Folate intake and the risk of prostate cancer: a systematic review and meta-analysis

Unmasking the Hidden Danger: A Decade-Long Systematic Review of Case-Control Studies on Single Occupational Risks and Prostate Cancer

The present systematic review addresses the influence of occupational exposures on prostate cancer risk. Eleven studies were analyzed for a range of occupational exposures, including but not limited to firefighting, physical activity, night shift work, chemical exposure, and solar ultraviolet radiation. The results of the review reveal that firefighters exposed to harmful substances, individuals engaged in physically strenuous work, and workers with chronic night shift routines showed an increased likelihood of developing prostate cancer. Moreover, the review identified an increased risk associated with exposure to certain chemicals, including alkylphenolic compounds and benzene-related substances. The evidence underscores the importance of considering the cumulative effect of multiple risk factors in a comprehensive risk assessment. However, the conclusions indicate the necessity for further research to deepen these relationships and develop more effective strategies for the prevention of prostate cancer.

Association between nut consumption and prostate cancer risk in adults: A systematic review and dose-response meta-analysis of observational studies

AIMS

Data on the association between nut consumption and prostate cancer risk are conflicting. Therefore, this systematic review and dose-response meta-analysis aimed to summarize available findings from observational studies on the associations of nut intake with risk of total, advanced, non-advanced, and fatal prostate cancers.

DATA SYNTHESIS

We searched the online databases of PubMed, Scopus, and Web of Science as well as Google Scholar using appropriate keywords to identify eligible articles up to September 2022. In total, 11 articles with a total sample size of 287,786 participants and 32,213 cases of prostate cancer were included in the current systematic review and meta-analysis. By comparing the highest and lowest intake of total nuts, pooled relative risks (RRs) and 95% confidence intervals (95% CIs) for total, advanced, non-advanced, and fatal prostate cancers were 0.94 (95% CI: 0.85-1.04, P = 0.22), 1.10 (95% CI: 0.98-1.24, P = 0.12), 0.97 (95% CI: 0.85-1.11, P = 0.69), 0.97 (95% CI: 0.79-1.18, P = 0.73), respectively, which indicated non-significant inverse associations for total, non-advanced, and fatal prostate cancers and a non-significant positive association for advanced prostate cancer. In the dose-response analyses, we found no evidence of a linear or non-linear association between total nut intake and prostate cancer risk. Data on other types of nuts, including walnut, tree nuts, peanut, and peanut butter, were not sufficient for performing a meta-analysis.

CONCLUSION

We found no significant association between nut intake and risk of total, advanced, non-advanced, and fatal prostate cancer. Further studies are required to confirm our findings.

PROSPERO REGISTRATION CODE

CRD42022347094.

ETHICAL APPROVAL

Not required.

The association between dietary intakes of methionine, choline and betaine and breast cancer risk: A systematic review and meta-analysis

BACKGROUND AND AIM

This study evaluates the associations between dietary intakes and circulating blood levels of methionine, choline or betaine and breast cancer risk, which remains currently unclear.

METHODS

Systematic searches for observational epidemiological studies were performed of the MEDLINE, Embase, and Web of Science databases through July, 2022. Two review authors independently screened titles and abstracts against the eligibility criteria at a first stage, and screened full texts of potentially eligible records at a second stage, followed by data extraction from qualified studies. Quality of evidence was assessed using the Newcastle-Ottawa scale quality assessment tool. Risk estimates were calculated using random-effects meta-analysis.

RESULTS

In total, 21 studies were selected for qualitative analyses and 18 studies were included in the meta-analyses. Random-effects analysis combining prospective cohort (N = 8) or case-control studies (N = 10) showed little evidence of an association between dietary intake of methionine or betaine and the risk of breast cancer. However, inconclusive evidence for a significant inverse association between choline intake and breast cancer risk was found in case-control studies (odds ratio [OR] estimates for highest vs. lowest intakes = 0.38; 95 % CI: 0.16-0.86) but not in prospective cohort studies (hazard ratio [HR] estimates for highest vs. lowest intakes = 1.01; 95 % CI: 0.92-1.12).

CONCLUSION

This study did not suggest an effect of dietary intake of methionine, choline, nor betaine on breast cancer risk, mainly due to the lack of precision of the combined risk estimates as few studies are available. To overcome this uncertainty, more well-designed studies with relevant individual-level covariates are needed.

A Multi-Level Systems Biology Analysis of Aldrin's Metabolic Effects on Prostate Cancer Cells

Although numerous studies support a dose-effect relationship between Endocrine disruptors (EDs) and the progression and malignancy of tumors, the impact of a chronic exposure to non-lethal concentrations of EDs in cancer remains unknown. More specifically, a number of studies have reported the impact of Aldrin on a variety of cancer types, including prostate cancer. In previous studies, we demonstrated the induction of the malignant phenotype in DU145 prostate cancer (PCa) cells after a chronic exposure to Aldrin (an ED). Proteins are pivotal in the regulation and control of a variety of cellular processes. However, the mechanisms responsible for the impact of ED on PCa and the role of proteins in this process are not yet well understood. Here, two complementary computational approaches have been employed to investigate the molecular processes underlying the acquisition of malignancy in prostate cancer. First, the metabolic reprogramming associated with the chronic exposure to Aldrin in DU145 cells was studied by integrating transcriptomics and metabolomics via constraint-based metabolic modeling. Second, gene set enrichment analysis was applied to determine (i) altered regulatory pathways and (ii) the correlation between changes in the transcriptomic profile of Aldrin-exposed cells and tumor progression in various types of cancer. Experimental validation confirmed predictions revealing a disruption in metabolic and regulatory pathways. This alteration results in the modification of protein levels crucial in regulating triacylglyceride/cholesterol, linked to the malignant phenotype observed in Aldrin-exposed cells.

