Nutrition and health

Objectives:
Epidemiologic studies of the relationship between nitrite or nitrate consumption and risk of non-Hodgkin lymphoma (NHL) remain controversial. Therefore, this review article has been conducted.

Does dietary intake of nitrite or nitrate increase risk of non-Hodgkin lymphoma?

Study design:
This review article included 8 case-control and 4 cohort studies with a total of 8,067 cases of non-Hodgkin lymphoma that reported the correlation between nitrate or nitrite consumption and risk of non-Hodgkin lymphoma published between 1996 and 2013.

NOS scores ranged from 4 to 8 with a mean value of 6.
Information on nitrate and nitrite intake was obtained by personal interview, telephone interview or mailed questionnaires.

There was no evidence of publication bias.

Results and conclusions:
The investigators found that high levels of nitrite dietary intake was linked to a significantly elevated risk of non-Hodgkin lymphoma of 55% [OR = 1.55, 95% CI = 1.27-1.88, I2 = 41.8%, p = 0.161]. 

The investigators found, however, no connection between the risk of non-Hodgkin lymphoma and high levels of nitrate dietary intake [OR = 1.02, 95% CI = 0.94-1.10, I2 = 14.2%, p = 0.308].

The investigators found that the risk of non-Hodgkin lymphoma increased by 26% for each additional microgram of nitrite consumed in the diet per day [OR = 1.26, 95% CI = 1.09-1.42].

The investigators found data from the high-quality studies indicated that nitrite consumption was positively associated with carcinogenicity, leading to non-Hodgkin lymphoma [OR = 1.44, 95% CI = 1.17-1.77] and positively correlated with the development of diffuse large B-cell lymphoma [OR = 1.55, 95% CI = 1.07-2.26], but not other non-Hodgkin lymphoma subtypes.

The investigators found, in addition, high levels of nitrite dietary intake was linked to a significantly elevated risk of non-Hodgkin lymphoma of 50% [OR = 1.50, 95% CI = 1.15-1.95] in females.
However, this increased risk was not significant in males [OR = 0.84, 95% CI = 0.52-1.36].

The investigators concluded that nitrite dietary intake, but not that of nitrate, raises the risk of developing non-Hodgkin lymphoma, particularly diffuse large B-cell lymphoma in females. In the future, better designed prospective research studies should be conducted to confirm these findings, clarify potential biological mechanisms and instruct clinicians about non-Hodgkin lymphoma prophylaxis.

Original title:
The relationship between consumption of nitrite or nitrate and risk of non-Hodgkin lymphoma by Yu M, Li C, [...], Jin J.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6969097/

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

The preservative sodium nitrite fights harmful bacteria in ham, salami and other processed and cured meats and also lends them their pink coloration.
 

Objectives:
Is there a causal relationship between dietary anthocyanins and reduced levels of systemic and vascular inflammation?

Study design:
This review article included 32 RCTs.

Results and conclusions:
The investigators found that dietary anthocyanins significantly decreased levels of C-reactive protein (CRP) [-0.33 mg/L, 95% CI = -0.55 to -0.11, p = 0.00], interleukin-6 (IL-6) [-0.41 ρg/mL, 95% CI = -0.70 to -0.13, p = 0.004], tumor necrosis factor-alpha (TNF-α) [-0.64 ρg/mL, 95% CI = -1.18 to -0.09, p = 0.023], intercellular adhesion molecule-1 [-52.4 ng/mL, 95% CI = -85.7 to -19.1, p = 0.002] and vascular adhesion molecule-1 (VCAM-1)  [-49.6 ng/mL, 95% CI = -72.7 to -26.5, p  0.001]. 

The investigators found that dietary anthocyanins significantly increased adiponectin level [0.75 μg/mL, 95% CI = 0.23 to 1.26, p = 0.004].

The investigators found subgroup analyses showed that administration of higher doses of anthocyanins (>300 mg/day) significantly decreased levels of CRP, IL-6, TNF-α and VCAM-1.

The investigators concluded that >300 mg/day dietary anthocyanins reduce the levels of systemic and vascular inflammation in the subjects.

Original title:
Impact of dietary anthocyanins on systemic and vascular inflammation: Systematic review and meta-analysis on randomised clinical trials by Fallah AA, Sarmast E, […], Jafari T.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31669599

Additional information of El Mondo:
Find here more information/studies about inflammation and anthocyanins.

Inflammation in the body can be measured by the following biomarker; the pro-inflammatory cytokines. The pro-inflammatory cytokines are the C-reactive protein (CRP), IL-1, interleukin-6 (IL-6), IL-8, MCP-1, the vascular adhesion molecule-1 (VCAM-1) and tumor necrosis factor alpha (TNF-α).

Objectives:
Previous studies had been published to explore the association about carbohydrate intake on esophageal cancer risk, with inconsistent results. Therefore, this review article (meta-analysis) has been conducted.

Does dietary intake of carbohydrate reduce esophageal cancer risk?

Study design:
This review article included 13 case-control studies that assessed a total of 3,033 patients.
The quality evaluation scores of each study ranged from 6 to 9 and the methodological quality was higher.

In the publication bias assessment, the results from funnel plots and Egger’s test detected no publication bias.

Results and conclusions:
The investigators found in overall analysis for the highest category versus lowest category of dietary carbohydrate a significantly reduced risk of 37.3% [summarized OR = 0.627, 95% CI = 0.505 to 0.778, I2 = 59.9%, p for heterogeneity = 0.001] for esophageal cancer.
Sensitivity analyses showed no single study had essential effect on the overall result.

