Nutritional advice

Objectives:
The influence of dietary fat upon breast cancer mortality remains largely understudied despite extensive investigation into its influence upon breast cancer risk. Therefore, this review article has been conducted.

Does higher total fat or saturated fat dietary intake increase risk of breast-cancer-specific death (breast cancer mortality) among women?

Study design:
This review article included 15 prospective cohort studies investigating total fat and/or saturated fat intake (g/day) and breast cancer mortality.

Results and conclusions:
The investigators found there was no difference in risk of breast-cancer-specific death [HR = 1.14, 95% CI = 0.86 to 1.52, p = 0.34, n = 6] or all-cause death [HR = 1.73, 95% CI = 0.82 to 3.66, p = 0.15, n = 4] for women in the highest versus lowest category of total fat dietary intake.
No difference because HR of 1 was found in the 95% CI of 0.82 to 3.66. HR of 1 means no risk/association.

The investigators found for the highest versus lowest category of saturated fat dietary intake, a significantly increased risk of 51% for breast-cancer-specific death among women [HR = 1.51, 95% CI = 1.09 to 2.09, p 0.01 n = 4].
Significant because HR of 1 was not found in the 95% CI of 1.09 to 2.09. HR of 1 means no risk/association.

The investigators concluded that higher saturated fat dietary intake increases risk of breast-cancer-specific death among women.

Original title:
Dietary fat and breast cancer mortality: A systematic review and meta-analysis by Brennan SF, Woodside JV, […], Cantwell MM.

Link:
https://pubmed.ncbi.nlm.nih.gov/25692500/

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

A diet high in saturated fat is a diet with more than 10 En% saturated fat.
The most easy way to follow a diet with more than 10 En% saturated fat is to choose only meals/products with more than 10 En% saturated fat. Check here which products contain more than 10 En% saturated fat.

However, the most practical way to follow a diet with more than 10 En% saturated fat is, all meals/products that you eat on a daily basis should contain on average more than 10 En% saturated fat.

To do this, use the 7-points nutritional profile app to see whether your daily diet contains more than 10 En% saturated fat.

However, a diet with more than 10 En% saturated fat is an unhealthy diet.

A diet low in saturated fat is a diet with maximum 7 En% saturated fat.
 

Objectives:
Women have a 50% risk of urinary tract infection (UTI) over their lifetime and 20-30% experience a subsequent urinary tract infection recurrence. Cranberry (Vaccinium spp.) has been advocated for treatment of urinary tract infection; however, its efficacy is controversial. Therefore, this review article (meta-analysis) has been conducted.

Does cranberry reduce the risk of urinary tract infection recurrence in healthy women?

Study design:
This review article included 7 RCTs conducted in healthy nonpregnant women aged ≥18 years with a history of urinary tract infection (n = 1498 participants).
Risk of bias indicated that 2 studies had high loss to follow-up or selective outcome reporting. Overall, the studies were relatively small, with only 2 having >300 participants.

Results and conclusions:
The investigators found that cranberry significantly reduced the risk of urinary tract infection by 26% [pooled risk ratio = 0.74, 95% CI = 0.55-0.98, I2 = 54%].

The investigators concluded that cranberry may be effective in preventing urinary tract infection recurrence in generally healthy women. May be effective because the studies were relatively small, with only 2 having >300 participants. Therefore, larger high-quality studies are needed to confirm these findings.

Original title:
Cranberry Reduces the Risk of Urinary Tract Infection Recurrence in Otherwise Healthy Women: A Systematic Review and Meta-Analysis by Zhuxuan Fu, DeAnn Liska, […], Mei Chung.

Link:
http://jn.nutrition.org/content/147/12/2282.abstract

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

Objectives:
Epidemiological studies have provided controversial evidence between beverage consumption and the risk of ulcerative colitis (UC). Therefore, this review article (meta-analysis) has been conducted.

Is there a relationship between beverage consumption and risk of ulcerative colitis?

Study design:
This review article included 13 case-control studies and 3 prospective cohort studies, with a total of 3,689 cases (subjects with ulcerative colitis) and 335,339 controls (subjects without ulcerative colitis).

Egger test detected no significant publication bias.

Results and conclusions:
The investigators found high intake of soft drinks versus low intake, significantly increased risk of ulcerative colitis with 69% [pooled RR = 1.69, 95% CI = 1.24-2.30, I2  =  12.9%, p  = 0 .332].
In subgroup analysis, no substantial changes of the primary result were found between subgroups.

The investigators found high tea consumption versus low consumption, significantly decreased risk of ulcerative colitis with 31% [pooled RR = 0.69, 95% CI = 0.58-0.83, I2  =  0.0%, p  = 0 .697].
In subgroup analysis, no substantial changes of the primary result were found between subgroups.

The investigators found no significant association between alcohol [pooled RR = 1.08, 95% CI = 0.66-1.51] or coffee consumption [pooled RR = 0.58, 95% CI = 0.33-1.05, I2  =  87.5%, p    0.001] and risk of ulcerative colitis. No significant association because RR of 1 was found in the 95% CI of 0.66 to 1.51. RR of 1 means no risk/association.

The investigators concluded high consumption of soft drinks increases the risk of ulcerative colitis, while high tea consumption decreases the risk.

