Nutrition and health

Objectives:
Observational studies have reported controversial evidence of the association between dietary fat intake and ovarian cancer. Therefore, this review article has been conducted.
Does dietary fat intake increase risk of ovarian cancer among women?

Study design:
This review article included 21 observational studies involved approximately 900,000 women.

Results and conclusions:
The investigators found a significant nonlinear association between dietary total fat intake with the risk of ovarian cancer, with a relatively steep slope at dietary total fat intake higher than 30 g/day [p non-linearity 0.01].

The investigators found, moreover, the risk of ovarian cancer was increased in non-linear form for both saturated and monounsaturated fat from 25 g/day [p non-linearity 0.05].

The investigators found in linear meta-analysis a 2% greater risk of ovarian cancer per 10 g/day increase in total dietary fat intake.

The investigators found in linear meta-analysis a 2% greater risk of ovarian cancer per 0.5 g/day increase in dietary trans fat intake.

The investigators found in linear meta-analysis a 1% greater risk of ovarian cancer per 2.5 g/day increase in dietary monounsaturated fat intake.
However, this association for monounsaturated fat was marginally significant [p = 0.052].

The investigators found in linear meta-analysis a 1% greater risk of ovarian cancer per 50 mg/day increase in dietary cholesterol intake.

The investigators concluded that dietary total, trans, saturated and partially monounsaturated fat as well as cholesterol intake increase risk of ovarian cancer among women.

Original title:
Dietary Fat Intake and Risk of Ovarian Cancer: A Systematic Review and Dose-Response Meta-Analysis of Observational Studies by Sadeghi A, Shab-Bidar S, […], Djafarian K.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31058552

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

Objectives:
Although many studies have shown that low zinc status is associated with diabetes, the putative effects of zinc supplementation on glycemic control are inconclusive. Therefore, this review article (meta-analysis) has been conducted.

Does zinc supplementation reduce risk of diabetes mellitus?

Study design:
This review article included 32 RCTs, involving a total of 1,700 participants in 14 countries.

Results and conclusions:
The investigators found overall, compared with their respective control groups, the subjects in the zinc supplementation group had a statistically significant reduction in concentrations of :
-fasting glucose [WMD = -14.15 mg/dL, 95% CI = -17.36 to -10.93 mg/dL];
-2-h postprandial glucose [WMD = -36.85 mg/dL, 95% CI = -62.05 to -11.65 mg/dL];
-fasting insulin [WMD = -1.82 mU/L, 95% CI = -3.10 to -0.54 mU/L];
-homeostasis model assessment for insulin resistance [WMD = -0.73, 95% CI = -1.22 to -0.24]:
-glycated hemoglobin [WMD = -0.55%, 95% CI = -0.84 to -0.27%] and;
-high-sensitivity C-reactive protein [WMD = -1.31 mg/L, 95% CI = -2.05 to -0.56 mg/L].

The investigators found, moreover, subgroup analyses revealed that the effects of zinc supplementation on fasting glucose were significantly influenced by diabetic status and the formulation of the zinc supplement.

The investigators concluded several key glycemic indicators are significantly reduced by zinc supplementation, particularly the fasting glucose in subjects with diabetes and in subjects who received an inorganic zinc supplement. Together, these findings support the notion that zinc supplementation may have clinical potential as an adjunct therapy for preventing or managing diabetes.

Original title:
Zinc supplementation improves glycemic control for diabetes prevention and management: a systematic review and meta-analysis of randomized controlled trials by Wang X, Wu W, [...], Wang F.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31161192

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

Objectives:
Iron has been shown to promote breast carcinogenesis in animal models through generation of oxidative stress and interaction with estrogen. Heme iron, which is found exclusively in animal-sourced foods, is suggested to have a more detrimental effect. Epidemiological evidence of the association between iron and breast cancer risk remains inconclusive and has not been comprehensively summarized. Therefore, this review article has been conducted.

Does dietary iron consumption increase breast cancer risk?

Study design:
This review article included 15 case-control studies and 12 prospective cohort studies.

Of the 17 studies assessing iron intake, 7 were cohort studies with study size ranging from 4,646 to 193,742 participants, follow-up ranging from 5.5 to 20 years and number of breast cancer cases ranging from 188 to 9,305. The remaining 10 studies were case-control studies, of which 4 were hospital-based, 3 were population-based and 3 were nested within existing cohorts, with case numbers ranging from 220 to 3,452.

Of the 11 studies assessing body iron status, 5 were cohort studies with study size ranging from 1,795 to 164,355 participants, follow-up ranging from 7.1 to 17.6 years and number of cases ranging from 80 to 3,238. The remaining 6 studies used a nested case-control or case-cohort design, with follow-up (where reported) ranging from 4 to 15.7 years and case numbers ranging from 107 to 795.

Overall, NOS scores ranged from 4 to 9 (mean = 7.0).

No publication bias was found.

Results and conclusions:
The investigators found compared to lowest category, highest dietary heme iron intake significantly increased risk of breast cancer with 12% [pooled RR = 1.12, 95% CI = 1.04-1.22, I2 = 39%, p heterogeneity = 0.15].

The investigators found each 1 mg/day increase in dietary heme iron intake, was associated with a statistically significant 8% increase in breast cancer risk [pooled RR = 1.08, 95% CI = 1.002–1.17].

The investigators found compared to lowest levels, highest serum iron levels significantly increased risk of breast cancer with 22% [pooled RR = 1.22, 95% CI = 1.01-1.47, I2 = 61%, p heterogeneity = 0.04].

The investigators found serum iron levels exhibited a J-shaped dose-response relationship with breast cancer risk, with strong evidence of a nonlinear effect [p nonlinearity  0.001].

Specifically, a steady increase in risk was noted for serum iron levels above ~ 100 μg/dL, with the association becoming statistically significant at just beyond ~ 125 μg/dL.

The investigators concluded that higher dietary heme iron intake and higher serum iron levels increase breast cancer risk. Further research is needed to better elucidate the association between iron intake/status and risk of breast cancer.

Original title:
Iron intake, body iron status, and risk of breast cancer: a systematic review and meta-analysis by Chang VC, Cotterchio M and Khoo E.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6555759/

Additional information of El Mondo:
Find more information/studies on iron consumption, review article/significantly and breast cancer right here.
 

Objectives:
Dietary proteins, including those obtained from animal and plant sources, have inconsistently been correlated with type 2 diabetes mellitus (T2DM) risk. Therefore, this review article (meta-analysis) has been conducted.

Does dietary protein intake increase risk of type 2 diabetes mellitus?

Study design:
This review article included 21 cohort studies with a total of 487,956 individuals and 38,350 T2DM cases (persons with type 2 diabetes mellitus).

Results and conclusions:
The investigators found high total dietary protein intake was associated with an increased risk of 10% for type 2 diabetes mellitus [RR = 1.10, p = 0.006] whereas moderate total dietary protein intake was not significantly associated with type 2 diabetes mellitus risk [RR = 1.00,  p = 0.917].  
Not significantly because the calculated p-value of 0.917 was larger than the p-value of 0.05.

