Nutrition and health

Objectives:
Hormonal effects of soy and isoflavones have been investigated in numerous trials with equivocal findings. Therefore, this review article has been conducted.

What are hormonal effects of soy and isoflavones in both pre- and postmenopausal women?

Study design:
This review article included 47 (11 of pre-, 35 of post- and 1 of perimenopausal women) randomized or residential crossover trials of soy or isoflavones for 4 or more weeks on estrogens, SHBG, FSH, LH, progesterone and thyroid hormones in women was assessed independently in duplicate.

The studies ranged from 4 to 104 weeks long: 29 were 4-12 weeks in duration, 9 were 13-26 weeks, 7 were 27-52 weeks and 2 were >1 year.

Results and conclusions:
The investigators found in premenopausal women, soy or isoflavone consumption did not affect primary outcomes estradiol, estrone or SHBG concentrations, but significantly reduced secondary outcomes FSH and LH [by approximately 20% using standardized mean difference (SMD), p = 0.01 and p = 0.05, respectively].

The investigators found in 10 studies that soy or isoflavone consumption increased menstrual cycle length by 1.05 days [95% CI = 0.13-1.97].

The investigators found in post-menopausal women, soy or isoflavone consumption had no statistically significant effects on estradiol, estrone, SHBG, FSH or LH, although there was a small statistically non-significant increase in total estradiol with soy or isoflavones [by approximately 14% using standardized mean difference (SMD), p = 0.07, 21 studies].

The investigators concluded isoflavone-rich soy products decrease FSH and LH in premenopausal women and may increase estradiol in post-menopausal women. The clinical implications of these modest hormonal changes remain to be determined.

Original title:
Effects of soy protein and isoflavones on circulating hormone concentrations in pre- and post-menopausal women: a systematic review and meta-analysis by Hooper L, Ryder JJ, […], Cassidy A.

Link:
http://humupd.oxfordjournals.org/content/15/4/423.full

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Objectives:
Prostate cancer (PCa) is the fifth leading cause of cancer-related deaths worldwide. Many epidemiological studies have investigated the association between prostate cancer and lycopene, however, results have been inconsistent. Therefore, this review article (meta-analysis) has been conducted.

Does lycopene reduce prostate cancer risk?

Study design:
This review article included 42 studies including 43,851 cases of prostate cancer reported from 692,012 participants.

Results and conclusions:
The investigators found dietary intake of lycopene was significantly associated with a reduced prostate cancer risk of 12% [RR = 0.88, 95% CI = 0.78-0.98, p = 0.017].

The investigators found circulating concentrations of lycopene were significantly associated with a reduced prostate cancer risk of 12% [RR = 0.88, 95% CI = 0.79-0.98, p = 0.019].

The investigators found sensitivity analyses within the dose-response analysis further revealed a significant linear dose-response for dietary lycopene and prostate cancer risk such that prostate cancer decreased by 1% for every additional 2 mg of lycopene consumed [p = 0.026].

The investigators found prostate cancer risk decreased by 3.5 to 3.6% for each additional 10 μg/dL of circulating lycopene in the linear and nonlinear models, respectively [p-linear = 0.004, p-non linear = 0.006].

The investigators found no association between lycopene and advanced prostate cancer. However, there was a trend for protection against prostate cancer aggressiveness [RR = 0.74, 95% CI = 0.55-1.00, p = 0.052].

The investigators concluded that higher dietary and circulating lycopene concentrations reduce prostate cancer risk. This was accompanied by dose-response relationships for dietary and circulating lycopene. Further studies are required to determine the mechanisms underlying these associations.

Original title:
Increased dietary and circulating lycopene are associated with reduced prostate cancer risk: a systematic review and meta-analysis by Rowles JL, Ranard KM, […], Erdman JW Jr.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28440323

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Objectives:
There are conflicting reports on the correlation between manganese (Mn) levels and breast cancer. Therefore, this review article (meta-analysis) has been conducted.

Does manganese deficiency increase risk of breast cancer?

Study design:
This review article included 11 case-control studies involving 1302 subjects.

There was no evidence of publication bias. Sensitivity analysis showed that excluding any one study from the pooled analysis did not vary the results substantially.

Results and conclusions:
The investigators found the random-effects meta-analysis results indicated that subjects with breast cancer had lower manganese levels in serum and hair than healthy controls [SMD = -1.51, 95% CI = -2.47 to -0.56, I2 = 97.8%, p 0.001].

The investigators found in subgroup analysis that subjects with breast cancer had lower manganese levels than healthy controls in China [SMD = -1.32, 95% CI = -2.33 to -0.32] and Korea [SMD = -4.08, 95% CI = -4.63 to -3.54], but not in Turkey [SMD = -0.96, 95% CI = -3.19 to 1.27].

