Diet and brain cancer in adults: a case-control study in northeast China

Unveiling the Effects of Cruciferous Vegetable Intake on Different Cancers: A Systematic Review and Dose-Response Meta-analysis

CONTEXT

Epidemiological studies indicated that cruciferous vegetable intake is associated with positive health outcomes. However, the role of cruciferous vegetables may have differential impacts on various cancers.

OBJECTIVE

This meta-analysis aims to review recent epidemiological studies on the link between cruciferous vegetables and various cancers. It seeks to identify the optimal intake dose and timing of cruciferous vegetables influencing their association with cancer risk.

DATA SOURCES

Studies on cruciferous vegetables and cancer were searched in PubMed, NCBI, Web of Science, and Elsevier databases from 1978 to June 2023.

DATA EXTRACTION

Extracted data from 226 relevant case-control and cohort studies were expressed by standardized mean difference and 95% CI, followed by the subgroup analysis to eliminate heterogeneity.

RESULTS

Intake of cruciferous vegetables can prevent cancers, with an odds ratio of 0.77 and risk ratio (RR) of 0.96. The intake levels of cruciferous vegetables associated with the risk of colorectal cancer, lung cancer, upper gastrointestinal cancer, gynecological cancer (ovarian cancer and endometrial cancer), bladder cancer, renal cancer, and prostate cancer were found to be 5.41 servings/week, 5.41 servings/week, 5.5 servings/week, 7.4 servings/week, 5.5 servings/week, 4.85 servings/week, and 3 servings/week, respectively. In a cohort followed for 2 to 15 years, limited consumption of cruciferous vegetables was correlated with a higher cancer RR. In the Asian population, cruciferous vegetables had a significant relationship with lung cancer, head and neck squamous cell carcinoma, and esophageal cancer. Conversely, cruciferous vegetables are predominantly associated with colorectal, renal, gynecological, and prostate cancer in the American population.

CONCLUSION

This study highlights the complex link between cruciferous vegetables and cancer, influenced by factors such as cancer type, region, intake level, and follow-up duration.

Dietary Recommendations for Glioma: A Mini-Review

PURPOSE OF REVIEW

Glioma is the most common type of brain cancer, associated with a high mortality rate. Diet is one of the most modifiable factors that can influence the risk of various cancers, including glioma. While the relationship between diet and glioma has been explored in recent years, the number of studies in this area remains limited, and the findings are often controversial. Moreover, all existing studies are observational, which means they may be influenced by a range of confounding variables. In this mini-review, we aim to provide a comprehensive and informative overview of the dietary recommendations related to glioma that have been published to date.

RECENT FINDINGS

Research suggests that adherence to healthy dietary patterns-such as the Mediterranean diet, Dietary Approaches to Stop Hypertension (DASH) diet, Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet, Paleolithic diet, high-protein dietary patterns, and vegetarian dietary patterns-may be associated with a reduced risk of glioma. These diets are rich in phytochemicals and antioxidants. Additionally, certain food groups, including fruits, vegetables, legumes, nuts, eggs, fresh fish, tea, and coffee, are emphasized for their protective effects against glioma. Conversely, adherence to unhealthy dietary patterns, such as the Western diet, or diets with high inflammatory potential, glycemic and insulinemic loads, and high consumption of grains (especially refined grains), processed meats, and processed fish, has been linked to an increased risk of glioma. Current studies suggest that following a healthy diet may reduce the odds of developing glioma. However, due to the limited number of studies and the observational nature of the existing research, further investigations with more robust designs, such as randomized controlled trials, are needed to clarify these associations.

Diet and Nutrients in Rare Neurological Disorders: Biological, Biochemical, and Pathophysiological Evidence

Background/Objectives: Rare diseases are a wide and heterogeneous group of multisystem life-threatening or chronically debilitating clinical conditions with reduced life expectancy and a relevant mortality rate in childhood. Some of these disorders have typical neurological symptoms, presenting from birth to adulthood. Dietary patterns and nutritional compounds play key roles in the onset and progression of neurological disorders, and the impact of alimentary needs must be enlightened especially in rare neurological diseases. This work aims to collect the in vitro, in vivo, and clinical evidence on the effects of diet and of nutrient intake on some rare neurological disorders, including some genetic diseases, and rare brain tumors. Herein, those aspects are critically linked to the genetic, biological, biochemical, and pathophysiological hallmarks typical of each disorder. Methods: By searching the major web-based databases (PubMed, Web of Science Core Collection, DynaMed, and Clinicaltrials.gov), we try to sum up and improve our understanding of the emerging role of nutrition as both first-line therapy and risk factors in rare neurological diseases. Results: In line with the increasing number of consensus opinions suggesting that nutrients should receive the same attention as pharmacological treatments, the results of this work pointed out that a standard dietary recommendation in a specific rare disease is often limited by the heterogeneity of occurrent genetic mutations and by the variability of pathophysiological manifestation. Conclusions: In conclusion, we hope that the knowledge gaps identified here may inspire further research for a better evaluation of molecular mechanisms and long-term effects.

Associations between dietary antioxidant vitamins and risk of glioma: an updated systematic review and meta-analysis of observational studies

Background

Epidemiological studies investigating the potential associations between antioxidant vitamins intake and risk of glioma have yielded inconsistent results. To address this, we carried out a systematic review and updated meta-analysis to explore the relationship between dietary antioxidant vitamins intake and risk of glioma.

Methods

We comprehensively searched electronic databases including PubMed, Web of Science, Embase, Scopus, China National Knowledge Infrastructure (CNKI) and Wan fang Data from their inception to March 2024. We employed fixed-effects or random-effects models to estimate the pooled relative risks (RRs) and 95% confidence intervals (CIs) for the associations between dietary antioxidant vitamins intake and risk of glioma. Publication bias was assessed through the visual inspection of the funnel plots and quantified by the Begg's and Egger's tests. Heterogeneity across studies was assessed using the Cochran's Q test and I-square (I2). Additionally, subgroup and sensitivity analyses were performed to explore potential sources of heterogeneity and evaluate the robustness of the results.

Results

Overall, a total of 15 articles involving 3,608 glioma cases and 771,930 participants were included in the final analysis. The pooled analyses revealed that the highest intake of vitamin C significantly reduced the risk of glioma (RR = 0.78; 95%CI: 0.63-0.96; P = 0.022), compared to the lowest intake. However, no significant associations were observed between vitamin A and vitamin E intake and the risk of glioma (P>0.05). Subgroup analyses revealed the inverse association between vitamin C intake and risk of glioma in the population-based case-control studies (RR = 0.82; 95%CI: 0.68-1.00, P = 0.049) and study quality <7(RR = 0.52, 95%CI: 0.29-0.92, P = 0.025).

Conclusion

Our findings show that higher intake of vitamin C is strongly associated with a reduced risk of glioma, although a dose-response relationship was not evident. Future large-scale prospective studies are warranted to confirm these findings.