The investigators found, moreover, an increased risk of 13% [RR = 1.13, p = 0.013] for type 2 diabetes mellitus was observed with high  dietary animal protein intake whereas moderate animal protein intake had little or no effect on type 2 diabetes mellitus risk [RR = 1.06, p = 0.058].

The investigators found, high dietary intake of plant protein did not affect type 2 diabetes mellitus risk [RR = 0.93, p = 0.074], whereas moderate intake was associated with a reduced risk of 6% for type 2 diabetes mellitus [RR = 0.94, p  0.001].

The investigators concluded high dietary total protein and dietary animal protein intakes are associated with an increased risk of type 2 diabetes mellitus, whereas moderate plant protein intake is associated with a decreased risk of type 2 diabetes mellitus.

Original title:
Dietary protein intake and subsequent risk of type 2 diabetes: a dose-response meta-analysis of prospective cohort studies by Ye J, Yu Q, [...], Wang Y.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30929078

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

A diet with high protein intake is a diet with a minimum of 35 En% protein (En% = energy percentage). These products from the supermarket contain at least 35 En% protein.
35 En% protein means that the amounts of protein contribute 35% to the total calories (kcal) of the diet.
If the diet contains 2000 kcal, 175 grams of protein contribute 35% to this 2000 kcal.
1 gram of protein gives 4 kcal. Thus, 175 grams of protein provide 700 kcal and 700 kcal is 35% of 2000 kcal.

A diet with moderate protein consumption is a diet with 20-25 En% protein. The easiest way to follow a diet with moderate protein consumption is to choose only products/meals that also contain 20-25 En% protein. These products from the supermarket contain 20-25 En% protein.

 

Objectives:
Is there an association between poultry and egg consumption and brain cancer risk?

Study design:
This review article included a total of 10 articles (6 articles for poultry consumption and 5 articles for egg consumption).

Results and conclusions:
The investigators found no association between poultry consumption and reduced risk of brain cancer [summarized relative risk = 0.901, 95% CI = 0.703-1.154, I2 = 60.7%, p = 0.018].
No association because RR of 1 was found in the 95% CI of 0.703 to 1.154. RR of 1 means no risk/association.

The investigators found in 4 studies no association between poultry consumption and reduced risk of brain cancer glioma [summarized relative risk = 0.873, 95% CI = 0.737-1.034, I2 = 0.0%, p = 0.838].

The investigators found no association between egg consumption and reduced risk of brain cancer [summarized relative risk = 0.998, 95% CI = 0.552-1.805, I2 = 82.6%, p = 0.001].

The investigators found no association between egg consumption and increased risk of brain cancer glioma [summarized relative risk = 1.472, 95% CI = 0.935-2.316].

The investigators concluded that poultry and egg consumption are not associated with the risk of brain cancer. Due to the limited quality of evidence currently available, more studies related to poultry and egg consumption for brain cancer is necessary.

Original title:
A meta-analysis of the association between poultry and egg consumption and the risk of brain cancer by Luo H, Sun P, [...], Guo Y.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30782302

Additional information of El Mondo:
Find more information/studies on poultry and egg consumption, review article/significantly and cancer right here.

Objectives:
Previous studies had demonstrated some associations between coffee and tea consumption and brain cancer risk resulted in an inconsistent relationship. Therefore, this review article has been conducted.

Does coffee or tea consumption reduce brain cancer risk?

Study design:
This review article included 8 cohort studies and 3 case-control studies, involving 2,583 cases (persons with brain cancer) among 1,684,262 participants.

Based on Egger’s test and funnel plot, there existed no publication bias.

Results and conclusions:
The investigators found highest category of coffee consumption significantly reduced risk of brain cancer with 21.5% [RR = 0.785, 95% CI = 0.580-0.984, I2 = 65.6%, p for heterogeneity = 0.001], when compared with the lowest category.

The investigators found in supgroup analysis highest category of coffee consumption significantly reduced risk of glioma with 24% [RR = 0.760, 95% CI = 0.548-0.972], when compared with the lowest category.

The investigators found in cohort studies highest category of coffee consumption significantly reduced risk of brain cancer with 14.2% [RR = 0.858, 95% CI = 0.700-0.992], when compared with the lowest category. However, this reduced risk was not significant in case-control studies.

The investigators found highest category of coffee consumption significantly reduced risk of brain cancer with 88.3% in Asian populations [RR = 0.217, 95% CI = 0.042-0.896], when compared with the lowest category. However, this reduced risk was not significant in other populations.

The investigators found sensitivity analysis showed pooled RR of coffee consumption ranged from 0.738 [95% CI = 0.542-0.961) to 0.905 [95% CI = 0.754-1.088].

The investigators found highest category of tea consumption significantly reduced risk of brain cancer with 20.2% in American populations [RR = 0.798, 95% CI = 0.646-0.986], when compared with the lowest category.

The investigators found sensitivity analysis showed pooled RR of tea consumption ranged from 0.863 [95% CI = 0.699-1.067] to 0.947 [95% CI = 0.763-1.176].

The investigators found highest category of coffee plus tea consumption significantly reduced risk of brain cancer with 31.6% [RR = 0.684, 95% CI = 0.481-0.975], when compared with the lowest category.

The investigators concluded higher consumption of coffee reduces risk of brain cancer in Asian populations and higher consumption of tea reduces risk of brain cancer in American population. However, future studies with detailed information about sex, lifestyle and some other related factors are warranted to further explore the association between coffee or tea consumption and risk of brain cancer.

Original title:
Association between tea and coffee consumption and brain cancer risk: an updated meta-analysis by Song Y, Wang Z, [....], Guo J.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6419842/

Additional information of El Mondo:
Find more information/studies on coffee and tea consumption, review article/significantly and cancer right here.
 

Objectives:
The role of gut microbiota in the management of diabetes has been shown. Several current trials are investigating the effect of probiotics and prebiotics, which are widely used to modulate intestinal microbiota, on inflammatory factors and biomarkers of oxidative stress in diabetic patient. However, their findings are controversial. Therefore, this review article (meta-analysis) has been conducted.

Do probiotic and synbiotic supplementation improve biomarkers of inflammation and oxidative stress in diabetic patients?

Study design:
This review article included 16 RCTs (n = 1,060).

Randomized controlled trials (RCTs) reported the effect of probiotics or synbiotics on circulating (serum and plasma) inflammatory marker (hs-CRP) and oxidative stress indicators (malondialdehyde [MDA], glutathione [GSH], nitric oxide [NO] and total antioxidant capacity [TAC]) among patients with diabetes.

The methodological quality varied across these trials.

Results and conclusions:
The investigators found probiotic and synbiotic supplementation significantly decreased hs-CRP level [SMD = -0.38, 95% CI = -0.51 to -0.24, p = 0.000] and the oxidative stress indicator malondialdehyde [SMD = -0.61, 95% CI = -0.89 to -0.32, p = 0.000] in diabetic patients compared to those in subjects receiving placebos.

