Folic acid for the prevention of colorectal adenomas: a randomized clinical trial

Impact of folic acid supplementation on the epigenetic profile in healthy unfortified individuals - a randomized intervention trial

Folate is an essential mediator in one-carbon metabolism, which provides methyl groups for DNA synthesis and methylation. The availability of active methyl groups can be influenced by the uptake of folic acid. We conducted a randomized intervention trial to test the influence of folic acid supplementation on DNA methylation in an unfortified population in Germany. A total of 16 healthy male volunteers (age range 23-61 y) were randomized to receive either 400 μg (n = 9) or 800 μg (n = 7) folic acid supplements daily for 8 weeks. Infinium Human Methylation 450K BeadChip Microarrays were used to assay site-specific DNA methylation across the genome. Microarray analyses were conducted on PBL DNA. We estimated several epigenetic clocks and mean DNA methylation across all autosomal probes on the array. AgeAccel was estimated as the residual variation in each metric. In virtually all participants, both serum and red blood cell (RBC) folate increased successively throughout the trial period. Participants with a larger increase in RBC folate had a larger increase in DNAmAge AgeAccel (Spearman Rho: 0.56, p-value = 0.03). No notable changes in the methylome resulting from the folic acid supplementation emerged. In this population with adequate folate levels derived from diet, an increase in RBC folate had a modest impact on the epigenetic clock predicting chronologic age.

Unveiling the Therapeutic Potential of Folate-Dependent One-Carbon Metabolism in Cancer and Neurodegeneration

Cellular metabolism is crucial for various physiological processes, with folate-dependent one-carbon (1C) metabolism playing a pivotal role. Folate, a B vitamin, is a key cofactor in this pathway, supporting DNA synthesis, methylation processes, and antioxidant defenses. In dividing cells, folate facilitates nucleotide biosynthesis, ensuring genomic stability and preventing carcinogenesis. Additionally, in neurodevelopment, folate is essential for neural tube closure and central nervous system formation. Thus, dysregulation of folate metabolism can contribute to pathologies such as cancer, severe birth defects, and neurodegenerative diseases. Epidemiological evidence highlights folate's impact on disease risk and its potential as a therapeutic target. In cancer, antifolate drugs that inhibit key enzymes of folate-dependent 1C metabolism and strategies targeting folate receptors are current therapeutic options. However, folate's impact on cancer risk is complex, varying among cancer types and dietary contexts. In neurodegenerative conditions, including Alzheimer's and Parkinson's diseases, folate deficiency exacerbates cognitive decline through elevated homocysteine levels, contributing to neuronal damage. Clinical trials of folic acid supplementation show mixed outcomes, underscoring the complexities of its neuroprotective effects. This review integrates current knowledge on folate metabolism in cancer and neurodegeneration, exploring molecular mechanisms, clinical implications, and therapeutic strategies, which can provide crucial information for advancing treatments.

The association between dietary folate intake and risk of colorectal cancer incidence: A systematic review and dose‒response meta-analysis of cohort studies

Background

Dietary components can influence the incidence of colorectal cancer (CRC). Folate is one of the compounds that plays an essential role in the formation of DNA structures, which can lead to or prevent tumorigenesis. The present study is the first systematic review and dose-response meta-analysis of cohort studies evaluating the association between dietary folate intake and the risk of CRC.

Methods

The PubMed/Medline, Scopus, and ISI Web of Science databases were systematically searched for cohort studies that assessed the association between folate intake and CRC up to January 2024. Summary relative risks (RRs) and 95 % confidence intervals (CIs) were calculated using a random effects model. Also, linear and nonlinear dose-response analyses were conducted for the dose-response associations between folate intake and risk of CRC.

Results

Eighteen prospective cohort studies with 931,469 participants, 14,860 CRC patients, 3536 colon cancer (CC) patients, and 1075 rectal cancer (RC) patients were included in the analysis. The summary RR of CRC for each 100-μg increase in dietary folate intake was 0.97 (95 % CI: 0.95-0.99, I2: 0.0 %, P-heterogeneity: 0.616), which can be related to BMI (0.97 (95 % CI: 0.95-0.99)); a more protective effect was also observed in subjects who drank alcohol (0.97 (95 % CI: 0.95-0.99)) and those who smoked (0.97 (95 % CI: 0.95-0.99)). Additionally, it was positively related to a 7 % lower risk of CC (0.93 (95 % CI: 0.87-0.99, I2: 33.7 %, P-heterogeneity: 0.159)), and the null relation for RC was 0.98 (95 % CI: 0.90-1.08), I2: 16.6 %, P-heterogeneity: 0.309). There was evidence of nonlinearity in which up to 500 μg/day dietary folate intake was inversely associated with CC (P nonlinearity = 0.04).

Conclusion

The findings showed an inverse association between dietary folate intake and the risk of CRC, especially in high-risk persons, those who have a higher BMI, alcohol drinkers, and smokers.

Associations between diet and nutritional supplements and colorectal cancer: A systematic review

Background and Aim

Colorectal cancer (CRC) is one of the most prevalent cancers around the world. The link between nutrients and the likelihood of developing CRC remains uncertain. The primary objective of the present study was to investigate the potential connection between dietary intake/dietary supplements and the occurrence of CRC through a literature review.

Methods

A comprehensive online search was conducted in PubMed, Scopus, Web of Science, and the Cochrane Library from January 1990 to March 2023 using appropriate keywords. A systematic search was conducted for clinical trials and cohort studies in order to determine the relationship between dietary components/supplements and CRC.

Results

The intake of long-chain n-3 polyunsaturated fatty acids (n-3 LCPUFAs), consisting of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), has the potential to decrease the likelihood of developing CRC (eight studies found positive effects and four studies found no association). Some other dietary components such as probiotics, prebiotics, and synbiotics may contribute to suppressing CRC development (three studies found positive effects, whereas three studies did not find any association). There is inconclusive evidence that supplementation with certain micronutrients including vitamin D (one trial found positive effects and another trial reported no association), folate, zinc, and selenium may reduce the risk of CRC.

Conclusion

Some dietary supplements such as n-3 LCPUFAs and probiotics have the potential to reduce the risk of developing CRC. Further studies are necessary to validate these results and understand the underlying mechanisms.

Effects of folate deficiency and sex on carcinogenesis in a mouse model of oral cancer

OBJECTIVES

To investigate the effects of dietary folate and sex on histopathology of oral squamous cell carcinoma in mice.

MATERIALS AND METHODS

Mice (C57Bl/6, 30/sex) were fed either a deficient folate or sufficient folate diet. Vehicle or 4-nitroquinoline1-oxide (50 μg/mL) in vehicle were administered in drinking water for 20 weeks, followed by 6 weeks of regular drinking water. Oral lesions were observed weekly. Tongues were studied for histopathologic changes. Immunohistochemical techniques were used to measure cell proliferation (Ki67+), and to quantify expression of folate receptor, reduced folate carrier, and proton-coupled folate transporter. T cells, macrophages, and neutrophils were counted and normalized to area.

RESULTS

All 4NQO-treated mice developed oral tumors. Dietary folate level did not affect tumor burden. More tumors were observed on the ventral aspect of the tongue than in other locations within the oral cavity. 4-nitroquinoline-1-oxide-treated mice displayed 27%-46% significantly lower expression of all three folate transport proteins; diet and sex had no effect on folate transporter expression. T-cell and neutrophil infiltration in tongues were 9.1-fold and 18.1-fold increased in the 4-nitroquinoline-1-oxide-treated mouse tongues than in controls.

CONCLUSION

Treatment with 4NQO was the primary factor in determining cancer development, decreased folate transport expression, and lymphoid cell infiltration.

Construction and validation of a folate metabolism-related gene signature for predicting prognosis in HNSCC

PURPOSE

Metabolic reprogramming is currently considered a hallmark of tumor and immune development. It is obviously of interest to identify metabolic enzymes that are associated with clinical prognosis in head and neck squamous cell carcinomas (HNSCC).

METHODS

Candidate genes were screened to construct folate metabolism scores by Cox regression analysis. Functional enrichment between high- and low-folate metabolism groups was explored by GO, KEGG, GSVA, and ssGSEA. EPIC, MCPcounter, and xCell were utilized to explore immune cell infiltration between high- and low-folate metabolism groups. Relevant metabolic scores were calculated and visually analyzed by the "IOBR" software package.

RESULTS

To investigate the mechanism behind metabolic reprogramming of HNSCC, 2886 human genes associated with 86 metabolic pathways were selected. Folate metabolism is significantly enriched in HNSCC, and that the six-gene (MTHFD1L, MTHFD2, SHMT2, ATIC, MTFMT, and MTHFS) folate score accurately predicts and differentiates folate metabolism levels. Reprogramming of folate metabolism affects CD8T cell infiltration and induces immune escape through the MIF signaling pathway. Further research found that SHMT2, an enzyme involved in folate metabolism, inhibits CD8T cell infiltration and induces immune escape by regulating the MIF/CD44 signaling axis, which in turn promotes HNSCC progression.