Interactions of SNPs in Folate Metabolism Related Genes on Prostate Cancer Aggressiveness in European Americans and African Americans

Background: Studies showed that folate and related single nucleotide polymorphisms (SNPs) could predict prostate cancer (PCa) risk. However, little is known about the interactions of folate-related SNPs associated with PCa aggressiveness. The study’s objective is to evaluate SNP–SNP interactions among the DHFR 19-bp polymorphism and 10 SNPs in folate metabolism and the one-carbon metabolism pathway associated with PCa aggressiveness. Methods: We evaluated 1294 PCa patients, including 690 European Americans (EAs) and 604 African Americans (AAs). Both individual SNP effects and pairwise SNP–SNP interactions were analyzed. Results: None of the 11 individual polymorphisms were significant for EAs and AAs. Three SNP–SNP interaction pairs can predict PCa aggressiveness with a medium to large effect size. For the EA PCa patients, the interaction between rs1801133 (MTHFR) and rs2236225 (MTHFD1), and rs1801131 (MTHFR) and rs7587117 (SLC4A5) were significantly associated with aggressive PCa. For the AA PCa patients, the interaction of DHFR-19bp polymorphism and rs4652 (LGALS3) was significantly associated with aggressive PCa. Conclusions: These SNP–SNP interactions in the folate metabolism-related genes have a larger impact than SNP individual effects on tumor aggressiveness for EA and AA PCa patients. These findings can provide valuable information for potential biological mechanisms of PCa aggressiveness.

Levodopa, homocysteine and Parkinson's disease: What's the problem?

Elevated circulating homocysteine levels have been associated with cognitive impairment and cardio-cerebro-vascular events. Levodopa treatment of Parkinson's disease tends to further elevate circulating homocysteine levels due to the metabolism of levodopa via catechol-O-methyltransferase (COMT). COMT co-factors are vitamins B12, B6 and folic acid. Accumulating deficiencies of these vitamins are presumed to be the substrate for the homocysteine elevation. B-vitamin therapy reduces homocysteine levels. This begs the question of whether Parkinson's disease patients on levodopa should be concurrently treated with ongoing B-vitamin therapy (versus long-term monitoring of B-vitamins/homocysteine). There is a substantial literature on this topic that has accumulated over the last quarter-century, and this topic is still debated. This review summarizes the relevant literature with the aim of approximating closure on this issue. Also, noteworthy is that Parkinson's disease patients with renal insufficiency may not tolerate cyanocobalamin, the standard oral B12 supplement due to facilitation of renal decline; alternatives are discussed.

Microbiota and prostate cancer

Prostate cancer remains the most frequently diagnosed non-skin malignancy in male patients, still representing one of the main causes of cancer-related death worldwide. Evidence is mounting that suggests the putative role of microbiota in the carcinogenesis as well as in modulating the efficacy and activity of anticancer treatments (e.g., chemotherapy, immune checkpoint inhibitors, targeted therapies) in a large number of hematological and solid tumors. However, few data are available regarding the interactions between prostate cancer and microbiome so far, in particular in terms of the impact of microbiota on disease development, pathogenesis, and response to medical treatments in this genitourinary malignancy. Herein, we provide an overview of current knowledge, novel insights and emerging therapeutic approaches related to gastrointestinal and genitourinary microbiome in prostate cancer patients, especially focusing on available evidence and published trials on this topic.

Advances in PSMA theranostics

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PSMA is an appealing target for theranostic because it is a transmembrane protein with a known substrate that is overexpessed on prostate cancer cells and internalizes upon ligand binding.

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There are a number of PSMA theranostic ligands in clinical evaluation, clinical trial, or clinically approved.

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PSMA theranostic ligands increase progression-free survival, overall survival, and pain in patients with metastatic castration resistant prostate cancer.

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A major obstacle to PSMA-targeted radioligand therapy is off-target toxicity in salivary glands.

The validation of prostate specific membrane antigen (PSMA) as a molecular target in metastatic castration-resistant prostate cancer has stimulated the development of multiple classes of theranostic ligands that specifically target PSMA. Theranostic ligands are used to image disease or selectively deliver cytotoxic radioactivity to cells expressing PSMA according to the radioisotope conjugated to the ligand. PSMA theranostics is a rapidly advancing field that is now integrating into clinical management of prostate cancer patients. In this review we summarize published research describing the biological role(s) and activity of PSMA, highlight the most clinically advanced PSMA targeting molecules and biomacromolecules, and identify next generation PSMA ligands that aim to further improve treatment efficacy. The goal of this review is to provide a comprehensive assessment of the current state-of-play and a roadmap to achieving further advances in PSMA theranostics.

Metagenomics studies for the diagnosis and treatment of prostate cancer

AIM

Mutation occurs in the prostate cell genes, leading to abnormal prostate proliferation and ultimately cancer. Prostate cancer (PC) is one of the most common cancers amongst men, and its prevalence worldwide increases relative to men's age. About 16% of the world's cancers are the result of microbes in the human body. Impaired population balance of symbiosis microbes in the human reproductive system is linked to PC development.

DISCUSSION

With the advent of metagenomics science, the genome sequence of the microbiota of the human body has been unveiled. Therefore, it is now possible to identify a higher range of microbiome changes in PC tissue via the Next Generation Technique, which will have positive consequences in personalized medicine. In this review, we intend to question the role of metagenomics studies in the diagnosis and treatment of PC.

CONCLUSION

The microbial imbalance in the men's genital tract might have an effect on prostate health. Based on next-generation sequencing-generated data, Proteobacteria, Firmicutes, Actinobacteria, and Bacteriodetes are the nine frequent phyla detected in a PC sample, which might be involved in inducing mutation in the prostate cells that cause cancer.

A MOF chemosensor for highly sensitive and ultrafast detection of folic acid in biofriendly medium, paper strips and real samples

A new dansyl functionalized Zr(iv) MOF was used for ultra-fast (<5 s), highly sensitive (detection limit: 1.3 nM) and selective fluorescence sensing of folic acid in bio-fluids, real samples and paper strips.

