Vitamin E and C supplementation and risk of cancer in men: posttrial follow-up in the Physicians' Health Study II randomized trial

Association between dietary vitamin C intake/blood level and risk of digestive system cancer: a systematic review and meta-analysis of prospective studies

Experimental studies have shown that vitamin C has anti-cancer effects, but previous meta-analyses have indicated that the role of vitamin C in digestive system cancers (DSCs) is controversial. In this study, a systematic review and meta-analysis of the relationship between dietary intake/plasma concentration of vitamin C and the risk of DSC was conducted, evaluating 32 prospective studies with 1 664 498 participants. Dose-response and subgroup analyses were also performed. Systematic literature searches were performed in PubMed, EMBASE and Web of Science databases until 9th September 2023. Vitamin C intake significantly reduced DSCs risk (RR = 0.88, 95% confidence interval (CI) 0.83 to 0.93). The subgroup analyses showed the risks of oral, pharyngeal, and esophageal (OPE) cancers (0.81, 0.72 to 0.93), gastric cancer (0.81, 0.68 to 0.95), and colorectal cancer (0.89, 0.82 to 0.98) were negatively correlated with vitamin C intake, and the effect of vitamin C was different between colon cancer (0.87, 0.77 to 0.97) and rectal cancer (1.00, 0.84 to 1.19). However, plasma vitamin C concentration was only inversely associated with gastric cancer risk (0.74, 0.59 to 0.92). Dose-response analysis revealed that 250 and 65 mg day-1 vitamin C intakes had the strongest protective effect against OPE and gastric cancers respectively. These estimates suggest that vitamin C intake could significantly reduce gastrointestinal cancer incidence, including OPE, gastric, and colon cancers. Plasma vitamin C has a significant reduction effect on the incidence of gastric cancer only, but additional large-scale clinical studies are needed to determine its impact on the incidence of DSCs.

Scientific opinion on the tolerable upper intake level for vitamin E

Following a request from the European Commission, 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 vitamin E. As α-tocopherol is recognised as the only essential form of vitamin E, the Panel restricted its evaluation to α-tocopherol. Systematic reviews of the literature were conducted to assess evidence on priority adverse health effects of excess intake of vitamin E, namely risk of impaired coagulation and bleeding, cardiovascular disease and prostate cancer. The effect on blood clotting and associated increased risk of bleeding is considered as the critical effect to establish an UL for vitamin E. No new evidence has been published that could improve the characterisation of a dose-response. The ULs for vitamin E from all dietary sources, which were previously established by the Scientific Committee on Food, are retained for all population groups, i.e. 300 mg/day for adults, including pregnant and lactating women, 100 mg/day for children aged 1-3 years, 120 mg/day for 4-6 years, 160 mg/day for 7-10 years, 220 mg/day for 11-14 years and 260 mg/day for 15-17 years. A UL of 50 mg/day is established for infants aged 4-6 months and a UL of 60 mg/day for infants aged 7-11 months. ULs apply to all stereoisomeric forms of α-tocopherol. ULs do not apply to individuals receiving anticoagulant or antiplatelet medications (e.g. aspirin), to patients on secondary prevention for CVD or to patients with vitamin K malabsorption syndromes. It is unlikely that the ULs for vitamin E are exceeded in European populations, except for regular users of food supplements containing high doses of vitamin E.

The role of vitamin C in the prevention of pancreatic cancer: a systematic-review

Introduction and aim

The aim of this systematic review was to assess the role of vitamin C in the prevention of pancreatic cancer (PC).

Methods

A comprehensive literature search was performed in PubMed, Embase and Web of Science up to August 2023, to identify randomized controlled trials (RCT), cohort studies and mendelian randomization studies based on prospective databases assessing the role of vitamin C in PC prevention.

Results

A total of twelve studies including European and North-American participants were included: two RCT, three mendelian randomization (MR) studies and seven cohort studies. Both RCT showed high quality in Cochrane risk of bias tool. Only one cohort study had <7 points in Newcastle Ottawa Scale. Both RCT found no association between the intake of 500 mg/day of vitamin C and the incidence of PC. Only one prospective cohort study found an association between vitamin C serum levels and a lower incidence of PC. The remaining cohort studies and MR studies found no association between dietary/supplements intake of vitamin C or circulating vitamin C levels and the incidence of PC.

Conclusion

There is no supporting evidence that vitamin C prevents PC development. Future prospective quality studies including high-risk populations are needed.

Vitamin E - a scoping review for Nordic Nutrition Recommendations 2023

Current evidence suggests that dietary vitamin E (as α-tocopherol) intake has a beneficial role in preventing certain chronic diseases. In contrast, there is no clear evidence for the benefit of α-tocopherol supplements in a generally healthy population. Deficiency symptoms are rare and mainly occur due to genetic or other factors affecting α-tocopherol absorption and/or metabolism, rather than a low α-tocopherol intake. No qualified systematic review was identified by the NNR2023 project for updating the dietary reference values (DRV).

Systematic comparison of Mendelian randomisation studies and randomised controlled trials using electronic databases

OBJECTIVE

To scope the potential for (semi)-automated triangulation of Mendelian randomisation (MR) and randomised controlled trials (RCTs) evidence since the two methods have distinct assumptions that make comparisons between their results invaluable.

METHODS

We mined ClinicalTrials.Gov, PubMed and EpigraphDB databases and carried out a series of 26 manual literature comparisons among 54 MR and 77 RCT publications.

RESULTS

We found that only 13% of completed RCTs identified in ClinicalTrials.Gov submitted their results to the database. Similarly low coverage was revealed for Semantic Medline (SemMedDB) semantic triples derived from MR and RCT publications -36% and 12%, respectively. Among intervention types that can be mimicked by MR, only trials of pharmaceutical interventions could be automatically matched to MR results due to insufficient annotation with Medical Subject Headings ontology. A manual survey of the literature highlighted the potential for triangulation across a number of exposure/outcome pairs if these challenges can be addressed.

CONCLUSIONS

We conclude that careful triangulation of MR with RCT evidence should involve consideration of similarity of phenotypes across study designs, intervention intensity and duration, study population demography and health status, comparator group, intervention goal and quality of evidence.

What Is the Role of Nutraceutical Products in Cancer Patients? A Systematic Review of Randomized Clinical Trials

Chemotherapy represents the main pharmacological cancer treatment. Recently, positive effects emerged with the combination of anticancer therapy and nutraceutical products. The aim of this systematic review is to collect and synthesize the available scientific evidence regarding the potential effects of nutraceuticals on cancer cells. A systematic literature search of randomized clinical trials of nutraceutical products in patients with cancer published up to 15 December 2022 was conducted using three data sources: Embase, PubMed, and Web of Science. The effect of high-dose isoflavone supplements on prostate cancer resulted in stabilization or reduction of PSA concentrations in 50% of isoflavone group patients six months after treatment. High doses of vitamin D supplementation plus chemotherapy in patients with advanced or metastatic colorectal cancer showed a median PFS of 13.0 months (95% CI, 10.1-14.7 months) for 49 patients. The effect of vitamin D supplementation on markers of inflammatory level and antioxidant capacity in women with breast cancer showed a significant increase in serum vitamin D concentration (28 ± 2.6 to 39 ± 3.5; p = 0.004) after 8 weeks of treatment. In conclusion, nutraceutical supplements represent a potentially growing sector and can be utilized in medical treatment or nutrition to provide integrated medical care.