The investigators found in subgroup analysis that the differences of manganese levels between patients with breast cancer and healthy controls were similar in different sample specimens:
serum [SMD = -1.24, 95% CI = -2.31 to -0.16];
hair [SMD = -1.99, 95% CI = -3.91 to -0.06] and;
different types of manganese measurement:

ICP-AAS [SMD = -1.14, 95% CI = -2.24 to -0.04];
GFAAS [SMD = -1.94, 95% CI = -2.38 to -1.49];
ICP-AES [SMD = -3.77, 95% CI = -4.70 to -2.85]. These findings can well explain that  the between-study variability was the main source of heterogeneity.

The investigators concluded there is an association between deficient manganese concentration and breast cancer. However, the subgroup analysis found that there was contradiction regarding races and geography, like China and Turkey. Thus this finding needs further confirmation by trans-regional multicenter, long-term observation in a cohort design to obtain better understanding of causal relationships between manganese levels and breast cancer, through measuring manganese at baseline to investigate whether the highest manganese category versus lowest was associated with breast cancer risk.

Original title:
The association between deficient manganese levels and breast cancer: a meta-analysis by Shen F, Cai WS, [...],Xu B.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4443096/

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

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

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

There was no evidence of publication bias.

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

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

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

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

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

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

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Objectives:
Prostate cancer (PCa) now remains the 2nd most frequently diagnosed cancer. In recent years, chemoprevention for prostate cancer becomes a possible concept. Especially, many phytochemicals rich foods are suggested to lower the risk of cancer. Among these foods, green tea is considered as effective prevention for various cancers. However, clinical trials and previous meta-analyses on the relationship between green tea consumption and the risk of prostate cancer have produced inconsistent outcomes. Therefore, this review article (meta-analysis) has been conducted.

Does green tea intake reduce prostate cancer risk?

Study design:
This review article included 4 cohort studies, 3 case-control studies and 3 RCTs. The cohort studies and case-control studies which investigated the association between green tea intake and prostate cancer risk included 1435 cases among 96,332 individuals and the 3 RCTs studied the relationship between EGCG and prostate cancer incidence included 87 volunteers in EGCG arms of 179 individuals.

No publication bias was found.

Results and conclusions:
The investigators found in observational studies (4 cohort studies and 3 case-control studies) for the highest versus lowest category of green tea intake a non-significant reduced prostate cancer risk of 8% [RR = 0.92, 95% CI = 0.77-1.11, I2 = 0%, p = 0.46] for all studies;

a non-significant reduced prostate cancer risk of 2.3% [RR = 0.977, 95% CI = 0.80-1.19] for cohort studies and;
a non-significant reduced prostate cancer risk of 27.7% [RR = 0.623, 95% CI = 0,368-1.056, I2  = 0%, p =  0.46] for case-control studies.

The investigators found no association between 1-5 cups of green tea per day and prostate cancer risk.

However, the investigators found 7 cups of green tea per day significantly reduced prostate cancer risk with 19% [RR = 0.81, 95% CI = 0.67-0.97]. The significant reduced prostate cancer risk increased to 26% [RR = 0.74, 95% CI = 0.59-0.93] for 9 cups and to 44% [RR = 0.56, 95% CI = 0.35-0.92) for 15 cups.

The investigators found in 3 RCTs when compared to placebo green tea catechins significantly reduced prostate cancer risk  with 62% [RR = 0.38, 95% CI = 0.16-0.86, p  =  0.02].

The investigators concluded that at least 7 cups/day green tea intake reduces prostate cancer. This is further confirmed by the potential protective effect of green tea catechins on prostate cancer. Further prospective study with accurate measurement of green tea intake is required to substantiate these conclusions.

Original title:
Green tea and the risk of prostate cancer: A systematic review and meta-analysis by Guo Y, Zhi F, […], Zhang X.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5380255/

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Objectives:
The association between meat consumption and the risk of hepatocellular carcinoma (HCC) is still inconclusive. Therefore, this review article has been conducted.

Does meat consumption increase risk of hepatocellular carcinoma?

Study design:
This review article included 7 cohort studies and 10 case-control studies.

Results and conclusions:
The investigators found for the highest vs. lowest consumption levels a non-significant increased risk for hepatocellular carcinoma of 10% [RR = 1.10, 95% CI = 0.85-1.42] for red meat, a non-significant increased risk of 1% [RR = 1.01, 95% CI = 0.79-1.28] for processed meat and a non-significant decreased risk of 3% [RR = 0.97, 95% CI = 0.85-1.11] for total meat. Non-significant means, there is no association with a 95% confidence.