Feasibility of dietary folic acid reduction intervention for men on active surveillance for prostate cancer

BACKGROUND & AIMS

Fortification of the US food supply has increased folic acid intake and resulted in a concomitant decrease in neural tube defects in women. However, a body evidence supports the hypothesis that increased circulating folate levels due to excessive dietary or supplemental folic acid may be harmful for men with prostate cancer. Therefore, this pilot study aimed to investigate the feasibility of a reduced folic acid dietary intervention in men on an active surveillance monitoring program for prostate cancer.

METHODS

Men with low-grade prostate cancer enrolled into a 12-week dietary folic acid reduction diet. Primary outcome was red blood cell (RBC) folate reduction at 12 weeks. Other outcomes include serum folate, homocysteine, and vitamin B12 levels. The number of patients who complete the trial and reasons for disenrollment or dropout were also assessed.

RESULTS

Twenty-eight participants were enrolled into the dietary intervention study. Six participants withdrew from the study and a total of 21 participants completed all baseline and week 12 biochemical assessments. Only 18 participants completed all dietary questionnaires. Participants withdrew from the study due to difficulty with the diet or personal reasons. A substantial reduction was noted in serum folate (p < 0.007), RBC folate (p < 0.001) and dietary consumption of folic acid from foods (p = 0.003) and supplements (p = 0.003) without reduction in serum homocysteine or vitamin B₁₂. Although an overall decrease in PSA from baseline to twelve weeks was found, the reduction was not significant (-3.55 ng/mL, p = 0.197).

CONCLUSIONS

This phase 1 feasibility study reduced dietary folic acid intake from food and supplements and successfully lowered serum and RBC folate without resulting harmful effects. Data from this study supports future intervention trials with a larger prostate cancer active surveillance population and has the potential to reduce prostate cancer progression. There are no interventions to reduce progression of prostate cancer in man on active surveillance.

Dietary Methyl-Group Donor Intake and Breast Cancer Risk in the European Prospective Investigation into Cancer and Nutrition (EPIC)

(1) Background: Methyl-group donors (MGDs), including folate, choline, betaine, and methionine, may influence breast cancer (BC) risk through their role in one-carbon metabolism; (2) Methods: We studied the relationship between dietary intakes of MGDs and BC risk, adopting data from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort; (3) Results: 318,686 pre- and postmenopausal women were followed between enrolment in 1992-2000 and December 2013-December 2015. Dietary MGD intakes were estimated at baseline through food-frequency questionnaires. Multivariable Cox proportional hazards regression models were used to quantify the association between dietary intake of MGDs, measured both as a calculated score based on their sum and individually, and BC risk. Subgroup analyses were performed by hormone receptor status, menopausal status, and level of alcohol intake. During a mean follow-up time of 14.1 years, 13,320 women with malignant BC were identified. No associations were found between dietary intakes of the MGD score or individual MGDs and BC risk. However, a potential U-shaped relationship was observed between dietary folate intake and overall BC risk, suggesting an inverse association for intakes up to 350 µg/day compared to a reference intake of 205 µg/day. No statistically significant differences in the associations were observed by hormone receptor status, menopausal status, or level of alcohol intake; (4) Conclusions: There was no strong evidence for an association between MGDs involved in one-carbon metabolism and BC risk. However, a potential U-shaped trend was suggested for dietary folate intake and BC risk. Further research is needed to clarify this association.

More Than Meets the Eye: Scientific Rationale behind Molecular Imaging and Therapeutic Targeting of Prostate-Specific Membrane Antigen (PSMA) in Metastatic Prostate Cancer and Beyond

Simple Summary

Prostate-specific membrane antigen (PSMA) is a transmembrane protein that is overexpressed in prostate cancer and correlates with the aggressiveness of the disease. PSMA is a promising target for imaging and therapeutics in prostate cancer patients validated in prospective trials. However, the role of PSMA in prostate cancer progression is poorly understood. In this review, we discuss the biology and scientific rationale behind the use of PSMA and other targets in the detection and theranostics of metastatic prostate cancer.

Abstract

Prostate cancer is the second most common cancer type in men globally. Although the prognosis for localized prostate cancer is good, no curative treatments are available for metastatic disease. Better diagnostic methods could help target therapies and improve the outcome. Prostate-specific membrane antigen (PSMA) is a transmembrane glycoprotein that is overexpressed on malignant prostate tumor cells and correlates with the aggressiveness of the disease. PSMA is a clinically validated target for positron emission tomography (PET) imaging-based diagnostics in prostate cancer, and during recent years several therapeutics have been developed based on PSMA expression and activity. The expression of PSMA in prostate cancer can be very heterogeneous and some metastases are negative for PSMA. Determinants that dictate clinical responses to PSMA-targeting therapeutics are not well known. Moreover, it is not clear how to manipulate PSMA expression for therapeutic purposes and develop rational treatment combinations. A deeper understanding of the biology behind the use of PSMA would help the development of theranostics with radiolabeled compounds and other PSMA-based therapeutic approaches. Along with PSMA several other targets have also been evaluated or are currently under investigation in preclinical or clinical settings in prostate cancer. Here we critically elaborate the biology and scientific rationale behind the use of PSMA and other targets in the detection and therapeutic targeting of metastatic prostate cancer.