CONCLUSIONS

Our study identified a novel and robust folate metabolic signature. A folate metabolic signature comprising six genes was effective in assessing the prognosis and reflecting the immune status of HNSCC patients. The target molecule of folate metabolic reprogramming, SHMT2, probably plays a very important role in HNSCC development and immune escape.

A novel automated multi-cycle magnetic solid-phase extraction coupled to LC-MS/MS to study the disorders of six functional B vitamins in patients with gastroenterology and hyperhomocysteinemia

B vitamins are essential for human life and their disorders can cause a variety of diseases. Solid-phase extraction (SPE) coupled to LC-MS/MS is a preferred technique for determining multiple B vitamins, however, their complexity in real biological matrices makes it hard to achieve satisfactory recovery and accuracy when simultaneous detection. In this study, a novel automated multi-cycle magnetic SPE (MSPE) coupled to the LC-MS/MS method was established using a mixed-mode anion exchange magnetic adsorbent for the simultaneous extraction of six functional B vitamins, including methylmalonic acid, riboflavin, pantothenic acid, 4-pyridoxic acid, folic acid, and 5-methyltetrahydrofolate. After three consecutive MSPE cycles, the recoveries of all analytes were between 51.5% and 89.6%. The method exhibited excellent sensitivity and linearity, with a dynamic range of 200-fold (R > 0.99 for all analytes), exceptional accuracy (ranging between 95.4% and 105.6%) and precision (with RSDs ≤ 6.2%) without significant matrix effects or interferences. Compared to manual SPE method, the automated multi-cycle MSPE method has better feasibility and greater vitamin coverage. It shows a high correlation with the manual method for the detection of 5-methyltetrahydrofolate and folate (R > 0.99). A study of patients from the gastroenterology department showed that those undergoing surgery and those with malignancies may be at risk of folate deficiency. In addition, patients with hyperhomocystinemia had higher levels of methylmalonic acid and lower levels of 5-methyltetrahydrofolate, which correlated with homocysteine levels (R = 0.404 and -0.311, respectively) and showed dose-response relationships. This method is highly automated and cost-effective, with minimal systematic error, making it suitable for the analysis of clinical samples.

Vitamin B12 status and folic acid supplementation influence mitochondrial heteroplasmy levels in mice

One-carbon metabolism is a complex network of metabolic reactions that are essential for cellular function including DNA synthesis. Vitamin B12 and folate are micronutrients that are utilized in this pathway and their deficiency can result in the perturbation of one-carbon metabolism and subsequent perturbations in DNA replication and repair. This effect has been well characterized in nuclear DNA but to date, mitochondrial DNA (mtDNA) has not been investigated extensively. Mitochondrial variants have been associated with several inherited and age-related disease states; therefore, the study of factors that impact heteroplasmy are important for advancing our understanding of the mitochondrial genome's impact on human health. Heteroplasmy studies require robust and efficient mitochondrial DNA enrichment to carry out in-depth mtDNA sequencing. Many of the current methods for mtDNA enrichment can introduce biases and false-positive results. Here, we use a method that overcomes these limitations and have applied it to assess mitochondrial heteroplasmy in mouse models of altered one-carbon metabolism. Vitamin B12 deficiency was found to cause increased levels of mitochondrial DNA heteroplasmy across all tissues that were investigated. Folic acid supplementation also contributed to elevated mitochondrial DNA heteroplasmy across all mouse tissues investigated. Heteroplasmy analysis of human data from the Framingham Heart Study suggested a potential sex-specific effect of folate and vitamin B12 status on mitochondrial heteroplasmy. This is a novel relationship that may have broader consequences for our understanding of one-carbon metabolism, mitochondrial-related disease and the influence of nutrients on DNA mutation rates.

Impact of Folinic Acid Dosing on Efficacy and Toxicity of High-Dose Methotrexate in Central Nervous System Lymphoma

INTRODUCTION

High-dose methotrexate (HDMTX)-based regimens are the treatment of choice in primary central nervous system lymphoma (PCNSL). Folinic acid (FA) rescue is used to mitigate the toxic effects of MTX on normal cells. However, the optimal dosing of FA in PCNSL remains uncertain.

METHODS

We analyzed the relationship between FA dosing and treatment efficacy and toxicity in a cohort of 36 PCNSL patients treated at our institute between the years 2014 and 2022. A combination of univariate and multivariate analyses using known prognostic factors were used to determine the association between FA dosing and treatment outcomes.

RESULTS

We found that higher per-treatment cumulative FA doses were associated with inferior progression-free survival (PFS), with a hazard ratio (HR) of 2.2 for each 100 mg/m2 increase in FA dose. We identified a threshold of 350 mg/m2/treatment, above which there was a significant reduction in PFS. Notably, lower FA doses did not result in increased toxicity.

CONCLUSION

Our findings suggest that optimizing FA dosing to avoid very high rescue doses may improve treatment outcomes in PCNSL patients receiving HDMTX. Further prospective studies are warranted to validate these findings.

Dietary Folate and Cofactors Accelerate Age-dependent p16 Epimutation to Promote Intestinal Tumorigenesis

The extent to which non-genetic environmental factors, such as diet, contribute to carcinogenesis has been long debated. One potential mechanism for the effects of environmental factors is through epigenetic modifications that affect gene expression without changing the underlying DNA sequence. However, the functional cooperation between dietary factors and cancer-causing epigenetic regulation is largely unknown. Here, we use a mouse model of age-dependent p16 epimutation, in which the p16 gene activity is directly controlled by promoter DNA methylation. We show p16 epimutation is modulated by folate and cofactors in dietary supplementation, which leads to increased colon cancer risk. Importantly, our findings provide functional evidence concerning the safety of folate fortification in the general population.

SIGNIFICANCE

Our study demonstrates that dietary folate and cofactors modulate tumor-suppressor gene methylation to increase intestinal tumorigenesis. Our findings highlight the need for monitoring the long-term safety of folate fortification in high-risk individuals.

Folic acid: friend or foe in cancer therapy

Folic acid plays a crucial role in diverse biological processes, notably cell maturation and proliferation. Here, we performed a literature review using articles listed in electronic databases, such as PubMed, Scopus, MEDLINE, and Google Scholar. In this review article, we describe contradictory data regarding the role of folic acid in cancer development and progression. While some studies have confirmed its beneficial effects in diminishing the risk of various cancers, others have reported a potential carcinogenic effect. The current narrative review elucidates these conflicting data by highlighting the possible molecular mechanisms explaining each point of view. Further multicenter molecular and genetic studies, in addition to human randomized clinical trials, are necessary to provide a more comprehensive understanding of the relationship between folic acid and cancer.

Preventive effects of chemical drugs on recurrence of colorectal adenomas: systematic review and Bayesian network meta-analysis

BACKGROUND

The onset of colorectal adenomas (CRAs) is significantly associated with colorectal cancer. The preventive effects of chemical drugs on the recurrence of CRAs have been evaluated in a large number of randomized controlled trials (RCTs). However, there are still uncertainties about the relative effectiveness of such chemical drugs.

METHODS

We searched relevant RCTs published in six databases up to February 2023. The quality of the included studies was assessed by using the Cochrane risk of bias assessment tool and Review Manager 5.4. Pairwise comparison and network meta-analysis (NMA) were conducted using RStudio to compare the effects of chemical drugs on the recurrence of CRAs.

RESULTS

Forty-five high-quality RCTs were included. A total of 35 590 (test group: 20 822; control group: 14 768) subjects with a history of CRAs have been enrolled and randomized to receive placebo treatment or one of 24 interventions. Based on surface under the cumulative ranking values and NMA results, difluoromethylornithine (DFMO) + Sulindac significantly reduced the recurrence of CRAs, followed by berberine and nonsteroidal antiinflammatory drugs.

CONCLUSION

DFMO + Sulindac is more effective in reducing the recurrence of CRAs but has a high risk of adverse events. Considering drug safety, tolerance, and compliance, berberine has a brighter prospect of clinical development. However, further studies are needed to verify our findings.

Uncovering the Hidden Dangers and Molecular Mechanisms of Excess Folate: A Narrative Review

This review delves into the intricate relationship between excess folate (vitamin B9) intake, especially its synthetic form, namely, folic acid, and its implications on health and disease. While folate plays a pivotal role in the one-carbon cycle, which is essential for DNA synthesis, repair, and methylation, concerns arise about its excessive intake. The literature underscores potential deleterious effects, such as an increased risk of carcinogenesis; disruption in DNA methylation; and impacts on embryogenesis, pregnancy outcomes, neurodevelopment, and disease risk. Notably, these consequences stretch beyond the immediate effects, potentially influencing future generations through epigenetic reprogramming. The molecular mechanisms underlying these effects were examined, including altered one-carbon metabolism, the accumulation of unmetabolized folic acid, vitamin-B12-dependent mechanisms, altered methylation patterns, and interactions with critical receptors and signaling pathways. Furthermore, differences in the effects and mechanisms mediated by folic acid compared with natural folate are highlighted. Given the widespread folic acid supplementation, it is imperative to further research its optimal intake levels and the molecular pathways impacted by its excessive intake, ensuring the health and well-being of the global population.