Role of Mediterranean diet in the development and recurrence of meningiomas: a narrative review

Several studies through the years have proven how an unhealthy nutrition, physical inactivity, sedentary lifestyle, obesity, and smoking represent relevant risk factors in cancer genesis. This study aims to provide an overview about the relationship between meningiomas and food assumption in the Mediterranean diet and whether it can be useful in meningioma prevention or it, somehow, can prevent their recurrence. The authors performed a wide literature search in PubMed and Scopus databases investigating the presence of a correlation between Mediterranean diet and meningiomas. The following MeSH and free text terms were used: "Meningiomas" AND "Diet" and "Brain tumors" AND "diet." Databases' search yielded a total of 749 articles. After duplicate removal, an abstract screening according to the eligibility criteria has been performed and 40 articles were selected. Thirty-one articles were excluded because they do not meet the inclusion criteria. Finally, a total of 9 articles were included in this review. It is widely established the key and protective role that a healthy lifestyle and a balanced diet can have against tumorigenesis. Nevertheless, studies focusing exclusively on the Mediterranean diet are still lacking. Thus, multicentric and/or prospective, randomized studies are mandatory to better assess and determine the impact of food assumptions in meningioma involvement.

Modifiable risk factors for glioblastoma: a systematic review and meta-analysis

Glioblastoma (GBM) is the most common and aggressive glioma histological subtype, associated with high disability and poor survival. The etiology of this condition is still mostly unknown, and evidence about risk factors is elusive. The aim of this study is to identify modifiable risk factors for GBM. Electronic search was performed by two reviewers independently using the keywords and MeSH terms 'glioblastoma' OR 'glioma' OR 'brain tumor' AND 'risk factor'. The inclusion criteria were (1) observational studies or experimental studies on humans, (2) studies assessing the association between glioblastoma and exposure to modifiable conditions, and (3) studies published in English or Portuguese. Studies on the pediatric population or about exposure to ionizing radiation were excluded. A total of 12 studies were included. Seven were case-control studies, and five were cohort studies. The risk factors assessed included body mass index, alcohol consumption, exposure to magnetic fields, diabetes mellitus type 2 (DM2), and use of non-steroidal anti-inflammatory drugs (NSAID). No significant link was found between GBM incidence and DM2 or magnetic field exposure. On the other hand, higher BMI, alcohol consumption, and NSAID use demonstrated a protective effect on GMB risk. However, given the limited number of studies, it is not possible to obtain a behavioral recommendation; instead, these findings are relevant to guide future basic scientific studies on GBM oncogenesis.

Nutrition and Diet: A Double-Edged Sword in Development and Treatment of Brain Tumors

Brain tumor (BT) is the second most common pediatric cancer, one of the most common cancers among adults, and the major cause of cancer-related morbidity and mortality worldwide. Both genetics and environment can contribute to BT induction. One of the environmental risks is diet which has not been proven as a certain hazard yet. The objective of the current chapter was to review the literature concerning both positive and negative effects of nutrition on BT risk.

Antioxidants in brain tumors: current therapeutic significance and future prospects

Brain cancer is regarded among the deadliest forms of cancer worldwide. The distinct tumor microenvironment and inherent characteristics of brain tumor cells virtually render them resistant to the majority of conventional and advanced therapies. Oxidative stress (OS) is a key disruptor of normal brain homeostasis and is involved in carcinogenesis of different forms of brain cancers. Thus, antioxidants may inhibit tumorigenesis by preventing OS induced by various oncogenic factors. Antioxidants are hypothesized to inhibit cancer initiation by endorsing DNA repair and suppressing cancer progression by creating an energy crisis for preneoplastic cells, resulting in antiproliferative effects. These effects are referred to as chemopreventive effects mediated by an antioxidant mechanism. In addition, antioxidants minimize chemotherapy-induced nonspecific organ toxicity and prolong survival. Antioxidants also support the prooxidant chemistry that demonstrate chemotherapeutic potential, particularly at high or pharmacological doses and trigger OS by promoting free radical production, which is essential for activating cell death pathways. A growing body of evidence also revealed the roles of exogenous antioxidants as adjuvants and their ability to reverse chemoresistance. In this review, we explain the influences of different exogenous and endogenous antioxidants on brain cancers with reference to their chemopreventive and chemotherapeutic roles. The role of antioxidants on metabolic reprogramming and their influence on downstream signaling events induced by tumor suppressor gene mutations are critically discussed. Finally, the review hypothesized that both pro- and antioxidant roles are involved in the anticancer mechanisms of the antioxidant molecules by killing neoplastic cells and inhibiting tumor recurrence followed by conventional cancer treatments. The requirements of pro- and antioxidant effects of exogenous antioxidants in brain tumor treatment under different conditions are critically discussed along with the reasons behind the conflicting outcomes in different reports. Finally, we also mention the influencing factors that regulate the pharmacology of the exogenous antioxidants in brain cancer treatment. In conclusion, to achieve consistent clinical outcomes with antioxidant treatments in brain cancers, rigorous mechanistic studies are required with respect to the types, forms, and stages of brain tumors. The concomitant treatment regimens also need adequate consideration.

Association between vitamins and risk of brain tumors: A systematic review and dose-response meta-analysis of observational studies

Background

Brain tumor is one of the important causes of cancer mortality, and the prognosis is poor. Therefore, early prevention of brain tumors is the key to reducing mortality due to brain tumors.

Objective

This review aims to quantitatively evaluate the association between vitamins and brain tumors by meta-analysis.

Methods

We searched articles on PubMed, Cochrane Library, Web of Science, and Embase databases from inception to 19 December 2021. According to heterogeneity, the fixed-effects model or random-effects model was selected to obtain the relative risk of the merger. Based on the methods described by Greenland and Longnecker, we explored the dose-response relationship between vitamins and the risk of brain tumors. Subgroup analysis, sensitivity analysis, and publication bias were also used for the analysis.

Results

The study reviewed 23 articles, including 1,347,426 controls and 6,449 brain tumor patients. This study included vitamin intake and circulating concentration. For intake, it mainly included vitamin A, vitamin B, vitamin C, vitamin E, β-carotene, and folate. For circulating concentrations, it mainly included vitamin E and vitamin D in the serum (25-hydroxyvitamin D and α-tocopherol). For vitamin intake, compared with the lowest intakes, the highest intakes of vitamin C (RR = 0.81, 95%CI:0.66–0.99, I² = 54.7%, P_{for heterogeneity} = 0.007), β-carotene (RR = 0.78, 95%CI:0.66–0.93, I² = 0, P_{for heterogeneity} = 0.460), and folate (RR = 0.66, 95%CI:0.55–0.80, I² = 0, P_{for heterogeneity} = 0.661) significantly reduced the risk of brain tumors. For serum vitamins, compared with the lowest concentrations, the highest concentrations of serum α-tocopherol (RR = 0.61, 95%CI:0.44–0.86, I² = 0, P_{for heterogeneity} = 0.656) significantly reduced the risk of brain tumors. The results of the dose-response relationship showed that increasing the intake of 100 μg folate per day reduced the risk of brain tumors by 7% (P_{−nonlinearity} = 0.534, RR = 0.93, 95%CI:0.90–0.96).

Conclusion

Our analysis suggests that the intake of vitamin C, β-carotene, and folate can reduce the risk of brain tumors, while high serum α-tocopherol concentration also has a protective effect on brain tumors. Therefore, vitamins may provide new ideas for the prevention of brain tumors.

