/S0261-5614%2812%2900005-2/abstract

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

According to WHO, a high salt intake is a salt intake of more than 5 grams salt per day.

A diet with more than 5 grams salt per day is a diet with mainly products/meals with more than 0.25 grams salt per 100 kcal. Check here which products contain maximum 5 grams salt per 100 kcal.
Use the 7-points nutritional profile app to see whether your daily diet contains maximum 5 grams salt per 100 kcal.
 

Objectives:
Is there a relationship between serum 25(OH)D (vitamin D blood level) and mortality risk in the general population?

Study design:
This review article included 14 prospective cohort studies that involved 5562 deaths out of 62548 individuals.
In the parametric model, which is based on 11 studies and 59231 individuals, the lowest quantile as the reference category has been used.

Evidence of heterogeneity for the RR was apparent when highest were compared with lowest categories [p = 0.008, I2 = 58%].

There was no evidence of publication bias.

Results and conclusions:
The investigators found for “highest compared with lowest” categories of 25(OH)D, a significant reduced risk of 29% for mortality [RR = 0.71, 95% CI = 0.50-0.91].

The investigators found in the parametric model, the estimated summary RRs of mortality were 0.86 [95% CI = 0.82-0.91], 0.77 [95% CI = 0.70-0.84] and 0.69 [95% CI = 0.60-0.78] for individuals with an increase of 12.5, 25 and 50 nmol 25(OH)D serum values/L, respectively, from a median reference category of ∼27.5 nmol/L.
However, no significant decrease in mortality was found above ∼87.5 nmol/L.

The investigators concluded there is a nonlinear decrease in mortality risk as circulating 25(OH)D increases, with optimal concentrations ∼75-87.5 nmol/L. Because many adults do not achieve these 25(OH)D values, large prospective randomized trials are urgently needed to investigate whether vitamin D supplementation is able to reduce mortality risk in the general population.

Original title:
Vitamin D deficiency and mortality risk in the general population: a meta-analysis of prospective cohort studies by Zittermann A, Iodice S, [...], Gandini S.

Link:
http://ajcn.nutrition.org/content/95/1/91.full

Additional information of El Mondo:
Find more information/studies on vitamin D 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:
Does soy isoflavone reduce the frequency and severity of hot flashes?

Study design:
This review article included 19 trials (13 included hot flash frequency, of which 10 for severity and 3 for composite scores).
17 trials were selected for meta-analyses to clarify the effect of soybean isoflavones on hot flash frequency (13 trials) and severity (9 trials).

Results and conclusions:
The investigators found intake of soy isoflavones (median = 54 mg aglycone equivalents) for 6 weeks to 12 months significantly reduced the frequency (combined fixed-effect and random effects model) of hot flashes by 20.6% [95% CI = -28.38 to -12.86, p 0.00001] compared with placebo [p heterogeneity = 0.0003, I2 = 67% for random effects model].

The investigators also found isoflavones significantly reduced hot flash severity by 26.2% [95% CI = -42.23 to -10.15, p = 0.001] compared with placebo [p heterogeneity 0.00001, I2 = 86% for random effects model].

The investigators found isoflavone supplements providing more than 18.8 mg of genistein (the median for all studies) were more than twice as potent at reducing hot flash frequency than lower genistein supplements.

The investigators concluded soy isoflavone supplements (54 mg per day for 6 weeks to 12 months), derived by extraction or chemical synthesis, are significantly more effective than placebo in reducing the frequency and severity of hot flashes. Additional studies are needed to further address the complex array of factors that may affect efficacy, such as dose, isoflavone form, baseline hot flash frequency and treatment duration.

Original title:
Extracted or synthesized soybean isoflavones reduce menopausal hot flash frequency and severity: systematic review and meta-analysis of randomized controlled trials by Taku K, Melby MK, […], Messina M.

Link:
http://journals.lww.com/menopausejournal/Abstract/2012/07000/Extracted_or_synthesized_soybean_isoflavones.11.aspx

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

Objectives:
In view of the vital role of oxidative stress in the pathogenesis of Alzheimer's disease (AD), the potential of antioxidant supplements to prevent AD have gained much interest, while there are conflicting results on this topic in recent years. Therefore, this review article has been conducted.