The investigators found for the highest category versus lowest category of dietary carbohydrate a significantly reduced risk of 43.1% [summarized OR = 0.569, 95% CI = 0.417 to 0.777] for esophageal adenocarcinoma.

The investigators found for the highest category versus lowest category of dietary carbohydrate a significantly reduced risk of 33.5% [summarized OR = 0.665, 95% CI = 0.453 to 0.975] for esophageal squamous cell carcinoma.

The investigators found in subgroup analysis by study design that the association was significant in population-based case-control studies, but not in the hospital-based case-control studies.

The investigators concluded that dietary intake of carbohydrate may contribute to the lower development of esophageal cancer. May contribute because this review article only included case-control studies and no cohort studies. As some limitations existed in tbjs meta-analysis, large scale prospective studies with detailed type of dietary carbohydrate intake are needed to verify these results.

Original title:
Dietary carbohydrate intake and the risk of esophageal cancer: a meta-analysis by Xuan F, Li W, […], Liu C.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7042123/

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

The 2 main subtypes of esophageal cancer are esophageal squamous-cell carcinoma (often abbreviated to ESCC) and esophageal adenocarcinoma (EAC).
 

Objectives:
Does post-diagnosis dietary supplement use decrease total mortality, cancer mortality and recurrence among cancer survivors?

Study design:
This review article included observational studies and randomized clinical trials (RCT).

Results and conclusions:
The investigators found in 4 observational studies, compared to no supplementation, calcium supplementation significantly reduced total mortality with 12% [RR = 0.88, 95% CI = 0.77 to 1.00, I2 = 0%] among all cancer survivors.

The investigators found in 3 observational studies, compared to no supplementation, calcium supplementation significantly reduced cancer mortality with 29% [RR = 0.71, 95% CI = 0.53 to 0.95, I2 = 0%] among all cancer survivors.

The investigators found in 2 observational studies, compared to no supplementation, calcium supplementation significantly reduced cancer mortality with 34% [RR = 0.66, 95% CI = 0.47 to 0.94, I2 = 0%] among colorectal cancer survivors.

The investigators found in 2 observational studies and 2 RCT’s, compared to no supplementation, vitamin D supplementation significantly reduced total mortality with 14% [RR = 0.86, 95% CI = 0.76 to 0.99, I2 = 0%] among all cancer survivors.

The investigators found in 4 observational studies, compared to no supplementation, vitamin C supplementation significantly reduced total mortality with 21% [RR = 0.79, 95% CI = 0.68 to 0.92, I2 = 0%] among breast cancer survivors.

The investigators found in 2 observational studies, compared to no supplementation, vitamin D supplementation significantly reduced total mortality with 15% [RR = 0.85, 95% CI = 0.72 to 0.99, I2 = 0%] among breast cancer survivors.

The investigators found in 3 observational studies, compared to no supplementation, vitamin E supplementation significantly reduced total mortality with 24% [RR = 0.76, 95% CI = 0.64 tot 0.90, I2 = 0%] among breast cancer survivors.

The investigators found in 2 observational studies, compared to no supplementation, multivitamins supplementation significantly reduced cancer recurrence with 21% [RR = 0.79, 95% CI = 0.64 to 0.97, I2 = 0%] among breast cancer survivors.

The investigators found in 2 observational studies, compared to no supplementation, vitamin C supplementation significantly reduced cancer recurrence with 24% [RR = 0.76, 95% CI = 0.64 to 0.91, I2 = 0%] among breast cancer survivors.

The investigators found in 2 observational studies, compared to no supplementation, vitamin E supplementation significantly reduced cancer recurrence with 31% [RR = 0.69, 95% CI = 0.55 to 0.85, I2 = 0%] among breast cancer survivors.

The investigators concluded post-diagnosis dietary supplement use (particularly calcium, vitamin C, D and E) decreases total mortality, cancer mortality and recurrence among cancer survivors.

Original title:
Dietary Supplement Use after Cancer Diagnosis in Relation to Total Mortality, Cancer Mortality and Recurrence: A Systematic Review and Meta-Analysis by Kanellopoulou A, Riza E, […], Benetou V.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32148118

Additional information of El Mondo:
Find more information/studies on calcium, vitamin C, D, E, breast cancer and colorectal cancer right here.

Objectives:
Is there a causal relationship between intake of pomegranate and decreased risk of getting inflammation in adults?

Study design:
This review article included 16 randomized controlled trials (RCTs) involving 572 subjects.

Results and conclusions:
The investigators found when compared to placebo, that pomegranate supplementation significantly reduced hs-CRP levels [WMD = -6.57 mg/L, 95% CI = -10.04 to -3.10, p = 0.000].

The investigators found when compared to placebo, that pomegranate supplementation significantly reduced IL-6 levels [WMD = -1.68 pg/mL, 95% CI = -3.52 to -0.157, p = 0.000].

The investigators found when compared to placebo, that pomegranate supplementation significantly reduced TNF-α levels [WMD = -2.37 pg/mL, 95% CI = -3.67 to -1.07, p = 0.00].