Association Between Folate and Health Outcomes: An Umbrella Review of Meta-Analyses

Background: There is no study that has systematically investigated the breadth and validity of the associations of folate and multiple health outcomes. We aimed to evaluate the quantity, validity, and credibility of evidence regarding associations between folate and multiple health outcomes by using umbrella review of meta-analysis. Methods: We searched the MEDLINE, EMBASE, and Cochrane Library databases from inception to May 20, 2018, to identify potential meta-analyses that examined the association of folate with any health outcome. For each included meta-analysis, we estimated the summary effect size and their 95% confidence interval using the DerSimonian and Laird random-effects model. We used the AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews) to assess methodological quality and the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation working group classification) to assess the quality of evidence for each outcome included in the umbrella review. Results: Overall, 108 articles reporting 133 meta-analyses of observational studies and 154 meta-analyses of randomized controlled trials (RCTs) were included in the study. Among them, 108 unique exposure-outcome-population triplets (referred to as unique meta-analyses hereafter) of RCTs and 87 unique meta-analyses of observational studies were reanalyzed. Beneficial effects of folate were observed in the all-cause mortality rate and in a number of chronic diseases, including several birth/pregnancy outcomes, several cancers, cardiovascular disease and metabolic-related outcomes, neurological conditions, and several other diseases. However, adverse effects of folate were observed for prostate cancer, colorectal adenomatous lesions, asthma or wheezing, and wheezing as an isolated symptom and depression. Conclusions: Current evidence allows for the conclusion that folate is associated with decreased risk of all-cause mortality and a wide range of chronic diseases. However, folate may be associated with an increased risk of prostate cancer. Further research is warranted to improve the certainty of the estimates.

Gene Polymorphisms Involved in Folate Metabolism and DNA Methylation with the Risk of Head and Neck Cancer

BACKGROUND

Folate is essential for DNA synthesis, repair, and methylation. Polymorphisms in genes associated with folate metabolism may alter these processes and, consequently, modulate cancer development.

AIM

We aimed to assess DNMT3B -149C/T (rs2424913), DNMT3B -283T/C (rs6087990), DNMT3B -579G/T (rs2424909), DHFR 19-pb ins/del (rs70991108), SHMT1 1420C/T (rs1979277), and TYMS 28-bp tandem repeat (rs34743033) polymorphisms with risk of head and neck cancer.

METHODS

A case-control study was conducted in 1,086 Brazilian individuals. Real-time and conventional polymerase chain reactions-PCR were performed for genotyping the polymorphisms.

RESULTS

The single nucleotide polymorphism (SNP), DNMT3B -283T/C, revealed a higher risk of head and neck squamous cell carcinoma (HNSCC) when compared with the C group in the codominant (p < 0.001), dominant (p <0.001), and overdominant (p= 0.001) models for T/C and C/C genotypes. DNMT3B -149C/T and DNMT3B -579G/T revealed no association between groups in any model. The DHFR 19-pb ins/del polymorphism protected against HNSCC development compared to the C group by the codominant (p < 0.001), dominant (p < 0.001), and overdominant (p < 0.001) models. In the TYMS, the 3R/3R genotype had a protective effect against HNSCC development compared with the C group by the recessive models (p= 0.009). In contrast, SHMT1 1420 C/T presented no association between the HNSCC and C groups. DHFR 19-pb ins/del polymorphisms protected against oral cavity cancer (p= 0.003), and only TYMS-28 3R/3R decreased the risk of tumor progression (p= 0.023). In the Kaplan-Meier curve, an association was found between DHFR ins/ins and TYMS -28 3R carriers with respect to relapse-free time; further, DNMT3B -579 T and TYMS-28 2R/2R carriers had longer survival times.

CONCLUSION

DNMT3B -283T/C is associated with higher risk, whereas DHFR 19-pb ins/del and TYMS 28 3R/3R protect against head and neck cancer. We also highlighted the association of TYMS 3R/3R genotype carriers with relapse-free cancer protection and survival time.

Pickled Vegetables Intake Impacts the Metabolites for Gastric Cancer

Purpose

An increased risk of gastric cancer (GC) for pickled vegetables intake has been suggested, but a complete understanding of its pathogenic origin is still lacking, especially from a metabolic viewpoint. We investigated the plasma metabolites and metabolic pathway alteration of GC related to pickled vegetables intake.

Methods

We analyzed plasma samples collected from 365 gastric cancer patients and 347 healthy individuals, and divided them into three subgroups according to the intake of pickled vegetables. Plasma samples were detected by untargeted metabolomics.

Results

Nine metabolites were significantly altered in GC patients among pickled vegetables intake groups (FDR P-value<0.05). All of them were associated with the risk of gastric cancer adjusted for gender, age, smoking status, Helicobacter pylori infection. Pathway analysis showed significant alteration in the folate biosynthesis pathway.

Conclusion

In short, we provide new insights from a metabolic perspective on the relationship between pickled vegetables intake and the occurrence of gastric cancer.

Association between methylenetetrahydrofolate reductase gene rs1801131 A/C polymorphism and urinary tumors' susceptibility

Background

The methylenetetrahydrofolate reductase (MTHFR) rs1801131 A/C variant results in a decrease in MTHFR enzymatic activity, which may play an important role in folate metabolism and is also an important source of DNA methylation and DNA synthesis. Several case-control studies have been conducted to assess the association of MTHFR rs1801131 polymorphism with the risk of urinary cancers, yet with conflicting conclusions. To derive a more precise estimation of above relationship, the association between the MTHFR rs1801131 A/C polymorphism and the risk of urinary cancer was performed.

Methods

A total of 28 case-control studies was identified. The odds ratios (OR) with 95% confidence intervals (CI) was calculated to assess.

Results

On one hand, we found that the MTHFR rs1801131 A/C polymorphism was associated with increased whole urinary cancers’ risk (for example CA vs. AA: OR = 1.12. 95%CI = 1.01–1.24). On the other hand, we found that the MTHFR rs1801131 A/C polymorphism might increase bladder cancer risk both in Asian (C-allele vs. A-allele: OR = 1.35. 95%CI = 1.15–1.60) and African populations (CA vs. AA: OR = 1.63. 95%CI = 1.17–2.25).

Conclusions

Our current analysis suggested that MTHFR rs1801131 A/C is associated with urinary cancers, especially bladder cancer.