Does dietary intake of vitamin C and E and β-carotene decrease risk of Alzheimer's disease?

Study design:
This review article included 7 articles (dietary intake, but no supplements).

Results and conclusions:
The investigators found a significant decreased risk for Alzheimer disease of 24% [pooled relative risk = 0.76 95% CI = 0.67-0.84] for dietary intake of vitamin E and of 17% [pooled relative risk = 0.83, 95% CI = 0.72-0.94] for dietary intake of vitamin C.

However, the investigators found a non-significant decreased risk of 12% [pooled relative risk = 0.88, 95% CI = 0.73-1.03] for dietary intake of β-carotene.

The investigators concluded dietary intakes of vitamin C and E lower the risk of Alzheimer's disease, with vitamin E exhibiting the most pronounced protective effects. The findings will be of significance to the prevention and interventional treatment of Alzheimer's disease.

Original title:
Dietary intakes of vitamin E, vitamin C, and β-carotene and risk of Alzheimer's disease: a meta-analysis by Li FJ, Shen L and Ji HF.

Link:
http://www.ncbi.nlm.nih.gov/pubmed/22543848

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

Objectives:
Does diabetes increase risk of incident dementia and mild cognitive impairment?

Study design:
This review article included 19 prospective longitudinal studies including 6184 subjects with diabetes and 38530 subjects without diabetes. All subjects were without dementia or mild cognitive impairment at baseline (=at the beginning of the study).

There was no publication bias.

Results and conclusions:
The investigators found persons with diabetes had a significant increased risk of 46% for Alzheimer's disease [RR = 1.46, 95% CI = 1.20-1.77]. Significant means that there is an association with a 95% confidence.

The investigators found persons with diabetes had a significant increased risk of 148% for vascular dementia [RR = 2.48, 95% CI = 2.08-2.96].

The investigators found persons with diabetes had a significant increased risk of 51% for any dementia [RR = 1.51, 95% CI = 1.31-1.74]. Significant because RR of 1 was not found in the 95% CI of 1.31 to 1.74. RR of 1 means no risk/association.

The investigators found persons with diabetes had a significant increased risk of 21% for mild cognitive impairment [RR = 1.21, 95% CI = 1.02-1.45].

The investigators concluded diabetes is a risk factor for incident dementia (including Alzheimer's disease, vascular dementia and any dementia) and mild cognitive impairment.

Original title:
Diabetes as a risk factor for dementia and mild cognitive impairment: a meta-analysis of longitudinal studies by Cheng G, Huang G, [...], Wang H.

Link:
http://onlinelibrary.wiley.com/doi/10.1111/j.1445-5994.2012.02758.x/epdf

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

Objectives:
An increased intake of magnesium might lower blood pressure (BP), yet evidence from clinical trials is inconsistent, perhaps as a result of small sample size or heterogeneity in study design. Therefore, this review article (meta-analysis) has been conducted.

Are there dose-dependent effects of magnesium supplementation on blood pressure?

Study design:
This review article included 20 RCTs included 14 of hypertensive and 6 of normotensive persons totaling 1220 participants.
The doses of magnesium ranged from 10 to 40 mmol/day (median: 15.4 mmol/day or 370 mg per day).

Results and conclusions:
The investigators found magnesium supplementation resulted in only a small overall non-significant reduction in blood pressure. The pooled net estimates of blood pressure change were -0.6 mmHg [95% CI = -2.2 to 1.0] for systolic blood pressure and -0.8 mmHg [95% CI = -1.9 to 0.4] for diastolic blood pressure.

However, the investigators found an apparent dose-dependent effect of magnesium, with significant reductions of 4.3 mmHg systolic blood pressure [95% CI = 6.3 to 2.2, p 0.001) and non-significant reductions of 2.3 mmHg diastolic blood pressure [95% CI = 4.9 to 0.0, p = 0.09) for each 10 mmol/day (240 mg/day) increase in magnesium dose.

The investigators concluded there is a dose-dependent blood pressure reductions, especially systolic blood pressure from magnesium supplementation. However, adequately powered trials with sufficiently high doses of magnesium supplements need to be performed to confirm this relationship.

Original title:
The effect of magnesium supplementation on blood pressure: a meta-analysis of randomized clinical trials by Jeea SH, Miller ER, [...], Klagb MJ.