The investigators found no association between pomegranate supplementation and CRP levels [WMD = 2.19 mg/dL, 95% CI = -3.28 to 7.67, p = 0.61], E-selectin levels [WMD = 8.42 ng/mL, 95% CI = -22.9 to 39.8, p = 0.599], ICAM levels [WMD = -17.38 ng/mL, 95% CI = -53.43 to 18.66, p = 0.107], VCAM levels [WMD = -69.32 ng/mL, 95% CI = -229.26 to 90.61, p = 0.396] or MDA levels [WMD = 0.031 μmol/L, 95% CI = -1.56 to 0.218, p = 0.746].

The investigators concluded pomegranate supplementation reduces hs-CRP levels, IL-6 levels and TNF-α levels in adults.

Original title:
The effects of pomegranate supplementation on biomarkers of inflammation and endothelial dysfunction: A meta-analysis and systematic review by Wang P, Zhang Q, [...], Yao G.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32147056

Additional information of El Mondo:
Find here more information/studies about fruit and chronic diseases.

Inflammation in humans can be measured by biomarkers, such as highly sensitive C-reactive protein (hs-CRP), interleukin-6 (IL-6) and the tumor necrosis factor alpha (TNF-α).

Inflammation in humans can lower the resistance. A low resistance makes the body susceptible to diseases.
 

Objectives:
Does high waist circumference increase liver cancer?

Study design:
This review article included  5 prospective cohort studies with 2,547,188 participants.
Participants were aged 46-58 years, with a mean age of 51 years.
The mean follow-up of participants in the studies was 7.8 years.
The mean quality (NOS scores) of the studies included was 7 (ranging from 5 to 9).

Funnel plots did not show significant asymmetry between the studies included.
Furthermore, Begg's and Egger's regression test did not show any significant publication bias (p = 0.62 and p = 0.60, respectively).

Results and conclusions:
The investigators found combined results of the studies included with random-effects model showed that the highest waist circumference category was significantly associated with an increased risk of 59% for liver cancer [HR = 1.59, 95% CI = 1.38-1.83, I2 = 0%, p = 0.42] compared to the lowest waist circumference category.

The investigators concluded that waist circumference is a significant risk factor related to the incidence of liver cancer.

Original title:
Waist Circumference and Risk of Liver Cancer: A Systematic Review and Meta-Analysis of over 2 Million Cohort Study Participants by Rahmani J, Kord Varkaneh H, [...], Zhang Y.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7024879/

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

Objectives:
Epidemiologic studies have investigated the association between nut intake and risk for multiple cancers. However, current findings are inconsistent and no definite conclusion has been drawn from prospective studies. Therefore, this review article has been conducted.

Does nut consumption reduce cancer risk?

Study design:
This review article included 33 cohort studies with more than 50,000 cancer cases.

Results and conclusions:
The investigators found when comparing the highest with the lowest category of nut consumption, high consumption of nuts significantly decreased risk of overall cancer with 10% [RR = 0.90, 95% CI = 0.85-0.95].
Significant association was only obtained for intake of tree nuts.

The investigators found when comparing the highest with the lowest category of nut consumption, high consumption of nuts significantly decreased risk of cancer from the digestive system with 17% [RR = 0.83, 95% CI = 0.77-0.89].

The investigators found per 20 g/day increase in nut consumption was related to a 10% [RR = 0.90, 95% CI = 0.82-0.99] decrease in cancer risk.

The investigators concluded that consumption of 20 grams of tree nuts per day reduces cancer of the digestive system.

Original title:
Nut Consumption and Risk of Cancer: A Meta-analysis of Prospective Studies by Long J, Ji Z, […], Cheng L.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32041895

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

Objectives:
The activity of hepatitis B virus (HBV) as a risk factor for the incidence and progression of chronic kidney disease (CKD) has not been clarified. Therefore, this review article has been conducted.

Does hepatitis B virus infection increase risk of chronic kidney disease?

Study design:
This review article included 33 studies with a total of 7,849,849 patients.

Results and conclusions:
The investigators found in 11 cohort studies with 1,056,645 patients, that a positive HBV serologic status (hepatitis B virus infection) significantly increased risk of incidence of chronic kidney disease with 40% [adjusted HR = 1.40, 95% CI = 1.16 to 1.69, p 0.001, I2 = 49.5%, p 0.0001].

The investigators found in 10 cross-sectional studies with 3,222,545 patients, no relationship between hepatitis B virus infection and prevalence of chronic kidney disease [adjusted OR = 1.04, 95% CI = 0.90 to 1.218, p = 0.5].

The investigators found meta-regression analysis reported a relationship between positive HBsAg status and incidence of chronic kidney disease in the general population [p 0.015].

The investigators concluded hepatitis B virus infection increases risk of developing of chronic kidney disease in the adult general population. Studies aimed to understand the mechanisms responsible of such association are underway.

Original title:
HBV infection is a risk factor for chronic kidney disease: Systematic review and meta-analysis by Fabrizi F, Cerutti R, […], Messa P.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32037008

Additional information of El Mondo:
Find here more information/studies about kidney disease.
 

Objectives:
Which factors are associated with the risk of stomach cancer?

Study design:
This review article included 232 observational studies involving 33,831,063 participants.

Results and conclusions:
The investigators found H. pylori infection significantly increased risk of stomach cancer with 156% [OR = 2.56, 95% CI = 2.18 to 3.00].

The investigators found formerly smoked significantly increased risk of stomach cancer with 43% [OR = 1.43, 95% CI = 1.29 to 1.59].

The investigators found currently smoking significantly increased risk of stomach cancer with 61% [OR = 1.61, 95% CI = 1.49 to 1.75].