Vitamin E Intake and Risk of Prostate Cancer: A Meta-Analysis

Vitamin E is a group of antioxidative tocopherols and tocotrienols that play a potential role in chemoprevention. Studies investigating the association between vitamin E and prostate cancer risk have been conflicting. We identified observational and interventional studies examining the association between vitamin E intake and prostate cancer risk from PubMed, EMBASE and the Cochrane Library. A random-effects model was used to perform a meta-analysis and estimate relative risks (RRs) and the corresponding 95% confidence intervals (CIs) of prostate cancer risk according to vitamin E intake. Subgroup analyses were conducted by study design, sample size, study population characteristics, geographical region, and dose of vitamin E intake. The association between dietary (RR = 0.97; 95% CI = 0.92-1.02) and supplemental (RR = 0.99; 95% CI = 0.94-1.04) vitamin E intake on prostate cancer risk was non-significant. In subgroup analyses, supplemental vitamin E was significantly associated with reduced prostate cancer risk in studies in Europe (RR = 0.81, 95% CI = 0.69-0.97). Overall, this meta-analysis demonstrates little evidence for a beneficial effect of vitamin E intake on prostate cancer risk but suggests that there may be some conditions in which supplements could confer a protective effect on prostate cancer risk.

Antioxidant Supplementation in Oxidative Stress-Related Diseases: What Have We Learned from Studies on Alpha-Tocopherol?

Oxidative stress has been proposed as a key contributor to lifestyle- and age-related diseases. Because free radicals play an important role in various processes such as immune responses and cellular signaling, the body possesses an arsenal of different enzymatic and non-enzymatic antioxidant defense mechanisms. Oxidative stress is, among others, the result of an imbalance between the production of various reactive oxygen species (ROS) and antioxidant defense mechanisms including vitamin E (α-tocopherol) as a non-enzymatic antioxidant. Dietary vitamins, such as vitamin C and E, can also be taken in as supplements. It has been postulated that increasing antioxidant levels through supplementation may delay and/or ameliorate outcomes of lifestyle- and age-related diseases that have been linked to oxidative stress. Although supported by many animal experiments and observational studies, randomized clinical trials in humans have failed to demonstrate any clinical benefit from antioxidant supplementation. Nevertheless, possible explanations for this discrepancy remain underreported. This review aims to provide an overview of recent developments and novel research techniques used to clarify the existing controversy on the benefits of antioxidant supplementation in health and disease, focusing on α-tocopherol as antioxidant. Based on the currently available literature, we propose that examining the difference between antioxidant activity and capacity, by considering the catabolism of antioxidants, will provide crucial knowledge on the preventative and therapeutical use of antioxidant supplementation in oxidative stress-related diseases.

Evaluating Risk: Benefit Ratio of Fat-Soluble Vitamin Supplementation to SARS-CoV-2-Infected Autoimmune and Cancer Patients: Do Vitamin-Drug Interactions Exist?

COVID-19 is a recent pandemic that mandated the scientific society to provide effective evidence-based therapeutic approaches for the prevention and treatment for such a global threat, especially to those patients who hold a higher risk of infection and complications, such as patients with autoimmune diseases and cancer. Recent research has examined the role of various fat-soluble vitamins (vitamins A, D, E, and K) in reducing the severity of COVID-19 infection. Studies showed that deficiency in fat-soluble vitamins abrogates the immune system, thus rendering individuals more susceptible to COVID-19 infection. Moreover, another line of evidence showed that supplementation of fat-soluble vitamins during the course of infection enhances the viral clearance episode by promoting an adequate immune response. However, more thorough research is needed to define the adequate use of vitamin supplements in cancer and autoimmune patients infected with COVID-19. Moreover, it is crucial to highlight the vitamin-drug interactions of the COVID-19 therapeutic modalities and fat-soluble vitamins. With an emphasis on cancer and autoimmune patients, the current review aims to clarify the role of fat-soluble vitamins in SARS-CoV-2 infection and to estimate the risk-to-benefit ratio of a fat-soluble supplement administered to patients taking FDA-approved COVID-19 medications such as antivirals, anti-inflammatory, receptor blockers, and monoclonal antibodies.

The Outcomes of Nutritional Support Techniques in Patients with Gastrointestinal Cancers

Gastrointestinal cancers represent a major cause of morbidity and mortality worldwide. A significant issue regarding the therapeutic management of these patients consists of metabolic disturbances and malnutrition. Nutritional deficiencies have a negative impact on both the death rates of these patients and the results of surgical or oncological treatments. Thus, current guidelines recommend the inclusion of a nutritional profile in the therapeutic management of patients with gastrointestinal cancers. The development of digestive endoscopy techniques has led to the possibility of ensuring the enteral nutrition of cancer patients without oral feeding through minimally invasive techniques and the avoidance of surgeries, which involve more risks. The enteral nutrition modalities consist of endoscopy-guided nasoenteric tube (ENET), percutaneous endoscopic gastrostomy (PEG), percutaneous endoscopic gastrostomy with jejunal tube extension (PEG-J), direct percutaneous endoscopic jejunostomy (DPEJ) or endoscopic ultrasound (EUS)-guided gastroenterostomy.

Vitamin C Intake and Ischemic Stroke

Vitamin C is an essential micronutrient with important antioxidant properties. Ischemic stroke is a major public health problem worldwide. Extensive evidence demonstrates that vitamin C has protective effects against cardiovascular disease, and there is a close relationship between vitamin C intake and ischemic stroke risk. Based on the evidence, we conducted this umbrella review to clarify the relationship between vitamin C intake and ischemic stroke risk from four perspectives: cellular mechanisms, animal experiments, clinical trials, and cohort studies.

Ascorbate as a Bioactive Compound in Cancer Therapy: The Old Classic Strikes Back

Cancer is a disease of high mortality, and its prevalence has increased steadily in the last few years. However, during the last decade, the development of modern chemotherapy schemes, new radiotherapy techniques, targeted therapies and immunotherapy has brought new hope in the treatment of these diseases. Unfortunately, cancer therapies are also associated with frequent and, sometimes, severe adverse events. Ascorbate (ascorbic acid or vitamin C) is a potent water-soluble antioxidant that is produced in most mammals but is not synthesised endogenously in humans, which lack enzymes for its synthesis. Ascorbate has antioxidant effects that correspond closely to the dose administered. Interestingly, this natural antioxidant induces oxidative stress when given intravenously at a high dose, a paradoxical effect due to its interactions with iron. Importantly, this deleterious property of ascorbate can result in increased cell death. Although, historically, ascorbate has been reported to exhibit anti-tumour properties, this effect has been questioned due to the lack of available mechanistic detail. Recently, new evidence has emerged implicating ferroptosis in several types of oxidative stress-mediated cell death, such as those associated with ischemia–reperfusion. This effect could be positively modulated by the interaction of iron and high ascorbate dosing, particularly in cell systems having a high mitotic index. In addition, it has been reported that ascorbate may behave as an adjuvant of favourable anti-tumour effects in cancer therapies such as radiotherapy, radio-chemotherapy, chemotherapy, immunotherapy, or even in monotherapy, as it facilitates tumour cell death through the generation of reactive oxygen species and ferroptosis. In this review, we provide evidence supporting the view that ascorbate should be revisited to develop novel, safe strategies in the treatment of cancer to achieve their application in human medicine.