Genome-wide interaction analysis of folate for colorectal cancer risk

BACKGROUND

Epidemiological and experimental evidence suggests that higher folate intake is associated with decreased colorectal cancer (CRC) risk; however, the mechanisms underlying this relationship are not fully understood. Genetic variation that may have a direct or indirect impact on folate metabolism can provide insights into folate's role in CRC.

OBJECTIVES

Our aim was to perform a genome-wide interaction analysis to identify genetic variants that may modify the association of folate on CRC risk.

METHODS

We applied traditional case-control logistic regression, joint 3-degree of freedom, and a 2-step weighted hypothesis approach to test the interactions of common variants (allele frequency >1%) across the genome and dietary folate, folic acid supplement use, and total folate in relation to risk of CRC in 30,550 cases and 42,336 controls from 51 studies from 3 genetic consortia (CCFR, CORECT, GECCO).

RESULTS

Inverse associations of dietary, total folate, and folic acid supplement with CRC were found (odds ratio [OR]: 0.93; 95% confidence interval [CI]: 0.90, 0.96; and 0.91; 95% CI: 0.89, 0.94 per quartile higher intake, and 0.82 (95% CI: 0.78, 0.88) for users compared with nonusers, respectively). Interactions (P-interaction < 5×10-8) of folic acid supplement and variants in the 3p25.2 locus (in the region of Synapsin II [SYN2]/tissue inhibitor of metalloproteinase 4 [TIMP4]) were found using traditional interaction analysis, with variant rs150924902 (located upstream to SYN2) showing the strongest interaction. In stratified analyses by rs150924902 genotypes, folate supplementation was associated with decreased CRC risk among those carrying the TT genotype (OR: 0.82; 95% CI: 0.79, 0.86) but increased CRC risk among those carrying the TA genotype (OR: 1.63; 95% CI: 1.29, 2.05), suggesting a qualitative interaction (P-interaction = 1.4×10-8). No interactions were observed for dietary and total folate.

CONCLUSIONS

Variation in 3p25.2 locus may modify the association of folate supplement with CRC risk. Experimental studies and studies incorporating other relevant omics data are warranted to validate this finding.

Scientific opinion on the tolerable upper intake level for folate

Following a request from the European Commission (EC), the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the revision of the tolerable upper intake level (UL) for folic acid/folate. Systematic reviews of the literature were conducted to assess evidence on priority adverse health effects of excess intake of folate (including folic acid and the other authorised forms, (6S)-5-methyltetrahydrofolic acid glucosamine and l-5-methyltetrahydrofolic acid calcium salts), namely risk of cobalamin-dependent neuropathy, cognitive decline among people with low cobalamin status, and colorectal cancer and prostate cancer. The evidence is insufficient to conclude on a positive and causal relationship between the dietary intake of folate and impaired cognitive function, risk of colorectal and prostate cancer. The risk of progression of neurological symptoms in cobalamin-deficient patients is considered as the critical effect to establish an UL for folic acid. No new evidence has been published that could improve the characterisation of the dose-response between folic acid intake and resolution of megaloblastic anaemia in cobalamin-deficient individuals. The ULs for folic acid previously established by the Scientific Committee on Food are retained for all population groups, i.e. 1000 μg/day for adults, including pregnant and lactating women, 200 μg/day for children aged 1-3 years, 300 μg/day for 4-6 years, 400 μg/day for 7-10 years, 600 μg/day for 11-14 years and 800 μg/day for 15-17 years. A UL of 200 μg/day is established for infants aged 4-11 months. The ULs apply to the combined intake of folic acid, (6S)-5-methyltetrahydrofolic acid glucosamine and l-5-methyltetrahydrofolic acid calcium salts, under their authorised conditions of use. It is unlikely that the ULs for supplemental folate are exceeded in European populations, except for regular users of food supplements containing high doses of folic acid/5-methyl-tetrahydrofolic acid salts.

The Heterogeneous Impact of Prediagnostic Folate Intake for Fluorouracil-Containing Induction Chemotherapy for Head and Neck Cancer

Fluorouracil (FU) exerts its antitumor activity by inhibiting folate-mediated one-carbon metabolism. Evidence that folate may play a role in the carcinogenic process via folate-mediated one-carbon metabolism has given rise to the hypothesis that pre-diagnostic folate intake may induce heterogeneous chemosensitivity to FU-containing induction chemotherapy (IC) in head and neck cancer. To assess this hypothesis, we conducted a cohort study to investigate whether the association between prediagnostic dietary folate intake and cancer survival differed between treatment regimens with and without FU-containing IC in 504 cases of locally advanced (stage III/IV) HNSCC, using an epidemiologic database combined with clinical data. In total, 240 patients were treated with FU-containing IC followed by definitive treatment, and 264 patients were treated with definitive treatment alone. Definitive treatment is defined as (1) the surgical excision of a tumor with clear margins, with or without neck lymph node dissection; or (2) radiotherapy with or without chemotherapy. In the overall cohort of the FU-containing IC group, a higher folate intake was significantly associated with better overall survival (adjusted hazard ratios (HRs) for the highest compared to the lowest folate tertiles (HRT3-T1) = 0.42, 95%CI, 0.25-0.76, Ptrend = 0.003). Conversely, no apparent association between prediagnostic folate intake and survival was observed with definitive treatment alone (HRT3-T1: 0.83, 95%CI, 0.49-1.42, Ptrend = 0.491)). A consideration of the cumulative dose of FU-containing IC showed that the survival impact of prediagnostic folate intake differed statistically significantly by treatment regimen (Pinteraction = 0.012). In conclusion, an association between prediagnostic folate intake and HNSCC survival significantly differed by FU-containing IC. This finding indicates that in the carcinogenic process, folate status causes HNSCC to be heterogenous in terms of one-carbon metabolism.

Perinatal folate levels do not influence tumor latency or multiplicity in a model of NF1 associated plexiform-like neurofibromas

OBJECTIVE

In epidemiological and experimental research, high folic acid intake has been demonstrated to accelerate tumor development among populations with genetic and/or molecular susceptibility to cancer. Neurofibromatosis type 1 (NF1) is a common autosomal dominant disorder predisposing affected individuals to tumorigenesis, including benign plexiform neurofibromas; however, understanding of factors associated with tumor risk in NF1 patients is limited. Therefore, we investigated whether pregestational folic acid intake modified plexiform-like peripheral nerve sheath tumor risk in a transgenic NF1 murine model.

RESULTS

We observed no significant differences in overall survival according to folate group. Relative to controls (180 days), median survival did not statistically differ in deficient (174 days, P = 0.56) or supplemented (177 days, P = 0.13) folate groups. Dietary folate intake was positively associated with RBC folate levels at weaning, (P = 0.023, 0.0096, and 0.0006 for deficient vs. control, control vs. supplemented, and deficient vs. supplemented groups, respectively). Dorsal root ganglia (DRG), brachial plexi, and sciatic nerves were assessed according to folate group. Mice in the folate deficient group had significantly more enlarged DRG relative to controls (P = 0.044), but no other groups statistically differed. No significant differences for brachial plexi or sciatic nerve enlargement were observed according to folate status.

Trends in Diet and Cancer Research: A Bibliometric and Visualization Analysis

Diet plays a critical role for patients across the cancer continuum. The World Cancer Research Fund International and the American Cancer Society have published evidence supporting the role of nutrition in cancer prevention. We conducted an analysis of the literature on dietary nutrients and cancer to uncover opportunities for future research. The objective of the bibliometric analysis was to describe trends in peer-reviewed publications on dietary components and cancer and to highlight research gaps. PubMed was queried for manuscripts with diet- and cancer-related keywords and Medical Subject Headings (MeSH) terms. Metadata covering 99,784 publications from 6469 journals were analyzed to identify trends since 1970 on diet topics across 19 tumor types. Publications focused largely on breast, colorectal, and liver cancer, with fewer papers linking diet with other cancers such as brain, gallbladder, or ovarian. With respect to "unhealthy" diets, many publications focused on high-fat diets and alcohol consumption. The largest numbers of publications related to "healthy" diets examined the Mediterranean diet and the consumption of fruits and vegetables. These findings highlight the need for additional research focused on under-investigated cancers and dietary components, as well as dietary studies during cancer therapy and post-therapy, which may help to prolong survivorship.

Increasing Cancer in Adolescents and Young Adults: Cancer Types and Causation Implications

Purpose: This study aimed to identify cancer incidence trends in the United States and globally in adolescents and young adults (AYAs) 15-39 years of age, by sex, and to speculate on causes for trend changes. Methods: For the United States, SEER*Stat was used to obtain average annual percent change (AAPC) trends in cancer incidence during the period 2000-2019 among 395,163 AYAs. For global data, the source was the Institute of Health Metrics and Evaluation and its sociodemographic index (SDI) classification system. Results: In the United States, the invasive cancer incidence increased during the period 2000-2019 in both females (AAPC: 1.05, 95% CI: 0.90-1.20, p << 0.001) and males (AAPC: 0.56, 95% CI: 0.43-0.69, p << 0.001). A total of 25 and 20 types of cancers increased statistically significantly in female and male AYAs, respectively. Among potential causes for the increases, the obesity epidemic in the United States strongly correlates with the overall cancer increase in both its female (Pearson correlation coefficient R2 = 0.88, p = 0.0007) and male (R2 = 0.83, p = 0.003) AYAs, as does the most common malignancy in American AYAs, breast cancer (R2 = 0.83, p = 0.003). Worldwide, cancer incidence in the age group increased steadily during the period 2000-2019 among high-middle, middle, and low-middle SDI countries, but not in low SDI countries and with slowing of increase in high SDI countries. Conclusions: The increases and their age-dependent profiles implicate several causations that are preventable, including obesity, overdiagnosis, unnecessary diagnostic radiation, human papilloma virus infection, and cannabis avoidance. The United States is beginning to reverse the increasing incidence, and prevention efforts should be augmented accordingly.