Link:
http://www.sciencedirect.com/science/article/pii/S0895706102029643

Additional information of El Mondo:
Find more studies/information on magnesium and lowering blood pressure right here.  

Objectives:
Quantification of the association between the intake of fruit and vegetables and risk of esophageal squamous cell carcinoma (ESCC) is controversial even though several studies have explored this association. Therefore, this review article (meta-analysis) has been conducted.

Does a high intake of vegetables and fruit decrease risk of esophageal squamous cell carcinoma?

Study design:
This review article included a total of 32 observational studies involving 10037 cases of esophageal squamous cell carcinoma.

There was no evidence of publication bias.

Results and conclusions:
The investigators found highest vs. lowest vegetable intake, significantly reduced risk of esophageal squamous cell carcinoma with 44% [SRR = 0.56, 95% CI = 0.45-0.69, p-heterogeneity 0.001]. Significant means there is an association with a 95% confidence.

The investigators found highest vs. lowest fruit intake, significantly reduced risk of esophageal squamous cell carcinoma with 47% [SRR = 0.53, 95% CI = 0.44-0.64, p-heterogeneity 0.001].

The investigators found similar results in a linear dose-response analysis and there was evidence of non-linear associations for intakes of fruit [p non-linearity 0.001] and vegetables [p non-linearity = 0.041].

The investigators concluded that intakes of vegetables and fruit reduce risk of esophageal squamous cell carcinoma. Further investigation with prospective designs, validated questionnaires and good control of important confounders is warranted.

Original title:
Intake of fruit and vegetables and risk of esophageal squamous cell carcinoma: A meta-analysis of observational studies by Liu J, Wang J, […], Lv C.

Link:
http://www.ncbi.nlm.nih.gov/pubmed/23319052

Additional information of El Mondo:
Find more information/studies on review, 95% CI and heterogeneity, vegetables and fruits and cancer right here.
 

Objectives:
Previous systematic reviews suggest beneficial effects of flavonoids on biomarkers of cardiovascular disease (CVD) risk, but have overlooked the impact of dose response or food complexity. Therefore, this review article has been conducted.

Do taking flavonoid supplements improve flow-mediated dilation (FMD) and blood pressure?

Study design:
This review article included 63 RCTs.

Results and conclusions:
The investigators found meta-analyses of combined flavonoid subclasses showed significant improvements in FMD [chronic: 0.73%, 95% CI = 0.17 to 1.30, 14 RCTs and acute: 2.33%, 95% CI = 1.58 to 3.08, 18 RCTs].

The investigators found meta-analyses of combined flavonoid subclasses showed significant improvements in blood pressures [systolic: -1.46 mmHg, 95% CI = -0.38 to -0.53, 63 RCTs and diastolic: -1.25 mmHg, 95% CI = -1.82 to -0.67, 63 RCTs].

The investigators found similar benefits were observed for the flavan-3-ol, catechol flavonoids (catechins, quercetin, cyanidin etc.), procyanidins, epicatechin and catechin subgroups.

The investigators found dose-response relationships were non-linear for FMD (R2 ≤ 0.30), with greater associations observed when applying polynomial regression analyses (R2 ≤ 0.72). However, there was no indication of a dose response for blood pressure.

The investigators concluded flavonoid subclasses supplements show significant improvements in FMD and blood pressure. However, the flavonoid bioactivity does not follow a classical linear dose-response association and this may have important biological implications.

Original title:
Relative impact of flavonoid composition, dose and structure on vascular function: A systematic review of randomised controlled trials of flavonoid-rich food products by Kay CD, Hooper L, […], Cassidy A.

Link:
http://onlinelibrary.wiley.com/doi/10.1002/mnfr.201200363/abstract;jsessionid=2CCB9E4E779A221E42AA38998C865DA6.d02t03?deniedAccessCustomisedMessage=&userIsAuthenticated=false

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

The optimal blood pressure for a healthy adult is120 mmHg systolic pressure and 80 mmHg diastolic pressure.

When blood flow increases through a vessel, the vessel dilates. This phenomenon has been coined flow-mediated dilatation (FMD). Flow-mediated dilation is an accepted technique to quantify endothelial function and has shown to have prognostic value for future cardiovascular disease (CVD).