The investigators found for the highest vs. lowest consumption levels a significant decreased risk for hepatocellular carcinoma of 31% [RR = 0.69, 95% CI = 0.58-0.81] for white meat and a significant decreased risk of 22% [RR = 0.78, 95% CI = 0.67-0.90] for fish. The results remained quite stable after stratification by the confounding factors.
Significant means, there is an association with a 95% confidence.

The investigators concluded a high level of white meat or fish consumption reduces the risk of hepatocellular carcinoma, while intake of red meat, processed meat or total meat is not associated with hepatocellular carcinoma risk. These results suggest that dietary intervention may be a promising approach for prevention of hepatocellular carcinoma, which still need to be confirmed by further well-designed prospective studies and experimental research.

Original title:
Systematic review with meta-analysis: meat consumption and the risk of hepatocellular carcinoma by Luo J, Yang Y, [...], Zhu Y.

Link:
http://www.ncbi.nlm.nih.gov/pubmed/24588342

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A review article of cohort studies or case-control studies will answer the following question:
"Should I change my diet?".

Objectives:
Is there an association between meat intake and risk of esophageal cancer?

Study design:
This review article included 7 cohort studies and 28 case-control studies.

Results and conclusions:
The investigators found for the highest versus lowest total meat consumption categories a non-significant increased risk of 19% [95% CI = 0.98-1.46] for esophageal cancer.

The investigators found for the highest versus lowest red meat consumption categories a significant increased risk of 55% [95% CI = 1.22-1.96] for esophageal cancer.

The investigators found for the highest versus lowest processed meat consumption categories a significant increased risk of 33% [95% CI = 1.04-1.69] for esophageal cancer.

The investigators found for the highest versus lowest white meat consumption categories a significant decreased risk of 28% [95% CI = 0.60-0.86] for esophageal cancer.

The investigators found for the highest versus lowest poultry consumption categories a significant decreased risk of 17% [95% CI = 0.72-0.96] for esophageal cancer.

The investigators found for the highest versus lowest fish consumption categories a non-significant decreased risk of 5% [95% CI = 0.76-1.19] for esophageal cancer.

The investigators found when stratified by histological subtype, positive associations among esophageal squamous cell carcinoma and red meat, white meat and poultry and esophageal adenocarcinoma with total meat and processed meat.

The investigators concluded red meat and processed meat consumption increase risk of esophageal cancer, while white meat and poultry decrease risk of esophageal cancer. Fish consumption is not associated with incidence of esophageal cancer.

Original title:
Meat consumption is associated with esophageal cancer risk in a meat- and cancer-histological-type dependent manner by Zhu HC, Yang X, […], Sun XC.

Link:
http://www.ncbi.nlm.nih.gov/pubmed/24395380

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Objectives:
Epidemiological studies assessing the relationship between dietary vitamin B2 and the risk of breast cancer have produced inconsistent results. Therefore, this review article (meta-analysis) has been conducted.

Does dietary vitamin B2 intake reduce breast cancer risk?

Study design:
This review article included 10 epidemiologic studies (cohort or patient-controle studies) comprising totally 12,268 breast cancer patients.

No publication bias was found.

Results and conclusions:
The investigators found comparing the highest to the lowest dietary vitamin B2 intake a significant reduced risk of 15% for breast cancer [pooled relative risk = 0.85, 95% CI = 0.76-0.95, I2 = 40.7%].

The investigators found dose-response analysis showed that an increment of 1 mg/day dietary vitamin B2 intake significantly reduced risk of breast cancer with 6% [relative risk = 0.94, 95% CI = 0.90-0.99].

The investigators concluded that dietary vitamin B2 intake, at least 1 mg/day, is related to the reduced risk of breast cancer. However, additional research is also necessary to further explore this association.

Original title:
Dietary vitamin B2 intake and breast cancer risk: a systematic review and meta-analysis by Yu L, Tan Y and Zhu L.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28035488

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Objectives:
Is there an association of intake of different vitamins and multiple-vitamin supplements and the incidence of colorectal cancer?

Study design:
This review article included 47 articles (cohort studies).

There was unacceptable heterogeneity for studies of multiple-vitamin supplements, so findings were inconclusive.

Results and conclusions:
The investigators found a significant reduced risk of 12% [multivariable-adjusted RR = 0.88, 95% CI = 0.81-0.95] for colorectal cancer when comparing the highest versus lowest dietary vitamin B9 (folate) intake. Significant means that there is an association with a 95% confidence.

The investigators found a significant reduced risk of 13% [multivariable-adjusted RR = 0.87, 95% CI = 0.77-0.99] for colorectal cancer when comparing the highest versus lowest dietary vitamin D intake. Significant because RR of 1 was not found in the 95% CI of 0.77 to 0.99. RR of 1 means no risk/association.

The investigators found a significant reduced risk of 12% [multivariable-adjusted RR = 0.88, 95% CI = 0.79-0.99] for colorectal cancer when comparing the highest versus lowest dietary vitamin B6 intake.