Systematic Review Registration

PROSPERO, identifier CRD42022300683.

A Meta-Analysis of Calcium Intake and Risk of Glioma

BACKGROUND

A meta-analysis was conducted to investigate the correlation between calcium intake and the risk of brain tumors (especially glioma).

METHODS

The PubMed, Web of Science, and Embase databases were searched for relevant papers on the association between calcium intake and glioma as of August 22, 2021. The odds ratio (OR) with a 95% confidence interval (CI) was calculated using a random-effects model. Egger's test was conducted to assess publication bias.

RESULTS

The meta-analysis includes four studies. The meta-analysis showed that calcium intake and the risk of brain tumors have a significant negative relationship (OR = 0.28; 95% CI: 0.11 to 0.72; P = 0.008). Dose-response analysis showed that for every 100 mg/day increase in calcium intake, the risk of glioma decreased by 7% (OR = 0.93; 95% CI: 0.88 to 0.98). In addition, compared with humans without calcium intake, when calcium intake is 455 mg/day, 800 mg/day and 1000 mg/day, the risk of glioma is 0.65 (95% CI 0.43, 0.97), 0.55 (95% CI 0.37, 0.82) and 0.37 (95% CI 0.15, 0.86).

CONCLUSION

There is a significant negative association between calcium intake and brain tumors (especially gliomas), but more high-quality studies are needed to verify these results.

The Epidemiology of Central Nervous System Tumors

This article reviews the current epidemiology of central nervous system tumors. Population-level basic epidemiology, nationally and internationally, and current understanding of germline genetic risk are discussed, with a focus on known and well-studied risk factors related to the etiology of central nervous system tumors.

Exploring the Pivotal Neurophysiologic and Therapeutic Potentials of Vitamin C in Glioma

Gliomas represent solely primary brain cancers of glial cell or neuroepithelial origin. Gliomas are still the most lethal human cancers despite modern innovations in both diagnostic techniques as well as therapeutic regimes. Gliomas have the lowest overall survival rate compared to other cancers 5 years after definitive diagnosis. The dietary intake of vitamin C has protective effect on glioma risk. Vitamin C is an essential compound that plays a vital role in the regulation of lysyl and prolyl hydroxylase activity. Neurons store high levels of vitamin C via sodium dependent-vitamin C transporters (SVCTs) to protect them from oxidative ischemia-reperfusion injury. Vitamin C is a water-soluble enzyme, typically seen as a powerful antioxidant in plants as well as animals. The key function of vitamin C is the inhibition of redox imbalance from reactive oxygen species produced via the stimulation of glutamate receptors. Gliomas absorb vitamin C primarily via its oxidized dehydroascorbate form by means of GLUT 1, 3, and 4 and its reduced form, ascorbate, by SVCT2. Vitamin C is able to preserve prosthetic metal ions like Fe2+ and Cu+ in their reduced forms in several enzymatic reactions as well as scavenge free radicals in order to safeguard tissues from oxidative damage. Therapeutic concentrations of vitamin C are able to trigger H2O2 generation in glioma. High-dose combination of vitamin C and radiation has a much more profound cytotoxic effect on primary glioblastoma multiforme cells compared to normal astrocytes. Control trials are needed to validate the use of vitamin C and standardization of the doses of vitamin C in the treatment of patients with glioma.

Association between dietary glycemic index and glycemic load and glioma: a case-control study

OBJECTIVE

Although glycemic index (GI) and load (GL) have been linked with several health outcomes, no information is available linking dietary GI and GL with glioma. This study aimed to investigate the relationship between dietary GI and GL and odds of glioma.

METHODS

This hospital-based case-control study was conducted between November 2009 and September 2011 in the hospital affiliated to Shahid Beheshti University of Medical Sciences. We recruited 128 newly diagnosed cases of glioma and 256 age- and sex-matched controls. All cases were pathologically diagnosed with glioma patients, with no history of any type of other pathologically confirmed cancers and chemotherapy or radiotherapy (due to cancers). Dietary GI and GL were measured by using a validated, self-administered, dish-based, semi-quantitative food-frequency questionnaire.

RESULT

A significant positive association was found between dietary GI and glioma (OR: 3.01; 95% CI: 1.75-5.17, P < 0.001); such that after considering for potential confounders, participants in the highest tertile of dietary GI had 3.51 times greater risk of glioma than those in the lowest tertile (OR: 3.51; 95% CI: 1.69-7.28, P_trend = 0.001). Furthermore, we observed a significant positive association between dietary and glioma (OR: 3.74; 95% CI: 1.97-6.11, P_trend < 0.001). This association remained significant even after further controlling for potential confounders (OR: 2.42; 95% CI: 1.02-5.69, P_trend= 0.04).

DISCUSSION

We observed a significant positive association between dietary GI and GL and risk of glioma in adults. However, prospective cohort studies are required to confirm this association.

Alcohol intake and risk of glioma: results from three prospective cohort studies

PURPOSE

The association between alcohol intake and glioma remains unclear. We evaluated the association between alcohol intake and incidence of glioma in three large, prospective cohort studies with repeated alcohol assessments.

METHODS

We harnessed data from three studies with repeat alcohol assessment to compute hazard ratios (HR) and 95% confidence intervals (CI) for glioma by overall alcohol intake and intake from specific beverages using Cox proportional hazards regression, adjusted for age, cohort, body mass index, smoking status, and caloric intake. Analyses were conducted separately for glioma overall and for glioblastoma (GBM).

RESULTS

We confirmed 554 incident glioma cases (362 GBM) among 237,505 participants with 6,216,378 person-years of follow up. Cumulative average alcohol intake was associated with reduced risk of glioma (HR = 0.75, 95%CI:0.56-0.99 comparing > 8-15 to ≤ 0.5 g/d; HR = 0.71, 95%CI:0.53-0.96 comparing > 15 g/d to ≤ 0.5 g/d). When stratified by sex, for the same comparisons, the HRs for men were 0.57 (95%CI:0.36-0.89) and 0.79 (0.53-1.16), and for women 0.90 (95%CI:0.62-1.30) and 0.62, 95%CI:0.39-0.97. Results were consistent when examining cumulative average, baseline, and recent intake, and with a 4 year lag.

CONCLUSION

These results provide evidence against a positive association between alcohol intake and glioma risk. Alcohol intake was associated with reduced risk of glioma in both men and women.

Chemical constituents and medicinal properties of Allium species

Allium species, belonging to Alliaceae family, are among the oldest cultivated vegetables used as food. Garlic, onions, leeks and chives, which belong to this family, have been reported to have medicinal properties. The Allium species constituents have been shown to have antibacterial and antioxidant activities, and, in addition, other biological properties. These activities are related to their rich organosulfur compounds. These organosulfur compounds are believed to prevent the development of cancer, cardiovascular, neurological, diabetes, liver diseases as well as allergy and arthritis. There have also been reports on toxicities of these compounds. The major active compounds of Allium species includes, diallyl disulfide, diallyl trisulfide, diallyl sulfide, dipropyl disulfide, dipropyl trisulfide, 1-propenylpropyl disulfide, allyl methyl disulfide and dimethyl disulfide. The aim of this review is to focus on a variety of experimental and clinical reports on the effectiveness, toxicities and possible mechanisms of actions of the active compounds of garlic, onions, leek and chives.