A Comprehensive Overview of the Complex Role of Oxidative Stress in Aging, The Contributing Environmental Stressors and Emerging Antioxidant Therapeutic Interventions

Introduction

Aging is a normal, inevitable, irreversible, and progressive process which is driven by internal and external factors. Oxidative stress, that is the imbalance between prooxidant and antioxidant molecules favoring the first, plays a key role in the pathophysiology of aging and comprises one of the molecular mechanisms underlying age-related diseases. However, the oxidative stress theory of aging has not been successfully proven in all animal models studying lifespan, meaning that altering oxidative stress/antioxidant defense systems did not always lead to a prolonged lifespan, as expected. On the other hand, animal models of age-related pathological phenotypes showed a well-correlated relationship with the levels of prooxidant molecules. Therefore, it seems that oxidative stress plays a more complicated role than the one once believed and this role might be affected by the environment of each organism. Environmental factors such as UV radiation, air pollution, and an unbalanced diet, have also been implicated in the pathophysiology of aging and seem to initiate this process more rapidly and even at younger ages.

Aim

The purpose of this review is to elucidate the role of oxidative stress in the physiology of aging and the effect of certain environmental factors in initiating and sustaining this process. Understanding the pathophysiology of aging will contribute to the development of strategies to postpone this phenomenon. In addition, recent studies investigating ways to alter the antioxidant defense mechanisms in order to prevent aging will be presented.

Conclusions

Careful exposure to harmful environmental factors and the use of antioxidant supplements could potentially affect the biological processes driving aging and slow down the development of age-related diseases. Maybe a prolonged lifespan could not be achieved by this strategy alone, but a longer healthspan could also be a favorable target.

Association between circulating vitamin E and ten common cancers: evidence from large-scale Mendelian randomization analysis and a longitudinal cohort study

BACKGROUND

The association between vitamin E and cancer risk has been widely investigated by observational studies, but the findings remain inconclusive. Here, we aimed to evaluate the causal effect of circulating vitamin E on the risk of ten common cancers, including bladder, breast, colorectal, esophagus, lung, oral and pharynx, ovarian, pancreatic, prostate, and kidney cancer.

METHODS

A Mendelian randomization (MR) analytic framework was applied to data from a cancer-specific genome-wide association study (GWAS) comprising a total of 297,699 cancer cases and 304,736 controls of European ancestry. Three genetic instrumental variables associated with circulating vitamin E were selected. Summary statistic-based methods of inverse variance weighting (IVW) and likelihood-based approach, as well as the individual genotyping-based method of genetic risk score (GRS) were used. Multivariable IVW analysis was further performed to control for potential confounding effects. Furthermore, the UK Biobank cohort was used as external validation, supporting 355,543 European participants (incident cases ranged from 437 for ovarian cancer to 4882 for prostate cancer) for GRS-based estimation of circulating vitamin E, accompanied by a one-sample MR analysis of dietary vitamin E intake underlying the time-to-event analytic framework.

RESULTS

Specific to cancer GWAS, we found that circulating vitamin E was significantly associated with increased bladder cancer risk (odds ratios [OR]_IVW = 6.23, P_IVW = 3.05×10^-3) but decreased breast cancer risk (OR_IVW = 0.68, P_IVW = 8.19×10^-3); however, the significance of breast cancer was dampened (P_{multivariable IVW} > 0.05) in the subsequent multivariable MR analysis. In the validation stage of the UK Biobank cohort, we did not replicate convincing causal effects of genetically predicted circulating vitamin E concentrations and dietary vitamin E intake on the risk of ten cancers.

CONCLUSIONS

This large-scale population study upon data from cancer-specific GWAS and a longitudinal biobank cohort indicates plausible non-causal associations between circulating vitamin E and ten common cancers in the European populations. Further studies regarding ancestral diversity are warranted to validate such causal associations.

Nutritional and Exercise Interventions in Cancer-Related Cachexia: An Extensive Narrative Review

One of the common traits found in cancer patients is malnutrition and cachexia, which affects between 25% to 60% of the patients, depending on the type of cancer, diagnosis, and treatment. Given the lack of current effective pharmacological solutions for low muscle mass and sarcopenia, holistic interventions are essential to patient care, as well as exercise and nutrition. Thus, the present narrative review aimed to analyze the nutritional, pharmacological, ergonutritional, and physical exercise strategies in cancer-related cachexia. The integration of multidisciplinary interventions could help to improve the final intervention in patients, improving their prognosis, quality of life, and life expectancy. To reach these aims, an extensive narrative review was conducted. The databases used were MedLine (PubMed), Cochrane (Wiley), Embase, PsychINFO, and CinAhl. Cancer-related cachexia is a complex multifactorial phenomenon in which systemic inflammation plays a key role in the development and maintenance of the symptomatology. Pharmacological interventions seem to produce a positive effect on inflammatory state and cachexia. Nutritional interventions are focused on a high-energy diet with high-density foods and the supplementation with antioxidants, while physical activity is focused on strength-based training. The implementation of multidisciplinary non-pharmacological interventions in cancer-related cachexia could be an important tool to improve traditional treatments and improve patients' quality of life.

Nutritional and surgical aspects in prostate disorders

Prostate disorders are commonplace in medicine, especially in older men, with prostatitis, benign prostatic hyperplasia, and prostate cancer being the most abundant pathologies. The complexity of this organ, however, turns treatment into a challenge. In this review, we aim to provide insight into the efficacy of alternative treatments, which are not normally used in conventional medicine, with a particular focus on nutrients. In order to understand why and how nutrition can be beneficial in diseases of the prostate, we give an overview of the known characteristics and features of this organ. Then, we provide a summary of the most prevalent prostate illnesses. Finally, we propose nutrition-based treatment in each of these prostate problems, based on in-depth research concerning its effects in this context, with an emphasis on surgery. Overall, we plead for an upgrade of this form of alternative treatment to a fully recognized mode of therapy for the prostate.

Causal associations between dietary antioxidant vitamin intake and lung cancer: A Mendelian randomization study

Background

Oxidative stress is currently considered to be closely related to the occurrence of respiratory tumors, especially lung cancer. Many observational studies have shown that increased antioxidant intake can reduce the risk of lung cancer, but the results are still controversial. Therefore, we performed a two-sample Mendelian randomized (MR) analysis to clarify the causal relationship between antioxidant vitamins and lung cancer.