The investigators found, in addition, probiotic and synbiotic supplementation significantly increased total antioxidant capacity [SMD = 0.31, 95% CI = 0.09 to 0.52, p = 0.006], nitric oxide [SMD = 0.62, 95% CI = 0.25 to 0.99, p = 0.001] and glutathione [SMD = 0.41, 95% CI = 0.26, 0.55, p = 0.000] levels.

The investigators concluded that probiotic and synbiotic supplementation improve biomarkers of inflammation and oxidative stress in diabetic patients. Further studies are needed to develop clinical practice guidelines for the management of inflammation and oxidative stress in these patients.

Original title:
The effect of probiotic and synbiotic supplementation on biomarkers of inflammation and oxidative stress in diabetic patients: A systematic review and meta-analysis of randomized controlled trials by Zheng HJ, Guo J, [...], Wang Y.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30794924

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

Oxidative stress is an imbalance between free radicals and antioxidants in your body. Antioxidants can reduce oxidative stress.
 

Objectives:
Results from earlier publications on the association of coffee and caffeine and risk of ovarian cancer are inconsistent. Therefore, this review article has been conducted.

Is there an association between coffee and caffeine consumption and risk of ovarian cancer among women?

Study design:
This review article included 22 case-control studies with a total of 40,140 participants, of which 8,568 patients with ovarian cancer. The participants were ≥ 17 years.

Results and conclusions:
The investigators found combining 21 effect sizes from 18 studies, no significant association was observed between total coffee consumption and risk of ovarian cancer [OR = 1.09, 95% CI = 0.94 to 1.26].

The investigators found no significant association between total caffeine intake and ovarian cancer risk [OR = 0.89, 95% CI = 0.55 to 1.45].

The investigators found, in addition, caffeinated coffee intake was not significantly associated with ovarian cancer risk [OR = 1.05, 95% CI = 0.87 to 1.28].

The investigators found, however, combining effect sizes from 5 studies, an inverse significant association between decaffeinated coffee intake and risk of ovarian cancer [OR = 0.72, 95% CI = 0.58 to 0.90].

The investigators concluded decaffeinated coffee consumption could reduce risk of ovarian cancer among women. Could reduce because this review article only included case-control studies and no cohort studies.

Original title:
Coffee and caffeine intake and risk of ovarian cancer: a systematic review and meta-analysis by Shafiei F, Salari-Moghaddam A , […], Esmaillzadeh A.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30833443

Additional information of El Mondo:
Find more information/studies on coffee consumption, review article/significantly and cancer right here.
 

Objectives:
Various mechanisms link higher total homocysteine to higher insulin resistance and risk of type 2 diabetes (T2D). Folate supplementation is recognized as a way to lower homocysteine. However, randomized controlled trials (RCTs) show inconsistent results on insulin resistance and type 2 diabetes outcomes. Therefore, this review article (meta-analysis) has been conducted.

Does folate supplementation improve insulin resistance and type 2 diabetes outcomes?

Study design:
This review article included 29 RCTs (22,250 participants) that assessed the effect of placebo-controlled folate supplementation alone or in combination with other B vitamins on fasting glucose, insulin, homeostasis model assessment for insulin resistance (HOMA-IR), glycated hemoglobin (HbA1c) or risk of type 2 diabetes.

The meta-analysis was conducted using both random- and fixed-effects models to calculate weighted mean differences (WMDs) or risk ratios with 95% CIs.
Heterogeneity was low in all meta-analyses.

Results and conclusions:
The investigators found when compared with placebo, folate supplementation significantly lowered fasting insulin [WMD = -13.47 pmol/L, 95% CI = -21.41 to -5.53 pmol/L, p 0.001] and HOMA-IR [WMD = -0.57 units, 95% CI = -0.76 to -0.37 units, p 0.0001], but no overall effects were observed for fasting glucose or HbA1c.

The investigators found subgroup analysis showed no signs of effect modification except for change in homocysteine, with the most pronounced effects in trials with a change of >2.5 µmol/L.
Changes in homocysteine after folate supplementation correlated with changes in fasting glucose [β = 0.07, 95% CI = 0.01 to 0.14, p = 0.025] and HbA1c [β = 0.46, 95% CI = 0.06 to 0.85, p = 0.02].

The investigators found only 2 studies examined folate supplementation on risk of type 2 diabetes and they found no change in RR [pooled RR = 0.91, 95% CI = 0.80 to 1.04, p = 0.16].

The investigators concluded that folate supplementation lowers fasting insulin and HOMA-IR. However, folate supplementation does not reduce risk of type 2 diabetes.

Original title:
Effect of folate supplementation on insulin sensitivity and type 2 diabetes: a meta-analysis of randomized controlled trials by Lind MV, Lauritzen L, [...], Eriksen JN.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30615110

Additional information of El Mondo:
Find more information/studies on diabetes and folate (also called folic acid) right here.
 

Objectives:
Do omega-3 fatty acids in fish consumption reduce risk of breast cancer in Asian patients?

Study design:
This review article included 4 cohort studies and 7 case-control studies with a total of 130,365 Asian patients.

There was not any study with significant publication bias included.

Results and conclusions:
The investigators found omega-3 fatty acids in fish consumption significantly reduced risk of  breast cancer in Asian patients with 20% [OR = 0.80, 95% CI = 0.73-0.87, p 0.00001].
Significant because OR of 1 was not found in the 95% CI of 0.73 to 0.87. OR of 1 means no risk/association.

The investigators concluded omega-3 fatty acids in fish consumption reduce breast cancer risk in Asian patients.

Original title:
Protective Effect of Omega-3 Fatty Acids in Fish Consumption Against Breast Cancer in Asian Patients: A Meta-Analysis by Nindrea RD, Aryandono T, […], Dwiprahasto I.

Link:
http://journal.waocp.org/?sid=Entrez:PubMed&id=pmid:30803190&key=2019.20.2.327

Additional information of El Mondo:
Find more information/studies on fish consumption, review article/significantly and breastcancer right here.

Fish containing omega-3 fatty acids are salmon, mackerel, herring, lake trout, bluefin tuna, sturgeon, sablefish, anchovy, albacore tuna, whitefish, arctic char, sardines, bluefish, mullet, halibut, striped bass, mahi mahi, pollock, rockfish, rainbow trout, shark, catfish, carp, cod, flounder, grouper, haddock, ocean perch, red snapper, swordfish, pike, sole and tilapia.

Objectives:
Although the relationship between dietary intake and serum levels of trans fatty acids and risk of breast cancer has been investigated extensively, findings are inconsistent. Therefore, this review article has been conducted.

Do dietary intake and serum levels of trans fatty acids increase risk of breast cancer?

Study design:
This review article included 6 cohort studies and 1 nested case-control study on total dietary trans fat intake and 1 cohort study and 4 nested case-control studies on serum trans fatty acids.

Participants were apparently healthy aged 26 years or older.