Dietary Pattern, Genomic Stability and Relative Cancer Risk in Asian Food Landscape

The incidence of cancer globally is increasing, partly due to lifestyle factors. Despite a better understanding of cancer biology and advancement in cancer management and therapies, current strategies in cancer treatment remain costly and cause socioeconomic burden especially in Asian countries. Hence, instead of putting more efforts in searches for new cancer cures, attention has now shifted to understanding how to mitigate cancer risk by modulating lifestyle factors. It has been established that carcinogenesis is multifactorial, and the important detrimental role of oxidative stress, chronic inflammation, and genomic instability is evident. To date, there is no study linking dietary pattern and genomic stability in cancer risk in the Asian food landscape. Thus, this present review article discusses recent literature on dietary pattern and genomic stability and its relationship with cancer risk in Asia.

A case-control study on dietary calcium intake and risk of glioma

Limited evidence exists regarding the association between dietary calcium intake and risk of glioma. The objective of this study was to determine the relationship between dietary calcium intake and risk of glioma in Iranian adults. In this hospital-based case-control study, we enrolled 128 newly-diagnosed cases of glioma and 256 age- and sex-matched controls. Patients with pathologically confirmed glioma (without any other cancers) were selected. Dietary intakes of study participants were collected through a validated 126-item food-frequency questionnaire. Dietary calcium intake was computed from dairy products in the questionnaire. Participants were categorized into quartiles of dietary calcium intake. Binary logistic regression was used to examine the association between dietary calcium intake and glioma. Higher dietary intake of calcium was associated with younger age, long duration of cell phone use, and frequent canned foods intake. After taking age, sex, and energy intake into account, participants with the greatest dietary calcium intake had 84% lower odds of glioma than those with the lowest intake [odds ratio (OR): 0.16; 95% confidence interval (CI), 0.07-0.37]. Further adjustment for other potential confounders including nutrient intakes did not significantly alter the association (OR: 0.22; 95% CI, 0.08-0.64). Even after additional adjustment for BMI, we found a significant inverse association between dietary calcium intake and odds of glioma (OR: 0.23; 95% CI, 0.08-0.65). We found an inverse protective association between high dietary calcium intake and odds of glioma. Further prospective cohort studies are needed to confirm these findings.

Natural Compounds in Glioblastoma Therapy: Preclinical Insights, Mechanistic Pathways, and Outlook

Simple Summary

Glioblastoma (GBM) is a tumor of the brain or spinal cord with poor clinical prognosis. Current interventions, such as chemotherapy and surgical tumor resection, are constrained by tumor invasion and cancer drug resistance. Dietary natural substances are therefore evaluated for their potential as agents in GBM treatment. Various substances found in fruits, vegetables, and other natural products restrict tumor growth and induce GBM cell death. These preclinical effects are promising but remain constrained by natural substances’ varying pharmacological properties. While many of the reviewed substances are available as over-the-counter supplements, their anti-GBM efficacy should be corroborated by clinical trials moving forward.

Abstract

Glioblastoma (GBM) is an aggressive, often fatal astrocyte-derived tumor of the central nervous system. Conventional medical and surgical interventions have greatly improved survival rates; however, tumor heterogeneity, invasiveness, and chemotherapeutic resistance continue to pose clinical challenges. As such, dietary natural substances—an integral component of the lifestyle medicine approach to chronic diseases—are examined as potential chemotherapeutic agents. These heterogenous substances exert anti-GBM effects by upregulating apoptosis and autophagy, inducing cell cycle arrest, interfering with tumor metabolism, and inhibiting proliferation, neuroinflammation, chemoresistance, angiogenesis, and metastasis. Although these beneficial effects are promising, natural substances’ efficacy in GBM is constrained by their bioavailability and blood–brain barrier permeability; various chemical formulations are proposed to improve their pharmacological properties. Many of the reviewed substances are available as over-the-counter dietary supplements, underscoring their viability as lifestyle interventions. However, clinical trials remain necessary to substantiate the in vitro and in vivo properties of natural substances.

Phytochemical Characterization and Screening of Antioxidant, Antimicrobial and Antiproliferative Properties of Allium × cornutum Clementi and Two Varieties of Allium cepa L. Peel Extracts

Onions are one of the most widely grown vegetable crops. As production increases, so does the generation of waste from various parts of the onion, raising the need for efficient ecological disposal and use of such waste products. However, onion waste products are a rich source of antioxidants with a range of biological properties, therefore, they could potentially be used in food and pharmaceutical industries. In the present study, we identified the main flavonols and anthocyanins in peel extracts of Allium × cornutum Clement ex Visiani, 1842, and two varieties of Allium cepa L. and tested their antioxidant, antimicrobial and antiproliferative properties. Quercetin 3,4'-diglucolside, quercetin 4'-monoglucoside and quercetin are the most abundant flavonols in all onion extracts detected by high-performance liquid chromatography (HPLC) method. The composition of anthocyanins varied in all extracts. 2,2'-diphenyl-1-picrylhydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) assays showed that the triploid onion A. × cornutum had the highest antioxidant power. Evaluation of antimicrobial activity by broth microdilution assay also showed that A. × cornutum had higher antimicrobial activity compared to the red and yellow onion varieties. Comparable antiproliferative activity was confirmed for all onion extracts tested on three cancer cell lines: Hela (cervical cancer cell line), HCT116 (human colon cancer cell line) and U2OS (human osteosarcoma cell line). The most abundant onion flavonols (quercetin 3,4'-diglucoside and quercetin 4'-monoglucoside) showed weaker antimicrobial as well as antiproliferative properties compared to the extracts, leading to the conclusion that other phytochemicals besides flavonols contribute to the biological activity of onion peel extracts. The results demonstrate the antioxidant and antimicrobial properties of onion peels, which have promising potential as cancer cell proliferation inhibitors.

Pharmacological Properties of Allium cepa, Preclinical and Clinical Evidences; A Review

Onion or Allium cepa (A. cepa) is one of the most important condiment plants grown and consumed all over the world. This plant has various therapeutic effects attributed to its constituents, such as quercetin, thiosulphinates and phenolic acids. In the present article, various pharmacological and therapeutic effects of A. cepa were reviewed. Different online databases using keywords such as onion, A. cepa, therapeutic effects, and pharmacological effects until the end of December 2019 were searched for this purpose. Onion has been suggested to be effective in treating a broad range of disorders, including asthma, inflammatory disorders, dysentery, wounds, scars, keloids and pain. In addition, different studies have demonstrated that onion possesses numerous pharmacological properties, including anti-cancer, anti-diabetic and anti-platelet properties as well as the effect on bone, cardiovascular, gastrointestinal, nervous, respiratory, and urogenital systems effects such as anti-osteoporosis, anti-hypertensive, antispasmodic, anti-diarrheal, neuro-protective, anti-asthmatic and diuretic effects. The present review provides detailed the various pharmacological properties of onion and its constituents and possible underlying mechanisms. The results of multiple studies suggested the therapeutic effect of onion on a wide range of disorders.