Methods

To assess the causal effect of dietary antioxidant vitamin intake on lung cancer, we conducted a two-sample MR analysis and we extracted single-nucleotide polymorphisms (SNPs) that are associated with antioxidants from genome-wide association studies (GWASs) of the UK biobank. We gathered summary data for lung cancer from the International Lung Cancer Consortium (ILCCO), including 11,348 cases and 15,861 controls, and applied the inverse-variance weighted (IVW) method as the primary MR analysis, and performed a sensitivity analysis to verify the results.

Results

The results showed that higher dietary retinol intake was causally associated with lung cancer overall [odds ratio (OR) = 1.844, 95% CI, 1.359-2.502, p = 0.00009], squamous cell lung cancer (OR = 2.162, 95% CI, 1.117-4.183, p = 0.022), and lung adenocarcinoma (OR = 1.706, 95% CI, 1.084-2.685, p = 0.021). Additionally, carotene was positively correlated with lung adenocarcinoma (OR = 1.510, 95% CI, 1.002-2.276, p = 0.049). However, there was a non-significant relationship between the intake of other dietary antioxidants (vitamin C and vitamin E) and lung cancer.

Conclusion

Our research showed that dietary retinol intake has an adverse impact on lung cancer, and carotene might increase the risk of adenocarcinoma. This highlights the importance of revealing the underlying mechanisms of dietary antioxidant vitamins in lung cancer and delivers an important health message that dietary antioxidant vitamin intake may not be necessary for the prevention of lung cancer. It also provides a basis for future research.

The Role of Vitamin C in Cancer Prevention and Therapy: A Literature Review

Vitamin C is a water-soluble antioxidant associated with the prevention of the common cold and is also a cofactor of hydrolases that participate in the synthesis of collagen and catecholamines, and in the regulation of gene expression. In cancer, vitamin C is associated with prevention, progression, and treatment, due to its general properties or its role as a pro-oxidant at high concentration. This review explores the role of vitamin C in cancer clinical trials and the aspects to consider in future studies, such as plasmatic vitamin C and metabolite excretion recording, and metabolism and transport of vitamin C into cancer cells. The reviewed studies show that vitamin C intake from natural sources can prevent the development of pulmonary and breast cancer, and that vitamin C synergizes with gemcitabine and erlotinib in pancreatic cancer. In vitro assays reveal that vitamin C synergizes with DNA-methyl transferase inhibitors. However, vitamin C was not associated with cancer prevention in a Mendelian randomized study. In conclusion, the role of vitamin C in the prevention and treatment of cancer is still an ongoing area of research. It is necessary that new phase II and III clinical trials be performed to collect stronger evidence of the therapeutic role of vitamin C in cancer.

Pre-diagnostic circulating concentrations of fat-soluble vitamins and risk of glioma in three cohort studies

Few prospective studies have evaluated the relation between fat-soluble vitamins and glioma risk. Using three cohorts-UK Biobank (UKB), Nurses' Health Study (NHS), and Health Professionals Follow-Up Study (HPFS), we investigated associations of pre-diagnostic concentrations of fat-soluble vitamins D, A, and E with incident glioma. In 346,785 participants (444 cases) in UKB, associations with vitamin D (25-hydroxyvitamin D [25(OH)D]) were evaluated by Cox proportional hazards regression. In NHS (52 cases, 104 controls) and HPFS (32 cases, 64 controls), associations with 25(OH)D, vitamin A (retinol), and vitamin E (α- and γ-tocopherol) were assessed using conditional logistic regression. Our results suggested plasma concentrations of 25(OH)D and retinol were not associated with glioma risk. Comparing the highest to lowest tertile, the multivariable hazard ratio (MVHR) for 25(OH)D was 0.87 (95% confidence interval [CI] 0.68-1.11) in UKB and the multivariable risk ratio (MVRR) was 0.97 (95% CI 0.51-1.85) in NHS and HPFS. In NHS and HPFS, the MVRR for the same comparison for retinol was 1.16 (95% CI 0.56-2.38). Nonsignificant associations were observed for α-tocopherol (MVRRtertile3vs1 = 0.61, 95% CI 0.29-1.32) and γ-tocopherol (MVRR tertile3vs1 = 1.30, 95% CI 0.63-2.69) that became stronger in 4-year lagged analyses. Further investigation is warranted on a potential association between α- and γ-tocopherol and glioma risk.

ESPEN practical guideline: Clinical Nutrition in cancer

BACKGROUND

This practical guideline is based on the current scientific ESPEN guidelines on nutrition in cancer patients.

METHODS

ESPEN guidelines have been shortened and transformed into flow charts for easier use in clinical practice. The practical guideline is dedicated to all professionals including physicians, dieticians, nutritionists and nurses working with patients with cancer.

RESULTS

A total of 43 recommendations are presented with short commentaries for the nutritional and metabolic management of patients with neoplastic diseases. The disease-related recommendations are preceded by general recommendations on the diagnostics of nutritional status in cancer patients.

CONCLUSION

This practical guideline gives guidance to health care providers involved in the management of cancer patients to offer optimal nutritional care.

Genome-wide Expression Analysis Identifies the Association between SEC14L2 and Castration-resistant Prostate Cancer Survival

Background: Mechanism of castration-resistant prostate cancer (CRPC) is still unclear. Our objective is to investigate the association between genes expression and CRPC through the genome-wide approach and functional researches.

Methods: Differentially expressed genes (DEGs) between PCa and CRPC tissues were identified using expression profile obtained from Gene Expression Omnibus database (GEO). Survival analysis was performed using online database Gene Expression Profiling Interactive Analysis (GEPIA). Oncomine database was further used to explore the relationship between DEGs expression levels with clinical parameters. After in silico study, SEC14L2-knockdown CRPC cells and normal prostatic epithelial cells were used for in vitro study to verify its biological functions.

Results: A total of 3 consistently changed DEGs (SEC14L2, DMD, SEL1L) were identified correlating with CRPC after cross validation in three independent datasets. Low expression of SEC14L2 was associated with poorer disease-free survival and higher Gleason score than normal/high expression of SEC14L2. SEC14L2 knockdown promoted cell proliferation, migration, invasion as well as cell cycle progression in CRPC cells (all P<0.05) while no significant effects were observed in normal prostatic epithelial cells.

Conclusions: Low expression of SEC14L2 was significantly associated with CRPC, and correlated with PCa aggressiveness and poorer prognosis. SEC14L2 might be a potential biomarker or drug target for CRPC.

Vitamin C Transporters and Their Implications in Carcinogenesis

Vitamin C is implicated in various bodily functions due to its unique properties in redox homeostasis. Moreover, vitamin C also plays a great role in restoring the activity of 2-oxoglutarate and Fe²⁺ dependent dioxygenases (2-OGDD), which are involved in active DNA demethylation (TET proteins), the demethylation of histones, and hypoxia processes. Therefore, vitamin C may be engaged in the regulation of gene expression or in a hypoxic state. Hence, vitamin C has acquired great interest for its plausible effects on cancer treatment. Since its conceptualization, the role of vitamin C in cancer therapy has been a controversial and disputed issue. Vitamin C is transferred to the cells with sodium dependent transporters (SVCTs) and glucose transporters (GLUT). However, it is unknown whether the impaired function of these transporters may lead to carcinogenesis and tumor progression. Notably, previous studies have identified SVCTs’ polymorphisms or their altered expression in some types of cancer. This review discusses the potential effects of vitamin C and the impaired SVCT function in cancers. The variations in vitamin C transporter genes may regulate the active transport of vitamin C, and therefore have an impact on cancer risk, but further studies are needed to thoroughly elucidate their involvement in cancer biology.