Folic Acid Supplementation Promotes Hypomethylation in Both the Inflamed Colonic Mucosa and Colitis-Associated Dysplasia

PURPOSE

The purpose of this study was to assess the effect of folic acid (FA) supplementation on colitis-associated colorectal cancer (CRC) using the azoxymethane/dextran sulfate sodium (AOM/DSS) model.

METHODS

Mice were fed a chow containing 2 mg/kg FA at baseline and randomized after the first DSS treatment to receive 0, 2, or 8 mg/kg FA chow for 16 weeks. Colon tissue was collected for histopathological evaluation, genome-wide methylation analyses (Digital Restriction Enzyme Assay of Methylation), and gene expression profiling (RNA-Seq).

RESULTS

A dose-dependent increase in the multiplicity of colonic dysplasias was observed, with the multiplicity of total and polypoid dysplasias higher (64% and 225%, respectively) in the 8 mg FA vs. the 0 mg FA group (p < 0.001). Polypoid dysplasias were hypomethylated, as compared to the non-neoplastic colonic mucosa (p < 0.05), irrespective of FA treatment. The colonic mucosa of the 8 mg FA group was markedly hypomethylated as compared to the 0 mg FA group. Differential methylation of genes involved in Wnt/β-catenin and MAPK signaling resulted in corresponding alterations in gene expression within the colonic mucosa.

CONCLUSIONS

High-dose FA created an altered epigenetic field effect within the non-neoplastic colonic mucosa. The observed decrease in site-specific DNA methylation altered oncogenic pathways and promoted colitis-associated CRC.

Randomized, Double-Blind, Placebo-Controlled Trial of MUC1 Peptide Vaccine for Prevention of Recurrent Colorectal Adenoma

PURPOSE

To assess whether MUC1 peptide vaccine produces an immune response and prevents subsequent colon adenoma formation.

PATIENTS AND METHODS

Multicenter, double-blind, placebo-controlled randomized trial in individuals age 40 to 70 with diagnosis of an advanced adenoma ≤1 year from randomization. Vaccine was administered at 0, 2, and 10 weeks with a booster injection at week 53. Adenoma recurrence was assessed ≥1 year from randomization. The primary endpoint was vaccine immunogenicity at 12 weeks defined by anti-MUC1 ratio ≥2.0.

RESULTS

Fifty-three participants received the MUC1 vaccine and 50 placebo. Thirteen of 52 (25%) MUC1 vaccine recipients had a ≥2-fold increase in MUC1 IgG (range, 2.9-17.3) at week 12 versus 0/50 placebo recipients (one-sided Fisher exact P < 0.0001). Of 13 responders at week 12, 11 (84.6%) responded to a booster injection at week 52 with a ≥2-fold increase in MUC1 IgG measured at week 55. Recurrent adenoma was observed in 31 of 47 (66.0%) in the placebo group versus 27 of 48 (56.3%) in the MUC1 group [adjusted relative risk (aRR), 0.83; 95% confidence interval (CI), 0.60-1.14; P = 0.25]. Adenoma recurrence occurred in 3/11 (27.3%) immune responders at week 12 and week 55 (aRR, 0.41; 95% CI, 0.15-1.11; P = 0.08 compared with placebo). There was no difference in serious adverse events.

CONCLUSIONS

An immune response was observed only in vaccine recipients. Adenoma recurrence was not different than placebo, but a 38% absolute reduction in adenoma recurrence compared with placebo was observed in participants who had an immune response at week 12 and with the booster injection.

CRISPR-mediated iron and folate biofortification in crops: advances and perspectives

Micronutrient deficiency conditions, such as anemia, are the most prevalent global health problem due to inadequate iron and folate in dietary sources. Biofortification advancements can propel the rapid amelioration of nutritionally beneficial components in crops that are required to combat the adverse effects of micronutrient deficiencies on human health. To date, several strategies have been proposed to increase micronutrients in plants to improve food quality, but very few approaches have intrigued `clustered regularly interspaced short palindromic repeats' (CRISPR) modules for the enhancement of iron and folate concentration in the edible parts of plants. In this review, we discuss two important approaches to simultaneously enhance the bioavailability of iron and folate concentrations in rice endosperms by utilizing advanced CRISPR-Cas9-based technology. This includes the 'tuning of cis-elements' and 'enhancer re-shuffling' in the regulatory components of genes that play a vital role in iron and folate biosynthesis/transportation pathways. In particular, base-editing and enhancer re-installation in native promoters of selected genes can lead to enhanced accumulation of iron and folate levels in the rice endosperm. The re-distribution of micronutrients in specific plant organs can be made possible using the above-mentioned contemporary approaches. Overall, the present review discusses the possible approaches for synchronized iron and folate biofortification through modification in regulatory gene circuits employing CRISPR-Cas9 technology.

Chemoprevention of colorectal cancer in general population and high-risk population: a systematic review and network meta-analysis

BACKGROUND

Many nutritional supplements and pharmacological agents have been reported to show preventive effects on colorectal adenoma and colorectal cancer (CRC). We performed a network meta-analysis to summarize such evidence and assess the efficacy and safety of these agents.

METHODS

We searched PubMed, Embase, and the Cochrane Library for studies published in English until October 31, 2021 that fit our inclusion criteria. We performed a systematic review and network meta-analysis to assess the comparative efficacy and safety of candidate agents (low-dose aspirin [Asp], high-dose Asp, cyclooxygenase-2 inhibitors [coxibs], calcium, vitamin D, folic acid, ursodeoxycholic acid [UDCA], estrogen, and progesterone, alone or in combination) for preventing colorectal adenoma and CRC. Cochrane risk-of-bias assessment tool was employed to evaluate the quality of each included study.

RESULTS

Thirty-two randomized controlled trials (278,694 participants) comparing 13 different interventions were included. Coxibs significantly reduced the risk of colorectal adenoma (risk ratio [RR]: 0.59, 95% confidence interval [CI]: 0.44-0.79, six trials involving 5486 participants), advanced adenoma (RR: 0.63, 95% CI: 0.43-0.92, four trials involving 4723 participants), and metachronous adenoma (RR: 0.58, 95% CI: 0.43-0.79, five trials involving 5258 participants) compared with placebo. Coxibs also significantly increased the risk of severe adverse events (RR: 1.29, 95% CI: 1.13-1.47, six trials involving 7109 participants). Other interventions, including Asp, folic acid, UDCA, vitamin D, and calcium, did not reduce the risk of colorectal adenoma in the general and high-risk populations compared with placebo.

CONCLUSIONS

Considering the balance between benefits and harms, regular use of coxibs for prevention of colorectal adenoma was not supported by the current evidence. Benefit of low-dose Asp for chemoprevention of colorectal adenoma still requires further evidence.

REGISTRATION

PROSPERO, No. CRD42022296376.

Associations between Folate and Alcohol Consumption with Colorectal Tumor Ki67 Expression in the Southern Community Cohort Study

Folate is hypothesized to accelerate cell proliferation in colorectal cancer (CRC) by supporting DNA synthesis, while alcohol is also linked to gastrointestinal epithelial proliferation, despite biological antagonism of folate. We report associations between folate and alcohol consumption with the proliferation marker Ki67 in CRC tumors from the Southern Community Cohort Study. Tumor samples were obtained from formalin-fixed paraffin-embedded tissue blocks. The percentage of cells expressing Ki67 was measured immunohistochemically. Exposures were assessed via questionnaire pre-diagnosis. Associations were assessed via linear regression. In 248 cases (40-78 years), neither dietary folate, folic acid supplements, nor total folate intake were associated with Ki67. Folic acid supplement use was associated with Ki67 in distal/rectal tumors (β [95% confidence interval]: 7.5 [1.2-13.8], p = .02) but not proximal tumors (-1.4 [-7.1-4.3], p=.62). A positive trend for total folate was observed for distal/rectal tumors (1.6 [0.0-3.3] per 200 μcg, p-trend=.05). Heavy drinking (women: ≥1 drink/day, men: ≥2 drinks/day) was associated with higher Ki67 (6.4 [1.0-11.9], vs. nondrinkers, p=.02), especially for distal/rectal tumors (10.4 [1.6-19.1], p=.02). Negative interaction between alcohol, total folate was observed for distal/rectal tumors (p-interaction=.06). Modest associations between folate, alcohol consumption and distal/rectal tumor Ki67 expression suggest accelerated proliferation, consistent with folate's role in DNA synthesis.