Original title:
Beverage consumption and risk of ulcerative colitis. Systematic review and meta-analysis of epidemiological studies by Nie JY and Zhao Q.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5728934/

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

Objectives:
The role of omega-3 polyunsaturated fatty acids (omega-3 or n-3 PUFAs) in the pathogenesis and treatment of children and adolescents with attention deficit hyperactivity disorder (ADHD) is unclear. Therefore, this review article (meta-analysis) has been conducted.

Do children and adolescents with attention deficit hyperactivity disorder (ADHD) benefit from n-3 PUFA supplementation?

Study design:
This review article included 7 RCTs and 7 case-control studies.

Results and conclusions:
The investigators found in 7 RCTs (n = 534 randomised youth with ADHD) n-3 PUFAs supplementation significantly improved ADHD clinical symptom scores [g = 0.38, p 0.0001].

The investigators found in 3 RCTs (n = 214 randomised youth with ADHD) n-3 PUFAs supplementation significantly improved cognitive measures associated with attention [g = 1.09, p = 0.001].

The investigators found children and adolescents with ADHD had lower levels of DHA [7 case-control studies, n = 412, g = -0.76, p = 0.0002], EPA (7 case-control studies, n = 468, g = -0.38, p = 0.0008] and total n-3 PUFAs [6 case-control studies, n = 396, g = -0.58, p = 0.0001].

The investigators concluded there is evidence that n-3 PUFAs supplementation monotherapy improves clinical symptoms and cognitive performances in children and adolescents with ADHD and that these youth have a deficiency in n-3 PUFAs levels. These findings provide further support to the rationale for using n-3 PUFAs as a treatment option for ADHD.

Original title:
Omega-3 Polyunsaturated Fatty Acids in Youths with Attention Deficit Hyperactivity Disorder (ADHD): A Systematic Review and Meta-Analysis of Clinical Trials and Biological Studies by Chang JC, Su KP, [...], Pariante CM.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28741625

Additional information of El Mondo:
Find more information/studies on chronic disease, n-3 PUFA right here.
EPA and DHA are n-3 PUFA.

Objectives:
What is the relationship between dietary intake of 12 major food groups, including whole grains, refined grains, vegetables, fruit, nuts, legumes, eggs, dairy, fish, red meat, processed meat and sugar-sweetened beverages and colorectal cancer (CRC) risk?

Study design:
This review article included cohort studies.

Results and conclusions:
The investigators found in the linear dose-response meta-analysis, that every 30 g/d whole grains significantly reduced risk of colorectal cancer with 5% [RR = 0.95, 95% CI = 0.93 to 0.97, n = 9 cohort studies].

The investigators found in the linear dose-response meta-analysis, that every 100 g/d vegetables significantly reduced risk of colorectal cancer with 3% [RR = 0.97, 95% CI = 0.96 to 0.98, n = 15 cohort studies].

The investigators found in the linear dose-response meta-analysis, that every 100 g/d fruit significantly reduced risk of colorectal cancer with 3% [RR = 0.97, 95% CI = 0.95 to 0.99, n = 16 cohort studies]. 

The investigators found in the linear dose-response meta-analysis, that every 200 g/d dairy products significantly reduced risk of colorectal cancer with 7% [RR = 0.93, 95% CI = 0.91 to 0.94, n = 15 cohort studies]. 

The investigators found in the linear dose-response meta-analysis, that every 100 g/d red meat significantly increased risk of colorectal cancer with 12% [RR = 1.12, 95% CI = 1.06 to 1.19, n = 21 cohort studies].

The investigators found in the linear dose-response meta-analysis, that every 50 g/d processed meat significantly increased risk of colorectal cancer with 17% [RR = 1.17, 95% CI = 1.10 to 1.23, n = 16 cohort studies].

The investigators found some evidence for a nonlinear relationship between dietary intake of vegetables, fruit and dairy products and risk of colorectal cancer.

The investigators concluded that daily dietary intake of 30g whole grains, 100g vegetables,100g fruit and 200g dairy products reduce risk of colorectal cancer, while daily dietary intake of 100g red meat and 50g processed meat increase risk of colorectal cancer.

Original title:
Food groups and risk of colorectal cancer by Schwingshackl L, Schwedhelm C, [...], Schlesinger S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29210053

Additional information of El Mondo:
Find more information/studies on different food groups and colorectal cancer right here.

Objectives:
Carnitine deficiency has been implicated as a potential pathway for cancer-related fatigue that could be treated with carnitine supplementation. Therefore, this review article (meta-analysis) has been conducted.

Does carnitine supplementation reduce cancer-related fatigue?

Study design:
This review article included 3 RCTs involving a total of 659 participants.

There were not enough studies to conduct sensitivity analyses to isolate potential sources of heterogeneity and test the robustness of findings.

Results and conclusions:
The investigators found in 3 RCTs involving a total of 659 participants that carnitine supplementation did not significantly reduce cancer-related fatigue [SMD = 0.06 points, 95% CI = -0.09 to 0.21, p = 0.45, I2 = 0%].
Clinical heterogeneity was evident from these studies in regards to the dose (2-4 g of carnitine per day), patient demographics (40-100% females included) and carnitine status.

The investigators concluded there is no evidence to support the use of carnitine supplementation (2-4 g of carnitine per day) for cancer-related fatigue.