Results and conclusions:
The investigators found no significant relationship between dietary intake of total trans fatty acids and risk of breast cancer [pooled effect size = 1.02, 95% CI = 0.95-1.10, p = 0.403].

The investigators found in 3 effect sizes from 2 cohort studies and 1 nested case-control study, no significant relation between dietary intake of conjugated linoleic acid (CLA) and risk of breast cancer [pooled effect size = 1.05, 95% CI = 0.95-1.17, p = 0.513].

The investigators found based on 5 effect sizes, each additional 1 g/day dietary intake of total trans fats was not significantly associated with risk of breast cancer [RR = 1.00, 95% CI = 0.99-1.01].

The investigators found high serum levels of trans fats were associated with an increased risk of 37% of breast cancer among postmenopausal women [pooled effect size = 1.37, 95% CI = 1.04-1.81, p = 0.02].

The investigators concluded dietary intake of trans fatty acids (also called trans fats) is not associated with risk of breast cancer. However, a significant positive association is seen between serum trans fats and risk of breast cancer in postmenopausal women.

Original title:
Dietary intake and serum levels of trans fatty acids and risk of breast cancer: A systematic review and dose-response meta-analysis of prospective studies by Anjom-Shoae J, Sadeghi O, […], Esmaillzadeh A.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30954361

Additional information of El Mondo:
Find more information/studies on trans fatty acids consumption, review article/significantly and breastcancer right here.

Objectives:
Epidemiological studies focusing on the association between folate and breast cancer risk reported inconsistent findings. Therefore, this review article has been conducted.

Does dietary folate intake reduce breast cancer risk?

Study design:
This review article included a total of 23 prospective cohort studies involving 41,516 cases (=women with breast cancer) among 1,171,048 individuals.

Results and conclusions:
The investigators found dietary folate intake significantly reduced risk of oestrogen-receptor-negative breast cancer with 12% [pooled risk ratio = 0.88, 95% CI = 0.78-1.00].

The investigators found dietary folate intake significantly reduced risk of oestrogen-receptor-negative/progesterone-receptor-negative breast cancer with 18% [pooled risk ratio = 0.82, 95% CI = 0.68-0.97].

The investigators found an increment of dietary folate intake of 100 μg per day was associated with a deceased risk of oestrogen-receptor-negative breast cancer with 6% [RR = 0.94, 95% CI = 0.88-0.99].

The investigators found an increment of dietary folate intake of 100 μg per day was associated with a deceased risk of oestrogen-receptor-negative/progesterone-receptor-negative breast cancer with 10% [RR = 0.90, 95% CI = 0.85-0.97].

The investigators found high dietary folate intake significantly reduced breast cancer risk in premenopausal women with 6% [RR = 0.94, 95% CI = 0.88-1.00].

The investigators found high dietary folate intake significantly reduced breast cancer risk in women with moderate or high levels of alcohol consumption with 18% [RR = 0.82, 95% CI = 0.72-0.94].

The investigators concluded that at least 100 μg per day dietary folate intake, reduce both oestrogen-receptor-negative and oestrogen-receptor-negative/progesterone-receptor-negative breast cancer, particularly among premenopausal women and women with moderate or high levels of alcohol consumption.

Original title:
Folate intake and the risk of breast cancer: an up-to-date meta-analysis of prospective studies by Zeng J, Wang K, [...], Chang H.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30647438

Additional information of El Mondo:
Find more information/studies on folate consumption, review article/significantly and breast cancer right here.

Objectives:
Evidence from randomized controlled trials (RCTs) suggests that viscous dietary fiber may offer beneficial effects on glycemic control and, thus, an improved cardiovascular disease risk profile. Therefore, this review article (meta-analysis) has been conducted.

Does viscous dietary fiber supplementation improve glycemic control in type 2 diabetes?

Study design:
This review article included 28 RCTs of ≥3 weeks in duration that assessed the effects of viscous fiber on markers of glycemic control in type 2 diabetes with a total of 1,394 participants.

Results and conclusions:
The investigators found that viscous fiber at a median dose of ∼13.1 g/day significantly reduced HbA1c in type 2 diabetes [MD = -0.58%, 95% CI = -0.88 to -0.28, p = 0.0002] compared with control and in addition to standard of care.

The investigators found that viscous fiber at a median dose of ∼13.1 g/day significantly reduced fasting blood glucose in type 2 diabetes [MD = -0.82 mmol/L, 95% CI = -1.32 to -0.31, p = 0.001] compared with control and in addition to standard of care. 

The investigators found that viscous fiber at a median dose of ∼13.1 g/day significantly reduced HOMA-insulin resistance in type 2 diabetes [MD = -1.89, 95% CI = -3.45 to -0.33, p = 0.02] compared with control and in addition to standard of care.

The investigators found the certainty of evidence was graded moderate for HbA1c, fasting glucose, fasting insulin and HOMA-IR and low for fructosamine.

The investigators concluded that 13.1 g/day viscous fiber supplements improve conventional markers of glycemic control beyond usual care and should be considered in the management of type 2 diabetes.

Original title:
Should Viscous Fiber Supplements Be Considered in Diabetes Control? Results From a Systematic Review and Meta-analysis of Randomized Controlled Trials by Jovanovski E, Khayyat R, […], Vuksan V.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30617143

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

Objectives:
Low fruit and vegetable intakes are recognized risk factors for noncommunicable diseases. Therefore, this review article has been conducted.

Do fruit or vegetables intakes reduce noncommunicable diseases, likes cancer, coronary heart disease and all-cause mortality?

Study design:
This review article included 64 reports investigating 98 risk-disease pairs. 56 pairs from 39 reports were assessed as statistically significant, involving 29 burden of diseases.

Results and conclusions:
The investigators found in linear dose analysis for each 100 g/day increase in fruit intakes a significantly reduced risk of 44% [RR = 0.56, 95% CI = 0.42 to 0.74] for esophageal cancer.
Significant means that there is an association with a 95% confidence.

The investigators found in linear dose analysis for each 100 g/day increase in fruit intakes a significantly reduced risk of 28% [RR = 0.72, 95% CI = 0.59 to 0.87] for mouth, pharynx and larynx cancer.

The investigators found in nonlinear dose analysis for the first 100 g/day increase in fruit intakes a significantly reduced risk of 14% [RR = 0.86, 95% CI = 0.84 to 0.88] for stroke.

The investigators found in nonlinear dose analysis for the first 100 g/day increase in fruit intakes a significantly reduced risk of 11% [RR = 0.89, 95% CI = 0.88 to 0.90] for all-cause mortality.

The investigators found in linear dose analysis for each 100 g/day increase in vegetable intakes a significantly reduced risk of 12% [RR = 0.88, 95% CI = 0.80 to 0.95] for renal cell cancer.

The investigators found in linear dose analysis for each 100 g/day increase in vegetable intakes a significantly reduced risk of 11% [RR = 0.89, 95% CI = 0.84 to 0.95] for non-Hodgkin lymphoma.

The investigators found in nonlinear dose analysis for the first 100 g/day increase in vegetable intakes a significantly reduced risk of 14% [RR = 0.86, 95% CI = 0.84 to 0.89] for coronary heart disease.