Folate intake and risk of colorectal cancer: a systematic review and up-to-date meta-analysis of prospective studies

PURPOSE

Colorectal cancer is one of the most commonly diagnosed and deadly cancers worldwide. Epidemiological studies on the relationship between folate intake and the risk of colorectal cancer have reported inconsistent findings since folate fortification in the USA. For this situation, we conducted a large number of data analyses to study the relationship between folate intake and colorectal cancer risk.

METHODS

PubMed and EMBASE databases were used to search the literature systematically. Eligible studies were reviewed and meta-analyzed to assess the relationship.

RESULTS

A total of 24 cohort studies involving 37 280 patients and 6 165 894 individuals were included. The results showed that high folate intake was associated with a reduced risk of colorectal cancer. The combined relative risk (RR) for the highest intake compared with the lowest was 0.88 [95% confidence interval (CI), 0.83-0.92, P  = 10 -4 ). Further studies indicated that the increase of folate intake may decrease the risk of colorectal cancer in people with medium or high alcohol consumption (RR = 0.97, 95% CI: 0.96-0.99, P  = 0.008; RR = 0.95, 95% CI: 0.92-0.98, P   =  0.003), but not in non-drinkers (RR = 1.00, 95% CI: 0.98-1.02, P  = 0.827). Next, high folate intake may decrease the risk of colon cancer (RR = 0.86, 95% CI: 0.81-0.92, P  = 10 -4 ) but not rectal cancer (RR = 0.92, 95% CI: 0.84-1.02, P  = 0.112). Additionally, the result that high folate intake may decrease the risk of colorectal cancer was observed in the USA and Europe but not in other regions.

CONCLUSION

High folate intake may be protective against colon cancer, particularly in people with middle or high alcohol consumption, but it still needs to be further confirmed.

Cohort profile: Biomarkers related to folate-dependent one-carbon metabolism in colorectal cancer recurrence and survival - the FOCUS Consortium

PURPOSE

The overarching goal of the FOCUS (biomarkers related to folate-dependent one-carbon metabolism in colorectal cancer (CRC) recurrence and survival) Consortium is to unravel the effect of folate and folate-mediated one-carbon metabolism (FOCM) biomarkers on CRC prognosis to provide clinically relevant advice on folate intake to cancer patients and define future tertiary prevention strategies.

PARTICIPANTS

The FOCUS Consortium is an international, prospective cohort of 2401 women and men above 18 years of age who were diagnosed with a primary invasive non-metastatic (stages I-III) CRC. The consortium comprises patients from Austria, two sites from the Netherlands, Germany and two sites from the USA. Patients are recruited after CRC diagnosis and followed at 6 and 12 months after enrolment. At each time point, sociodemographic data, data on health behaviour and clinical data are collected, blood samples are drawn.

FINDINGS TO DATE

An increased risk of cancer recurrences was observed among patients with higher compared with lower circulating folic acid concentrations. Furthermore, specific folate species within the FOCM pathway were associated with both inflammation and angiogenesis pathways among patients with CRC. In addition, higher vitamin B6 status was associated with better quality of life at 6 months post-treatment.

FUTURE PLANS

Better insights into the research on associations between folate and FOCM biomarkers and clinical outcomes in patients with CRC will facilitate the development of guidelines regarding folate intake in order to provide clinically relevant advice to patients with cancer, health professionals involved in patient care, and ultimately further tertiary prevention strategies in the future. The FOCUS Consortium offers an excellent infrastructure for short-term and long-term research projects and for combining additional biomarkers and data resulting from the individual cohorts within the next years, for example, microbiome data, omics and multiomics data or CT-quantified body composition data.

Intermediate role of gut microbiota in vitamin B nutrition and its influences on human health

Vitamin B consists of a group of water-soluble micronutrients that are mainly derived from the daily diet. They serve as cofactors, mediating multiple metabolic pathways in humans. As an integrated part of human health, gut microbiota could produce, consume, and even compete for vitamin B with the host. The interplay between gut microbiota and the host might be a crucial factor affecting the absorbing processes of vitamin B. On the other hand, vitamin B supplementation or deficiency might impact the growth of specific bacteria, resulting in changes in the composition and function of gut microbiota. Together, the interplay between vitamin B and gut microbiota might systemically contribute to human health. In this review, we summarized the interactions between vitamin B and gut microbiota and tried to reveal the underlying mechanism so that we can have a better understanding of its role in human health.

Effect Modification of Selenium Supplementation by Intake and Serum Concentrations of Antioxidants on the Development of Metachronous Colorectal Adenoma

BACKGROUND

Selenium (Se) is a trace element that has been investigated as a potential chemopreventive agent for colorectal cancer. Dietary intake of other antioxidant nutrients may modify the effect of Se.

OBJECTIVE

We examined the association between intake and serum concentrations of retinol, β-carotene, β-cryptoxanthin, lycopene, lutein/zeaxanthin, and α- and γ-tocopherol and the development of metachronous colorectal adenoma, and if these nutrients modified the effect of Se.

METHODS

We conducted a prospective study of 1874 participants from the Se Trial with data for antioxidant intake, as well as a subcohort of 508 participants with serum biomarker concentrations.

RESULTS

Statistically significantly lower odds for the development of metachronous adenoma were observed for those participants in the highest tertile of intake for lutein/zeaxanthin compared to the lowest, with an OR (95% CI) of 0.72 (0.56-0.94). No effect modification for intake of any nutrient was observed. However, circulating concentrations of lycopene exhibited statistically significant effect modification of selenium supplementation (p < 0.06).

CONCLUSION

These findings show that intake and circulating concentrations of antioxidant nutrients were not consistently associated with reduced odds for the development of metachronous lesions, although blood concentrations of lycopene may modify the effect of selenium supplementation.

Optimum dose of oral folic acid supplementation in transfusion-dependent thalassemia: a randomized controlled trial

AIM AND OBJECTIVES

We compared the effect of different doses of oral folic acid (FA) supplementation (5 mg/day vs. 2.5 mg/day vs. 5 mg/week) on the proportion of children with folate excess (serum folate &gt;20 ng/ml) and plasma homocysteine (Hcys) excess (&gt;15 µmol/l) in transfusion-dependent thalassemia (TDT).

MATERIALS AND METHODS

Children with TDT aged 5-18 years received oral FA in doses of 5 mg/day (Group 1), 2.5 mg/day (Group 2) and 5 mg/week (Group 3) for 9 months, after a wash-off period of 8 weeks. Folate levels (Serum and RBC) and plasma Hcys levels were measured after the therapy.

RESULTS

Ninety children were randomized to receive one of the three interventions (30 per group). After wash-off period, the median serum folate levels were significantly lower and five children developed folate deficiency; the median [interquartile range (IQR)] serum folate levels (ng/dl) were comparable in the three groups [Group 1: 6.5 (3.3-14.2), Group 2: 5.1 (2.6-10.5) and Group 3: 4.8 (3.4-10.0)]. After 9 months of intervention, the median (IQR) serum folate levels (ng/ml) were comparable in all participants [Group 1: 18.0 (6.5-28), Group 2: 13.5 (6.4-24.5) and Group 3: 9.7 (5.3-22.5); p = 0.11]. Proportion of children with serum folate excess was 40%, 26.7% and 26.7% in Group 1, Group 2 and Group 3 (p = 0.48). Proportion of children with RBC folate excess was 92%, 86.7% and 86.7% in Group 1, Group 2 and Group 3 (p = 0.79). Hyperhomocysteinemia was seen in eight children with no significant difference between median Hcys levels in the groups (p = 0.75).

CONCLUSION

Folic acid supplementation is recommended in TDT with 5 mg weekly dose being adequate.

Folic acid depletion as well as oversupplementation helps in the progression of hepatocarcinogenesis in HepG2 cells

Folate ingestion below and above the physiologic dose has been shown to play a tumorigenic role in certain cancers. Also, excessive folate supplementation after establishment of pre-established lesions led to an advancement in the growth of a few tumors. However, such information has not yet been achieved in the case of HCC. In our study, HepG2 cells were administered with three different concentrations of folic acid i.e. folic acid normal (FN) (2.27 µM), folic acid deficient (FD) (no folic acid), folic acid oversupplementation (FO) (100 µM) for 10 days. Intracellular folate levels were assayed by Elecsys Folate III kit based method. The migratory and invasive abilities were estimated by transwell migration and matrigel invasion methods respectively. FACS was done to evaluate cell viability and apoptosis. Agarose-coated plates were used to access cancer stem cells (CSCs) number. Quantitative RT-PCR and western blotting approaches were used for gene and protein expression of certain tumor suppressor genes (TSGs), respectively. FD cells depicted increased migration, invasion, apoptosis, necrosis and decreased cell viability, CSCs. On the other hand, FO cells showed increased migration, invasion, cell viability and number of CSCs and decreased apoptosis and necrosis. TSGs revealed diminished expression with both FA modulations with respect to FN cells. Thus, FA deficiency as well as abundance enhanced the HCC progression by adapting different mechanisms.