The investigators found a significant reduced risk of 14% [multivariable-adjusted RR = 0.86, 95% CI = 0.76-0.97] for colorectal cancer when comparing the highest versus lowest dietary vitamin B2 intake.

The investigators found, however, no association between both dietary vitamine A, C, E, B3 and B12 and the risk of colorectal cancer.

The investigators concluded high dietary vitamin B9 (folate), D, B6 and B2 intake reduces risk of colorectal cancer, but further study is needed.

Original title:
Vitamin and multiple-vitamin supplement intake and incidence of colorectal cancer: a meta-analysis of cohort studies by Liu Y, Yu Q, […], Li K.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/25491145

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Objectives:
Red meat intake has been associated with risk of colorectal cancer, potentially mediated through heterocyclic amines. The metabolic efficiency of N-acetyltransferase 2 (NAT2) required for the metabolic activation of such amines is influenced by genetic variation. The interaction between red meat intake, NAT2 genotype and colorectal cancer has been inconsistently reported. Therefore, this review article has been conducted.

Is there an interaction between red meat intake, NAT2 genotype and colorectal cancer?

Study design:
This review article included 11 retrospective case-control studies with 8,290 colorectal cancer cases and 9,115 controls (subjects without colorectal cancer).

Results and conclusions:
The investigators found the highest quartile of red meat intake was associated with a 41% increased risk of colorectal cancer compared with the lowest quartile [OR = 1.41, 95% CI = 1.29-1.55].
However, a significant association was observed only for studies with retrospective diet data, not for studies with diet prospectively assessed before cancer diagnosis.

The investigators found when combining all studies, high red meat intake was similarly associated with colorectal cancer in those with a rapid/intermediate NAT2 genotype [OR = 1.38, 95% CI = 1.20-1.59] as with a slow genotype [OR = 1.43, 95% CI = 1.28-1.61, p interaction = 0.9].

The investigators concluded high red meat intake was associated with increased risk of colorectal cancer only from retrospective case-control studies and not modified by NAT2 enzyme activity.

Original title:
Red Meat Intake, NAT2, and Risk of Colorectal Cancer: A Pooled Analysis of 11 Studies by Ananthakrishnan AN, Du M, […], Chan AT.

Link:
http://cebp.aacrjournals.org/content/cebp/24/1/198.full.pdf

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Objectives:
The association between dietary carbohydrate intake and colorectal cancer risk remains controversial. Therefore, this review article (meta-analysis) has been conducted.

Does higher dietary carbohydrate intake increase colorectal cancer risk?

Study design:
This review article included 8 case-controle studies en 9 prospective cohort studies involving 14,402 colorectal cancer patients among 846004 participants; 17 studies with 9,235 cases were to assess the association on colon cancer and 13  studies with 3,272 cases were to  assess the association on rectum cancer. 

No publication bias was found.

Results and conclusions:
The investigators found no association between dietary carbohydrate intake and colorectal cancer risk [pooled RR = 1.08, 95% CI = 0.93-1.23, I2 = 68.3%, p-heterogeneity 0.001]. No association because RR of 1 was found in the 95% CI of 0.93 to 1.23. RR of 1 means no risk/association.

The investigators found no association between dietary carbohydrate intake and colon cancer risk [pooled RR = 1.09, 95% CI = 0.95-1.25, I2 = 48.3%].

The investigators found no association between dietary carbohydrate intake and rectum cancer risk [pooled RR = 1.17, 95% CI = 0.98-1.39, I2 = 17.8%].

The investigators found in subgroup analyses for study design, a non-significant association for both case-control studies [summary RR = 1.40, 95% CI = 0.93-2.09] and cohort studies [summary RR = 0.99, 95% CI = 0.85-1.15].  

The investigators found in stratified analysis by geographic locations, higher dietary   carbohydrate intake had no significant association on colorectal cancer risk among American populations [summary RR = 1.08, 95% CI = 0.89-1.30], European populations [summary RR = 1.23, 95% CI = 0.91-1.64] or Asian population [summary RR = 0.98, 95% CI = 0.65-1.46].

The investigators found higher dietary carbohydrate intake significantly increased risk of colorectal cancer with 23% in men populations [summary RR = 1.23, 95% CI = 1.01-1.57], but not in women populations.

The investigators concluded that higher dietary carbohydrate intake increases colorectal cancer risk in men populations. Further studies are wanted to confirm this relationship.

Original title:
A meta-analysis between dietary carbohydrate intake and colorectal cancer risk: Evidence from 17 observational studies by Huang J, Pan G, [...], Zhu Z.

Link:
http://www.bioscirep.org/content/ppbioscirep/early/2017/03/15/BSR20160553.full.pdf

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Objectives:
Previous observational studies regarding the existence of an association between folate intake and the risk of breast cancer have been inconsistent. Therefore, this review article has been conducted.