The investigators found in nonlinear dose analysis for the first 100 g/day increase in vegetable intakes a significantly reduced risk of 13% [RR = 0.87, 95% CI = 0.84 to 0.90] for all-cause mortality.

The investigators found in nonlinear dose analysis clear increases in protective associations were observed with the first 200 g/day of fruit or vegetable intakes, whereas little further increase or even decrease in protective associations were reported beyond 300 g/day intakes.

The investigators found canned fruit intakes were positively associated with all-cause and cardiovascular disease mortality.

The investigators found pickled vegetable intakes were positively associated with stomach cancer.

The investigators concluded that 100-300 g/day of fruit or vegetables intakes reduce certain cancers, coronary heart disease and all-cause mortality. These findings support existing recommendations for fruit and vegetable intakes. Current comparative risk assessments might significantly underestimate the protective associations of fruit and vegetable intakes.

Original title:
The Associations of Fruit and Vegetable Intakes with Burden of Diseases: A Systematic Review of Meta-Analyses by Yip CSC, Chan W and Fielding R.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30639206

Additional information of El Mondo:
Find more information/studies on fruit and vegetable consumption, coronary heart disease and cancer right here.

Objectives:
Diabetes prevention is a public health priority. Vitamin D supplementation may help prevent the development of diabetes in persons at increased risk. Therefore, this review article has been conducted.

Does vitamin D supplementation reduce risk of type 2 diabetes?

Study design:
This review article included 28 RCTs with 3,848 participants.

The sample size varied from 23 to 511.
The mean age of participants ranged from 26 years to 71 years.
The duration of follow-up across studies ranged from 2 months to 5 years, with a median follow-up of 22 weeks [interquartile range (IQR): 14 to 48 weeks], a duration long enough to detect changes in measured outcomes.

The average vitamin D supplementation dose of 88 µg/d (3500 IU/d).
All included trials measured the effect of vitamin D supplementation on serum 25(OH)D concentrations.

Results and conclusions:
The investigators found overall, serum 25(OH)D concentrations in the treated arms (vitamin D-supplemented groups) significantly improved by 45.1 nmol/L [95% CI = 41.3 to 48.9, p 0.001, I2 = 97.4%].

The investigators found compared with the control group, vitamin D supplementation significantly reduced HbA1c level by -0.48% [95% CI = -0.79 to -0.18, p = 0.002, I2 = 92.1%].
However, after adjusting the effect size for potential publication bias using the “trim and fill” method, 4 potentially missing studies were imputed in the funnel plot and the effect size increased from -0.48% [95% CI = -0.79 to -0.18] to -0.71% [95% CI = -1.02 to -0.39].

The investigators found compared with the control group, vitamin D supplementation significantly reduced fasting plasma glucose level by -0.46 mmol/L [95% CI = -0.74 to -0.19, p = 0.001, I2 = 92.4%].  
However, after adjusting the effect size for potential publication bias using the “trim and fill” method, 6 potentially missing studies were imputed in the funnel plot and the effect size increased -0.46 mmol/L [95% CI = -0.74 to ­0.19] to -0.72 mmol/L [95% CI =-1.02 to -0.42].

The investigators found compared with the control group, vitamin D supplementation significantly reduced HOMA-IR level by -0.39 [95% CI = -0.68 to -0.11, p = 0.007, I2 = 91.3%].
However, after adjusting the effect size for potential publication bias using the “trim and fill” method, 5 potentially missing studies were imputed in the funnel plot and the effect size increased from -0.39 [95% CI = -0.68 to -0.11] to -0.62 [95% CI = -0.92 to -0.32].

The investigators found in subgroup analysis both HbA1c and HOMA-IR showed a greater reduction over time among overweight/obese individuals compared with prediabetics [HbA1c = -0.98 ± 0.45 vs -0.29 ± 0.14, p = 0.1 and HOMA-IR = -0.62 ± 0.23 vs -0.07 ± 0.16, p = 0.05].

The investigators found in subgroup analysis vitamin D supplementation significantly decreased HbA1c [p = 0.05], fasting plasma glucose level [p = 0.05] and HOMA-IR [p = 0.1] to a greater extent when serum 25(OH)D concentration achieved was above 86 nmol/L.

The investigators found in subgroup analysis vitamin D supplementation for less than 6 months provided a larger effect size on HbA1c in comparison with long durations [-0.75 ± 0.33 vs -0.25 ± 0.11, p = 0.1].

The investigators found in subgroup analysis HbA1c showed greater improvement in populations with a mean age younger than 45 years in comparison with older populations [-1.15 ± 0.6 vs -0.30 ± 0.1, p = 0.05].

The investigators found in subgroup analysis greater reductions were found within HbA1c and fasting plasma glucose levels when baseline (at the beginning of the study) mean serum 25(OH)D concentration was ≥50 nmol/L, whereas the lowering effect was significantly less in the subgroup with baseline mean 25(OH)D 50 nmol/L [HbA1c = -0.79 ± 0.25 vs -0.14 ± 0.13, p = 0.04 and fasting plasma glucose level = -0.69 ± 0.21 vs -0.11 ± 0.10, p = 0.05].

The investigators concluded 88 µg/d vitamin D supplementation during 22 weeks improves glycemic measures and insulin sensitivity and may be useful as part of a preventive strategy for type 2 diabetes, particularly among overweight/obese individuals younger than 45 years.

Original title:
Vitamin D Supplementation, Glycemic Control, and Insulin Resistance in Prediabetics: A Meta-Analysis by Mirhosseini N, Vatanparast H, [...], Kimball SM.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6016617/

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

HbA1c, FPG, HOMA-IR and plasma glucose after 2-hour oral glucose tolerance test (2HPG) are different parameters associated with (pre)diabetes.

 

Objectives:
Epidemiological studies regarding the association between dietary fiber intake and ovarian cancer risk are still inconsistent. Therefore, this review article has been conducted.

Does dietary fiber intake reduce ovarian cancer risk?

Study design:
This review article included 10 case-control studies and 3 cohort studies, with a total of 5,777 ovarian cancer cases and 142,189 participants.

All the included studies provided RRs that were adjusted for energy intake and most provided RRs that were adjusted for age, oral contraceptive use, menopausal status and parity.
All the original studies measured dietary intakes using a food-frequency questionnaire. NOS scores ranged from 6 to 8 and 7 studies were considered high quality.

Funnel plot shapes demonstrated a symmetrical distribution and no evidence of publication bias was detected by the Egger’s regression test [p = 0.73].

Results and conclusions:
The investigators found for the highest vs. the lowest category of dietary fiber intake a significantly reduced risk of 22% [pooled multivariable RR = 0.78, 95% CI = 0.70 to 0.88, I2 = 4.20%, p = 0.40] for ovarian cancer.

The investigators found a significantly reduced risk of 12% [summarized RR = 0.88, 95% CI = 0.82 to 0.93, I2 = 7.3%, p = 0.38] for ovarian cancer per 10 g/day increase of dietary fiber intake.