The investigators found currently drinking significantly increased risk of stomach cancer with 19% [OR = 1.19, 95% CI = 1.10 to 1.29].

The investigators found formerly drank significantly increased risk of stomach cancer with 73% [OR = 1.73, 95% CI = 1.17 to 2.56].

The investigators found intake of fruits ≥3 times/week significantly decreased risk of stomach cancer with 52% [OR = 0.48, 95% CI = 0.37 to 0.63].

The investigators found intake of vegetables ≥3 times/week significantly decreased risk of stomach cancer with 38% [OR = 0.62, 95% CI = 0.49 to 0.79].

The investigators found using pickled vegetables significantly increased risk of stomach cancer with 28% [OR = 1.28, 95% CI = 1.09 to 1.51].

The investigators found green tea significantly decreased risk of stomach cancer with 12% [OR = 0.88, 95% CI = 0.80 to 0.97].

The investigators concluded that both smoking, drinking and H. pylori infection increase the risk of stomach cancer, while both ≥3 times/week fruit and vegetables and green tea reduce the risk of developing stomach cancer.

Original title:
Risk factors for stomach cancer: a systematic review and meta-analysis by Poorolajal J, Moradi L, [...], Gohari-Ensaf F.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32023777

Additional information of El Mondo:
Find more information/studies on alcohol, tea, vegetable and fruit and cancer right here.

Objectives:
Lead is a known risk factor for amyotrophic lateral sclerosis (ALS). However, the results of studies exploring the relationship between lead exposure and the occurrence of ALS are inconsistent. Therefore, this review article has been conducted.

Does a high lead exposure increase risk of ALS?

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

Results and conclusions:
The investigators found a high lead exposure significantly increased risk of ALS with 28% [OR = 1.28, 95% CI = 1.02 to 1.63].
Subgroup and sensitivity analyses showed stable results.

The investigators concluded a high lead exposure increases risk of ALS.

Original title:
Population-based study of environmental/occupational lead exposure and amyotrophic lateral sclerosis: a systematic review and meta-analysis by Meng E, Mao Y, […], Jin W.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31578652

Additional information of El Mondo:
Find here more information/studies about chronic diseases.
 

Objectives:
Does dietary intake of fiber reduce risk of endometrial cancer?

Study design:
This review article included 16 studies, involving 6,563 cases (persons with endometrial cancer).

Results and conclusions:
The investigators found dietary fiber intake significantly reduced risk of endometrial cancer with 14% [RR = 0.86, 95% CI = 0.78 to 0.93].
In stratified analysis, this trend was more pronounced in the case-control studies and in studies conducted in the Americas and Asia.

The investigators found dietary fiber intake significantly reduced risk of endometrial cancer with 26% after adjusting for education level [RR = 0.74, 95% CI = 0.60 to 0.88].

The investigators found dietary fiber intake significantly reduced risk of endometrial cancer with 30% after adjusting for age [RR = 0.70, 95% CI = 0.57 to 0.83].

The investigators found dietary fiber intake significantly reduced risk of endometrial cancer with 19% in studies with NOS scores of 6 (the higher the NOS scores, the more reliable the studies are) [RR = 0.81, 95% CI = 0.67 to 0.95].

The investigators found dietary fiber intake significantly reduced risk of endometrial cancer with 25% in studies with NOS scores of 7 [RR = 0.75, 95% CI = 0.62 to 0.88].

The investigators concluded dietary fiber intake reduces risk of endometrial cancer. Further efforts should be made to confirm these findings.

Original title:
Association between dietary fiber and endometrial cancer: a meta-analysis by Li H, Mao H, [...], Nan Y.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31584301

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

Objectives:
Many studies have been reported that dietary meat intake may be associated with the risk of asthma in children, but the results are inconsistent. Therefore, this review article has been conducted.

Does dietary meat intake increase asthma in children?

Study design:
This review article included a total of 9 articles.

No publication bias was detected.

Results and conclusions:
The investigators found dietary meat intake 3 or more times per week compared with never/occasionally intake had no significant association with asthma risk among children [OR = 1.27, 95% CI  =  0.80-2.01, p =  0.308].
Not significant because OR of 1 was found in the 95% CI of 0.80 to 2.01. OR of 1 means no risk/association.

The investigators found, similarly, daily dietary intake of meat did not affect the risk of asthma in children when compared with never/occasionally intake [OR  =  1.13, 95% CI  =  0.93-1.37, p  =  0.234].

The investigators concluded dietary meat intake is not a risk factor for asthma in children. Due to some limitations that exist in this review article, more studies are needed to further assess the association between dietary meat intake and asthma risk in children.

Original title:
Dietary meat intake and risk of asthma in children: evidence from a meta-analysis by Zhang D, Cao L, [...], Wang Z.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31895767

Additional information of El Mondo:
Find here more information/studies about meat consumption and chronic diseases.
 

Objectives:
Does dietary intake of garlic reduce risk of colorectal cancer?

Study design:
This review article included 11 studies involving 12,558 cases (persons with colorectal cancer).

There was no notable evidence of publication bias.

Results and conclusions:
The investigators found for the highest versus the lowest garlic consumption categories, a significantly reduced risk of 20% [integrated relative risk = 0.80, 95% CI = 0.69 to 0.91] for colorectal cancer.
The sensitivity analysis revealed no notable alterations of the integrated results.
Significant means that there is an association with a 95% confidence.