Brain tumor diagnostic model and dietary effect based on extracellular vesicle microbiome data in serum

The human microbiome has been recently associated with human health and disease. Brain tumors (BTs) are a particularly difficult condition to directly link to the microbiome, as microorganisms cannot generally cross the blood–brain barrier (BBB). However, some nanosized extracellular vesicles (EVs) released from microorganisms can cross the BBB and enter the brain. Therefore, we conducted metagenomic analysis of microbial EVs in both serum (152 BT patients and 198 healthy controls (HC)) and brain tissue (5 BT patients and 5 HC) samples based on the V3–V4 regions of 16S rDNA. We then developed diagnostic models through logistic regression and machine learning algorithms using serum EV metagenomic data to assess the ability of various dietary supplements to reduce BT risk in vivo. Models incorporating the stepwise method and the linear discriminant analysis effect size (LEfSe) method yielded 12 and 29 significant genera as potential biomarkers, respectively. Models using the selected biomarkers yielded areas under the curves (AUCs) >0.93, and the model using machine learning resulted in an AUC of 0.99. In addition, Dialister and [Eubacterium] rectale were significantly lower in both blood and tissue samples of BT patients than in those of HCs. In vivo tests showed that BT risk was decreased through the addition of sorghum, brown rice oil, and garlic but conversely increased by the addition of bellflower and pear. In conclusion, serum EV metagenomics shows promise as a rich data source for highly accurate detection of BT risk, and several foods have potential for mitigating BT risk.

The gut microbiome affects brain health via tiny packets of microbial metabolites called extracellular vesicles (EVs) that are small enough to pass through the blood–brain barrier. The brain was thought to be sheltered from the microbiome’s effect on health by this barrier, which blocks microbes from entering the brain via the blood. Yoon-Keun Kim at MD Healthcare Inc. and Sun Ha Paek at Seoul National University, both in Seoul, South Korea, and co-workers compared the EVs in the blood of brain cancer patients and healthy individuals, and found the two groups harbored different types of microbes. Feeding mice brown rice oil, sorghum, and garlic markedly shifted their EV profiles towards those of the healthy microbiome. These results provide a foundation for investigating new methods for brain cancer risk assessment and dietary interventions to reduce that risk.

Association between fish intake and glioma risk: a systematic review and meta-analysis

Objectives

We investigated the association between the consumption of fresh and processed fish and glioma risk using a meta-analysis approach.

Methods

We selected and analyzed observational studies that discussed the relationships between fresh and processed fish intake on glioma risk from PubMed, Web of Science, Embase, and the SinoMed and Wanfang databases from inception to 31 March 2020. Studies were selected according to pre-established eligibility criteria and data were extracted separately by two researchers. A meta-analysis was conducted based on a random-effects model to provide pooled odds ratios (OR) and 95% confidence intervals (CIs).

Results

Eight studies considered the relationship between fish intake (seven fresh and seven processed fish) and glioma risk and were included in this meta-analysis. The OR effect size for fresh fish intake and glioma risk was 0.72 (95%CI 0.53–0.97) and the overall OR effect size for processed fish intake and glioma risk was 1.88 (95%CI 1.06–3.34).

Conclusion

Dietary intake of fresh fish may reduce the risk of glioma, but consumption of processed fish may increase the risk of glioma. This study had some limitations, and further studies are therefore required to clarify the associations between fish intake and glioma risk.

Testing for causality between systematically identified risk factors and glioma: a Mendelian randomization study

BACKGROUND

Whilst epidemiological studies have provided evidence of associations between certain risk factors and glioma onset, inferring causality has proven challenging. Using Mendelian randomization (MR), we assessed whether associations of 36 reported glioma risk factors showed evidence of a causal relationship.

METHODS

We performed a systematic search of MEDLINE from inception to October 2018 to identify candidate risk factors and conducted a meta-analysis of two glioma genome-wide association studies (5739 cases and 5501 controls) to form our exposure and outcome datasets. MR analyses were performed using genetic variants to proxy for candidate risk factors. We investigated whether risk factors differed by subtype diagnosis (either glioblastoma (n = 3112) or non-glioblastoma (n = 2411)). MR estimates for each risk factor were determined using multiplicative random effects inverse-variance weighting (IVW). Sensitivity analyses investigated potential pleiotropy using MR-Egger regression, the weighted median estimator, and the mode-based estimator. To increase power, trait-specific polygenic risk scores were used to test the association of a genetically predicated increase in each risk factor with glioma onset.

RESULTS

Our systematic search identified 36 risk factors that could be proxied using genetic variants. Using MR, we found evidence that four genetically predicted traits increased risk of glioma, glioblastoma or non-glioblastoma: longer leukocyte telomere length, liability to allergic disease, increased alcohol consumption and liability to childhood extreme obesity (> 3 standard deviations from the mean). Two traits decreased risk of non-glioblastoma cancers: increased low-density lipoprotein cholesterol (LDLc) and triglyceride levels. Our findings were similar across sensitivity analyses that made allowance for pleiotropy (genetic confounding).

CONCLUSIONS

Our comprehensive investigation provides evidence of a causal link between both genetically predicted leukocyte telomere length, allergic disease, alcohol consumption, childhood extreme obesity, and LDLc and triglyceride levels, and glioma. The findings from our study warrant further research to uncover mechanisms that implicate these traits in glioma onset.

The Association Between Index of Nutritional Quality (INQ) and Glioma and Evaluation of Nutrient Intakes of These Patients: A Case-Control Study

INTRODUCTION

Glioma is the most common adult brain tumors. Dietary factors may play a role in the etiology of glioma. The Index of Nutritional Quality (INQ) provides a general overview for the nutrient content of a food or a diet. This study aimed to investigate the association between INQ and glioma and nutrient intakes.

MATERIAL AND METHODS

This study was included 128 patients and 256 controls. Dietary intakes of the subjects were evaluated by a food frequency questionnaire (FFQ) and FFQ-derived dietary data were used to calculate INQ scores. Logistic regression was used to calculate the odds ratios and 95% confidence intervals.

RESULTS

Cases had higher intake of total fat, saturated fatty acid (SFA), meats, hydrogenated oils and controls had higher intake of monounsaturated fatty acid, polyunsaturated fatty acid, calcium, dairy, fruits, and nuts. Only the INQ of vitamin C, vitamin E, calcium, and fiber are higher in controls. An inverse association was observed between glioma and INQ of calcium, vitamin E, vitamin C, and fiber.

CONCLUSION

The results of this study propose a healthy diet such as high intake of vitamins C and E, calcium, fiber, food groups like fruits and vegetables, and low-fat milk and nuts; and low consumption of total fat, SFA, and red meat may be protective against glioma.

Tea and coffee consumption in relation to glioma: a case-control study

PURPOSE

Data on the link between tea and coffee consumption and risk of glioma are controversial. We aimed to examine the association between tea and coffee consumption and glioma in Iranian adults.