Dietary Intervention for Preventing Colorectal Cancer: A Practical Guide for Physicians

Colorectal cancer (CRC) is a disease with high prevalence and mortality. Estimated preventability for CRC is approximately 50%, indicating that altering modifiable factors, including diet and body weight, can reduce CRC risk. There is strong evidence that dietary factors including whole grains, high-fiber, red and processed meat, and alcohol can affect the risk of CRC. An alternative strategy for preventing CRC is use of a chemopreventive supplement that provides higher individual exposure to nutrients than what can be obtained from the diet. These include calcium, vitamin D, folate, n-3 polyunsaturated fatty acids, and phytochemicals. Several intervention trials have shown that these dietary chemopreventives have positive protective effects on development and progression CRC. Research on chemoprevention with phytochemicals that possess anti-inflammatory and/or, anti-oxidative properties is still in the preclinical phase. Intentional weight loss by bariatric surgery has not been effective in decreasing long-term CRC risk. Physicians should perform dietary education for patients who are at high risk of cancer for changing their dietary habits and behaviour. An increased understanding of the role of individual nutrients linked to the intestinal micro-environment and stages of carcinogenesis would facilitate the development of the best nutritional formulations for preventing CRC.

The efficacy of chemopreventive agents on the incidence of colorectal adenomas: A systematic review and network meta-analysis

Colorectal cancer (CRC) is the fourth most common cancer and third leading cause of cancer-related death worldwide. Use of chemopreventive agents (CPAs) to reduce the incidence of precursor colorectal adenomas could lower the future burden of CRC. Many classes of potential CPAs have been investigated. To identify the most effective CPAs, we conducted a systematic review and a network meta-analysis (NMA). An electronic search was performed through August 2020 to identify all randomized controlled trials (RCTs) assessing the efficacy of CPAs in reducing the incidence of colorectal adenomas at the time of surveillance colonoscopy among patients who had previously undergone polypectomy during an index colonoscopy. In total, 33 RCTs were included in the NMA, which was conducted under a Bayesian inference framework. Random effects models were used with adjustment for follow-up length and control group event rates to yield relative risks (RRs) and 95% credible intervals (CrIs). Our full network consisted of 13 interventions in addition to a placebo arm. Of 20,925 included patients, 7766 had an adenoma. Compared to placebo, the combination of difluoromethylornithine (DFMO) + Sulindac (RR 0.24, CrI 0.10-0.55) demonstrated a protective effect, while aspirin had a RR of 0.77 (CrI 0.60-1.00), celecoxib 800 mg had a RR of 0.56 (CrI 0.31-1.01) and metformin had a RR of 0.56 (CrI 0.22-1.39). Our results suggest that select CPAs may be efficacious in preventing the development of adenomas. Further studies are needed to identify those patients most likely to benefit and the minimum effective dosages of CPAs.

MR1-dependence of unmetabolized folic acid side-effects

The fortification of flour with folic acid for the prevention of neural tube defects (NTD) is currently mandated in over eighty countries worldwide, hence compelling its consumption by the greater part of the world’s population. Notwithstanding its beneficial impact on rates of NTD, pervasive folic acid supplementation has invariably led to additive daily intakes reaching well beyond their original target, resulting in the circulation of unmetabolized folic acid. Associated idiopathic side-effects ranging from allergies to cancer have been suggested, albeit inconclusively. Herein, we hypothesize that their inconsistent detection and elusive etiology are linked to the in vivo generation of the immunosuppressive folic acid metabolite 6-formylpterin, which interferes with the still emerging and varied functions of Major Histocompatibility Complex-related molecule 1 (MR1)-restricted T cells. Accordingly, we predict that fortification-related adverse health outcomes can be eliminated by substituting folic acid with the bioequivalent folate vitamer 5-methyltetrahydrofolate, which does not break down into 6-formylpterin.

The relationship between folic acid and colorectal cancer; a literature review

The objective

this study aims to investigate the relationship between folic acid and colorectal cancer (CRC).

Methods

google scholar, Pubmed, Pubmed central were searched from 1994 to 2022 for articles on the association between folic acid and CRC using the combinations: folic acid and colorectal cancer risk, folic acid and colorectal cancer survival, folic acid and colorectal cancer recurrence.

Main message

to describe and discuss the effect that folic acid might play on colorectal cancer (CRC) risk, recurrence and survivals, taking into account the possible differences between the men and women.

Conclusion

Our article supports the idea that says: vit-B9 has a dual-modulator effect on CRC carcinogenesis. However, its role in preventing recurrence and improving survival rates remains unresolved with a possible potential role of folate metabolism genotype variations. Therefore, more evidence from clinical studies is needed.

•

Colorectal cancer is one of the most life-threatening tumors.

•

Folic acid plays important role in multiple pathologies.

•

Folic acid has a dual-modulator effect on the colorectal cancer tumorgenesis.

•

The role of folate in preventing recurrence and improving survival rates remains unresolved.

Plasma Metabolomics Analysis of Aspirin Treatment and Risk of Colorectal Adenomas

Despite substantial observational and experimental evidence that aspirin use can provide protection against the development of colorectal neoplasia, our understanding of the molecular mechanisms involved is inadequate and limits our ability to use this drug effectively and safely for chemoprevention. We employed an untargeted plasma metabolomics approach using liquid chromatography with high-resolution mass spectroscopy to explore novel metabolites that may contribute to the chemopreventive effects of aspirin. Associations between levels of metabolic features in plasma and aspirin treatment were investigated among 523 participants in a randomized placebo-controlled clinical trial of two doses of aspirin (81 or 325 mg/day) and were linked to risk of colorectal adenoma occurrence over 3 years of follow-up. Metabolic pathways that were altered with aspirin treatment included linoleate and glycerophospholipid metabolism for the 81-mg dose and carnitine shuttle for both doses. Metabolites whose levels increased with 81 mg/day aspirin treatment and were also associated with decreased risk of adenomas during follow-up included certain forms of lysophosphatidylcholine and lysophosphatidylethanolamine as well as trihydroxyoctadecenoic acid, which is a derivative of linoleic acid and is upstream of cyclooxygenase inhibition by aspirin in the linoleate and arachidonic acid metabolism pathways. In conclusion, our findings regarding lysophospholipids and metabolites in the linoleate metabolism pathway may provide novel insights into the chemopreventive effects of aspirin in the colorectum, although they should be considered hypothesis-generating at this time.

PREVENTION RELEVANCE

This research used metabolomics, an innovative discovery-based approach, to identify molecular changes in human blood that may help to explain how aspirin use reduces the risk of colorectal neoplasia in some individuals. Ultimately, this work could have important implications for optimizing aspirin use in the prevention of colorectal cancer.

The Associations of Multivitamin and Antioxidant Use With Mortality Among Women and Men Diagnosed With Colorectal Cancer

Background

Colorectal cancer survivors often use multivitamins and other over-the-counter dietary supplements, but evidence is limited regarding their potential associations with mortality.

Methods

This prospective analysis included women and men from the Cancer Prevention Study-II Nutrition Cohort who were cancer-free at baseline (1992 or 1993) and diagnosed with colorectal cancer through June 2015. Detailed information on multivitamin use, vitamin C supplements, and vitamin E supplements was self-reported on questionnaires at baseline, in 1997, and every 2 years thereafter. Pre- and postdiagnosis data were available for 3176 and 2006 colorectal cancer survivors, respectively, among whom 2116 (648 from colorectal cancer) and 1256 (242 from colorectal cancer) died. Multivariable-adjusted Cox proportional hazards regression models examined associations. All statistical tests were 2-sided.

Results

Among colorectal cancer survivors, 49.7% and 58.5% reported multivitamin use before and after diagnosis, respectively (vitamin C use before and after diagnosis: 27.8% and 28.1%; vitamin E use before and after diagnosis: 27.5% and 29.4%, respectively). There were no statistically significant associations of pre- or postdiagnosis multivitamin use with all-cause, colorectal cancer-specific, or noncolorectal cancer mortality. Vitamin C was also not associated with any mortality outcomes. However, prediagnosis vitamin E use was associated with a non-statistically significant increased risk of all-cause mortality (multivariable adjusted hazard ratio = 1.08, 95% confidence intervals = 0.96 to 1.23) and all other noncolorectal cancer mortality (multivariable adjusted hazard ratio = 1.13, 95% confidence intervals = 0.97 to 1.31).

Conclusions

These results suggest that multivitamin use before or after diagnosis is not associated with mortality in colorectal cancer survivors. However, vitamin E use may be associated with increased risk of mortality and merits further investigation.

Vitamin and Mineral Supplements for the Primary Prevention of Cardiovascular Disease and Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Cardiovascular disease and cancer are the 2 leading causes of death in the US, and vitamin and mineral supplementation has been proposed to help prevent these conditions.

OBJECTIVE

To review the benefits and harms of vitamin and mineral supplementation in healthy adults to prevent cardiovascular disease and cancer to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed (publisher-supplied records only), Cochrane Library, and Embase (January 2013 to February 1, 2022); prior reviews.