The investigators found in case-control studies for the highest versus the lowest garlic consumption categories, a significantly reduced risk of 29% [relative risk = 0.71, 95% CI = 0.60 to 0.84] for colorectal cancer.
Significant because relative risk of 1 was not found in the 95% CI of 0.60 to 0.84. Relative risk of 1 means no risk/association.

The investigators found in cohort studies for the highest versus the lowest garlic consumption categories, a non-significantly reduced risk of 1% [relative risk = 0.99, 95% CI = 0.80 to 1.23] for colorectal cancer.
Non-significantly because relative risk of 1 was found in the 95% CI of 0.80 to 1.23. Relative risk of 1 means no risk/association.

The investigators concluded that dietary intake of garlic could reduce risk of colorectal cancer. Could reduce because the risk was not significant in cohort studies.

Original title:
Garlic intake and the risk of colorectal cancer: A meta-analysis by Zhou X, Qian H, […], Zeng L.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31895803

Additional information of El Mondo:
Find more information/studies on significantly/cohort studies, garlic consumption and colorectal cancer right here.

Objectives:
Some evidence indicates that carotenoids may reduce the risk of bladder cancer (BC), but the association is unclear. Therefore, this review article has been conducted.

Do carotenoids (β-cryptoxanthin, α-carotene, β-carotene and lutein and zeaxanthin) reduce risk of bladder cancer?

Study design:
This review article included a total of 22 studies (case-control and cohort studies) involving 516,740 adults.

Results and conclusions:
The investigators found for the highest compared with the lowest category of carotenoid dietary intake a non-significantly reduced risk of 12% [RR = 0.88, 95% CI = 0.76 to 1.03] for bladder cancer.
Non-significantly because RR of 1 was found in the 95% CI of 0.76 to 1.03. RR of 1 means no risk/association.

The investigators found for the highest compared with the lowest category of circulating carotenoid concentrations a non-significantly reduced risk of 64% [RR = 0.36, 95% CI = 0.12 to 1.07] for bladder cancer.

The investigators found for the highest compared with the lowest category of circulating lutein and zeaxanthin concentrations a significantly reduced risk of 47% [RR = 0.53, 95% CI = 0.33 to 0.84] for bladder cancer.
Significantly because RR of 1 was not found in the 95% CI of 0.33 to 0.84. RR of 1 means no risk/association.

The investigators found dose-response analysis showed that bladder cancer risk significantly decreased by 42% [RR = 0.58, 95% CI = 0.36 to 0.94] for every 1 mg increase in daily dietary β-cryptoxanthin intake.

The investigators found dose-response analysis showed that bladder cancer risk significantly decreased by 76% [RR = 0.24, 95% CI = 0.08 to 0.67] for every 1 μmol/L increase in circulating concentration of α-carotene.

The investigators found dose-response analysis showed that bladder cancer risk significantly decreased by 27% [RR = 0.73, 95% CI = 0.57 to 0.94] for every 1 μmol/L increase in circulating concentration of β-carotene.

The investigators found dose-response analysis showed that bladder cancer risk significantly decreased by 56% [RR = 0.44, 95% CI = 0.28 to 0.67] for every 1 μmol/L increase in circulating concentrations of lutein and zeaxanthin.

The investigators concluded dietary β-cryptoxanthin intake and circulating concentrations of α-carotene, β-carotene and lutein and zeaxanthin reduce risk of bladder cancer.

Original title:
Carotenoid Intake and Circulating Carotenoids Are Inversely Associated with the Risk of Bladder Cancer: A Dose-Response Meta-analysis by Wu S, Liu Y, […], Ramirez AG.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31800007

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

 

Objectives:
The morbidity of eczema has increased in the recent years and the methods to prevent or ameliorate its effects are becoming more important. Therefore, this review article has been conducted.

Do vitamin supplements reduce risk of eczema?

Study design:
This review article included 10 RCTs with a total of 456 patients.
The sample sizes ranged from 5 to 57. The studies were published from 2008 to 2018.
5 studies were conducted on atopic dermatitis, 3 studies were conducted on pediatric atopic dermatitis and 2 studies were conducted on winter-related atopic dermatitis.

Results and conclusions:
The investigators found that the SCORAD index or EASI scores significantly decreased in patients given vitamin D3 (cholecalciferol) supplements [mean difference = -5.96, 95% CI = -7.69 to -4.23, I2 = 33%].

The investigators found that the SCORAD index significantly decreased after the topical application of vitamin B12-containing cream [mean difference = -3.19, 95% CI = -4.27 to -2.10, I2 = 0%]. 

The investigators found that the SCORAD index significantly improved after vitamin E supplementation [mean difference = -5.72, 95% CI = -11.41 to -0.03, I2 = 0%]. 

The investigators concluded vitamin D3, B12 and E supplements could be important therapeutics to help manage eczema patients.

Original title:
Assessment of the Effectiveness of Vitamin Supplement in Treating Eczema: A Systematic Review and Meta-Analysis by Zhu Z, Yang Z, [...], Liu H.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6875217/

Additional information of El Mondo:
Find here more information/studies about vitamin B12, D and E and chronic disease.

Objectives:
Is there an association between dietary fat intake and the risk of three major types of skin cancer including basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and cutaneous malignant melanoma (CMM)?

Study design:
This review article included 3 prospective cohort studies (175,675 participants and 30,915 basal cell carcinoma cases, 4,106 squamous cell carcinoma cases and 1,638 cutaneous malignant melanoma cases) and 9 case-control studies (328 basal cell carcinoma cases, 493 squamous cell carcinoma cases, 1,547 cutaneous malignant melanoma cases and 2,660 controls).