Does a higher dietary folate intake reduce breast cancer risk?

Study design:
This review article included 14 prospective cohort studies that reported data on 677,858 individuals.
The participant follow-up period ranged 4.7-17.4 years and the number of individuals per study ranged 11,699-88,818.
There was no publication bias.

Results and conclusions:
The investigators found no association between dietary folate intake and breast cancer risk for highest versus lowest category  [RR =  0.97, 95% CI = 0.90-1.05, p  = 0.451, I2 =  57.5%, p = 0.004].

The investigators found dose-response meta-analysis findings showed no association between the risk of breast cancer and a 100 µg/day increase in dietary folate intake [RR = 0.99, 95% CI = 0.98-1.01, p = 0.361, I2 = 66.2%, p 0.001].

The investigators found evidence of a nonlinear relationship between dietary folate intake and the risk of breast cancer.

A daily dietary folate intake of 200-320 µg was associated with a reduced risk of breast cancer. However, daily folate intake levels >400 µg was associated with a increased risk of breast cancer.

The investigators found overall folate intake level was associated with a reduced breast cancer risk of 36% if the patients had a daily alcohol intake >10 g [RR for highest versus lowest category = 0.64, 95% CI = 0.43-0.97].

The investigators concluded there are no effects of increased dietary folate intake on the incidence of breast cancer. But, a daily dietary folate intake of 200-320 µg was associated with a reduced risk of breast cancer. However, daily folate intake levels >400 µg was associated with a increased risk of breast cancer. Future studies should focus on specific populations in order to analyze primary breast cancer prevention.

Original title:
Folate Intake and the Risk of Breast Cancer: A Dose-Response Meta-Analysis of Prospective Studies by Zhang YF, Shi WW, […], Zhou YH.

Link:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4059748/

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Objectives:
There is no published systematic review and meta-analysis regarding the effect of olive oil consumption on cancer occurrence. Therefore, this review article has been conducted.

Does olive oil consumption reduce cancer risk?

Study design:
This review article included 19 case-control studies (13800 cancer patients and 23340 controls).

Random effects meta-analysis was applied in order to evaluate the research hypothesis.
Heterogeneity of the effect-size measures was observed in studies performed in the Mediterranean region (n = 15, p = 0.0002), whereas no heterogeneity was observed in non-Mediterranean studies (n = 4, p = 0.12).

Results and conclusions:
The investigators found when comparing with the lowest, the highest category of olive oil consumption was significantly associated with lower odds of having any type of cancer [log odds ratio = -0.41, 95% CI = -0.53 to -0.29, Cohran's Q = 47.52, p = 0.0002, I2 = 62%].

The investigators found both Mediterranean and non-Mediterranean people reported olive oil intake were less likely to have developed any type of cancer.

The investigators found olive oil consumption was significantly associated with lower odds of developing breast cancer [logOR = -0.4,  95% CI = -0.78 to -0.12] and a cancer of the digestive system [logOR = -0.36, 95% CI = -0.50 to -0.21] compared with the lowest intake.

The investigators concluded olive oil consumption probably reduces risk of any type of cancer, especially breast cancer and cancer of the digestive system. Probably, because this review article only included case-control studies and there was heterogeneity.
The reduced risk is similar to studies performed in Mediterranean as well as non-Mediterranean countries. However, it is still unclear whether olive oil's monounsaturated fatty acid content or its antioxidant components are responsible for its beneficial effects.

Original title:
Olive oil intake is inversely related to cancer prevalence: a systematic review and a meta-analysis of 13800 patients and 23340 controls in 19 observational studies by Psaltopoulou T, Kosti RI, […], Panagiotakos DB.

Link:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3199852/

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Objectives:
Is there an association between serum non-ceruloplasmin copper and Alzheimer's disease risk?

Study design:
This review article included studies carried out from 1996 until March 2013.

Ten studies were analyzed in the meta-analysis for Non-Cp copper and % Non-Cp copper reaching a pooled total of 599 Alzheimer's disease subjects and 867 controls.
For Adj-Cp copper, 14 studies were analyzed with a pooled total of 879 Alzheimer's disease subjects and 1712 controls.
27 studies were considered for systemic total copper meta-analysis, with a pooled total of 1393 Alzheimer's disease subjects and 2159 controls.

Results and conclusions:
The investigators found all copper indices analyzed were significantly higher in Alzheimer's disease subjects compared to healthy controls.

The investigators concluded serum non-ceruloplasmin copper is higher in Alzheimer's disease.

Original title:
Meta-analysis of serum non-ceruloplasmin copper in Alzheimer's disease by Squitti R, Simonelli I, […], Bush AI.