Associations between Lifestyle Factors and Vitamin E Metabolites in the General Population

The antioxidant vitamin E (α-tocopherol, α-TOH) protects lipids from oxidation by reactive oxygen species. We hypothesized that lifestyle factors associate with vitamin E metabolism marked by urinary α-tocopheronolactone hydroquinone (α-TLHQ) and α-carboxymethyl-hydroxychroman (α-CEHC levels), as potential reflection of lipid oxidation. We conducted a cross-sectional study in the Netherlands Epidemiology of Obesity Study. Serum α-TOH, and urinary α-TLHQ and α-CEHC were quantified by liquid chromatography coupled with tandem mass spectrometry. Information on the lifestyle factors (sleep, physical activity (PA), smoking and alcohol) were collected through questionnaires. Multivariable linear regression analyses were performed to assess the associations between the lifestyle factors and α-TOH measures. A total of 530 participants (46% men) were included with mean (SD) age of 56 (6) years. Of the examined lifestyle factors, only poor sleep was associated with a higher serum α-TOH (mean difference: 4% (95% CI: 1, 7%)). Current smoking was associated with higher urinary α-CEHC (32%: (14%, 53%)), with evidence of a dose–response relationship with smoking intensity (low pack years, 24% (2, 52%); high pack years, 55% (25, 93%)). Moderate physical activity was associated with a lower α-TLHQ relative to α-CEHC (−17%: (−26, −6%), compared with low PA). Only specific lifestyle factors associate with vitamin E metabolism. Examining serum α-TOH does not provide complete insight in vitamin E antioxidant capacity.

Approach to prevention of non-alcoholic fatty liver disease after liver transplantation

Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of liver disease and non-alcoholic steatohepatitis (NASH) related cirrhosis is third common indication for liver transplantation (LT). Patients who have NASH related cirrhosis and are candidates for LT often have multiple comorbidities. These comorbidities need to be addressed before and after transplantation as it affects overall survival. Like hepatitis B, hepatitis C, primary biliary cirrhosis, autoimmune hepatitis which recurs after transplantation, NASH also recurs after transplant however the impact of the recurrence on allograft and patient outcomes is unclear. Limited data suggests that it does not affect graft and patient survival. De novo NAFLD which is defined as occurrence of fatty liver in a patient who did not have fatty liver prior to LT can also occur in the allograft of patients transplanted for non-NAFLD liver disease. Obesity, hyperlipidemia, diabetes as well as steroid dose and duration after LT are common predictors of recurrence of NAFLD after transplantation. Studies on prevention and treatment of NASH in post-transplant patients are lacking. Prevention of weight gain, regular exercises, weight reducing surgery, limited steroid use or steroid free regimen have been tried with varying success. Future studies for the prevention of NAFLD/NASH are required especially in post liver transplant patient.

Selenium, antioxidants, cardiovascular disease, and all-cause mortality: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Antioxidants have been promoted for cardiovascular disease (CVD) risk reduction and for the prevention of cancer. Our preliminary analysis suggested that only when selenium was present were antioxidant mixtures associated with reduced all-cause mortality.

OBJECTIVE

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to determine the effect of selenium supplementation alone and of antioxidant mixtures with or without selenium on the risk of CVD, cancer, and mortality.

METHODS

We identified studies using the Cochrane Library, Medline, and Embase for potential CVD outcomes, cancer, and all-cause mortality following selenium supplementation alone or after antioxidant supplement mixtures with and without selenium up to June 5, 2020. RCTs of ≥24 wk were included and data were analyzed using random-effects models and classified by the Grading of Recommendations, Assessment, Development, and Evaluation approach.

RESULTS

The meta-analysis identified 9423 studies, of which 43 were used in the final analysis. Overall, no association of selenium alone or antioxidants was seen with CVD and all-cause mortality. However, a decreased risk with antioxidant mixtures was seen for CVD mortality when selenium was part of the mix (RR: 0.77; 95% CI: 0.62, 0.97; P = 0.02), with no association when selenium was absent. Similarly, when selenium was part of the antioxidant mixture, a decreased risk was seen for all-cause mortality (RR: 0.90; 95% CI: 0.82, 0.98; P = 0.02) as opposed to an increased risk when selenium was absent (RR: 1.09; 95% CI: 1.04, 1.13; P = 0.0002).

CONCLUSION

The addition of selenium should be considered for supplements containing antioxidant mixtures if they are to be associated with CVD and all-cause mortality risk reduction. This trial was registered at https://www.crd.york.ac.uk/PROSPERO/ as CRD42019138268.

Trying to Solve the Puzzle of the Interaction of Ascorbic Acid and Iron: Redox, Chelation and Therapeutic Implications

Iron and ascorbic acid (vitamin C) are essential nutrients for the normal growth and development of humans, and their deficiency can result in serious diseases. Their interaction is of nutritional, physiological, pharmacological and toxicological interest, with major implications in health and disease. Millions of people are using pharmaceutical and nutraceutical preparations of these two nutrients, including ferrous ascorbate for the treatment of iron deficiency anaemia and ascorbate combination with deferoxamine for increasing iron excretion in iron overload. The main function and use of vitamin C is its antioxidant activity against reactive oxygen species, which are implicated in many diseases of free radical pathology, including biomolecular-, cellular- and tissue damage-related diseases, as well as cancer and ageing. Ascorbic acid and its metabolites, including the ascorbate anion and oxalate, have metal binding capacity and bind iron, copper and other metals. The biological roles of ascorbate as a vitamin are affected by metal complexation, in particular following binding with iron and copper. Ascorbate forms a complex with Fe³⁺ followed by reduction to Fe²⁺, which may potentiate free radical production. The biological and clinical activities of iron, ascorbate and the ascorbate–iron complex can also be affected by many nutrients and pharmaceutical preparations. Optimal therapeutic strategies of improved efficacy and lower toxicity could be designed for the use of ascorbate, iron and the iron–ascorbate complex in different clinical conditions based on their absorption, distribution, metabolism, excretion, toxicity (ADMET), pharmacokinetic, redox and other properties. Similar strategies could also be designed in relation to their interactions with food components and pharmaceuticals, as well as in relation to other aspects concerning personalized medicine.

Are vitamins relevant to cancer risks? A Mendelian randomization investigation

OBJECTIVE

The relationship between vitamin intake and the occurrence of cancer is controversial. The aim of this study was to examine the genetic associations between vitamins D, E, and B₁₂ and five cancers (i.e., colorectal cancer, breast cancer, prostate cancer, malignant melanoma, and squamous cell carcinoma).