METHODS

In this hospital-based case-control study, we enrolled 128 pathologically confirmed new cases of glioma and 256 age- and sex-matched controls. Dietary intakes of study participants including tea and coffee consumption was assessed using the validated Block-format 123-item semi-quantitative FFQ. Participants were categorized based on tertiles of tea and coffee consumption. Data on potential confounders were also collected through the use of pre-tested questionnaire.

RESULTS

Individuals with the greatest tea consumption were less likely to have glioma compared with those with the lowest consumption (0.36; 0.20-0.68). This inverse association was not changed after controlling for energy intake. The association remained statistically significant even after taking other potential confounders, including dietary intakes of red and processed meats, legumes and nuts, fruits, salt and mutual effects of tea and coffee consumption, into account (0.33; 0.13-0.86). Additional adjustments for BMI did not alter the association. After controlling for potential confounders, including dietary intakes and BMI, coffee consumption was inversely associated with odds of glioma; such that individuals in the top category of coffee consumption were 91% less likely to have glioma compared with those in the bottom category (0.09; 0.03-0.24). Considering coffee and tea intake combined, those in the highest tertile were 65% less likely to have glioma compared with those in the lowest tertile (0.35; 0.15-0.83).

CONCLUSION

We found an inverse association between tea and coffee consumption and odds of glioma, even after controlling for a wide range of confounders.

Fish intake and the risk of brain tumor: a meta-analysis with systematic review

Background

Fish, rich in ω-3 polyunsaturated fatty acids, has been found to be associated with lower risk of several types of cancer risk, and beneficial for brain development. However, the association between fish intake and brain tumor risk is still inconsistent. Therefore, we conducted a meta-analysis to clarify the association.

Methods

Relevant studies were identified from PubMed and EMBASE databases. The pooled relative risks were obtained by the fixed-effects model when no substantial heterogeneity was observed. Otherwise, the random-effects model was employed. Subgroup and publication bias analyses were also performed.

Results

Nine observational studies were included in the meta-analysis. The pooled relative risk of brain cancer for the highest vs. lowest category of fish intake was 0.83 (95% confidence interval [CI]: 0.70–0.99). No significant heterogeneity was detected. Dose-response analysis showed that the RR per 100 g/day increase in fish intake was 0.95 (95% CI: 0.91–0.98). The results remained unchanged in subgroup and sensitivity analyses.

Conclusions

The results of our meta-analysis suggest that fish intake might be associated with lower risk of brain cancer risk. The finding should be further confirmed by future cohort studies with validated questionnaires and strict control of confounders.

Electronic supplementary material

The online version of this article (doi:10.1186/s12937-016-0223-4) contains supplementary material, which is available to authorized users.

Adherence to the Dietary Approaches to Stop Hypertension-style diet in relation to glioma: a case–control study

Data on the association of adherence to the Dietary Approaches to Stop Hypertension (DASH)-style and glioma are scarce. We aimed to examine the association between adherence to the DASH-style diet and glioma in Iranian adults. In this study, 128 pathologically confirmed cases of glioma were recruited from hospitals and 256 age- and sex-matched controls were enrolled from other wards of the hospital. Dietary intakes were assessed using a 126-item validated FFQ. Adherence to the DASH-style diet was followed considering the healthy and non-healthy foods emphasised in the DASH dietary pattern. After controlling for potential confounders, individuals with the greatest adherence to the DASH diet were 72 % less likely to have glioma compared with those with the lowest adherence (OR 0·28; 95 % CI 0·13, 0·57). Individuals with the highest consumption of fruits had lower odds for having glioma compared with those with the lowest intake (OR 0·31; 95 % CI 0·14, 0·68). A protective association was also observed between consumption of legumes and nuts and risk of glioma (OR 0·23; 95 % CI 0·10, 0·53). We found a significant positive association between red and processed meat (OR 2·60; 95 % CI 1·16, 5·81) and salt intakes (OR 2·87; 95 % CI 1·30, 6·34) and risk of glioma, after taking all potential confounders into account. Adherence to the DASH-style dietary pattern was inversely associated with glioma. In addition, some components of the DASH diet, including red meats and salt intakes, were positively associated with glioma. Consumption of nuts and legumes as well as fruits was inversely associated with glioma. Prospective cohort studies are required to confirm our findings.

Epidemiology

More than 250,000 new cases of primary malignant brain tumors are diagnosed annually worldwide, 77% of which are gliomas. A small proportion of gliomas are caused by the inheritance of rare high-penetrance genetic variants or high-dose radiation. Since 2009, inherited genetic variants in 10 regions near eight different genes have been consistently associated with glioma risk via genome-wide association studies. Most of these variants increase glioma risk by 20-40%, but two have higher relative risks. One on chromosome 8 increases risk of IDH-mutated gliomas sixfold and another that affects TP53 function confers a 2.5-fold increased risk of glioma. Functions of some of the other risk variants are known or suspected, but future research will determine functions of other risk loci. Recent progress also has been made in defining subgroups of glioma based on acquired alterations within tumors. Allergy history has been consistently associated with reduced glioma risk, though the mechanisms have not yet been clarified. Future studies will need to be large enough so that environmental and constitutive genetic risk factors can be examined within molecularly defined, etiologically homogeneous subgroups.

Smoking and Glioma Risk: Evidence From a Meta-Analysis of 25 Observational Studies

To systematically assess the relationship between smoking and glioma risk.A dose-response meta-analysis of case-control and cohort studies was performed. Pertinent studies were identified by searching database and reference lists. Random-effects model was employed to pool the estimates of the relative risks (RRs) with corresponding 95% confidence intervals (CIs).A total of 19 case-control and 6 cohort studies were included. Overall, compared with those who never smoked, the pooled RR and 95% CI was 0.98 (0.92-1.05) for ever smoker. The subgroups were not significantly different regarding risk of glioma except the group of age at start smoking (RR = 1.17, 95% CI: 0.93-1.48 for age < 20; RR = 1.25, 95% CI: 1.02-1.52 for age ≥ 20). Dose-response analysis also suggested no significant association between smoking and the risk of glioma, although some evidence for a linear relationship between smoking and glioma risk was observed.In conclusion, this meta-analysis provides little support for a causal relationship between smoking and risk of glioma.

Red and processed meat consumption and risk of glioma in adults: A systematic review and meta-analysis of observational studies

BACKGROUND

These findings from several observational studies, investigated the association between red meat consumption and gliomas, were inconsistent. We conducted a systematic review and meta-analysis of observational studies to summarize available date on the relation between meat intake and risk of glioma.

MATERIALS AND METHODS

A systematic literature search of relevant reports published until May 2014 of the PubMed/Medline, ISI Web of Knowledge, Excerpta Medica database, Ovid database, Google Scholar, and Scopus databases was conducted. From 723 articles yielded in the preliminary literature search, data from eighteen publications (14 case-control, three cohort, and one nested case-control study) on unprocessed red meat, processed meat, and/or total red meat consumption in relation to glioma in adults were included in the analysis. Quality assessment of studies was performed. Random effects model was used to conduct the meta-analysis.