Link:
http://www.ncbi.nlm.nih.gov/pubmed/24072069

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Objectives:
Does DHA, alone or combined with EPA, contribute to improved memory function in older adults with mild memory complaints?

Study design:
This review article included 15 intervention trials and 13 observational studies. Most intervention trials were conducted with subjects ≥ 45 years of age (n = 11). The majority of studies were conducted in subjects without cognitive complaints (n = 9) and ranged from 28-730 days in duration, averaging 4-6 months.

Results and conclusions:
The investigators found episodic memory of subjects with mild memory complaints significantly improved in response to DHA supplementation, alone or in combination with EPA [p 0.004].

The investigators found regardless of cognitive status at baseline, >1 g/day DHA/EPA significantly improved episodic memory of subjects with mild memory complaints [p 0.04].

The investigators found there was a trend for episodic memory improvement in response to supplementation in subjects 45 years or older [p 0.058].

The investigators found DHA intake above the mean DHA level studied (580 mg/day) significantly improved episodic memory in all subjects [p 0.009] and in subjects with mild memory complaints [p 0.019]. Significant means that there is an association with a 95% confidence.

The investigators found observational studies supported a beneficial association between intake/blood levels of DHA/EPA and memory function in older adults.

The investigators concluded DHA (>580 mg/day), alone or combined with EPA (>1 g/day DHA/EPA), contributes to improved memory function in older adults (45 years or older) with mild memory complaints.

Original title:
Docosahexaenoic Acid and Adult Memory: A Systematic Review and Meta-Analysis by Yurko-Mauro K, Alexander DD and Van Elswyk ME.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4364972/

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This meal provides at least 580 mg DHA.
1 g/day DHA/EPA corresponds to meals providing 4 days of DHA&EPA.

Episodic memory is the type of long-term, declarative memory in which we store memories of personal experiences that are tied to particular times and places.
Some examples of episodic memory:

• Your skiing vacation last winter;
• The first time you traveled by airplane;
• Your first high school day.

Objectives:
Increased consumption of fruit and vegetables has been shown to be associated with a reduced risk of cognitive impairment and dementia in many epidemiological studies; although sometimes the results are inconsistent. Moreover, the strength of the favorable relation remains uncertain due to the differences in sample selections, methodological approaches, analytical techniques and outcome definitions. Therefore, this meta-analysis (review article) has been conducted.

Does an increased consumption of fruit and vegetables reduce risk of cognitive impairment and dementia?

Study design:
This review article included 5 cohort studies and 4 cross-sectional studies with a total of 31,104 participants and 4,583 incident cases of cognitive impairment and dementia.

There was no potential publication bias in the meta-analysis and the dose-response meta-analysis.

Results and conclusions:
The investigators found an increased consumption of fruit and vegetables was associated with a significant reduction of 20% in the risk of cognitive impairment and dementia [OR = 0.80, 95% CI = 0.71-0.89, I2 = 55.2%, p = 0.005].

The investigators found subgroup analyses showed an inverse association between fruit and vegetable consumption and risk of cognitive impairment and dementia in participants with mean age over 65 years [OR = 0.80, 95% CI = 0.71-0.91] and combined sexes [OR = 0.71, 95% CI = 0.66-0.78]. However, studies from the United States and with full marks of study quality score did not show statistical significances.

The investigators found dose-response meta-analysis showed that an increment of 100g per day of fruit and vegetable consumption was related to a 13% [OR = 0.87, 95% CI = 0.77-0.99, I2 = 39.8%, p = 0.173] reduction in cognitive impairment and dementia risk.

The investigators concluded that an increased consumption of fruit and vegetables, at least 100g per day of fruit and vegetable consumption is associated with a reduced risk of cognitive impairment and dementia.

Original title:
Increased Consumption of Fruit and Vegetables Is Related to a Reduced Risk of Cognitive Impairment and Dementia: Meta-Analysis by Jiang X, Huang J, [...], Zhang Z.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5293796/

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Find more information/studies on elderly and consumption of fruit and vegetables right here.
 

Objectives:
Many studies suggest that high-fat diets are linked to the etiology of non-Hodgkin's lymphoma (NHL). However, the findings are inconsistent and therefore the association between fat and non-Hodgkin's lymphoma remains unclear. Therefore, this review article (meta-analysis) has been conducted.

Does a high fat dietary intake increase non-Hodgkin's lymphoma risk?

Study design:
This review article included two cohort studies and eight case-control studies.

The funnel plot revealed no evidence for publication bias.

Results and conclusions:
The investigators found a significant higher risk of 26% for non-Hodgkin's lymphoma for total fat consumption [RR = 1.26, 95% CI = 1.12-1.42]. Significant because RR of 1 was not found in the 95% CI of 1.12 to 1.42. RR of 1 means no risk/association.