Results and conclusions:
The investigators found pooled results indicated that dietary consumption of total fat and saturated fat were not associated with 3 major types of skin cancer.

The investigators found high consumption of monounsaturated fat was significantly associated with a decreased risk of 10% for basal cell carcinoma [RR = 0.90, 95% CI = 0.85 to 0.96]. 

The investigators found high consumption of polyunsaturated fat was significantly associated with an increased risk of 19% for squamous cell carcinoma [RR = 1.19, 95% CI = 1.06 to 1.33]. 

The investigators concluded high consumption of monounsaturated fat decreases risk of basal cell carcinoma while high consumption of polyunsaturated fat increases risk of squamous cell carcinoma. However, these findings should be confirmed by further evidence from well-designed and large-scale prospective cohort studies.

Original title:
Dietary Fat Intake and the Risk of Skin Cancer: A Systematic Review and Meta-Analysis of Observational Studies by Ruan L, Cheng SP and Zhu QX.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31298947

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

Objectives:
Low-potassium diets are recommended to reduce serum potassium (Sk) and prevent complications of chronic kidney disease (CKD), but evidence underpinning this recommendation has not been systematically reviewed and synthesized. Therefore, this review article has been conducted.

Do patients with chronic kidney disease benefit from low-potassium diets?

Study design:
This review article included 7 studies  with 3,489 participants.

Results and conclusions:
The investigators found in very-low-quality studies that restricted (1,295 mg/d) versus unrestricted (1,570 mg/d) dietary potassium lowered serum potassium by 0.22 mEq/L [95% CI = -0.33 to -0.10, I2 = 0%].

The investigators found in very-low-quality studies that lower (1,725 mg/d) versus higher (4,558 mg/d) dietary potassium was not significantly associated with disease progression [HR = 1.14, 95% CI = 0.77 to 1.70, I2 = 57%].

The investigators found in very-low-quality studies that lower (1,670 mg/d), compared with higher (4,414 mg/d) dietary potassium intake was associated with a 40% reduction in mortality hazard [HR = 0.60, 95% CI = 0.40 to 0.89, I2 = 56%].

The investigators concluded very-low-quality evidence supports consensus that dietary potassium restriction reduces serum potassium in normokalemia and is associated with a reduced risk of death in those with chronic kidney disease. However, high-quality randomized controlled trials are needed to confirm these findings.

Original title:
Effect of Dietary Potassium Restriction on Serum Potassium, Disease Progression, and Mortality in Chronic Kidney Disease: A Systematic Review and Meta-Analysis by Morris A, Krishnan N, […], Lycett D.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31734057

Additional information of El Mondo:
Find here more information/studies about potassium and kidney disease.

Objectives:
Parkinson's disease (PD) is the most common neurodegenerative disease after Alzheimer's dementia. Whereas the exact etiology of Parkinson's disease remains unknown, risk of developing Parkinson's disease seems to be related to a combination of genetic and environmental factors. This also includes abnormal exposure to trace elements of nutritional and toxicological interest. Therefore, this review article has been conducted.

Is there a relationship between exposure to trace elements and Parkinson’s disease risk?

Study design:
This review article included 56 case-control studies reporting data for selenium (cases/controls: 588/721), copper (2,190/2,522), iron (2,956/3,469) and zinc (1,798/1,913) contents in cerebrospinal fluid (CSF) and blood.

Results and conclusions:
The investigators found patients with Parkinson's disease had significantly higher levels of selenium in cerebrospinal fluid compared with controls [+51.6%, WMD = 5.49, 95% CI = 2.82 to 8.15], while levels in serum were similar [-0.2%, WMD = -0.22, 95% CI = -8.05 to 7.62].

The investigators found patients with Parkinson's disease had non-significantly higher levels of copper in cerebrospinal fluid compared with controls [+4.5%, WMD = 1.87, 95% CI = -3.59 to 7.33] and non-significantly lower levels of copper in serum [WMD = -42.79, 95% CI = -134.35 to 48.76].

The investigators found patients with Parkinson's disease had significantly higher levels of iron in cerebrospinal fluid compared with controls [+9.5%, WMD = 9.92, 1.23 to 18.61] and significantly lower levels of iron both in serum/plasma [-5.7%, WMD = -58.19, 95% CI = -106.49 to -9.89] and whole blood [-10.8%, WMD = -95.69, 95% CI = -157.73 to -33.65].

The investigators found patients with Parkinson's disease had significantly lower levels of zinc in cerebrospinal fluid compared with controls [-10.8%, WMD = -7.34, 95% CI = -14.82 to -0.14] and significantly lower levels of zinc in serum/plasma [-7.5%, WMD = -79.93, 95% CI = -143.80 to -16.06].

The investigators found a longer duration of the disease tends to be associated with overall lower trace element levels in either cerebrospinal fluid or blood.

The investigators concluded higher levels of both selenium and iron in cerebrospinal fluid increase Parkinson's disease, while higher levels of zinc in cerebrospinal fluid decrease Parkinson's disease.