METHODS

This study started from genome-wide association data for three vitamins (N = 11 238) and five cancers (N = 373 316). The study analyzed their associations using Mendelian randomization (MR) methods. Additionally, survival analysis was performed using data from The Cancer Genome Atlas (TCGA) to further evaluate some MR results.

RESULTS

MR analysis indicated that intake of vitamins D, E, and B₁₂ is not relevant to the risk for the five cancers (P_MR > Bonferroni-corrected P = 0.02). Some of the results were supported by epidemiological observations; some were further supported by survival analysis using TCGA data.

CONCLUSION

There is no genetic evidence to support the association between intake of vitamins D, E, and B₁₂ and the risk for colorectal, breast, and prostate cancers, malignant melanoma, and squamous cell carcinoma.

Drugs for preventing lung cancer in healthy people

BACKGROUND

This is the second update of this Cochrane Review. Some studies have suggested a protective effect of antioxidant nutrients and higher dietary levels of fruits and vegetables on lung cancer.

OBJECTIVES

To determine whether vitamins and minerals and other potential agents, alone or in combination, reduce lung cancer incidence and lung cancer mortality in healthy populations.

SEARCH METHODS

We searched CENTRAL, MEDLINE and Embase from 1974 to May 2019 and screened references included in published studies and reviews.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing vitamins or mineral supplements with placebo, administered to healthy people with the aim of preventing lung cancer.

DATA COLLECTION AND ANALYSIS

Four review authors independently selected the trials to be included in the review, assessed their methodological quality and extracted data. For dichotomous outcomes we calculated risk ratios (RRs) and 95% confidence intervals (CIs) and pooled results using the random-effects model. We assessed the risk of bias using Cochrane's 'Risk of bias' assessment tool and certainty of evidence using the GRADE approach.

MAIN RESULTS

In this update, we identified three new trials for a total of 12 studies. Six analysed vitamin A, three vitamin C, three combined vitamin D3 + calcium, four vitamin E combined with other products, one selenium supplements and nine studied combinations of two or more products. Four studies included only men and five only women. Vitamin A results in little to no difference in lung cancer incidence (RR 1.09, 95% CI 1.00 to 1.19; 5 RCTs, 212314 participants; high-certainty evidence) and lung cancer mortality (RR 1.06, 95% CI 0.81 to 1.38; 3 RCTs, 190118 participants; high-certainty evidence). But in smokers or asbestos workers vitamin A increases the risk of lung cancer incidence (RR 1.10, 95% CI 1.01 to 1.20; 3 RCTs, 43995 participants; high-certainty evidence), lung cancer mortality (RR 1.18, 95% CI 1.01 to 1.38; 2 RCTs, 29426 participants; high-certainty evidence) and all-cause mortality (RR 1.09, 95% CI 1.05 to 1.13; 2 RCTs, 32883 participants; high-certainty evidence). Vitamin A increases the risk of minor side effects, such as yellowing of the skin and minor gastrointestinal symptoms (high-certainty evidence). Vitamin C likely results in little to no difference in lung cancer incidence (RR 1.29, 95% CI 0.67 to 2.49; 2 RCTs, 14953 participants; moderate-certainty evidence). In women, vitamin C increases the risk of lung cancer incidence (RR 1.84, 95% CI 1.14 to 2.95; 1 RCT, 7627 participants; high-certainty evidence). In men, vitamin C results in little to no difference in mortality for lung cancer (RR 0.81, 95% CI 0.53 to 1.23; 1 RCT, 7326 participants; high-certainty evidence). Vitamin D + calcium may result in little to no difference in lung cancer incidence in postmenopausal women (RR 0.90, 95% CI 0.39 to 2.08; 3 RCTs, 37601 women; low-certainty evidence). Vitamin E results in little to no difference in lung cancer incidence (RR 1.01, 95% CI 0.90 to 1.14; 3 RCTs, 36841 participants; high-certainty evidence) or to lung cancer mortality (RR 0.96, 95% CI 0.77 to 1.18; 2 RCTs, 29214 participants; high-certainty evidence), but increases the risk of haemorrhagic strokes (hazard ratio (HR), 1.74, 95% CI 1.04 to 2.91; 1 RCT, 14641 participants; high-certainty evidence). Calcium results in little to no difference in lung cancer incidence in postmenopausal women (RR 0.65, 95% CI 0.13 to 3.18; 1 RCT, 733 participants) or in risk of renal calculi (RR 1.94, 95% CI 0.20 to 18.57; 1 RCT, 733 participants; low-certainty evidence). Selenium in men results in little to no difference in lung cancer incidence (RR 1.11, 95% CI 0.80 to 1.54; 1 RCT, 17448 participants; high-certainty evidence) and lung cancer mortality (RR 1.09, 95% CI 0.72 to 1.66; 1 RCT, 17448 participants; high-certainty evidence) and increases the risk for grade 1 to 2 dermatitis (RR 1.16, 95% CI 1.04 to 1.31; 1 RCT, 17448 participants; high-certainty evidence) and for alopecia (RR 1.28, 95% CI 1.07 to 1.53; 1 RCT, 17448 participants; high-certainty evidence). The combination of vitamins A, C, E + selenium + zinc results in little to no difference in lung cancer incidence (RR 0.64, 95% CI 0.28 to 1.48; 1 RCT, 12741 participants; high-certainty evidence).

AUTHORS' CONCLUSIONS

Well-designed RCTs have shown no beneficial effect of supplements for the prevention of lung cancer and lung cancer mortality in healthy people. Vitamin A supplements increase lung cancer incidence and mortality in smokers or persons exposed to asbestos. Vitamin C increases lung cancer incidence in women. Vitamin E increases the risk of haemorrhagic strokes.

Vitamin E and cancer prevention: Studies with different forms of tocopherols and tocotrienols

α-Tocopherol (α-T) is the major form of vitamin E (VE) in animals and has the highest activity in carrying out the essential antioxidant functions of VE. Because of the involvement of oxidative stress in carcinogenesis, the cancer prevention activity of α-T has been studied extensively. Lower VE intake or nutritional status has been shown to be associated with increased cancer risk, and supplementation of α-T to populations with VE insufficiency has shown beneficial effects in lowering the cancer risk in some intervention studies. However, several large intervention studies with α-T conducted in North America have not demonstrated a cancer prevention effect. More recent studies have centered on the γ- and δ-forms of tocopherols and tocotrienols (T3). In comparison with α-T, these forms have much lower systemic bioavailability but have shown stronger cancer-preventive activities in many studies in animal models and cell lines. γ-T3 and δ-T3 generally have even higher activities than γ-T and δ-T. In this article, we review recent results from human and laboratory studies on the cancer-preventive activities of different forms of tocopherols and tocotrienols, at nutritional and pharmacological levels. We aim to elucidate the possible mechanisms of the preventive actions and discuss the possible application of the available information for human cancer prevention by different VE forms.

Ageing, age-related diseases and oxidative stress: What to do next?