The investigators found subgroup analysis showed a significant higher risk of 41% for diffuse large B-cell lymphoma for total fat consumption [RR = 1.41, 95% CI = 1.08-1.84]. However, there was no significant association between total fat consumption and increase risk of follicular lymphoma [RR = 1.21, 95% CI = 0.97-1.52], small lymphocytic lymphoma/chronic lymphocytic leukemia [RR = 0.91, 95% CI = 0.68-1.23] nor with T cell lymphoma [RR = 1.12, 95% CI = 0.60-2.09].
No significant because RR of 1 was found in the 95% CI of 0.60 to 2.09. RR of 1 means no risk/association.

The investigators concluded that total fat consumption increases non-Hodgkin's lymphoma; especially diffuse large B-cell lymphoma.

Original title:
Dietary Fat Consumption and Non-Hodgkin's Lymphoma Risk: A Meta-analysis by Han TJ, Li JS, [...], Xu HZ.

Link:

https://www.ncbi.nlm.nih.gov/pubmed/28094569

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

Lymphoma is the most common blood cancer. The two main forms of lymphoma are Hodgkin lymphoma and non-Hodgkin lymphoma (NHL). The human body has two main types of lymphocytes that can develop into lymphomas:

1. B lymphocytes (B cells) and;
2. T lymphocytes (T cells).

B-cell lymphomas are much more common than T-cell lymphomas and account for approximately 85 percent of all non-Hodgkin lymphomas. Diffuse large B cell lymphomas (DLBCLs) are the commonest subtype of non-Hodgkin's lymphoma. They constitute about 30 to 40% of adult non-Hodgkin's lymphoma.

A high total fat consumption corresponds to a diet with >35 En% fat and/or >10 En% saturated fat. A diet with >35 En% fat is a diet with a lot of products/meals providing >35 En% fat.
 

Objectives:
Several epidemiological studies investigating the association between dietary vitamin E intake and the risk of lung cancer have demonstrated inconsistent results. Therefore, this review article (meta-analysis) has been conducted.

Does dietary vitamin E intake reduce lung cancer risk?

Study design:
This review article included 9 cohort studies with 4,164 lung cancer cases among 435,532 participants.

The Egger’s test showed no evidence of publication bias [t = 1.24, p = 0.246].

Results and conclusions:
The investigators found for the highest versus lowest categories of dietary vitamin E intake a reduced risk of 16% for lung cancer [pooled RR = 0.84, 95% CI = 0.76-0.93, I2 = 41.1%].

The investigators found in subgroup analysis by geographic location a significant inverse association of dietary vitamin E intake with lung cancer for the European and American populations [pooled RR = 0.85, 95% CI = 0.75-0.95), but not for the Asian population. Significant means that there is an association with a 95% confidence.

The investigators found every 2 mg/d increase in dietary vitamin E intake statistically decreased the risk of lung cancer by 5% [RR = 0.95, 95% CI = 0.91-0.99, p linearity = 0.0237].

The investigators concluded that higher dietary vitamin E intake; at least 2 mg per day exerts a protective effect against lung cancer.

Original title:
Association of dietary vitamin E intake with risk of lung cancer: a dose-response meta-analysis by Zhu YJ, Bo YC, [...], Qiu CG.

Link:
http://apjcn.nhri.org.tw/server/APJCN/26/2/271.pdf

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

Objectives:
Epidemiological studies suggest that soya consumption as a source of phyto-oestrogens and isoflavones may be associated with a reduced risk of colorectal cancer. However, findings have not yet been synthesised for all groups of phyto-oestrogens. Therefore, this review article (meta-analysis) has been conducted.

Does soya consumption reduce colorectal cancer risk?

Study design:
This review article included 16 studies (case-control studies and cohort studies).

Results and conclusions:
The investigators found in case-controle studies a significant reduced risk of 24% [pooled RR = 0.76, 95% CI = 0.69-0. 84] for colorectal cancer when comparing the highest phyto-oestrogens with the lowest intake category. However, the reduced risk for colorectal cancer was not significant in cohort studies [pooled RR = 0.95, 95% CI = 0.85-1.06].

The investigators found in case-controle studies a significant reduced risk of 23% [pooled RR = 0.77, 95% CI = 0.69-0. 85] for colorectal cancer when comparing the highest isoflavones with the lowest intake category. However, the reduced risk for colorectal cancer was not significant in cohort studies [pooled RR = 0.94, 95% CI = 0.84-1.05].

The investigators found in case-controle studies a significant reduced risk of 30% [pooled RR = 0.70, 95% CI = 0.56-0. 89] for colorectal cancer when comparing the highest lignans with the lowest intake category. However, the reduced risk for colorectal cancer was not significant in cohort studies [pooled RR = 1.00, 95% CI = 0.64-1.57].