Original title:
Selenium and Other Trace Elements in the Etiology of Parkinson's Disease: A Systematic Review and Meta-Analysis of Case-Control Studies by Adani G, Filippini T, […], Vinceti M.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31454800

Additional information of El Mondo:
Find here more information/studies about iron, zinc, selenium and chronic disease
 

Objectives:
Does omega-3 fatty acids supplementation improve serum levels of inflammatory biomarkers (C-reactive protein [CRP], high-sensitivity CRP [hs-CRP], tumor necrosis factor-alpha, interleukin-6) and albumin in patients on hemodialysis?

Study design:
This review article included 8 RCTs comprising 371 patients on hemodialysis.

Results and conclusions:
The investigators found omega-3 supplementation significantly decreased serum levels of CRP in patients on hemodialysis [SMD = -1.95 mg/dL, 95% CI = -3.09 to -0.80] and hs-CRP [SMD = -2.09, 95% CI = -3.62 to -0.56].

The investigators found, however, omega-3 supplementation did not significantly improved albumin [SMD = 0.91, 95% CI = -0.78 to 2.59], tumor necrosis factor-alpha [SMD = -1.51, 95% CI = -3.24 to 0.22] and interleukin-6 levels [SMD = 0.72, 95% CI = -0.56 to 1.99] in patients on hemodialysis.

The investigators concluded omega-3 supplementation leads to a significant decrease in serum levels of CRP and hs-CRP in patients on hemodialysis.

Original title:
The Effect of Omega-3 Supplementation on Serum Levels of Inflammatory Biomarkers and Albumin in Hemodialysis Patients: A Systematic Review and Meta-analysis by Dezfouli M, Moeinzadeh F, [...], Feizi A.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31420233

Additional information of El Mondo:
Find here more information/studies about omega-3 fatty acids and kidney disease.  
 

Objectives:
The results of epidemiological studies on the relationship between fruit and vegetable intake and lung cancer risk were inconsistent among participants with different smoking status. Therefore, this review article has been conducted.

Do dietary intakes of fruit and vegetables reduce risk of lung cancer?

Study design:
This review article included a total of 12 prospective cohort studies.
The duration of follow-up ranged from 4 to 12.9 years.
No publication bias was found.

Results and conclusions:
The investigators found for dietary consumption of fruit a significantly reduced risk of 14% [summary RR = 0.86, 95% CI = 0.78 to 0.94, I2 = 0.0%, p = 0.642] for lung cancer among current smokers.

Significant means that there is an association with a 95% confidence.

The investigators found for dietary consumption of fruit a significantly reduced risk of 9% [summary RR = 0.91, 95% CI = 0.84 to 0.99, I2 = 0.0%, p = 0.653] for lung cancer among former smokers.
Significant because RR of 1 was not found in the 95% CI of 0.84 to 0.99. RR of 1 means no risk/association.

The investigators found stratified analysis showed that dietary consumption of fruit significantly reduced risk of lung cancer with 23% [RR = 0.77, 95% CI = 0.62 to 0.96] in current smoking subjects from Europe.

The investigators found in linear dose-response analysis that an increase of 100 grams of fruit intake per day was associated with a 5% reduction [RR = 0.95, 95% CI = 0.93 to 0.97, p for trend 0.001] in current smokers.

The investigators found in linear dose-response analysis that an increase of 100 grams of fruit intake per day was associated with a 5% reduction [RR = 0.95, 95% CI = 0.93 to 0.99, p for trend = 0.001] in former smokers.

The investigators found for dietary consumption of vegetables a significantly reduced risk of 13% [summary RR = 0.87, 95% CI = 0.78 to 0.97, I2 = 25.4%, p = 0.226] for lung cancer among current smokers.

The investigators found in linear dose-response analysis that an increase of 100 grams of vegetable intake per day was associated with a 3% lower risk of lung cancer in current smokers [95% CI = 0.96 to 1.00, p for trend = 0.057]. 

The investigators concluded that fruit consumption, at least 100g per day decreases lung cancer risk among current smokers and former smokers, while vegetables consumption, at least 100g per day decreases lung cancer risk of current smokers. These findings may have considerable public health significance for the prevention of lung cancer through dietary interventions.

Original title:
The Associations of Fruit and Vegetable Intake with Lung Cancer Risk in Participants with Different Smoking Status: A Meta-Analysis of Prospective Cohort Studies by Wang C, Yang T, [...], Li D.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6723574/

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

 

Objectives:
Findings of epidemiological studies regarding the association between carrot consumption and lung cancer risk remain inconsistent. Therefore, this review article has been conducted.

Do dietary intakes of carrot reduce risk of lung cancer?

Study design:
This review article included a total of 17 case-control studies and 1 prospective cohort study, involving 202,969 individuals and 5,517 patients with lung cancer.

Results and conclusions:
The investigators found in 18 studies a significantly reduced risk of 42% [pooled OR = 0.58, 95% CI = 0.45 to 0.74] for lung cancer by comparing the highest category with the lowest category of carrot consumption.
Exclusion of any single study did not materially alter the pooled OR.

The investigators found based on subgroup analyses for the types of lung cancer a significantly reduced risk of 66% [pooled OR = 0.34, 95% CI = 0.15 to 0.79] for the lung cancer adenocarcinoma by comparing the highest category with the lowest category of carrot consumption.

The investigators found based on subgroup analyses for the types of lung cancer a significantly reduced risk of 39% [OR = 0.61, 95% CI = 0.46 to 0.81] for mixed types of lung cancer by comparing the highest category with the lowest category of carrot consumption.

The investigators concluded that carrot consumption decreases the risk of lung cancer, especially for adenocarcinoma.