RESULTS

We found a positive significant association between unprocessed red meat intake and risk of glioma (relative risk [RR] = 1.30; 95% confidence interval [CI]: 1.08-1.58) after excluding three studies with uncertain type of brain cancer. This analysis included only one cohort study which revealed no relation between unprocessed red meat intake and glioma (RR = 1.75; 95% CI: 0.35-8.77). Consumption of processed meats was not related to increased risk of glioma in population-based case-control studies (RR = 1.26; 95% CI: 1.05-1.51) and reduced risk in hospital-based case-controls (RR = 0.79; 95% CI: 0.65-0.97). No significant association was seen between processed red meat intake and risk of glioma in cohort studies (RR: 1.08; 95% CI: 0.84-1.37). Total red meat consumption was not associated with risk of adult glioma in case-control or cohort studies.

CONCLUSION

In this meta-analysis of 18 observational studies, we found a modest positive association between unprocessed red meat intake and risk of gliomas based almost entirely on case-control studies. Processed red meat was overall not associated with risk of gliomas in case-control or cohort studies.

Association between Dietary Vitamin A Intake and the Risk of Glioma: Evidence from a Meta-analysis

The results from epidemiological studies between dietary vitamin A intake and glioma risk is not consistent. Thus, a meta-analysis was conducted to confirm the exact relationship between them. PubMed and Web of Knowledge were used to search the relevant articles up to May 2015. Pooled relative risk (RR) with 95% confidence interval (CI)was calculated using random-effect model. Egger’s test was used to assess the small-study effect. At the end, seven articles with eight case-control studies involving 1841 glioma cases and 4123 participants were included. Our study indicated that highest category of dietary vitamin A intake was significantly associated with reduced risk of glioma (RR = 0.80, 95% CI = 0.62–0.98, p = 0.014, I² = 54.9%). Egger’s test did not find any publication bias. In conclusion, our study indicated that higher category of dietary vitamin A intake could reduce the glioma risk. However, we could not do a dose-response analysis for vitamin A intake with glioma risk due to the limited data in each reported individual article. Due to this limitation, further studies with detailed dose, cases and person-years for each category is wanted to assess this dose-response association.

Association between Vitamin C Intake and Glioma Risk: Evidence from a Meta-Analysis

Background: The field of quantifying the association between the intake of vitamin C and risk of glioma still has conflicts. Thus, we performed a comprehensive meta-analysis to test the hypothesis that a high intake of vitamin C may be a protective effect on glioma risk. Methods: Pertinent studies were identified by a search in PubMed and Web of Knowledge up to June 2014. The random-effect model was used to combine study-specific results. Publication bias was estimated using Begg' funnel plot and Egger's regression asymmetry test. Results: Thirteen articles with 15 studies (2 cohort study and 13 case-control studies) involving 3,409 glioma cases about vitamin C intake and glioma risk were used in this meta-analysis. The combined relative risks (RRs) of glioma associated with vitamin C intake was 0.86 (95% CIs = 0.75-0.99). Overall, significant protective associations were also found in the American population (RRs = 0.85, 95% CIs = 0.73-0.98) and case-control studies (RRs = 0.80, 95% CIs = 0.69-0.93). No publication bias was found. Conclusions: Our analysis indicated that vitamin C intake might decrease the risk of glioma, especially among the Americans.

Birth desires and intentions of women diagnosed with a meningioma

OBJECT To the authors' knowledge, no previous study has examined the impact of meningioma diagnosis on women's birth desires and intentions. In an exploratory study, the authors surveyed women affected by meningioma to determine their attitudes toward childbearing and the influences, including physician recommendations, on this major life decision and compared their responses to those of women in the general population. METHODS Meningioma survivors from the Meningioma Mommas online support group participated in an online survey that included questions on their birth desires and intentions, whether the risk of disease recurrence influenced their reproductive decisions, and risks communicated to them by their physicians. Using chi-square and rank-sum tests, the authors compared the survey participants' responses with those of the general population as assessed by the 2006-2010 National Survey of Family Growth. Logistic regression was used to adjust for differences in age, race, ethnicity, education, parity, pregnancy status, and infertility status in these populations. RESULTS Respondents with meningioma were more likely than those in the general population to report wanting a baby (70% vs 54%, respectively), intending to have a baby (27% vs 12%, respectively), and being very sure about this intention (10% vs 2%, respectively). More than half (32 of 61) of the women of childbearing age reported being advised by a physician about potential risk factors for recurrence of the meningioma, and pregnancy was the most commonly cited risk factor (26 of 61). The most common factor influencing birth desires and intentions was risk of the meningioma returning and requiring more treatment, which was reported by nearly two-thirds of the women in their childbearing years. CONCLUSIONS A majority of the meningioma survivors of childbearing age who completed the survey reported a desire for children, although concern about the risk of meningioma recurrence was an important factor for these women when making reproductive decisions. Physicians are in a position to educate their patients on potential risk factors for recurrence and to provide contact information for services such as counseling and family planning.

Vitamin E intake is not associated with glioma risk: evidence from a meta-analysis

BACKGROUND

Epidemiological studies evaluating the association between vitamin E intake and glioma risk have produced inconsistent results. Thus, we conducted a meta-analysis to summarize the evidence from epidemiological studies of vitamin E intake with the risk of glioma.

METHODS

Pertinent studies were identified by a search in pubmed and web of knowledge up to August 2014. The random-effect model was used to combine the results. Publication bias was estimated using the Egger's regression asymmetry test.

RESULTS

Twelve studies including 3180 glioma cases about vitamin E intake with the risk of glioma were included in this meta-analysis. The combined relative risk (RR) of glioma associated with vitamin E intake was 0.88 (95% CI = 0.69-1.12). The association was significant neither in the case-control studies nor in the cohort studies. No publication biases were found.

CONCLUSIONS

Our analysis indicated that vitamin E intake is not associated with the risk of glioma.

Association between fruit and vegetable intake and risk for glioma: a meta-analysis

OBJECTIVE

Epidemiologic studies evaluating the association between the intake of vegetables and fruit and the risk for glioma have produced inconsistent results. Therefore, the aim of this study was to test the hypothesis that higher vegetable and fruit intake may have a protective effect on risk for glioma.

METHODS

Pertinent studies were identified by a search in PubMed, Web of Knowledge, and Wan Fang Med Online up to January 2014. Random-effect model was used to combine study-specific results. Publication bias was estimated using Begg's funnel plot and Egger's regression asymmetry test.

RESULTS

Fifteen studies involving 5562 cases focusing on vegetable intake and 17 studies involving 3994 cases of fruit intake compared with the risk for glioma were included in this meta-analysis. The combined relative risk (RR) of glioma associated with vegetable intake was 0.775 (95% confidence interval [CI], 0.688-0.872) overall, and the association for subgroup analysis by study design, sources of control, ethnicity, and number of cases was consistent with overall data. For fruit intake and glioma risk, significant protective associations were found in an Asian population (RR, 0.573; 95% CI, 0.346-0.947), but not in a white population. No publication bias was found.

CONCLUSIONS

This analysis indicated that intake of vegetables might have a protective effect on glioma. The intake of fruit might have a protective effect on glioma in the Asian population; however, the results need to be confirmed.