Preventing Lethal Prostate Cancer with Diet, Supplements, and Rx: Heart Healthy Continues to Be Prostate Healthy and "First Do No Harm" Part II

PURPOSE OF REVIEW

To discuss the overall and latest observations of the effect of diet, lifestyle, supplements, and some prescription heart healthy medications for prostate cancer prevention.

RECENT FINDINGS

The concept of maximizing heart health to prevent aggressive prostate cancer continues to be solidified with the addition of more prospective observational and randomized controlled trial data. Heart healthy is prostate healthy, and heart unhealthy is prostate unhealthy. The primary goal of reducing the risk of all-cause and cardiovascular disease (CVD) morbidity and mortality also coincides with maximizing prostate cancer prevention. The obesity epidemic in children and adults along with recent diverse research has only strengthened the nexus between heart and prostate health. Greater dietary adherence toward a variety of healthy foods is associated with a graded improved probability of CVD and potentially aggressive cancer risk reduction. Preventing prostate cancer via dietary supplements should encourage a "first do no harm," or less is more approach until future evidence can reverse the concerning trend that more supplementation has resulted in either no impact or an increased risk of prostate cancer. Supplements to reduce side effects of some cancer treatments appear to have more encouraging data. A discussion of quality (QC) before utilizing any pill also requires attention. Medications or interventions that potentially improve heart health including statins, aspirin, and metformin (S.A.M.), specific beta-blocker medications, and even preventive vaccines are in general generic, low-cost, "natural," and should continue to garner research interest. A watershed moment in medical education has arrived where the past perception of a diverse number of trees seemingly separated by vast distances, in reality, now appear to exist within the same forest.

S-Adenosylmethionine (SAMe) in major depressive disorder (MDD): a clinician-oriented systematic review

BACKGROUND

Major depressive disorder (MDD) is a recurrent illness with high rates of chronicity, treatment-resistance, and significant economic impact. S-Adenosylmethionine (SAMe), a molecule that is formed naturally in the human body, has shown antidepressant effects and may expand the available options for treating MDD. This systematic review examines the evidence concerning the efficacy of SAMe as monotherapy or in combination with antidepressants.

METHODS

A systematic search in Medline, Psychinfo, AMED, and Cochrane Controlled Trials Register was conducted for any reference recorded up to March 2020. Double-blind, randomised controlled trials, comparing the antidepressant efficacy of SAMe to placebo or/and to other antidepressants, were selected. Two authors evaluated each study independently and then, reconciled findings.

RESULTS

Eight trials, with a total of 11 arms and 1011 subjects, evaluating the efficacy of SAMe used as monotherapy or as adjunctive therapy (512 individuals), were included in this review. The study duration ranged between 2 and 12 weeks and the daily dose of SAMe varied from 200 to 3200 mg. Five comparisons evaluated the differences between SAMe and placebo and SAMe resulted significantly better than placebo in three of these studies. Four comparisons evaluated the differences between SAMe and other antidepressants (imipramine or escitalopram) and showed no significant difference. One study showed that SAMe was significantly better than placebo in accelerating the response to imipramine from day 4 to day 12, but the mean scores were not statistically different at the day 14 endpoint. One study showed that SAMe combined with serotonin reuptake inhibitors (SSRI) was better than PBO combined with SSRI. The studies reported only mild, transient or non-clinically relevant side effects.

CONCLUSIONS

The existing trials of SAMe, used as monotherapy or add on to another antidepressants, have shown encouraging and generally positive results. However, more evidence is necessary before definitive conclusions can be drawn. Larger, double-blind randomised controlled studies are warranted to confirm the antidepressant effectiveness of SAMe.

Folate and Its Impact on Cancer Risk

PURPOSE OF REVIEW

Research has evaluated the potential impact of folate on cancer risk with conflicting findings. Studies have demonstrated increased risk, no effect, and decreased risk. This review summarizes findings of mixed results between folate intake, serum levels, gene polymorphisms, and cancer risk based on meta-analyses from the past five years.

RECENT FINDING

Low or deficient folate status is associated with increased risk of many cancers. Folic acid supplementation and higher serum levels are associated with increased risk of prostate cancer. Gene polymorphisms may impact risk in certain ethnic groups. Folate has been studied extensively due to its role in methylation and nucleotide synthesis. Further prospective studies are needed to clarify optimal levels for nutrient remediation and risk reduction in those at risk, as well as elucidate the association between high intake, high serum levels, and prostate cancer risk. Future considerations for cancer risk may include gene interactions with nutrients and environmental factors.

The Protective Effect of Dietary Phytosterols on Cancer Risk: A Systematic Meta-Analysis

BACKGROUNDS/AIMS

Many studies have explored the association between dietary phytosterols and cancer risk, but the results have been inconsistent. We aimed to provide a synopsis of the current understanding of phytosterol intake for cancer risk through a systematic evaluation of the results from previous studies.

METHODS

We performed a literature search of PUBMED, EMBASE, CNKI, and Wanfang, and studies published before May 2019 focusing on dietary total phytosterols, β-sitosterol, campesterol, stigmasterol, β-sitostanol, and campestanol, as well as their relationships with cancer risk, were included in this meta-analysis. Summaries of the relative risks from 11 case-control and case-cohort studies were eventually estimated by randomized or fixed effects models.

RESULTS

The summary relative risk for the highest versus the lowest intake was 0.63 (95% confidence interval [CI] = 0.49-0.81) for total phytosterols, 0.74 (95% CI = 0.54-1.02) for β-sitosterol, 0.72 (95% CI = 0.51-1.00) for campesterol, 0.83 (95% CI = 0.60-1.16) for stigmasterol, 1.12 (95% CI = 0.96-1.32) for β-sitostanol, and 0.77 (95% CI = 0.65-0.90) for campestanol. In a dose-response analysis, the results suggested a linear association for campesterol and a nonlinear association for total phytosterol intake.

CONCLUSION

Our findings support the hypothesis that high phytosterol intake is inversely related to risk of cancer. Further studies with prospective designs that control for vital confounders and investigate the important anticancer effects of dietary phytosterols are warranted.