Original title:
Is carrot consumption associated with a decreased risk of lung cancer? A meta-analysis of observational studies by Xu H, Jiang H, […], Lu Z.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31552816

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

 

Objectives:
Environmental risk factors regrading rheumatoid arthritis (RA) have not been explored extensively. Selenium (Se), zinc (Zn) and copper (Cu) nutrients were reported to associate with rheumatoid arthritis, but the results were inconsistent. Therefore, this review article has been conducted.

Is there a relationship between serum selenium, zinc and copper levels and rheumatoid arthritis risk?

Study design:
This review article included 41 studies.

Results and conclusions:
The investigators found meta-analysis of 16 studies involving 806 rheumatoid arthritis patients and 959 health controls showed that serum selenium levels [SMD = -1.04, 95% CI = -1.58 to -0.50] were significantly decreased in rheumatoid arthritis patients.

The investigators found meta-analysis of 23 studies involving 1,398 rheumatoid arthritis patients and 1,299 health controls showed that serum zinc levels [SMD = -1.20, 95% CI = -1.74 to -0.67] were significantly decreased in rheumatoid arthritis patients.

The investigators found meta-analysis of 26 studies involving 1,723 rheumatoid arthritis patients and 1,451 health controls showed that serum copper levels [SMD = 1.26, 95% CI = 0.63 to 1.89] were significantly increased in rheumatoid arthritis patients.

The investigators found meta-regression reported that steroid use was positively related to serum level of selenium in rheumatoid arthritis [β = 0.041, 95% CI = 0.002 to 0.079].

The investigators found differences in serum selenium, zinc and copper between rheumatoid arthritis patients and controls were all related with the geographical distribution.

The investigators concluded patients with rheumatoid arthritis have significant decreased serum selenium and zinc levels and increased serum copper levels than health controls, suggesting potential roles of selenium, zinc and copper in the pathogenesis of rheumatoid arthritis. Patients and rheumatologist should give enough attention to the monitor of these elements during follow up.

Original title:
Common trace metals in rheumatoid arthritis: A systematic review and meta-analysis by Ma Y, Zhang X, […], Pan F.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31442958

Additional information of El Mondo:
Find here more information/studies about selenium, zinc and copper and chronic disease.


 

Objectives:
Systematic inflammation plays a major role in all stages of chronic diseases. Recent evidence suggests that coenzyme Q10 (CoQ10), as an anti-inflammatory agent, has shown beneficial effects on the inflammatory process of various human diseases. However, several trials have examined the effects of coenzyme Q10 on pro-inflammatory cytokines with contrasting results. Therefore, this review article has been conducted.

Does coenzyme Q10 supplementation reduce inflammation in humans?

Study design:
This review article included 9 RCTs with a total of 509 patients (269 in the coenzyme Q10 arm and 240 in the control arm).

Results and conclusions:
The investigators found that oral coenzyme Q10 supplementation (60-500 mg/day for 8-12 weeks) resulted in significant reduction of TNF-α [SMD = -0.44, 95% CI = -0.81 to -0.07 mg/dL, I2 = 66.1%, p  = 0.00] and IL-6 levels [SMD = -0.37, 95% CI = -0.65 to -0.09, I2 = 57.2%, p  = 0.01], respectively.

The investigators found subgroup analyses represented a significant reduction of TNF-α and IL-6 levels in patients with BMI  26.
Due to the small number of studies and patients included in each subgroup, these subgroup analyses need to be interpreted cautiously.

The investigators concluded there is a significant effect of 60-500 mg/day coenzyme Q10 supplements for 8-12 weeks on some of the inflammatory markers among patients with chronic diseases which could attenuate the inflammatory state. However, well-designed studies with a larger sample size are required. Note that the results should be interpreted with caution because of the evidence of heterogeneity and limited number of studies.

Original title:
Can coenzyme Q10 supplementation effectively reduce human tumor necrosis factor-α and interleukin-6 levels in chronic inflammatory diseases? A systematic review and meta-analysis of randomized controlled trials by Vafa M.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31185284

Additional information of El Mondo:
Find here more information/studies about chronic disease and coenzyme Q10.

Objectives:
There is little evidence whether eggs affect inflammation. Therefore, this review article has been conducted.

Does egg consumption increase risk of inflammation?

Study design:
This review article included 8 RCTs assessed high sensitivity c-reactive protein (hs-CRP), 4 RCTs assessed interleukin-6 (IL-6) and 5 RCTs assessed tumor necrosis factor alpha (TNF-α).

Results and conclusions:
The investigators found egg consumption did not affect hs-CRP [WMD = 0.24 mg/L, 95% CI = -0.43 to 0.90, I2 = 53.8%, p = 0.48], IL-6 [WMD = 0.20 pg/mL, 95% CI =  -0.71 to 1.11, I2 = 69.3%, p = 0.50] and TNF-α [WMD = -0.38 pg/mL, 95% CI = -0.87 to 0.10, I2 = 0.00%, p = 0.12] relative to controls.

The investigators concluded that egg consumption has no effect on serum biomarkers of inflammation in adults.

Original title:
Effect of Egg Consumption on Inflammatory Markers: A Systematic Review and Meta-Analysis of Randomized Controlled Clinical Trials by Sajadi Hezaveh Z, Khalighi Sikaroudi M, […], Soltani S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31259415

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

Inflammation in human body can be measured by means of biomarkers. These biomarkers are hs-CRP, IL-6 and TNF-α.
 

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.