Alcohol consumption and risk of glioma: a meta-analysis of 19 observational studies

The relationship between risk of glioma and alcohol consumption has been widely studied, but results have been conflicting. We therefore conducted a meta-analysis of observational studies to systematically assess the relationship between alcohol drinking and risk of glioma. Two electronic databases (PubMed and EMBASE) were searched from inception to 8 August 2013 to identify pertinent studies that linked alcohol drinking with glioma risk. We used a random-effects model to calculate the overall relative risk (RR) with corresponding 95% confidence intervals (CIs). Fifteen case-control and four cohort studies were identified for this analysis. The combined RR for total alcohol drinkers versus non-drinkers was 0.96 (95% CI: 0.89–1.04). In the subgroup analysis by geographic area, a significant association was observed in North American studies (RR = 0.78, 95% CI: 0.65–0.93), but not in European or Asian/Australian studies. In the subgroup analysis by study design, a borderline significant association emerged in population-based case-control studies (RR = 0.82, 95% CI: 0.68–0.99), but not in hospital-based case-control studies (RR = 1.00, 95% CI: 0.99–1.01) or cohort group (RR = 1.03, 95% CI: 0.88–1.20). Our results show no material association between alcohol consumption and risk of glioma existed. Further prospective evidences are needed to confirm this association.

Residential radon and brain tumour incidence in a Danish cohort

Background

Increased brain tumour incidence over recent decades may reflect improved diagnostic methods and clinical practice, but remain unexplained. Although estimated doses are low a relationship between radon and brain tumours may exist.

Objective

To investigate the long-term effect of exposure to residential radon on the risk of primary brain tumour in a prospective Danish cohort.

Methods

During 1993–1997 we recruited 57,053 persons. We followed each cohort member for cancer occurrence from enrolment until 31 December 2009, identifying 121 primary brain tumour cases. We traced residential addresses from 1 January 1971 until 31 December 2009 and calculated radon concentrations at each address using information from central databases regarding geology and house construction. Cox proportional hazards models were used to estimate incidence rate-ratios (IRR) and 95% confidence intervals (CI) for the risk of primary brain tumours associated with residential radon exposure with adjustment for age, sex, occupation, fruit and vegetable consumption and traffic-related air pollution. Effect modification by air pollution was assessed.

Results

Median estimated radon was 40.5 Bq/m³. The adjusted IRR for primary brain tumour associated with each 100 Bq/m³ increment in average residential radon levels was 1.96 (95% CI: 1.07; 3.58) and this was exposure-dependently higher over the four radon exposure quartiles. This association was not modified by air pollution.

Conclusions

We found significant associations and exposure-response patterns between long-term residential radon exposure radon in a general population and risk of primary brain tumours, adding new knowledge to this field. This finding could be chance and needs to be challenged in future studies.

Risk of second primary malignancies after nasopharyngeal carcinoma: a population-based cohort study in Taiwan

BACKGROUND

The purpose of this study was to examine the risk of second primary malignancy (SPM) after nasopharyngeal carcinoma (NPC).

METHODS

We compared the incidence of SPM in patients diagnosed with NPC at the end of 2009 using the data extracted from the Taiwan Longitudinal Health Insurance Database between 2001 and 2008 (n = 10,299), with age-matched controls (1:10; n = 102,990).

RESULTS

We found a 55% increased risk of SPM in patients diagnosed with NPC, compared to the risk of first malignancy in the age-matched controls (incidence rate ratio [IRR] = 1.55; p < .0001). Although the diagnosis of SPM was negatively correlated with the survival of patients with NPC (p = .0011), primary NPC did not display any synergic effect on the survival of patients with SPM, compared to age-matched controls with a newly diagnosed malignancy (p = .8986).

CONCLUSION

NPC is associated with an increased risk of developing an SPM.

The activity of class I, II, III and IV of alcohol dehydrogenase (ADH) isoenzymes and aldehyde dehydrogenase (ALDH) in brain cancer

The brain being highly sensitive to the action of alcohol is potentially susceptible to its carcinogenic effects. Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) are the main enzymes involved in ethanol metabolism, which leads to the generation of carcinogenic acetaldehyde. Human brain tissue contains various ADH isoenzymes and possess also ALDH activity. The purpose of this study was to compare the capacity for ethanol metabolism measured by ADH isoenzymes and ALDH activity in cancer tissues and healthy brain cells. The samples were taken from 62 brain cancer patients (36 glioblastoma, 26 meningioma). For the measurement of the activity of class I and II ADH isoenzymes and ALDH activity, the fluorometric methods were used. The total ADH activity and activity of class III and IV isoenzymes were measured by the photometric method. The total activity of ADH, and activity of class I ADH were significantly higher in cancer cells than in healthy tissues. The other tested classes of ADH and ALDH did not show statistically significant differences of activity in cancer and in normal cells. Analysis of the enzymes activity did not show significant differences depending on the location of the tumor. The differences in the activity of total alcohol dehydrogenase, and class I isoenzyme between cancer tissues and healthy brain cells might be a factor for metabolic changes and disturbances in low mature cancer cells and additionally might be a reason for higher level of acetaldehyde which can intensify the carcinogenesis.

On the origin of cancer metastasis

Metastasis involves the spread of cancer cells from the primary tumor to surrounding tissues and to distant organs and is the primary cause of cancer morbidity and mortality. In order to complete the metastatic cascade, cancer cells must detach from the primary tumor, intravasate into the circulatory and lymphatic systems, evade immune attack, extravasate at distant capillary beds, and invade and proliferate in distant organs. Currently, several hypotheses have been advanced to explain the origin of cancer metastasis. These involve an epithelial mesenchymal transition, an accumulation of mutations in stem cells, a macrophage facilitation process, and a macrophage origin involving either transformation or fusion hybridization with neoplastic cells. Many of the properties of metastatic cancer cells are also seen in normal macrophages. A macrophage origin of metastasis can also explain the long-standing "seed and soil" hypothesis and the absence of metastasis in plant cancers. The view of metastasis as a macrophage metabolic disease can provide novel insight for therapeutic management.

A comparative profile of methanol extracts of Allium cepa and Allium sativum in diabetic neuropathy in mice

Introduction:

Diabetic Neuropathy (DN) is a major microvascular complication of uncontrolled diabetes. This may result from increased oxidative stress that accompanies diabetes. Hence plants with antioxidant action play an important role in management of diabetes and its complications.

Materials and Methods:

This study was designed to evaluate preventive as well as curative effect of methanol extracts of outer scales and edible portions of two plants with established antioxidant action - Allium cepa and Allium sativum, in induced DN in albino mice. Mice were divided into control, diabetic and test extracts treated groups. Test extracts were administered daily at a dose of 200 mg/kg p.o. for 21 days, in the preventive group prior to onset of DN, and in the curative group after the onset of DN. Hyperalgesia and oxidative stress markers were assessed. STZ-diabetic mice showed a significant thermal hyperalgesia (as assessed by the tail-flick test), indicating development of DN.

Results:

Treatment with test extracts prevented loss in body weight, decreased plasma glucose level, and significantly ameliorated the hyperalgesia, TBARS, serum nitrite and GSH levels in diabetic mice.

Conclusion:

Methanol extract of outer scales of onion has shown most significant improvement; may be due to higher content of phenolic compounds in outer scales of A. cepa.