The investigators found there was no evidence for a nonlinear association between dietary fiber intake and ovarian cancer risk [p for nonlinearity = 0.83].

The investigators found in subgroup analysis a significantly reduced risk of 23% [pooled RR = 0.77, 95% CI = 0.66 to 0.90] for ovarian cancer in case-control studies. However, the reduced risk was not significant in cohort studies [pooled RR = 0.84, 95% CI = 0.65 to 1.10].

The investigators found sensitivity analysis showed that none of the studies influenced the combined results substantially, with a range from 0.77 [95% CI = 0.68 to 0.87] to 0.81 [95% CI = 0.71 to 0.91].

The investigators concluded that 10g dietary fiber intake per day may reduce the risk of ovarian cancer with 12%. May reduce because the reduced risk was not significant in cohort studies.

Original title:
Dietary fiber intake and reduced risk of ovarian cancer: a meta-analysis by Zheng B, Shen H, […], Qin Y.

Link:
https://nutritionj.biomedcentral.com/articles/10.1186/s12937-018-0407-1

Additional information of El Mondo:
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Objectives:
High potato intake has been suggested as a risk factor for the development of type 2 diabetes. Therefore, this review article has been conducted.

Does potato intake increase risk of type 2 diabetes?

Study design:
This review article included 6 prospective cohort studies with a total of 4,545,230 person-year of follow-up and 17,758 diabetes cases.

Results and conclusions:
The investigators found for every increment of 1 serving/day of total potato consumption a significantly increased risk of 20% [HR = 1.20, 95% CI = 1.13 to 1.127, p 0.001, I2 = 27.1%, p for heterogeneity = 0.23] for type 2 diabetes both in men en women.

The investigators found for 2 servings/day of total potato consumption a significantly increased risk of 44% [HR = 1.44, 95% CI = 1.28 to 1.63] for type 2 diabetes both in men en women.

The investigators found for 3 servings/day of total potato consumption a significantly increased risk of 74% [HR = 1.74, 95% CI = 1.45 to 2.09] for type 2 diabetes both in men en women.

The investigators found significant evidence of a non-linear association between total potato consumption and risk of type 2 diabetes [X2 = 17.5, p for linearity 0.001].

The investigators concluded that long-term high consumption of potato (each serving a day increase) is strongly associated with increased risk of type 2 diabetes. These findings suggest that diet-health policy may be of importance in the prevention of diabetes.

Original title:
Potato consumption and risk of type 2 diabetes: A dose-response meta-analysis of cohort studies by Bidel Z, Teymoori F, […], Nazarzadeh M.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30144898

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

According to the USDA Dietary Guidelines a serving of potato is 1 cup diced, mashed or baked or 1 medium boiled potato.

 

Objectives:
Several B vitamins are essential in the one-carbon metabolism pathway, which is central to DNA methylation, synthesis and repair. Moreover, an imbalance in this pathway has been linked to certain types of cancers. Therefore, this review article has been conducted.

Is there a relationship between dietary vitamin intake and risk of esophageal cancer (EC)?

Study design:
This review article included 24 patient-control studies and 2 cohort studies with a total of 510,954 participants and 6,404 esophageal cancer cases, which included 1,919 esophageal adenocarcinoma (EAC) patients, 2,010 esophageal squamous cell carcinoma (ESCC) patients and 2,475 esophageal cancer (EC) patients.

The quality scores of all studies ranged from 6 to 8, with a median score of 7.

There was no significant publication bias in the final analysis with respect to vitamin B2 [p = 0.244], vitamin B6 [p = 0.068], folate [p = 0.054] or vitamin B12 [p = 0.093].

A sensitivity analysis revealed that no individual study affected the pooled effect size.

Results and conclusions:
The investigators found for the highest level versus the lowest level of dietary folate intake, a significantly reduced risk of 38% [pooled OR = 0.62, 95% CI = 0.56-0.68, I2 = 40.2%] for esophageal cancer.
Subgroup analysis revealed that this inverse correlation (reduced risk) was present in the US [OR = 0.58, 95% CI = 0.51-0.67], Europe [OR = 0.51, 95% CI = 0.40-0.65] and Australia [OR = 0.74, 95% CI = 0.58-0.95], but not in Asia [OR = 0.77, 95% CI = 0.59-1.01].

The investigators found in dose-response analysis that each 100 μg/day increase in dietary folate intake significantly reduced the risk of esophageal cancer by 12% [OR = 0.88, 95% CI = 0.86-0.91].
Significant means that there is an association with a 95% confidence.

The investigators found for the highest level versus the lowest level of dietary vitamin B6 intake, a significantly reduced risk of 41% [pooled OR = 0.59, 95% CI = 0.52-0.66, I2 = 46.8%] for esophageal cancer.
This inverse relationship remained significant in subgroup analyses for esophageal adenocarcinoma [OR = 0.58, 95% CI = 0.49-0.68] and esophageal squamous cell carcinoma [OR = 0.47, 95% CI = 0.33-0.67].

The investigators found in dose-response analysis, a significantly reduced risk of 18% [OR = 0.82, 95% CI = 0.76-0.88] for esophageal cancer for 2.0 mg/day of dietary vitamin B6 intake.

The investigators found in dose-response analysis, a significantly reduced risk of 33% [OR = 0.67, 95% CI = 0.59-0.75] for esophageal cancer for 2.5 mg/day of dietary vitamin B6 intake.

The investigators found in dose-response analysis, a significantly reduced risk of 45% [OR = 0.55, 95% CI = 0.44-0.67] for esophageal cancer for 3.0 mg/day of dietary vitamin B6 intake.

The investigators found in dose-response analysis that each 1 mg/day increase in dietary B6 increase significantly reduced the risk of esophageal cancer by 16% [OR = 0.84, 95% CI = 0.80-0.89].

The investigators found for the highest level versus the lowest level of dietary vitamin B12 intake, a significantly increased risk of 30% [pooled OR = 1.30, 95% CI = 1.05-1.62, I2 = 73.5%] for esophageal cancer.
A subgroup analysis based on geographic location revealed similar results in the US [OR = 1.26, 95% CI = 1.03-1.53] and Europe [OR = 2.54, 95% CI = 1.16-5.53], but not in Australia [OR = 0.93, 95% CI = 0.73-1.19].
A subgroup analysis based on histological type revealed that this correlation was present among patients with esophageal adenocarcinoma [OR = 1.47, 95% CI = 1.02-2.11], but not among patients with esophageal squamous cell carcinoma [OR = 1.00, 95% CI = 0.63-1.61].

The investigators found in dose-response analysis that each 1 μg/day increase in dietary B12 intake significantly increased the risk of esophageal cancer by 2% [OR = 1.02, 95% CI = 1.00-1.03].

The investigators concluded that both dietary vitamin B6 intake (at least 1 mg/day) and dietary folate intake (at least 100 μg/day) are inversely correlated with esophageal cancer risk, whereas dietary vitamin B12 intake (at least 1 μg/day) increases esophageal cancer risk.