Among other mechanisms, oxidative stress has been postulated to play an important role in the rate of ageing. Oxidative damage contributes to the hallmarks of ageing and essential components in pathological pathways which are thought to drive multiple age-related diseases. Nonetheless, results from studies testing the hypothesis of oxidative stress in ageing and diseases showed controversial results. While observational studies mainly found detrimental effects of high oxidative stress levels on disease status, randomized clinical trials examining the effect of antioxidant supplementation on disease status generally showed null effects. However, re-evaluations of these counterinitiative observations are required considering the lack of reliability and specificity of traditionally used biomarkers for measuring oxidative stress. To facilitate these re-evaluations, this review summarizes the basic knowledge of oxidative stress and the present findings regarding the role of oxidative damage in ageing and age-related diseases. Meanwhile, two approaches are highlighted, namely proper participants selection, together with the development of reliable biomarkers. We propose that oxidized vitamin E metabolites may be used to accurately monitor individual functional antioxidant level, which might serve as promising key solutions for future elucidating the impact of oxidative stress on ageing and age-related diseases.

The Role of Antioxidants in Cancer, Friends or Foes?

Consumption of dietary supplements by millions of people is increasing [1]. Between 64 to 81% of cancer patients and survivors use multivitamin supplements after the cancer diagnosis [2]. The use of antioxidants during cancer therapy has been a hot topic in medical science for the last 20 years without clear answers and recommendations. It seems that antioxidants are able to I) decrease the cancer formation risk by quenching ROS that are involved in cancer initiation and progression and II) assist in survival of cancer/precancer cells once the malignant transformation already occurred. Antioxidants were shown to assist cancer initiation, interfere with cancer treatment by reducing its efficacy and patient survival, and vice versa, there are reports of beneficial antioxidant effect during the cancer treatment.

Diet and lifestyle considerations for patients with prostate cancer

PURPOSE

To review the literature and provide recommendations on diet and lifestyle considerations in patients with prostate cancer using evidence from randomized controlled trials (RCTs) with additional considerations based on observational evidence.

MATERIALS AND METHODS

We initiated our search on ClinicalTrials.gov combining the term "prostate cancer" with a variety of diet and lifestyle factors. We then supplemented our summary of publications from registered trials by including other publications available on Pubmed.

RESULTS

There is a well-established benefit of exercise for improving functional outcomes and pelvic floor muscle training for improving treatment-related adverse effects. Multimodality interventions that integrate several factors (e.g., low-saturated fat, plant-based, whole-food diets with exercise, and stress reduction) appear to have the most clinically significant benefit for patients with prostate cancer. Ongoing multimodality interventions are including the efficacy of implementation strategies as observed outcomes. Limited RCT evidence suggests a clinically significant benefit for guided imagery/progressive muscle relaxation, Pilates, and lycopene-rich diets and a modest benefit for green tea, qigong, massage, and avoidance of nonprescribed vitamin and mineral supplements. Observational and single arm trial evidence indicates a need for further exploration of acupuncture, coffee, cruciferous vegetables, fish, Larrea tridentata, mushrooms, and vegetable-derived fats and avoidance of eggs, dairy, poultry with skin, processed red meat, and saturated fat. Published trials suggest no benefit from hypnosis, milk thistle, pomegranate, soy, or omega-3 fatty acid supplementation.

CONCLUSIONS

Our search demonstrated that most diet and lifestyle factors identified from observational studies have limited data from RCTs. Few items have shown early evidence of benefit. The best recommendation for patients with prostate cancer is to form a habit of wellness through healthy eating, aerobic and resistance exercise, and psychological well-being. Future trial development should consider how interventions can be implemented into real world practice.

Fatty liver disease in persons with HIV infection

The leading cause of non-HIV-related mortality is liver disease. Fatty liver disease can be characterized as alcoholic or nonalcoholic in nature. Alcohol use is prevalent among individuals with HIV infection and can lead to medication nonadherence, lower CD4+ cell count, inadequate viral suppression, and disease progression. The pathogenesis of nonalcoholic fatty liver disease (NAFLD) in individuals with HIV infection includes metabolic syndrome, hyperuricemia, HIV-related lipodystrophy, genetic polymorphisms, medications, HIV itself, and the gut microbiome. The prevalence of NAFLD in persons with HIV infection ranges from 30% to 65% depending on the modality of diagnosis. Individuals with HIV infection and NAFLD are at higher risk of cardiovascular disease; however, there is a dearth of longitudinal outcomes studies on this topic. Current therapies for NAFLD, such as vitamin E and pioglitazone, have not been studied in persons with HIV infection. There are several drugs in phase II and III clinical trials that specifically target NAFLD in HIV, including CC chemokine receptor 5 inhibitors, growth hormone-releasing factor agonists, and stearoyl-CoA desaturase inhibitors. Persons with HIV should be screened for NAFLD while pursuing aggressive risk factor modification and lifestyle changes, given the increased risk of cardiovascular mortality.

Non-Alcoholic Fatty Liver Disease, an Overview

Nonalcoholic fatty liver disease (NAFLD) affects 25% of people worldwide. Patients with fatty liver disease are primarily asymptomatic. Currently, specialists are predicting that fatty liver related cirrhosis will the be leading reason for liver transplants in the next 10-20 years, displacing hepatitis C and alcohol related liver transplants. NAFLD exists on a spectrum of simple steatosis to steatosis with inflammation and different levels of fibrosis. It is currently estimated that 20% of simple steatosis patients will progress to nonalcoholic steatohepatitis (NASH). Patients with NASH are at risk for further progression to cirrhosis and hepatocellular carcinoma. There is no single factor that triggers progression from simple steatosis to NASH, however, we do know that NASH is more prevalent in patients with obesity, diabetes, and metabolic syndrome. NAFLD is thought to be the hepatic manifestation of metabolic syndrome, and is closely tied with hyperinsulinemia. Currently there are no approved FDA treatments for NAFLD. NAFLD is typically found incidentally on imaging such as abdominal ultrasound and CT. Elevations in alanine aminotransferase (ALT) may prompt the clinician to evaluate for NAFLD however ALT should not be used as a diagnostic tool. The gold standard for diagnosis of NAFLD and NASH is a liver biopsy. Only a liver biopsy can distinguish simple steatosis from NASH. In patients whom NAFLD is suspected, appropriate biochemical assessment and imaging should be evaluated. Also, the presence of fibrosis should be assessed. Weight loss and dietary modifications are currently the only recommendations provided to NAFLD patients. There is histological improvement seen in in patients whom lose 5-10% of their body weight. Certain dietary factors play a role in the development of NAFLD including excessive caloric intake and high fructose consumption. There are pharmacological treatments currently being studied as well as non-pharmacological agents. This overview focuses on evaluation, management and treatments in NAFLD.

Vitamin E consumption and the risk of bladder cancer

Background: Vitamin E has anti-cancer properties, which was demonstrated mainly due to its antioxidant effect. Several epidemiological studies have investigated the association between vitamin E consumption and the risk of bladder cancer. However, the results were inconsistent. The meta-analysis study aimed to evaluate the association of vitamin E consumption and the risk of bladder cancer.