Original title:
Efficacy and Effectiveness of Carnitine Supplementation for Cancer-Related Fatigue: A Systematic Literature Review and Meta-Analysis by Marx W, Teleni L, [...], Isenring E.

Link:
http://www.mdpi.com/2072-6643/9/11/1224/htm

Additional information of El Mondo:
Find more information/studies on carnitine, randomized controlled trials/cohort studies/subgroup analysis and cancer right here.

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

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

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

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

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

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

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

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

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

Objectives:
Previous studies regarding the relationship between carrot intake and risk of urothelial cancer have reported conflicting results. Therefore, this review article (meta-analysis) has been conducted.

Does a high consumption of carrot reduce urothelial cancer risk?

Study design:
This review article included a total of 6 epidemiological studies (4 case-control and 2 cohort studies) with 1,523 urothelial cancer cases.

There was no significant publication bias by Begg's test (p = 0.348) or Egger's test (p = 0.130).

Results and conclusions:
The investigators found overall analysis indicated a significantly reduced risk of 37% for urothelial cancer for high intake of carrot [OR = 0.63, 95% CI = 0.44-0.90, I2 = 79.6%, p 0.001].

The investigators found in the subgroup analysis by study design, a significantly reduced risk of 55% for urothelial cancer in case-control studies [OR = 0.45, 95% CI = 0.25-0.81]. However, this reduced risk was not significant in cohort studies [OR = 0.91, 95% CI = 0.67-1.24].
Not significant because OR of 1 was found in the 95% CI of 0.67 to 1.24. OR of 1 means no risk/association.

The investigators found, when separately analyzed by carrot type, a significantly reduced risk of 31% for cooked carrot [OR = 0.69, 95% CI 0.51-0.94], but the reduced risk was not significant for raw carrot [OR = 0.84, 95% CI = 0.37-1.93].

The investigators found in the stratified analysis by geographical region, a non-significantly reduced risk of 38% [OR = 0.62, 95% CI = 0.37-1.06], a non-significantly reduced risk of 30% [OR = 0.70, 95% CI = 0.29-1.67] and a non-significantly reduced risk of 47% [OR = 0.53, 95% CI = 0.22-1.26] for Europe, Asia and USA, respectively.

The investigators also found a non-significantly reduced risk of 44% [OR = 0.56, 95% CI = 0.27-1.17] and a non-significantly reduced risk of 27% [OR = 0.73, 95% CI = 0.12-4.60] for male and female, respectively.

The investigators concluded that a high intake of carrot might be associated with a low incidence of urothelial cancer. Might be associated because the reduced risk was not significant in cohort studies. Considering the limited included studies and huge heterogeneity, further large well-designed prospective cohort studies are warranted to confirm these findings.

Original title:
Carrot intake and incidence of urothelial cancer: a systematic review and meta-analysis by Luo X, Lu H, [...], Wang S.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5652827/

Additional information of El Mondo:
Find more information/studies on carrot consumption, randomized controlled trials/cohort studies/subgroup analysis and cancer right here.

Objectives:
Surgical resection remains the primary treatment for gastrointestinal (GI) malignancy including early-stage cancer. Omega-3 polyunsaturated fatty acids (n-3 PUFAs) have been reported to have beneficial clinical and immune-modulating effects in the prognosis of gastrointestinal cancer patients undergoing surgery. Therefore, this review article (meta-analysis) has been conducted.

What is the impact of n-3 PUFA supplementation on postoperative inflammation status and immune function of gastrointestinal cancer patients?

Study design:
This review article included a total of 9 RCTs with 623 participants.

The homogeneous test detected no statistical heterogeneity between studies.

There was no evidence of publication bias following assessment by funnel plot, Egger’s test [p > 0.05] and Begg’s test [p > 0.05].

Results and conclusions:
The investigators found the n-3 PUFAs regime significantly resulted in lower levels of C-reactive protein [p 0.05], interleukin-6 [p 0.01] and higher levels of albumin, CD3+ T cells, CD4+ T cells and CD4+/CD8+ ratio [p 0.05] compared with the isocaloric nutrition regime.

The investigators found, however, no significant difference in the level of tumor necrosis factor-α between the n-3 PUFAs regime and the isocaloric nutrition regime [p = 0.17].

The investigators found that the level of CD8 + T cells significantly decreased compared with the isocaloric nutrition regime [p 0.0001].

The investigators concluded that n-3 PUFAs are effective in improving the nutritional status and immune function of gastrointestinal cancer patients undergoing surgery as they effectively enhance immunity and attenuate the inflammatory response. Although further larger trials are needed, these fatty acids should be widely used in the clinic.

Original title:
Effects of omega-3 fatty acids on patients undergoing surgery for gastrointestinal malignancy: a systematic review and meta-analysis by Yu J, Liu L, [...], Yang F.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5391568/

Additional information of El Mondo:
Find more information/studies on n-3 PUFA consumption and cancer right here.
 

Objectives:
The aim of this review article (meta-analysis) is to compare empirically derived dietary patterns in relation to cancer risk.

Study design:
This review article included observational studies, which evaluated the association with cancer risk between a posteriori derived dietary patterns.

Results and conclusions:
The investigators found a significantly 64% increased risk of cancer for the adoption of high-meat compared to plant-based dietary patterns [RR = 1.64, 95% CI = 1.02-2.63].