STUDY SELECTION

English-language randomized clinical trials (RCTs) of vitamin or mineral use among adults without cardiovascular disease or cancer and with no known vitamin or mineral deficiencies; observational cohort studies examining serious harms.

DATA EXTRACTION AND SYNTHESIS

Single extraction, verified by a second reviewer. Quantitative pooling methods appropriate for rare events were used for most analyses.

MAIN OUTCOMES AND MEASURES

Mortality, cardiovascular disease events, cancer incidence, serious harms.

RESULTS

Eighty-four studies (N=739 803) were included. In pooled analyses, multivitamin use was significantly associated with a lower incidence of any cancer (odds ratio [OR], 0.93 [95% CI, 0.87-0.99]; 4 RCTs [n=48 859]; absolute risk difference [ARD] range among adequately powered trials, -0.2% to -1.2%) and lung cancer (OR, 0.75 [95% CI, 0.58-0.95]; 2 RCTs [n=36 052]; ARD, 0.2%). However, the evidence for multivitamins had important limitations. Beta carotene (with or without vitamin A) was significantly associated with an increased risk of lung cancer (OR, 1.20 [95% CI, 1.01-1.42]; 4 RCTs [n=94 830]; ARD range, -0.1% to 0.6%) and cardiovascular mortality (OR, 1.10 [95% CI, 1.02-1.19]; 5 RCTs [n=94 506] ARD range, -0.8% to 0.8%). Vitamin D use was not significantly associated with all-cause mortality (OR, 0.96 [95% CI, 0.91-1.02]; 27 RCTs [n=117 082]), cardiovascular disease (eg, composite cardiovascular disease event outcome: OR, 1.00 [95% CI, 0.95-1.05]; 7 RCTs [n=74 925]), or cancer outcomes (eg, any cancer incidence: OR, 0.98 [95% CI, 0.92-1.03]; 19 RCTs [n=86 899]). Vitamin E was not significantly associated with all-cause mortality (OR, 1.02 [95% CI, 0.97-1.07]; 9 RCTs [n=107 772]), cardiovascular disease events (OR, 0.96 [95% CI, 0.90-1.04]; 4 RCTs [n=62 136]), or cancer incidence (OR, 1.02 [95% CI, 0.98-1.08]; 5 RCTs [n=76 777]). Evidence for benefit of other supplements was equivocal, minimal, or absent. Limited evidence suggested some supplements may be associated with higher risk of serious harms (hip fracture [vitamin A], hemorrhagic stroke [vitamin E], and kidney stones [vitamin C, calcium]).

CONCLUSIONS AND RELEVANCE

Vitamin and mineral supplementation was associated with little or no benefit in preventing cancer, cardiovascular disease, and death, with the exception of a small benefit for cancer incidence with multivitamin use. Beta carotene was associated with an increased risk of lung cancer and other harmful outcomes in persons at high risk of lung cancer.

Vitamin, Mineral, and Multivitamin Supplementation to Prevent Cardiovascular Disease and Cancer: US Preventive Services Task Force Recommendation Statement

Importance

According to National Health and Nutrition Examination Survey data, 52% of surveyed US adults reported using at least 1 dietary supplement in the prior 30 days and 31% reported using a multivitamin-mineral supplement. The most commonly cited reason for using supplements is for overall health and wellness and to fill nutrient gaps in the diet. Cardiovascular disease and cancer are the 2 leading causes of death and combined account for approximately half of all deaths in the US annually. Inflammation and oxidative stress have been shown to have a role in both cardiovascular disease and cancer, and dietary supplements may have anti-inflammatory and antioxidative effects.

Objective

To update its 2014 recommendation, the US Preventive Services Task Force (USPSTF) commissioned a review of the evidence on the efficacy of supplementation with single nutrients, functionally related nutrient pairs, or multivitamins for reducing the risk of cardiovascular disease, cancer, and mortality in the general adult population, as well as the harms of supplementation.

Population

Community-dwelling, nonpregnant adults.

Evidence Assessment

The USPSTF concludes with moderate certainty that the harms of beta carotene supplementation outweigh the benefits for the prevention of cardiovascular disease or cancer. The USPSTF also concludes with moderate certainty that there is no net benefit of supplementation with vitamin E for the prevention of cardiovascular disease or cancer. The USPSTF concludes that the evidence is insufficient to determine the balance of benefits and harms of supplementation with multivitamins for the prevention of cardiovascular disease or cancer. Evidence is lacking and the balance of benefits and harms cannot be determined. The USPSTF concludes that the evidence is insufficient to determine the balance of benefits and harms of supplementation with single or paired nutrients (other than beta carotene and vitamin E) for the prevention of cardiovascular disease or cancer. Evidence is lacking and the balance of benefits and harms cannot be determined.

Recommendation

The USPSTF recommends against the use of beta carotene or vitamin E supplements for the prevention of cardiovascular disease or cancer. (D recommendation) The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of the use of multivitamin supplements for the prevention of cardiovascular disease or cancer. (I statement) The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of the use of single- or paired-nutrient supplements (other than beta carotene and vitamin E) for the prevention of cardiovascular disease or cancer. (I statement).

Alterations in Bacterial Metabolism Contribute to the Lifespan Extension Exerted by Guarana in Caenorhabditis elegans

Guarana (Paullinia cupana) is a widely consumed nutraceutical with various health benefits supported by scientific evidence. However, its indirect health impacts through the gut microbiota have not been studied. Caenorhabditis elegans is a useful model to study both the direct and indirect effects of nutraceuticals, as the intimate association of the worm with the metabolites produced by Escherichia coli is a prototypic simplified model of our gut microbiota. We prepared an ethanoic extract of guarana seeds and assessed its antioxidant capacity in vitro, with a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, and in vivo, utilizing C. elegans. Additionally, we studied the impact of this extract on C. elegans lifespan, utilizing both viable and non-viable E. coli, and assessed the impact of guarana on E. coli folate production. The extract showed high antioxidant capacity, and it extended worm lifespan. However, the antioxidant and life-extending effects did not correlate in terms of the extract concentration. The extract-induced life extension was also less significant when utilizing dead E. coli, which may indicate that the effects of guarana on the worms work partly through modifications on E. coli metabolism. Following this observation, guarana was found to decrease E. coli folate production, revealing one possible route for its beneficial effects.

Dietary Supplement Use during Pregnancy: Perceptions versus Reality

This study aimed to examine the prevalence, associated factors and perceptions of dietary supplement use among pregnant Chinese women. A cross-sectional study was conducted to collect data about prevalence, purchase channels, perceptions, and related factors of dietary supplement use from 572 pregnant women, through a face-to-face survey, using a self-designed questionnaire. Of the respondents, 94.8% used at least one dietary supplement, whereas 29.8% used more than four supplements in the previous month. The majority of the pregnant women were highly educated (81.2% had a bachelor’s degree or above) and had the perception that dietary supplements could prevent and improve (89.2%), or treat, nutrition-related diseases (78.7%). Multivariate analysis showed that pregnant women who had used multiple (more than four) supplements were more likely to have a larger gestational age, received fertility treatment, more prenatal visits, and hypothyroidism during pregnancy. Furthermore, pregnant women not only purchased dietary supplements through hospitals (72.6%) and pharmacies (45.1%), but overseas Daigou or online purchases (31.8%) were also a major channel of purchase. A high prevalence of dietary supplement use during pregnancy was observed, with extensive and repeated consumption of nutrients. Pregnant women’s craze for dietary supplements calls for more comprehensive guidelines in China.

Chinese consensus on prevention of colorectal neoplasia (2021, Shanghai)

Most patients with colorectal cancer (CRC) were diagnosed in advanced stage and the prognosis is poor. Therefore, early detection and prevention of CRC are very important. As with other cancers, there is also the tertiary prevention for CRC. The primary prevention is etiological prevention, which is mainly the treatment of adenoma or inflammation for preventing the development into cancer. The secondary prevention is the early diagnosis and early treatment for avoiding progressing to advanced cancer. The tertiary prevention belongs to the broad category of prevention, mainly for advanced CRC, through surgical treatment and postoperative adjuvant chemotherapy, radiotherapy, targeted therapy, immunotherapy for preventing tumor recurrence or metastasis. This consensus is based on the recent domestic and international consensus guidelines and the latest progress of international researches in the past five years. This consensus opinion seminar was hosted by the Chinese Society of Gastroenterology and Cancer Collaboration Group of Chinese Society of Gastroenterology, and was organized by the Division of Gastroenterology and Hepatology & Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University. The consensus opinion contains 60 statement clauses, the standard and basis of the evidence-based medicine grade and voting grade of the statement strictly complied with the relevant international regulations and practice.

The Ability of Nutrition to Mitigate Epigenetic Drift: A Novel Look at Regulating Gene Expression

Epigenetic drift causes modification in gene expression during aging and a myriad of physiological changes that are mostly undesirable, remove youthful phenotype and are related to biological decay and disease onset. The epigenome is considered a stable regulator of genetic expression. Moreover, evidence is now accumulating that commonly available compounds found in foods can influence the epigenome to embrace a more youthful and therefore, more disease resistant state. Here we explore the correlation between nutriment and the epigenetic regulation through various types of alimentation. The aim is not to discuss specific chemicals involved in disease onset. Instead, we offer a brief glance at pathogens and offer a practical pathway into epigenetic regulation, hypothesizing that epigenetic drift might be attenuated by several foods able to drive a more youthful and disease resistant phenotype.