Can folate replacement induce lymphoma progression?

A 43-year-old Japanese man with a low haemoglobin level of 1.3 g/dL and multiorgan dysfunction syndrome (MODS) was admitted to our hospital. He was diagnosed with folate deficiency, which was initially attributed to his malnutrition. He was transfused with several units of packed red blood cells and treated with folate, thiamine and vitamin B₁₂ supplements; he showed a prompt haematological response and recovery from MODS. However, 3 weeks after the initial recovery, he had a relapse of pancytopenia and developed high-grade fever along with rapidly enlarging, generalised lymphadenopathy. Bone marrow biopsy revealed hemophagocytosis, and lymph node biopsy revealed peripheral T-cell lymphoma, not otherwise specified. Folate supplementation may have promoted lymphoma progression.

Genotoxicity of tetrahydrofolic acid to hematopoietic stem and progenitor cells

Metabolically reactive formaldehyde is a genotoxin and a carcinogen. Mice lacking the main formaldehyde-detoxifying gene Adh5 combined with the loss of the Fanconi anemia (FA) DNA repair pathway rapidly succumbed to bone marrow failure (BMF) primarily due to the extensive ablation of the hematopoietic stem cell (HSC) pool. However, the mechanism by which formaldehyde mediates these toxic effects is still unknown. We uncover a detrimental role of tetrahydrofolic acid (THF) in cells lacking Adh5 or the FA repair pathway. We show that Adh5- or FA-deficient cells are hypersensitive to formaldehyde and to THF, presenting DNA damage and genome instability. THF cytotoxicity involved imbalance of the nucleotide pool by deregulation of the thymidylate synthase (TYMS) enzyme, which stalled replication forks. In mice, THF exposure had widespread effects on hematopoiesis, affecting the frequency and the viability of myeloid- and lymphoid-committed precursor cells. Moreover, the hematopoietic stem and progenitor cells (HSPC) showed genomic instability, reduced colony-forming capacity and increased frequency of cycling and apoptotic HSCs upon THF exposure. Overall, our data reveal that the physiological pool of THF and formaldehyde challenge the stability of the genome of HSPCs that might lead to blood disorders.

An update of research evidence on nutrition and prostate cancer

BACKGROUND

Prostate cancer (PCa) remains a leading cause of mortality in US and other countries. Preclinical and clinical studies have examined the role of nutrition and dietary intake on the incidence and progression of PCa with mixed results.

OBJECTIVE

The objective of this chapter is to provide an update of recent published literature and highlight progress in the field.

MAIN FINDINGS

Low carbohydrate intake, soy protein, ω3 fat, green teas, tomatoes and tomato products and the herbal mixture-zyflamend showed promise in reducing PCa risk or progression. On the contrary, a higher animal fat intake and a higher β-carotene status may increase risk. A "U" shape relationship may exist between folate, vitamin C, vitamin D and calcium with PCa risk. Conclusion Despite the inconclusive findings, the potential for a role of dietary intake for the prevention and treatment of PCa remains promising. Maintaining a healthy body weight and following a healthy dietary pattern including antioxidant rich fruits and vegetables, reduced animal fat and refined carbohydrates, should be encouraged.

CONCLUSION

Despite the inconclusive findings, the potential for a role of dietary intake for the prevention and treatment of PCa remains promising. Maintaining a healthy body weight and following a healthy dietary pattern including antioxidant rich fruits and vegetables, reduced animal fat and refined carbohydrates, should be encouraged.

Association between folate intake and risk of head and neck squamous cell carcinoma: An overall and dose-response PRISMA meta-analysis

The results of published studies about the relationships between folate intake and risk of head and neck squamous cell carcinoma (HNSCC) remained inconsistent. Hence, a comprehensive and dose-response meta-analysis was performed to clarify the association between folate intake and HNSCC risk.The electric searches of Pubmed, Medline, and EMBASE databases were performed to identify the studies examining the relationship between folate intake and HNSCC risk on April 5, 2017. According to the inclusion criteria, finally 9 studies were included in this meta-analysis. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the strength of associations. Dose-response analysis was conducted to quantitate the relationship between dietary folate intake and HNSCC risk.The pooled OR for assessing the risk of HNSCC and folate intake in the highest level versus lowest level was 0.505 (95% CI 0.387-0.623). The linearity model of dose-response analysis indicated that with increased 100 μg/d folate intake, the risk of HNSCC decreased 4.3% degree (OR 0.957, 95% CI 0.935-0.980).These results indicate that folate is a protective nutrient against HNSCC carcinogenesis.

Clinical use of nutraceuticals in the adjunctive treatment of depression in mood disorders

OBJECTIVES

The aim of this paper is to detail a summary of the current evidence in this area, to better inform clinical practice. Our recent systematic reviews and meta-analyses of nutrient pharmacotherapies in the treatment unipolar depression revealed primarily positive results for replicated studies testing S-adenosyl methionine (SAMe), methylfolate, omega-3 (EPA or ethyl-EPA), and Vitamin D; with supportive isolated studies found for creatine and an amino acid combination. Mixed results were found for zinc, folic acid, Vitamin C, and tryptophan; and non-significant study results for inositol. In bipolar depression, omega-3 and N-acetyl cysteine (NAC) were found to have supportive evidence, with an isolated study using a chelated mineral formula also displaying efficacy. No major adverse effects were noted in the studies (aside from occasional minor digestive disturbances with omega-3 and NAC).

CONCLUSIONS

Several clinical considerations are needed when psychiatrists are considering prescribing nutrients, including knowledge of drug interactions, supplement safety and quality issues, individual psychological and biochemical individualities, in addition to cost factors.