The investigators found a significantly 12% lower risk of cancer for individuals adopting a plant-based dietary pattern over a mixed one [RR = 0.88, 95% BI = 0.82-0.95].

The investigators concluded that plant-based dietary patterns decrease cancer risk; meanwhile meat-based dietary patterns increase cancer risk.

Original title:
Differences in the association between empirically derived dietary patterns and cancer: a meta-analysis by Bella F, Godos J, […], Sciacca S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/27894200

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

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

Do EPA and DHA supplements reduce risk of cardiovascular diseases?

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

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

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

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

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

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

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

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

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

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

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

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

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

Does resveratrol supplementation reduce risk of non-communicable diseases?

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

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

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

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

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

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

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

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

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

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

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

Objectives:
Increasing evidence suggests that high consumption of meat is linked to lung cancer but the previous meta-analyses did not properly address the role of tobacco smoking as a potential confounder. Therefore, this review article (meta-analysis) has been conducted.

Does high consumption of meat increase lung cancer risk among never and non-smokers?

Study design:
This review article included 14 independent observational studies and a total of 5,368 subjects with lung cancer.
There was no indication of publication bias.

Results and conclusions:
The investigators found in 11 studies, a statistically significant 24% increased risk of lung cancer for high consumption of red meat [Summary Relative Risk = 1.24, 95% CI = 1.01-1.51, I2 = 31%].

The investigators found no significant associations between high consumption of other types of meat, fish or for heterocyclic amines and lung cancer risk.

The investigators found no significant risk estimates for the increase of one serving per week of any type of meat or fish.

The investigators concluded a high intake of red meat increases the risk of lung cancer among never and non-smokers.

Original title:
Carcinogenicity of High Consumption of Meat and Lung Cancer Risk Among Non-Smokers: A Comprehensive Meta-Analysis by Gnagnarella P, Caini S, […], Gandini S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29016198

Additional information of El Mondo:
Find more information/studies on meat consumption, randomized controlled trials/cohort studies/subgroup analysis and cancer right here.

According to international recommendations, adults should aim to have a maximum of 70g red meat per day or 500g per week (cooked weight).
 

Objectives:
Several studies have investigated the relationship between serum selenium concentration and cervical cancer, but the results were inconsistent. Therefore, this review article (meta-analysis) has been conducted.

Do high serum selenium levels reduce risk of cervical cancer among women?

Study design:
This review article included 12 studies investigating the association by univariate analysis and 5 studies by multivariate analysis.

Results and conclusions:
The investigators found in univariate analysis, that serum selenium levels in women with cervical cancer were significantly lower than in women without cervical cancer [SMD = -4.86, 95% CI = -6.03 to -3.69]. Subgroup analysis showed consistent results.

The investigators found in multivariate analysis, that serum selenium levels in women with cervical cancer were significantly lower than in women without cervical cancer [OR = 0.55, 95% CI = 0.42-0.73].

The investigators found after treatment, the serum selenium levels increased significantly [SMD = 2.59, 95% CI = 0.50-4.69].

The investigators concluded high serum selenium levels reduce risk of cervical cancer among women.

Original title:
Serum Selenium Levels and Cervical Cancer: Systematic Review and Meta-Analysis by He D, Wang Z, […], Chen D.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28255860

Additional information of El Mondo:
Find more information/studies on selenium, randomized controlled trials/cohort studies/subgroup analysis and cancer right here.

Univariate analysis is the simplest form of analyzing data. "Uni" means "one", thus in other words your data has only one variable.

High serum selenium levels can be obtained by consuming selenium-rich food items and/or taking selenium supplements.
 

Objectives:
Several epidemiological studies have suggested that vitamin E could reduce the risk of uterine cervical neoplasm. However, controversial data were presented by different reports. Therefore, this review article (meta-analysis) has been conducted.

Do both high vitamin E intake and circulating vitamin E levels reduce risk of uterine cervical neoplasm?

Study design:
This review article included 15 case-control studies, involving 3,741 cases (those with uterine cervical neoplasm) and 6,328 controls (those without uterine cervical neoplasm).

There was no obvious publication bias.

Results and conclusions:
The investigators found in pooled analysis that the highest intake of vitamin E significantly reduced risk of cervical neoplasia with 42% [OR = 0.58, 95% CI = 0.47-0.72, I2 = 83%]. In addition, both vitamin E intake and blood levels of vitamin E were negatively correlated with cervical neoplasia risk.

The investigators found in subgroup analysis that the highest intake of dietary vitamin E significantly reduced risk of cervical neoplasia with 32% [OR = 0.68, 95% CI = 0.49-0.94, I2 = 70%].

The investigators found in subgroup analysis that the highest vitamin E blood levels significantly reduced risk of cervical neoplasia with 48% [OR = 0.52, 95% CI = 0.40-0.69, I2 = 86%].

The investigators found in subgroup analysis that vitamin E significantly reduced risk of cervical neoplasia with 40% [OR = 0.60, 95% CI = 0.45-0.78, I2 = 84%] in studies conducted in America and Europe.

The investigators found in subgroup analysis that the highest intake of vitamin E significantly reduced risk of cervical neoplasia with 46% [OR = 0.54, 95% CI = 0.39-0.76, I2 = 75%] in studies conducted in Asia.