The investigators found dose-response analysis yielded an 8% reduced risk of colorectal neoplasms for every 20 mg/d increase in isoflavones intake in Asians [pooled RR = 0.92, 95% CI = 0.86-0.97].

The investigators found dose-response analysis showed a non-linear inverse association with colorectal cancer risk for lignans intake, but no association for circulating enterolactone concentrations was observed.

The investigators concluded every 20 mg/d increase in isoflavones dietary intake reduces risk of colorectal neoplasms with 8% in Asians.

Original title:
Phyto-oestrogens and colorectal cancer risk: a systematic review and dose-response meta-analysis of observational studies by Jiang R, Botma A, […], Chang-Claude J.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28091359

Additional information of El Mondo:
Find more information/studies on isoflavones, colorectal cancer and cohort study/review article right here.

Objectives:
Some observational studies have shown that elevated serum selenium levels are associated with reduced prostate cancer risk. However, not all published studies support these results. Therefore, this review article (meta-analysis) has been conducted.

Does an elevated serum selenium level reduce prostate cancer risk?

Study design:
This review article included 12 case-control studies, 4 cohort studies and 1 RCT with 6,136 prostate cancer cases among 34,901 participants.

Results and conclusions:
The investigators found elevated serum selenium levels significantly decreased prostate cancer risk with 24% [pooled OR = 0.76, 95% CI = 0.64 to 0.91, I2  =  60.8%, p  =  0.001].  Significant means that there is an association with a 95% confidence.

The investigators found in subgroup analysis, an inverse association between elevated serum selenium levels and prostate cancer risk in case-control studies, current and former smokers, high-grade cancer cases, advanced cancer cases and different populations. However, such correlations were not found among cohort studies, nonsmokers, low-grade cancer cases and early stage cancer cases.

The investigators concluded that elevated serum selenium levels may decrease high-grade prostate cancer among current and former smokers. May decrease because the inverse relationship between elevated serum selenium levels and prostate cancer risk was not significant among cohort studies. Therefore, further cohort studies and randomized control trials based on non-Western populations are required.

Original title:
Serum selenium levels and prostate cancer risk: A MOOSE-compliant meta-analysis by Cui Z, Liu D, […], Liu G.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5293444/

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

Objectives:
Data on the longitudinal association of walking pace with the risk of cognitive decline and dementia are inconsistent and inconclusive. Therefore, this meta-analysis (review) of prospective cohort studies has been conducted.

Does walking pace reduce risk of cognitive decline or dementia in elderly populations?

Study design:
This review article included 17 prospective cohort studies, including 10 studies reporting the RR of cognitive decline (9,949 participants and 2,547 events) and 10 presenting the RR of dementia (14,140 participants and 1,903 events).

Results and conclusions:
The investigators found for the lowest comparing to the highest category of walking pace, a significant increased risk of 89% [pooled RR = 1.89, 95% CI = 1.54-2.31] for cognitive decline in elderly populations.

The investigators found for the lowest comparing to the highest category of walking pace, a significant increased risk of 66% [pooled RR = 1.66, 95% CI = 1.43-1.92] for dementia in elderly populations.

The investigators found with every 1 dm/s (360 m/h) decrement in walking pace, the risk of dementia was significantly increased by 13% [RR = 1.13, 95% CI = 1.08-1.18].

The investigators concluded that slow or decreased walking pace is associated with elevated risk of cognitive decline and dementia in elderly populations.

Original title:
Walking Pace and the Risk of Cognitive Decline and Dementia in Elderly Populations: A Meta-analysis of Prospective Cohort Studies by Quan M, Xun P, [...], He K.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/27927757

Additional information of El Mondo:
Find here more information/studies about elderly and sport nutrition.

According to WHO in order to improve cardiorespiratory and muscular fitness, bone and functional health, reduce the risk of NCDs, depression and cognitive decline:

• Older adults (aged 65 and above) should do at least 150 minutes of moderate-intensity aerobic physical activity throughout the week or do at least 75 minutes of vigorous-intensity aerobic physical activity throughout the week or an equivalent combination of moderate- and vigorous-intensity activity.
• Aerobic activity should be performed in bouts of at least 10 minutes duration.
• For additional health benefits, older adults should increase their moderate-intensity aerobic physical activity to 300 minutes per week, or engage in 150 minutes of vigorous-intensity aerobic physical activity per week, or an equivalent combination of moderate-and vigorous-intensity activity.
• Older adults, with poor mobility, should perform physical activity to enhance balance and prevent falls on 3 or more days per week.
• Muscle-strengthening activities, involving major muscle groups, should be done on 2 or more days a week.
• When older adults cannot do the recommended amounts of physical activity due to health conditions, they should be as physically active as their abilities and conditions allow.