METHODS

We conducted a systematic literature search in the electronic databases, which included MEDLINE, EMBASE and the Cochrane Library till 1 January 2016. The pooled relative risk ratios (RRs) with 95% confidence intervals (CIs) were calculated depending on the heterogeneity among studies. Subgroup analysis and sensitivity analysis were also performed. Publication bias was assessed using Begg's test and Egger's test.

RESULTS

A total of 11 prospective studies (3 randomized clinical trials and 8 cohort studies) including 575601 participants were identified to be eligible for our present meta-analysis. The pooled RRs with 95% CI for highest versus lowest vitamin E consumption was 0.89 (0.78-1.00). An inverse linear association between vitamin E consumption and bladder cancer risk was detected in the dose response analysis. The results were also stable in the subgroup analysis and sensitivity analysis. Meanwhile, no obvious publication bias was observed.

CONCLUSIONS

Our study indicates that vitamin E consumption was inversely associated with the risk of bladder cancer.

Autophagy, Aging, and Longevity

Autophagy is a conserved process that degrades intracellular components through lysosomes, thereby maintaining energy homeostasis and renewal of organelles. Mounting evidence indicates that autophagy plays a key role in aging and aging-related diseases. Enhanced autophagy can delay aging and prolong life span. The absence of autophagy leads to the accumulation of mutant and misfolded proteins in the cell, which is the basis for the emergence and development of neurodegenerative diseases and other aging-related diseases. It will be of importance to develop approaches to extend the lifespan and improve the health of elderly individuals through the modulation of autophagy.

Vitamin C in the critically ill - indications and controversies

Ascorbic acid (vitamin C) elicits pleiotropic effects in the body. Among its functions, it serves as a potent anti-oxidant, a co-factor in collagen and catecholamine synthesis, and a modulator of immune cell biology. Furthermore, an increasing body of evidence suggests that high-dose vitamin C administration improves hemodynamics, end-organ function, and may improve survival in critically ill patients. This article reviews studies that evaluate vitamin C in pre-clinical models and clinical trials with respect to its therapeutic potential.

Vitamin C Intake and Risk of Prostate Cancer: The Montreal PROtEuS Study

Background: Vitamin C is a reducing agent and free radical scavenger, acting as antioxidant in plasma membranes and within cells. Based on these properties, a role for vitamin C in cancer incidence has been suspected. There are as yet few large population-based studies focusing on prostate cancer, with the preponderant evidence leaning toward the absence of an association. Nevertheless, many previous studies overlooked prostate cancer aggressiveness, as well as screening and detection issues, which could bias potential associations.

Methods: The Prostate Cancer and Environment Study (PROtEuS) is a population-based case-control study conducted in Montreal, Canada. In-person interviews, conducted with 1,916 histologically confirmed prostate cancer cases and 1,985 population controls, elicited information on a wide range of socio-demographic, lifestyle, and medical factors, including PSA screening. Usual frequency of consumption of 63 food items two years prior to diagnosis/interview was collected, along with use of dietary supplements. Odds ratios (OR) and 95% confidence intervals (CI) between vitamin C intake and prostate cancer were estimated using logistic or polytomous regression, adjusting for potential confounders.

Results: We observed no association between dietary intakes of vitamin C (OR for upper vs. lower tertile: 0.95, 95%CI 0.77, 1.18), estimated using the residual method to account for energy intake, or between regular use of vitamin C supplements and/or multivitamins (OR 0.90, 95%CI 0.76–1.05), and overall prostate cancer. Analyses considering disease aggressiveness, or restricted to subjects recently screened with PSA, thereby limiting the potential for undiagnosed cancers in non-cases, generated results consistent with those from the main analyses.

Conclusion: Our findings document the absence of an association between recent dietary vitamin C intake, or supplementation, and prostate cancer incidence overall or prostate cancer grade at diagnosis. Based on this, and other available evidence, vitamin C intake does not seem to hold promises with regard to prostate cancer prevention.

Nutraceuticals in prostate cancer therapeutic strategies and their neo-adjuvant use in diverse populations

Prostate cancer (PCa) is the most frequently diagnosed malignancy and second leading cause of cancer mortality in American males. Notably, men of African descent in the United States and Caribbean have the highest PCa mortality rates compared to men with European ancestry. Although current therapeutics are quite potent and effective, disease resistance, progression to metastasis, therapy-associated toxicities and efficacy-related issues in diverse populations develop over time. Thus, non-toxic and efficacious therapeutic strategies are needed to address these major obstacles for the clinical treatment and management of PCa. In this regard, preclinical and population-based efficacy studies have shown the potential of natural non-toxic nutraceuticals as potent anti-PCa agents. Accordingly, the implementation of nutraceutical intervention and genetic testing in diverse populations might aid in the development and design of precision medicine strategies to reduce the burden of chemotherapy-associated toxicities, suppress disease resistance, and treat both localized and advanced PCa. Consequently, additional large-scale and inclusive clinical studies are required to fully assess efficacy and therapeutic limitations of these agents in PCa. This review discusses the most current clinical research on selected nutraceutical agents and their efficacy in the context of clinico-pathological outcomes and disease susceptibility in diverse PCa clinical and epidemiological studies.

Vitamin intake and pancreatic cancer risk reduction: A meta-analysis of observational studies

BACKGROUND

The relationship between vitamin intake and pancreatic cancer (PC) risk is disputed. We aimed to investigate the association between vitamin intake and the risk of PC via meta-analysis.

METHODS

We conducted a meta-analysis of studies concerning vitamin intake and the risk of PC from EMBASE, MEDLINE, and Cochrane Library. The search yielded 25 correlative studies including 1,214,995 individuals. The relative risks (RR) were examined by a random-effect model or fixed-effect model. Subgroup analysis, dose-response analysis, sensitivity analysis, meta-regression, and publication bias analysis were used to analyze studies.

RESULTS

The RR of PC in the highest vitamin intake group was 0.90 (95% confidence interval, 0.83-0.98) compared with that in the lowest vitamin intake in the prospective studies. Different increments of vitamin intake and the risk of PC were examined with dose-response analysis, and a decrease in the risk of PC was observed with vitamin D (25%) and vitamin B12 (27%).

CONCLUSIONS

This meta-analysis found that vitamin intake can decrease the risk of PC, particularly vitamin D and vitamin B12.

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.

Dietary Supplements Commonly Used by Cancer Survivors: Are There Any Benefits?

Following a cancer diagnosis, dietary supplements are reportedly used by 20%-80% of individuals. Supplements are most commonly used by breast cancer survivors, followed by patients with prostate, colorectal, and lung cancers, which is not surprising since these are the most common types of cancer diagnosed in adults. Reasons cited for such use include improving quality of life, reducing symptoms related to treatment and/or the disease process, and recommendation from medical practitioners; family and friends may also be an influence. However, controversy surrounds the use of dietary supplements, particularly during treatment-specifically, whether supplements affect treatment efficacy is unknown. This article discusses the evidence related to common dietary supplements used to prevent cancer or a recurrence.