The investigators found subgroup analysis stratified by different types of cervical neoplasm indicated that the highest intake (or serum level) of vitamin E significantly decreased risk of cervical cancer with 47% [OR = 0.53, 95% CI = 0.390.73, I2 = 77%] and cervical intraepithelial neoplasia (CIN) with 46% [OR = 0.54, 95% CI = 0.43-0.70, I2 = 79%]. Meanwhile, sensitivity analysis to assess the influence of each single study on the pooled ORs by omitting a research in each turn, showed combined ORs were not substantially different, indicating that the results of this meta-analysis were stable and reliable.

The investigators concluded that both vitamin E intake and circulating vitamin E levels could reduce cervical neoplasia risk, including cervical cancer and cervical intraepithelial neoplasia. In other words, sufficient supplementation of vitamin E might reduce the risk of cervical neoplasia. However, more randomized controlled trials and cohort studies with high quality are required to further validate this inverse relationship.

Original title:
Effect of vitamin E supplementation on uterine cervical neoplasm: A meta-analysis of case-control studies by Hu X, Li S, [...], Zhu X.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5567498/

Additional information of El Mondo:
Find more information/studies on vitamin E, randomized controlled trials/cohort studies/subgroup analysis and cancer right here.

Higher intake of vitamin E is an intake which covers the recommended daily allowance of vitamin E of at least 1 day.

Objectives:
Dietary fat may play a role in lung carcinogenesis. Findings from epidemiologic studies, however, remain inconsistent. Therefore, this review article (meta-analysis) has been conducted.

Is there an association between dietary fat intake and the risk of lung cancer?

Study design:
This review article included 10 prospective cohort studies with a total of 1,445,850 participants, of which 18,822 incident cases (subjects with lung cancer).

The mean follow-up was 9.4 years. 

Results and conclusions:
The investigators found high intakes of total fat were associated with a 7% significant increased risk of lung cancer [for highest v lowest quintile: HR = 1.07, 95% CI = 1.00 to 1.15].

The investigators found high intakes of saturated fat were associated with a 14% significant increased risk of lung cancer [for highest v lowest quintile: HR = 1.14, 95% CI = 1.07 to 1.22].

The investigators found high intakes of saturated fat were associated with a 23% significant increased risk of lung cancer among current smokers [for highest v lowest quintile: HR = 1.23, 95% CI = 1.13 to 1.35, p for trend 0.001].

The investigators found high intakes of saturated fat were associated with a 61% significant increased risk of squamous cell lung cancer [for highest v lowest quintile: HR = 1.61, 95% CI = 1.38 to 1.88].

The investigators found high intakes of saturated fat were associated with a 40% significant increased risk of small cell carcinoma lung cancer [for highest v lowest quintile: HR = 1.40, 95% CI = 1.17 to 1.67].

The investigators found a high intake of polyunsaturated fat was associated with a 8% significant decreased risk of lung cancer [for highest v lowest quintile: HR = 0.92, 95% CI = 0.87 to 0.98, p for trend = 0.02].

The investigators found a 5% energy substitution of saturated fat with polyunsaturated fat was associated with a 16% and 17% lower risk of small cell and squamous cell carcinoma, respectively.

The investigators found no associations for monounsaturated fat.

The investigators concluded that high intakes of polyunsaturated fat decrease risk of lung cancer, while high intakes of saturated fat increase risk of lung cancer, particularly among smokers and for squamous cell and small cell carcinoma.

Original title:
Dietary Fat Intake and Lung Cancer Risk: A Pooled Analysis by Yang JJ, Yu D1, […], Shu XO.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28742456

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

A daily diet with high intakes of saturated fat is a diet that is largely made up of meals/products with more than 10 En% saturated fat, with a small part of meals/products with less than 10 En% saturated fat. Practically, this means that all meals/products that you eat on a daily basis should contain on average more than 10 En% saturated fat.
Check here which products contain more than 10% En% saturated fat.

A daily diet with low intakes of saturated fat is a diet that is largely made up of meals/products with less than 7 En% saturated fat, with a small part of meals/products with more than 7 En% saturated fat. Practically, this means that all meals/products that you eat on a daily basis should contain on average less than 7 En% saturated fat.
Check here which products contain less than 7% En% saturated fat.

Objectives:
Recently, several randomized controlled trials (RCTs) reported the association between the use of vitamin or antioxidant supplements and the risk of bladder cancer. However, those findings remain inconsistent and some studies even reported that vitamin and antioxidant supplements increased the risk of bladder cancer. Therefore, this review article (meta-analysis) has been conducted.

Is there an association between the use of vitamin or antioxidant supplements and the risk of bladder cancer?

Study design:
This review article included 14 RCTs with a total of 147,383 participants, which involved 89,972 in the supplement group and 57,411 in the control group.

The supplementation and follow-up periods ranged between 1 and 13 years.

The types of vitamin and antioxidant supplements were as follows: vitamin A, vitamin B6, vitamin C, vitamin D, vitamin E, beta-carotene, folic acid and selenium.
The dosage regimens in individual trials were as follows: vitamin A (200 mg or 25,000, 36,000 or 40,000 IU daily), vitamin B6 (25 or 100 mg daily), vitamin C (2,000 mg daily), vitamin D (1,600 IU daily), vitamin E (50 mg or 400 IU daily), beta-carotene (20 or 30 mg daily; 50 mg alternate day; 75 mg daily for 3-month cycles), folic acid (1.6 mg daily) and selenium (200 μg daily).