Original title:
Intake of Dietary One-Carbon Metabolism-Related B Vitamins and the Risk of Esophageal Cancer: A Dose-Response Meta-Analysis by Qiang Y, Li Q, […], Wang F.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6073467/

Additional information of El Mondo:
Find more information/studies on folate, vitamin B6 and B12 and cancer right here.

Objectives:
Many studies were conducted to explore the relationship between dietary protein intake and risk of prostate cancer, obtaining inconsistent results. Therefore, this review article has been conducted.

Does dietary protein intake increase risk of prostate cancer?

Study design:
This review article included a total of 8 cohort studies, 5 case-control studies and 1 RCT, comprising 13,483 prostate cancer cases among 286,245 participants.

Begg’s funnel plots and Egger’s test [p = 0.296] indicated that no publication bias was found in overall analysis.

Results and conclusions:
The investigators found in the overall analysis there was no association with prostate cancer risk when comparing the highest protein intake with the lowest protein intake [summary RR = 0.993, 95% CI = 0.930-1.061, I2 = 0.0%, p = 0.656].
The sensitivity analysis showed that there is no single study that had potential effects on the overall result while removing a study at a time.

The investigators found in the stratified analysis by protein type, the association was non-significant on prostate cancer risk in both animal protein intake [RR = 1.001, 95% CI = 0.917-1.092] and vegetable protein intake [RR = 0.986, 95% CI = 0.904-1.076].
Non-significant because RR of 1 was found in the 95% CI of 0.917 to 1.092. RR of 1 means no risk/association.

The investigators found there was also no significant association in cohort studies [RR = 1.080, 95% CI = 0.964-1.209] and in case-control studies [RR = 0.960, 95% CI = 0.874-1.055].

The investigators found there was no association with prostate cancer localized-stage disease risk when comparing the highest protein intake with the lowest protein intake [summary RR = 1.263, 95% CI = 0.953-1.674].

The investigators found there was no association with prostate cancer advanced-stage disease risk when comparing the highest protein intake with the lowest protein intake [summary RR = 0.973, 95% CI = 0.745-1.272].

The investigators concluded that there is no effect on prostate cancer with high-protein intake. Since some limitations exited in this review article, future studies are wanted to confirm the result.

Original title:
Association between dietary protein intake and prostate cancer risk: evidence from a meta-analysis by Ye M, Yan T and Jing D.

Link:
https://wjso.biomedcentral.com/articles/10.1186/s12957-018-1452-0

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

Objectives:
There has been accumulating evidence that several micronutrients may play a protective role in the risk of solid cancers. However, their role in hematological malignancies remains to be elucidated. Therefore, this review article has been conducted.

Is there a relationship between vitamin intake and risk of non-Hodgkin lymphoma?

Study design:
This review article included a total of 12 cohort studies.

Results and conclusions:
The investigators found null associations regarding
-supplemented vitamin A [pooled RR = 0.92, 95% CI = 0.80-1.07];
-supplemented vitamin C [pooled RR = 1.00, 95% CI = 0.90-1.12];
-total vitamin D [pooled RR = 1.05, 95% CI = 0.91-1.20];
-supplemented vitamin E [pooled RR = 0.98, 95% CI = 0.88-1.10] and;
-dietary lycopene intake [pooled RR = 1.00, 95% CI = 0.86-1.16] and risk of non-Hodgkin lymphoma.

The investigators found no summary estimates were provided for other hematological malignancies due to the limited number of studies.

The investigators concluded there is no association between vitamin A, C, D, E and lycopene and risk of non-Hodgkin lymphoma.

Original title:
Micronutrient Intake and Risk of Hematological Malignancies in Adults: A Systematic Review and Meta-analysis of Cohort Studies by Psaltopoulou T, Ntanasis-Stathopoulos I, […], Sergentanis TN.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30288994

Additional information of El Mondo:
Find more information/studies on vitamin A, C, D, E and lycopene right here.

Objectives:
There were inconsistent results with respect to the correlation between consumption of wine and the development of colorectal cancer (CRC). Therefore, this review article has been conducted.

Does consumption of wine increase colorectal cancer risk?

Study design:
This review article included a total of 8 case-control studies and 9 cohort studies, involving 12,110 colorectal cancer cases.

Results and conclusions:
The investigators found that wine drinking was not associated with any greater risk for colorectal cancer [SRR = 0.99, 95% CI = 0.89-1.10, p-heterogeneity 0.001] compared with nondrinkers.

The investigators found subgroup analyses (to get more information) indicated that null associations were observed in men and women for colon and rectal cancer.

The investigators found subgroup analyses showed neither light to moderate [2 drinks/day: SRR = 0.93, 95% CI = 0.80-1.08, I2 = 69.2%] nor heavy [≥2 drinks/day: SRR = 1.00, 95% CI = 0.86-1.16, I2 = 39.9%] consumption of wine was associated statistically with colorectal cancer risk.

The investigators concluded that wine consumption is not associated with the risk of colorectal cancer. Furthermore, null associations are found in men and women for colon and rectal cancer.

Original title:
Wine consumption and colorectal cancer risk: a meta-analysis of observational studies by Xu W, Fan H, [...], Ge Z.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30247171

Additional information of El Mondo:
Find more information/studies on review article/significant/heterogeneity, colorectal cancer and wine consumption right here.

Objectives:
Does dietary carrot intake reduce breast cancer risk?

Study design:
This review article included a total of 10 articles involving 13,747 cases (women with breast cancer).

A significant heterogeneity was observed among studies.

Results and conclusions:
The investigators found for the highest compared with the lowest dietary carrot intake a significantly reduced risk of 21% for breast cancer [OR = 0.79, 95% CI = 0.68 to 0.90]. Omission of any single study (=sensitivity analysis) had little effect on the combined risk estimate.

The investigators found in the subgroup analyses separated by study design, the inverse associations were more pronounced in the case-control studies than in the cohort studies, while the associations did not significantly differ by geographical region, study quality, exposure assessment.

The investigators concluded that high intake of dietary carrot reduces breast cancer risk.

Original title:
Association between dietary carrot intake and breast cancer: A meta-analysis by Chen H, Shao F, […], Miao Q.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30212943

Additional information of El Mondo:
Find more information/studies on review article/significant/heterogeneity, breast cancer and carrot consumption right here.

Objectives:
Several studies have been published about the effect of garlic on lipid profile and blood glucose in diabetic patients. Which, the results mostly contradict with each other. Therefore, this review article has been conducted.

Does garlic improve lipid profile and blood glucose in diabetic patients?

Study design:
This review article included 33 articles with a total of 1,273 individuals, with a mean of 39 samples per study.

Results and conclusions:
The investigators found the concentration of serum total cholesterol significantly decreased wih 16.87 mg/dL [95% CI = -21.01 to -12.73, p = 0.001] in the garlic group when compared with the placebo group.