Managing folate deficiency implies filling the gap between laboratory and clinical assessment

The characterization of folate status in subjects at risk of deficiency and with altered vitamin homeostasis is crucial to endorse preventive intervention health policies, especially in developed countries. Several physiological changes (i.e. pregnancy), clinical situations and diseases have been associated to increased requirement, impaired intake and absorption of folate. However clinical practice guidelines (CPG) endorse folic acid supplementation generally discarding the use of its determination in serum to assess the risk of deficiency and/or its concentration at baseline. Poor confidence on the diagnostic accuracy of serum folate assays still persists in the current CPGs although recent standardization efforts have greatly improved inter-method variability and precision. In this review we critically appraise the methodological issues concerning laboratory folate determination and the evidence on the potential adverse effects of folic acid exposure. The final aim is to build a sound background to promote serum folate-based cost-effective health care policies by optimizing folic acid supplementation in subjects at risk of deficiency and with altered folate homeostasis. Our first result was to adjust in relation to current serum folate assays the thresholds reported by CPGs as index of folate status, defined on the association with metabolic and hematologic indicators. We identify a statistically significant difference between the estimated thresholds and accordingly show that the assessment of folate status actually changes in relation to the assay employed. The use of the method-dependent thresholds here reported may pragmatically endorse the stewardship of folic acid supplementation in clinical practice and increase the cost-effectiveness of health care policies.

Future incidence and mortality of colorectal carcinoma in the United States: an updated overview of risk factors and preventative measures

According to the Global Cancer Observatory (GLOBOCAN) 2020, colorectal carcinoma (CRC) was the second leading cause of cancer death globally. Current literature utilizes reported databases such as Surveillance, Epidemiology, and End Results (SEER) to better understand the epidemiology of CRC. The global cancer observatory’s “Cancer Tomorrow” data visualization tools was used to predict the future incidence and mortality of colorectal cancers until 2030 as a guided tool to look over ways to reduce incidence by controlling risk factors of CRC. The total number of CRC is expected to rise by 2030, with a percent change of 17.3%. The expected percent change in colon cancer is more than rectal cancer (19.8% vs. 11.6%). The estimated number of deaths secondary to CRC is expected to increase in 2030, an estimated percent change of 22.2%. The incidence and mortality rate was higher in men vs. women; however, the gap seems to be closing on trend analysis. Major risk factors for CRC include familial syndromes, family history, race, gender, obesity, diet, alcohol, and smoking. Risk can be reduced by exercise and dietary changes, fiber intake, vitamin D, calcium, and minerals. Individualized screening based on age, gender, and additional risk factors could be an option that needs further comparative data to propose a definitive benefit over established screening guidelines.

Proliferation, apoptosis and their regulatory protein expression in colorectal adenomas and serrated lesions

BACKGROUND

Adenomas and serrated lesions represent heterogeneous sets of early precursors in the colorectum with varying malignant potential. They are often distinguished by their histopathologic differences, but little is known about potential differences in regulation of epithelial proliferation and apoptosis.

METHODS

We conducted a protein expression analysis using tissue microarrays of 625 colorectal adenomas and 142 serrated lesions to determine potential differences in regulation of epithelial proliferation and apoptosis. We quantitated proliferation with Ki-67; apoptosis with activated caspase-3 (CASP3); up- and down-regulators of proliferation with cyclin D1, p16INK2, and p21Cip1; and apoptosis regulators with BAX, BCL2, and survivin. Linear mixed effects models and circos diagrams were used to determine relationships among expression and lesion characteristics.

RESULTS

Adenomas had a significantly higher CASP-3 labeling index (LI) than serrated lesions, resulting in a lower net growth ratio (Ki-67 LI/activated CASP-3 LI, p-value<0.0001). Cyclin D1 LI, p16 LI and p21 LI were lower in adenomas compared to serrated lesions, while expression of both BCL2 and BAX were higher (p <0.001). Among adenomas, cyclin D1 LI and p16 LI levels increased with greater villous component, and the highest BAX expression was detected in adenomas larger than 2 cm (both p<0.0001). Right-sided adenomas had higher CASP3 LI than left colorectal adenomas (p = 0.008). Significant differences in cyclin D1 LI, p21 LI and survivin LI were also observed across histopathologic subtypes of serrated lesions.

CONCLUSIONS

Our findings demonstrate different patterns of regulatory protein expression in adenomas than serrated lesions, especially involving apoptosis. ClinicalTrials.gov Identifier: NCT00272324.

Fatty acid metabolism and colon cancer protection by dietary methyl donor restriction

INTRODUCTION

A methyl donor depleted (MDD) diet dramatically suppresses intestinal tumor development in Apc-mutant mice, but the mechanism of this prevention is not entirely clear.

OBJECTIVES

We sought to gain insight into the mechanisms of cancer suppression by the MDD diet and to identify biomarkers of cancer risk reduction.

METHODS

A plasma metabolomic analysis was performed on Apc^Δ14/+ mice maintained on either a methyl donor sufficient (MDS) diet or the protective MDD diet. A group of MDS animals was also pair-fed with the MDD mice to normalize caloric intake, and another group was shifted from an MDD to MDS diet to determine the durability of the metabolic changes.

RESULTS

In addition to the anticipated changes in folate one-carbon metabolites, plasma metabolites related to fatty acid metabolism were generally decreased by the MDD diet, including carnitine, acylcarnitines, and fatty acids. Some fatty acid selectivity was observed; the levels of cancer-promoting arachidonic acid and 2-hydroxyglutarate were decreased by the MDD diet, whereas eicosapentaenoic acid (EPA) levels were increased. Machine-learning elastic net analysis revealed a positive association between the fatty acid-related compounds azelate and 7-hydroxycholesterol and tumor development, and a negative correlation with succinate and β-sitosterol.

CONCLUSION

Methyl donor restriction causes dramatic changes in systemic fatty acid metabolism. Regulating fatty acid metabolism through methyl donor restriction favorably effects fatty acid profiles to achieve cancer protection.

Supplemental Vitamins and Minerals for Cardiovascular Disease Prevention and Treatment: JACC Focus Seminar

This is an update of the previous 2018 systematic review and meta-analysis of vitamin and mineral supplementation on cardiovascular disease outcomes and all-cause mortality. New randomized controlled trials and meta-analyses were identified by searching the Cochrane library, Medline, and Embase, and data were analyzed using random effects models and classified by the Grading of Recommendations Assessment Development and Evaluation approach. This updated review shows similar findings to the previous report for preventive benefits from both folic acid and B vitamins for stroke and has been graded with moderate quality. No effect was seen for the commonly used multivitamins, vitamin D, calcium, and vitamin C, and an increased risk was seen with niacin (with statin) for all-cause mortality. Conclusive evidence for the benefit of supplements across different dietary backgrounds, when the nutrient is sufficient, has not been demonstrated.

AGA Clinical Practice Update on Chemoprevention for Colorectal Neoplasia: Expert Review

DESCRIPTION

The purpose of this expert review is to describe the role of medications for the chemoprevention of colorectal neoplasia. Neoplasia is defined as precancerous lesions (e.g., adenoma and sessile serrated lesion) or cancer. The scope of this review excludes dietary factors and high-risk individuals with hereditary syndromes or inflammatory bowel disease.

METHODS

The best practice advice statements are based on a review of the literature to provide practical advice. A formal systematic review and rating of the quality of evidence or strength of recommendation were not performed. BEST PRACTICE ADVICE 1: In individuals at average risk for CRC who are (1) younger than 70 years with a life expectancy of at least 10 years, (2) have a 10-year cardiovascular disease risk of at least 10%, and (3) not at high risk for bleeding, clinicians should use low-dose aspirin to reduce CRC incidence and mortality. BEST PRACTICE ADVICE 2: In individuals with a history of CRC, clinicians should consider using aspirin to prevent recurrent colorectal neoplasia. BEST PRACTICE ADVICE 3: In individuals at average risk for CRC, clinicians should not use non-aspirin NSAIDs to prevent colorectal neoplasia because of a substantial risk of cardiovascular and gastrointestinal adverse events. BEST PRACTICE ADVICE 4: In individuals with type 2 diabetes, clinicians may consider using metformin to prevent colorectal neoplasia. BEST PRACTICE ADVICE 5: In individuals with CRC and type 2 diabetes, clinicians may consider using metformin to reduce mortality. BEST PRACTICE ADVICE 6: Clinicians should not use calcium or vitamin D (alone or together) to prevent colorectal neoplasia. BEST PRACTICE ADVICE 7: Clinicians should not use folic acid to prevent colorectal neoplasia. BEST PRACTICE ADVICE 8: In individuals at average risk for CRC, clinicians should not use statins to prevent colorectal neoplasia. BEST PRACTICE ADVICE 9: In individuals with a history of CRC, clinicians should not use statins to reduce mortality.