Publication bias was not observed [Begg's funnel plot, symmetrical and Egger's test, p for bias = 0.378].

Results and conclusions:
The investigators found in fixed-effect meta-analysis of all 14 trials that vitamin or antioxidant supplementation was not associated with the risk of bladder cancer [RR = 1.04, 95% CI = 0.92-1.17, I2 = 39.7%].

The investigators found regarding types of supplements, any type of vitamin and antioxidant supplements had no beneficial effect on the risk of bladder cancer:
-vitamin A [RR = 0.86, 95% CI = 0.65-1.13, I2 = 61.7%, n = 5];
-vitamin B6 [RR = 0.77, 95% CI = 0.49-1.20, I2 = 78.8%, n = 3];
-vitamin C [RR = 0.74, 95% CI = 0.36-1.54, I2 = 88.8%, n = 2];
-vitamin D [RR = 1.05, 95% CI = 0.85-1.29, n = 1];
-vitamin E [RR = 0.91, 95% CI = 0.69-1.19, I2 = 60.9%, n = 6];
-beta-carotene [RR = 1.19, 95% CI = 0.96-1.46, I2 = 0.0%, n = 6];
-folate [RR = 1.05, 95% CI = 0.85-1.29, n = 1] and
-selenium [RR = 1.09, 95% CI = 0.81-1.46, I2 = 0.0%, n = 2].

The investigators found overall, there was no significant effect of vitamin and antioxidant supplements in the subgroup meta-analyses by various factors such as dose of supplements, type of cancer prevention, methodological quality, duration of treatment, provider of supplements, type of control and number of participants.
However, the risk of bladder cancer was marginally increased in trials with the use of beta-carotene alone [RR = 1.44, 95% CI = 1.00-2.09, I2 = 0.0%, n = 3].

The investigators concluded that vitamin and antioxidant supplements have no overall preventive effect against bladder cancer. Instead, subgroup meta-analyses showed that beta-carotene supplementation marginally increased the risk of bladder cancer. Even though further large, high-quality trials are required to confirm these associations, the effects (either beneficial or harmful) of vitamin or antioxidant supplements on bladder cancer should not be overemphasized.

Original title:
Effects of Vitamin and Antioxidant Supplements in Prevention of Bladder Cancer: a Meta-Analysis of Randomized Controlled Trials by Park SJ, Myung SK, […], Lee YJ.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5334161/

Additional information of El Mondo:
Find more information/studies on vitamins, selenium, beta-carotene, antioxidants and cancer right here.

Objectives:
Protective effects of calcium supplementation against colorectal adenomas have been documented in systematic reviews; however, the results have not been conclusive. Therefore, this review article (meta-analysis) has been conducted.

Does calcium supplementation reduce colorectal adenomas?

Study design:
This review article included 5 RCTs involving 2,234 patients with a history of adenomas.
Based on visual inspection of the funnel plots as well as on quantitative measurement that used the Egger regression test, there was weak evidence of publication bias.
No major serious adverse events were associated with the use of calcium, but there was an increase in the incidence of hypercalcemia [p  = 0 .0095].
Random errors were evaluated with trial sequential analyses (TSAs). However, TSA indicated a lack of firm evidence for a beneficial effect of calcium supplementation.

Results and conclusions:
The investigators found quantitative pooling of results from all 5 RCTs indicated that the use of supplemental calcium lasting 3 to 5 years showed a statistically significant 17% reduction in risk of any recurrent colorectal adenomas [RR = 0.83, 95% CI = 0.75-0.93, I2  =  8.5%, p  =  0.36].

The investigators found in the sensitivity analysis of 3 trials with low bias risk a statistically significant 12% reduction in the recurrence of any colorectal adenomas [RR = 0.88, 95% CI = 0.79-0.99, I2  =  0%, p  =  0.54] in patients who were administered supplemental calcium versus placebo.

The investigators found no association between supplemental calcium and recurrence of advanced colorectal adenomas in trials with low risk of bias [RR = 1.02, 95% CI = 0.67-1.55, I2 =  17.5%].

The investigators found in the subgroup analysis of 3 trials with elemental calcium dose ≤ 1200 mg/day, a statistically significant 16% reduction in the recurrent of any colorectal adenomas [RR = 0.84, 95% CI = 0.73-0.97, I2  =  38.5%, p  = 0 .19].

However, a greater reduction of 26% [RR = 0.74, 95% CI = 0.56-0.97, I2  =  0%, p  = 0 .70] was observed in the subgroup analysis of 2 trials with elemental calcium dose ≥ 1600 mg/day.
Subgroup analyses demonstrated no statistically significant association with the reduction of advanced colorectal adenomas in any doses.

The investigators concluded the available good quality RCTs suggests a possible beneficial effect of calcium supplementation – preferably at least 1600 mg/day elemental calcium – on the recurrence of colorectal adenomas. However, TSA indicated that the accumulated evidence is still inconclusive. Therefore, large well-designed randomized trials with low risk of bias are needed.