The investigators found the concentration of serum LDL cholesterol (bad cholesterol) significantly decreased with 9.65 mg/dL [95% CI = -15.07 to -4.23, p = 0.001] in the garlic group when compared with the placebo group.

The investigators found the concentration of serum triglycerides significantly decreased with 12.44 mg/dL [95% CI = -18.19 to -6.69, p = 0.001] in the garlic group when compared with the placebo group.

The investigators found the concentration of serum HDL cholesterol (good cholesterol) significantly increased with 3.19 mg/dL [95% CI = 1.85 to 4.53, p = 0.001] in the garlic group when compared with the placebo group.

The investigators found the concentration of serum fasting blood sugar significantly decreased with 10.90 mg/dL [95% CI = -16.40 to -5.40, p = 0.001] in the garlic group when compared with the placebo group.

The investigators found the concentration of serum HbA1c significantly decreased with 0.60 mg/dL [95% CI = -0.98 to -0.22, p = 0.001] in the garlic group when compared with the placebo group.

The investigators concluded that garlic improves lipid profile as well as glucose parameters and can be therapeutically effective in patients suffering from cardiovascular diseases and diabetes.

Original title:
The effect of garlic on lipid profile and glucose parameters in diabetic patients: A systematic review and meta-analysis by Shabani E, Sayemiri K and Mohammadpour M.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30049636

Additional information of El Mondo:
Find more information/studies on diabetes, cholesterol, meta-analyses/heterogeneity and garlic right here.

 

Objectives:
Do dietary flavonoid intake reduce colorectal cancer risk?

Study design:
This review article included 5 prospective cohort and 7 case-control studies with a tolal of 17,481 cases (persons with colorectal cancer) and 740,859 controls (persons without colorectal cancer).

All studies were adjusted for a wide range of potential confounders of colorectal cancer, such as age, gender, BMI, physical activity, family history of colorectal cancer, education, energy intake, alcohol, fiber intake, red and processed meat intake, tobacco, aspirin and non-steroidal anti-inflammatory drug.

There was no publication bias.

Results and conclusions:
The investigators found that there was no significant association between colorectal cancer risk and total flavonoid intake, with a pooled OR from the combination of the included studies of 0.73 [95% CI = 0.48-1.10] for the highest category of intake vs. the lowest category. Similarly, no association between the intake of flavanones or flavan-3-ols and the risk of colorectal cancer was observed.

The investigators found in subgroup analysis of both cohort and case-control studies that when compared with the lowest, the highest intake of dietary flavonols significanty reduced risk of colorectal cancer with 30% [OR = 0.70, 95% CI = 0.54-0.90]. Nevertheless, substantial heterogeneities existed across the studies.
However, this reduced risk was not significant in cohort studies [pooled RR = 1.00, 95% CI = 0.92-1.08].

The investigators found in subgroup analysis of both cohort and case-control studies that when compared with the lowest, the highest intake of dietary flavones significanty reduced risk of colorectal cancer with 21% [OR = 0.79, 95% CI = 0.83-0.99]. Nevertheless, substantial heterogeneities existed across the studies.
However, this reduced risk was not significant in cohort studies [pooled RR = 1.02, 95% CI = 0.94-1.11].

The investigators found in subgroup analysis of both cohort and case-control studies that when compared with the lowest, the highest intake of dietary anthocyanidins significanty reduced risk of colorectal cancer with 22% [OR = 0.78, 95% CI = 0.64-0.95]. Nevertheless, substantial heterogeneities existed across the studies. 
However, this reduced risk was not significant in cohort studies [pooled RR = 1.00, 95% CI = 0.91-1.10].

The investigators found dose-response meta-analysis indicated that an increment of dietary flavones intake of 1 mg per day significantly reduced risk of colorectal cancer with 9% [pooled OR = 0.91, 95% CI = 0.84-0.99].

The investigators found dose-response meta-analysis indicated that an increment of dietary flavonols intake of 10 mg per day significantly reduced risk of colorectal cancer with 14% [pooled OR = 0.86, 95% CI = 0.76-0.97].

The investigators found that high intake of flavonols significantly decreased risk of colon cancer with 20% [OR = 0.80, 95% CI = 0.68-0.94].
Significantly means that there is an association with a 95% confidence.

The investigators found that high intake of flavones significantly decreased risk of rectal cancer with 18% [OR = 0.82, 95% CI = 0.70-0.97].
Significantly because OR of 1 was not found in the 95% CI of 0.70 to 0.97. OR of 1 means no risk/association.

The investigators concluded that high intake of dietary flavonols, flavones and anthocyanidins may decrease the risk of colorectal cancer. May decrease because substantial heterogeneities existed across the studies and the reduced risk was not significant in cohort studies.

Original title:
Dietary Flavonoids and the Risk of Colorectal Cancer: An Updated Meta-Analysis of Epidemiological Studies by Chang H, Lin Lei L, […], Guohua Zhao G.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6073812/

Additional information of El Mondo:
Find more information/studies on review article/significant/publication bias, colorectal cancer and flavonoids right here.

The results of a review article are only reliable when they are also found in cohort studies. Thus, the significantly reduced risk must be found in both patient-control studies (more sensitive to errors) and cohort studies (less susceptible to errors).

Objectives:
Controversial results have been reported concerning the influence of calcium intake on prostate cancer risk. Therefore, this review article has been conducted.

Does calcium intake increase prostate cancer risk?

Study design:
This review article included 11 cohort studies and 1 case control study.

The average age of majority was between 50-70 years and also about 83%of articles had been performed in the USA.

Begg’s test showed the effect of publication bias was significant for relationship between calcium intake and total prostate cancer [p = 0.02] and the relationship between total calcium and localized prostate cancer [p = 0.03].

Results and conclusions:
The investigators found that total calcium intake significantly increased the total prostate cancer risk with 15% [overall RR = 1.15, 95% CI = 1.04-1.27, I2 = 59.7%, p = 0.006].
Sensitivity analysis by removing one study at the same time indicated that the overall RR was robust.

The investigators found in studies with follow-up more than 10 years a significantly increased risk of 22% [RR = 1.22, 95% CI = 1.07-1.38] for total prostate for total calcium intake.

The investigators found in 9 studies a significantly increased risk of 9% [RR = 1.09, 95% CI = 1.01-1.18] for total prostate cancer for 750 mg calcium intake per day.

The investigators found in 8 cohort studies, no association between total calcium intake and localized prostate cancer [RR = 1.05, 95% CI = 0.96-1.14].

The investigators found in 7 cohort studies, no association between total calcium intake and advance prostate cancer [RR = 1.15, 95% CI = 0.89-1.50].

The investigators concluded that calcium intake of 750 mg per day could be considered as a risk factor for total prostate cancer. Could be because there was publication bias.

Original title:
Total Calcium (Dietary and Supplementary) Intake and Prostate Cancer: a Systematic Review and Meta-Analysis by Rahmati S, Azami M, […], Sayehmiri K.

Link:
http://journal.waocp.org/?sid=Entrez:PubMed&id=pmid:29936714&key=2018.19.6.1449

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