Associations between dietary folate intake and risks of esophageal, gastric and pancreatic cancers: an overall and dose-response meta-analysis

There are still some controversies on the association between dietary folate intake and the risk of upper gastrointestinal cancers including esophageal, gastric and pancreatic cancers. Hence, a comprehensive meta-analysis on all available literatures was performed to clarify the relationship between dietary folate intake and risks of upper gastrointestinal cancers. An electric search was performed up to December 12^th, 2016 within the PubMed, MEDLINE AND EMBASE databases. Ultimately, a total of 46 studies which evaluated the association between folate intake and risks of upper gastrointestinal cancers were included. According to the data from included studies, the pooled results showed significant association between folate intake and esophageal (OR = 0.545, 95%CI = 0.432-0.658), gastric (OR=0.762, 95%CI=0.648-0.876) and pancreatic (OR=0.731, 95%CI=0.555-0.907) cancers. Linearity dose-response analysis indicated that with 100μg/day increment in dietary folate intake, the risk of esophageal, gastric and pancreatic cancers would decrease by 9%, 1.5% and 6%, respectively. These findings indicated that higher level of dietary folate intake could help for preventing upper gastrointestinal cancers including esophageal, gastric and pancreatic cancers.

Folic acid and diseases - supplement it or not?

INTRODUCTION

folic acid is a water soluble vitamin, which is synthetically-produced and found in fortified foods and supplements. Folate is found naturally in plants, such as the dark green leafy vegetables. Folate is not synthesized de novo by humans, therefore the daily requirements are met from the dietary intake of folic acid supplements or food rich in this vitamin. Folate deficiency could lead to numerous common health problems. Hyperhomocysteinemia and the possibility of malignancy developments are the long term consequences of this deficit albeit contradictory findings on these claims.

METHODS

the articles included in this review focused on recent updated evidence-based reports and meta-analyses on the associations of the serum folate/folic acid and the various diseases found globally.

RESULTS

the benefit of folic acid supplementation in the pre-conception period for the prevention of neural tube defects (NTDs) was well established and it was suggested that counseling sessions should be given to women with previous pregnancies affected by NTDs. However, supplementation of folic acid and its medicinal effects in the treatment of other diseases were contradictory and unclear.

CONCLUSION

more detailed investigations into the health benefits of folic acid are needed before it could be recommended for supplementation, treatment or prevention of some of the diseases discussed in this review.

MTHFR c.677C>T Inhibits Cell Proliferation and Decreases Prostate Cancer Susceptibility in the Han Chinese Population in Shanghai

Methylenetetrahydrofolate reductase (MTHFR) c.677C>T and c.1298A>C variants were known to be associated with prostate cancer (PCa) risk with conflicting results, because of MTHFR and nutrient status interaction in the prostate development. In this large-scale, hospital-based, case-control study of 1817 PCa cases and 2026 cancer-free controls, we aimed to clarify the association between these two MTHFR variants and PCa risk in Shanghai and to explore the underlying molecular mechanisms. We found that both the heterozygous CT (adjusted OR = 0.78, 95% CI: 0.67-0.92) and the homozygous TT genotypes (adjusted OR = 0.68, 95% CI: 0.55-0.83) of c.677C>T were associated with a significantly decreased risk of PCa compared with homozygous wild-type CC genotype, respectively, using multivariate logistic regression. Furthermore, we confirmed that MTHFR c.677T allele was related to an increased serum homocysteine level in the Han Chinese population in Shanghai. In the cultured PCa cell lines, we observed that MTHFR c.677T could elevate the cellular homocysteine level and cause DNA damage, thus increasing cell apoptosis and finally inhibiting cell proliferation. In conclusion, MTHFR c.677T was a protective factor of PCa risk in ethnic Han Chinese males by inducing DNA damage and cell apoptosis.

Effect of vitamin B supplementation on cancer incidence, death due to cancer, and total mortality: A PRISMA-compliant cumulative meta-analysis of randomized controlled trials

BACKGROUND

Observational studies have suggested that vitamin B supplementation is associated with cancer risk, but this association remains controversial. A pooled data-based meta-analysis was conducted to summarize the evidence from randomized controlled trials (RCTs) investigating the effects of vitamin B supplementation on cancer incidence, death due to cancer, and total mortality.

METHODS

PubMed, EmBase, and the Cochrane Library databases were searched to identify trials to fit our analysis through August 2015. Relative risk (RR) was used to measure the effect of vitamin B supplementation on the risk of cancer incidence, death due to cancer, and total mortality using a random-effect model. Cumulative meta-analysis, sensitivity analysis, subgroup analysis, heterogeneity tests, and tests for publication bias were also conducted.

RESULTS

Eighteen RCTs reporting the data on 74,498 individuals were included in the meta-analysis. Sixteen of these trials included 4103 cases of cancer; in 6 trials, 731 cancer-related deaths occurred; and in 15 trials, 7046 deaths occurred. Vitamin B supplementation had little or no effect on the incidence of cancer (RR: 1.04; 95% confidence interval [CI]: 0.98-1.10; P = 0.216), death due to cancer (RR, 1.05; 95% CI: 0.90-1.22; P = 0.521), and total mortality (RR, 1.00; 95% CI: 0.94-1.06; P = 0.952). Upon performing a cumulative meta-analysis for cancer incidence, death due to cancer, and total mortality, the nonsignificance of the effect of vitamin B persisted. With respect to specific types of cancer, vitamin B supplementation significantly reduced the risk of skin melanoma (RR, 0.47; 95% CI: 0.23-0.94; P = 0.032).

CONCLUSION

Vitamin B supplementation does not have an effect on cancer incidence, death due to cancer, or total mortality. It is associated with a lower risk of skin melanoma, but has no effect on other cancers.

Germline genetic profiling in prostate cancer: latest developments and potential clinical applications

Familial and twin studies have demonstrated a significant inherited component to prostate cancer predisposition. Genome wide association studies have shown that there are 100 single nucleotide polymorphisms which have been associated with the development of prostate cancer. This review aims to discuss the scientific methods used to identify these susceptibility loci. It will also examine the current clinical utility of these loci, which include the development of risk models as well as predicting treatment efficacy and toxicity. In order to refine the clinical utility of the susceptibility loci, international consortia have been developed to combine statistical power as well as skills and knowledge to further develop models that could be used to predict risk and treatment outcomes.