Original title:
Effects of calcium on the incidence of recurrent colorectal adenomas: A systematic review with meta-analysis and trial sequential analysis of randomized controlled trials by Veettil SK, Ching SM, […], Chaiyakunapruk N.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5556213/

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

Colorectal adenomas can lead to colorectal cancer.

Objectives:
With only 5-10% of breast cancer cases attributed to genetic inheritance, prevention efforts have focused on modifiable risk factors. Physical activity plays a role in reducing breast cancer risk; however, the interaction between physical activity and other modifiable risk factors, such as obesity, has received little attention. Therefore, this review article (meta-analysis) has been conducted.

What is the relationship between physical activity and breast cancer and how it may be modified by body mass index (BMI)?

Study design:
This review article included 18 cohort and 11 case-control studies.

Results and conclusions:
The investigators found overall, a significant reduction of 15% for breast cancer risk in postmenopausal women with a BMI 25 kg/m² for high versus low levels of physical activity [RR = 0.85, 95% CI = 0.79-0.92]. 

The investigators found overall, a significant reduction of 13% for breast cancer risk in postmenopausal women with a BMI ≥25 kg/m² for high versus low levels of physical activity for women [RR = 0.87, 95% CI = 0.81-0.93]. 

The investigators found overall, a non-significant reduction of 7% for breast cancer risk in postmenopausal women with a BMI ≥30 kg/m² for high versus low levels of physical activity for women [RR = 0.93, 95% CI = 0.76-1.13]. 

The investigators found, however, physical activity was not associated with a significant reduction in risk of breast cancer in premenopausal women in any BMI group.

The investigators concluded high levels of physical activity reduce risk of breast cancer in postmenopausal women with a BMI until 30. Since the included studies used diverse methods for assessment of physical activity and categories of BMI, results should be interpreted with caution and additional work is needed.

Original title:
Does obesity modify the relationship between physical activity and breast cancer risk? by Neil-Sztramko SE, Boyle T, […], Campbell KL.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28803384

Additional information of El Mondo:
Find more information/studies on breast cancer, BMI and physical activity right here.

Objectives:
In the 2007 World Cancer Research Fund/American Institute for Cancer Research Second Expert Report, the expert panel judged that there was strong evidence that alcoholic drinks and body fatness increased esophageal cancer risk, whereas fruits and vegetables probably decreased its risk. The judgments were mainly based on case-control studies. As part of the Continuous Update Project (CUP), this review article (meta-analysis) has been conducted.

What is the relationship between nutrition and esophageal cancer risk?

Study design:
This review article included a total of 57 cohort studies, used in previous 13 meta-analyses.

Results and conclusions:
The investigators found a significant reduced risk of 11% for esophageal adenocarcinoma for every increment of 100g/day vegetable intake [RR = 0.89, 95% CI = 0.80-0.99, n = 3].

The investigators found a significant increased risk of 47% for esophageal adenocarcinoma for every 5 unit increment in BMI [RR = 1.47, 95% CI = 1.34-1.61, n = 9].

The investigators found a significant reduced risk of 16% for esophageal squamous cell carcinoma for every increment of 100g/day fruit intake [RR = 0.84, 95% CI = 0.75-0.94, n = 3].

The investigators found a significant reduced risk of 36% for esophageal squamous cell carcinoma for every 5 unit increment in BMI [RR = 0.64, 95% CI = 0.56-0.73, n = 8].

The investigators found a significant increased risk of 59% for esophageal squamous cell carcinoma for every increment of 50g/day processed meat intake [RR = 1.59, 95% CI = 1.11-2.28, n = 3].

The investigators found a significant increased risk of 37% for esophageal squamous cell carcinoma for every increment of 100g/day processed and red meat intake [RR = 1.37, 95% CI = 1.04-1.82, n = 3].

The investigators found a significant increased risk of 25% for esophageal squamous cell carcinoma for every increment of 10g/day alcohol intake [RR = 1.25, 95% CI = 1.12-1.41, n = 6].

The investigators concluded evidence from cohort studies shows a protective role of vegetables and body weight control in esophageal adenocarcinomas development. For squamous cell carcinomas, higher intakes of red and processed meats and alcohol increase the risk, whereas fruits intake has a protective role.

Original title:
An update of the WCRF/AICR systematic literature review and meta-analysis on dietary and anthropometric factors and esophageal cancer risk by Vingeliene S, Chan DSM, […], Norat T.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28666313

Additional information of El Mondo:
Find more information/studies on vegetable, fruit, alcohol and meat consumption, significant/cohort/95% CI and cancer right here.
 

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

Does quercetin supplementation reduce CRP levels?

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

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

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

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

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

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

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

Objectives:
The relationship between intake of fish and n-3 fatty acids and endometrial cancer risk has not been consistent across epidemiological studies. Therefore, this review article (meta-analysis) has been conducted.

Do fish consumption and dietary EPA and DHA intake reduce endometrial cancer risk?

Study design:
This review article included 4 prospective cohort studies, 1 case-cohort study and 11 case-control studies (including 8 population-based case-control studies and 3 hospital-based case-control studies).
The prospective cohort studies had a mean follow-up of 6.5 to 9.1 years.
The highest category of fish ranged from >1-2 servings/week to >15.4 servings/week,
The highest category of DHA ranged from 143 to 227 mg/d.
The highest category of EPA ranged from 74.7 to 127 mg/d.