Role of diet in prostate cancer: the epigenetic link

Diet is hypothesized to be a critical environmentally related risk factor for prostate cancer (PCa) development, and specific diets and dietary components can also affect PCa progression; however, the mechanisms underlying these associations remain elusive. As for a maturing organism, PCa's epigenome is plastic and evolves from the pre-neoplastic to the metastatic stage. In particular, epigenetic remodeling relies on substrates or cofactors obtained from the diet. Here we review the evidence that bridges dietary modulation to alterations in the prostate epigenome. We propose that such diet-related effects offer a mechanistic link between the impact of different diets and the course of PCa development and progression.

Divergence between dietary folate intake and concentrations in the serum and red blood cells of aging males in the United States

BACKGROUND & AIMS

As part of a broader study examining the relationship between serum folate concentrations and prostate cancer progression, we determined if there are age related changes in serum folate concentration compared to folate intake in the U.S. male population.

METHODS

Weighted data from the 2007-2008 and 2009-2010 NHANES databases was analyzed. A subpopulation of male participants was selected who were older than one year of age, had completed two days of dietary recall including supplement usage, and had fasted for at least 4 h prior to having their serum folate measured. Total dietary folate equivalent (DFE) intake (mcg) represented the combination of all natural food folate and folic acid from fortification and dietary supplements. Geometric means of serum folate (nM), red blood cell (RBC) folate (nM), and DFE intake were calculated for nine consecutive age groups, with each group generally representing a 10 year span. Analysis was then focused on males older than 20 years of age.

RESULTS

A total of 19,142 subjects were in the initial NHANES population, which represented over 294 million people within the United States. Applying our inclusion criteria created a final subpopulation size of 3775. Subsequent analysis of the age groups for all males older than 20 years found the following: The mean serum folate (nM) with 95% CI levels ranged from 28.2 (26.6, 29.9) to 55.1 (47.5, 63.9). RBC folate (nM) concentrations with 95% CI levels without any fasting exclusions ranged from 795.6 (741.5, 853.7) to 1038.4 (910.7, 1184.2). Serum and RBC folate concentrations were significantly higher with age across these age groups (p < 0.001). However, the mean total daily DFE intake did not significantly differ ranging from 640.4 (574.7, 713.7) to 720.2 (665, 780) mcg, (p = 0.373). Serum folate concentrations in men with total daily DFE intake of at least 1000 mcg increased more significantly with increasing age than serum folate concentrations in men with less than 400 mcg of total daily DFE intake (p < 0.001). There was a similar trend with the RBC folate concentrations (p = 0.054).

CONCLUSIONS

We observed higher serum and RBC folate concentrations and a divergence between dietary folate intake and these folate concentrations in older males. This phenomenon was evident at total DFE intakes that were significantly less than the 1000 mcg tolerable upper intake level currently recommended by the Institute of Medicine.

Nutrition, dietary interventions and prostate cancer: the latest evidence

Prostate cancer (PCa) remains a leading cause of mortality in US men and the prevalence continues to rise world-wide especially in countries where men consume a 'Western-style' diet. Epidemiologic, preclinical and clinical studies suggest a potential role for dietary intake on the incidence and progression of PCa. 'This minireview provides an overview of recent published literature with regard to nutrients, dietary factors, dietary patterns and PCa incidence and progression. Low carbohydrates intake, soy protein, omega-3 (w-3) fat, green teas, tomatoes and tomato products and zyflamend showed promise in reducing PCa risk or progression. A higher saturated fat intake and a higher β-carotene status may increase risk. A 'U' shape relationship may exist between folate, vitamin C, vitamin D and calcium with PCa risk. Despite the inconsistent and inconclusive findings, the potential for a role of dietary intake for the prevention and treatment of PCa is promising. The combination of all the beneficial factors for PCa risk reduction in a healthy dietary pattern may be the best dietary advice. This pattern includes rich fruits and vegetables, reduced refined carbohydrates, total and saturated fats, and reduced cooked meats. Further carefully designed prospective trials are warranted.

Folate intake, serum folate levels, and prostate cancer risk: a meta-analysis of prospective studies

Background

Studies have reported inconsistent results concerning the existence of associations of folate intake and serum folate levels with prostate cancer risk. This study sought to summarise the evidence regarding these relationships using a dose–response meta-analysis approach.

Methods

In January 2014, we performed electronic searches of PubMed, Embase, and the Cochrane Library to identify studies examining the effect of folate on the incidence of prostate cancer. Only prospective studies that reported effect estimates with 95% confidence intervals (CIs) of the incidence of prostate cancer for more than 2 categories of folate were included.

Results

Overall, we included 10 prospective studies reporting data on 202,517 individuals. High dietary folate intake had little or no effect on prostate cancer risk (risk ratio [RR] = 1.02; 95% CI = 0.95–1.09; P = 0.598). The dose–response meta-analysis suggested that a 100 μg per day increase in dietary folate intake has no significant effect on the risk of prostate cancer (RR = 1.01; 95% CI = 0.99–1.02; P = 0.433). However, high serum folate levels were associated with an increased risk of prostate cancer (RR = 1.21; 95% CI = 1.05–1.39; P = 0.008). The dose–response meta-analysis indicated that a 5 nmol/L increment of serum folate levels was also associated with an increased risk of prostate cancer (RR = 1.04; 95% CI = 1.00–1.07; P = 0.042).

Conclusions

Our study indicated that dietary folate intake had little or no effect on prostate cancer risk. However, increased serum folate levels have potentially harmful effects on the risk of prostate cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2458-14-1326) contains supplementary material, which is available to authorized users.