When fish intake was reported in unit of g/d, it was converted to serving/week by assuming 1 serving = 100g.
Overall, all 16 studies were classified as high-quality studies.
There was no publication bias.

Results and conclusions:
The investigators found a non-significant association between the highest vs. lowest category of fish consumption and endometrial cancer risk [RR = 1.04, 95% CI = 0.84-1.30, I2 = 80.4%].
According to the subgroup analyses, the null association persisted in strata according to study design, location, type of controls, number of cases, publication year and adjustments of energy intake, reproductive factors and smoking.

The investigators found in subgroup analyses for every one additional serving/week of fish intake, a significant reduced risk of 10% for endometrial cancer in studies conducted in Europe [RR = 0.90, 95% CI = 0.84-0.97]. Significant means that there is an association with a 95% confidence.

The investigators found in subgroup analyses for every one additional serving/week of fish intake, a significant increased risk of 15% for endometrial cancer in studies conducted in Asia [RR = 1.15, 95% CI = 1.10-1.21]. Significant because RR of 1 was not found in the 95% CI of 1.10 to 1.21. RR of 1 means no risk/association.

The investigators found in studies adjusting for smoking for every one additional serving/week of fish intake, a significant reduced risk of 5% for endometrial cancer [RR = 0.95, 95% CI = 0.91-1.00].

The investigators found in studies without an adjustment of smoking for every one additional serving/week of fish intake, a significant increased risk of 14% for endometrial cancer [RR = 1.14, 95% CI = 1.09-1.19].

The investigators found a non-significant inverse association between the highest category of DHA intake and endometrial cancer risk [RR = 0.85, 95% CI = 0.64-1.11, I2 = 59.6%]. However, the dose-response analysis suggested a significant non-linear relationship between DHA intake and endometrial cancer risk [p = 0.04 and p for heterogeneity = 0.39], with a decreased risk being detected for an intake of DHA no more than 175 mg/d.

The investigators concluded that there is a significant inverse association between every one additional serving/week of fish intake and endometrial cancer risk in studies conducted in Europe and studies adjusted for smoking. Furthermore, there is a significant non-linear relationship between DHA intake and risk of endometrial cancer, with a decreased risk being detected for an intake of DHA no more than 175 mg/d. Further well-designed studies are warranted to better characterize the relationship between fish, n-3 PUFA and endometrial cancer development.

Original title:
Dietary n-3 polyunsaturated fatty acids, fish consumption, and endometrial cancer risk: a meta-analysis of epidemiological studies by Hou R, Yao SS, […], Jiang L.

Link:
http://www.impactjournals.com/oncotarget/index.php?journal=oncotarget&page=article&op=view&path[]=18295&path[]=58664

Additional information of El Mondo:
Find more information/studies on fish consumption, significant/cohort/95% CI and cancer right here.
These fish contain 175 mg DHA.
 

Objectives:
Although several epidemiological studies have investigated the association between dietary calcium intake and the risk of esophageal cancer, the results are inconsistent. Therefore, this review article (meta-analysis) has been conducted.

Does dietary calcium intake reduce risk of esophageal cancer?

Study design:
This review article included 3 cohort studies and 14 case-control studies, including 3,396 cases (subjects with esophageal cancer) and 346,815 controls (subjects without esophageal cancer).

Egger’s test showed no evidence of significant publication bias.

The sample size was large enough to evaluate the effect of calcium intake on esophageal cancer.

A dose-response effect analysis could not be performed due to the incomplete data of dietary calcium intake.

The average of highest dietary calcium intake in Asian populations was 621 mg/day.

Results and conclusions:
The investigators found for highest vs. lowest dietary calcium intake a significant reduced risk of 20% for esophageal cancer [pooled OR = 0.80, 95% CI = 0.71-0.91, I2 = 33.6%].
This significant reduced risk was also found in studies conducted in Asia [OR = 0.67, 95% CI = 0.52-0.86, I2 = 0.0%], studies published after 2000 [OR = 0.64, 95% CI = 0.53-0.77, I2 = 0.0%), studies adjusted for dietary energy intake [OR = 0.83, 95% CI = 0.70-0.98, I2 = 3.6%], studies of esophageal squamous cell carcinoma [OR = 0.76, 95% CI = 0.60-0.96, I2 = 28.3%], cohort studies [OR = 0.67, 95% CI = 0.54-0.84, I2 = 23.6%] and studies with high quality score [OR = 0.76, 95% CI = 0.66-0.87, I2 = 12.7%].

The investigators found in sensitivity analysis (conducted by leaving one study out in turn and pooling the ORs of the remaining studies) the summary ORs did not substantially change, which indicated that the results were statistically robust.

The investigators concluded that a higher intake (621 mg/day) of dietary calcium has protective effect against esophageal cancer - especially esophageal squamous cell cancer - in Asian populations. To further solidify the association of dietary calcium intake with the risk of esophageal cancer, well-designed studies - especially prospective cohort studies with validated FFQ and adjusted for dietary energy intake - should be conducted.

Original title:
Protective Effect of Dietary Calcium Intake on Esophageal Cancer Risk: A Meta-Analysis of Observational Studies by Li Q, Cui, L, […], Wang L.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5452240/

Additional information of El Mondo:
Find more information/studies on calcium, significant/cohort/95% CI and cancer right here.
 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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