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Cureus Jun 2021Vitamin E is a fat-soluble vitamin and an antioxidant that prevents the peroxidation of lipid in vitro. The antioxidant role of vitamin E in preventing adverse... (Review)
Review
Vitamin E is a fat-soluble vitamin and an antioxidant that prevents the peroxidation of lipid in vitro. The antioxidant role of vitamin E in preventing adverse cardiovascular outcomes is controversial as some studies support it, while others reject it. Therefore, this review aims to determine whether there is an association between vitamin E and cardiovascular diseases (CVDs). An electronic search was done to find out relevant articles. Papers were shortlisted after the initial title and abstract screen. A full-text study was done, and inclusion and exclusion criteria were applied before the quality assessment of each paper was done. Only high-quality papers were selected for analysis. Full-text articles of the last ten years were included, while non-English articles, gray literature, and animal studies were excluded. The majority of the papers, including 75% of the total population in this review, suggested no role of vitamin E in preventing CVD and CVD mortality. Some studies also suggested that a high level of vitamin E can be associated with adverse cardiovascular outcomes. Thus, one should be prudent about taking vitamin E supplementation for cardiovascular risk prevention.
PubMed: 34277234
DOI: 10.7759/cureus.15616 -
Clinical Nutrition ESPEN Apr 2023Robust evidence have shown diet or dietary components in playing a direct role on cancer chemoprevention such as breast cancer (BC), and also prevention against cancer... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Robust evidence have shown diet or dietary components in playing a direct role on cancer chemoprevention such as breast cancer (BC), and also prevention against cancer therapy side effects. In this context, vitamin E isoforms have been associated with tumor suppression pathways, mainly related to proliferation, invasion, metastasis, tumor metabolism and chemoresistance.
OBJECTIVE
Therefore, we performed a systematic review with meta-analysis to assess the effects of vitamin E consumption and/or supplementation on breast cancer risk, treatment, and outcomes.
METHODS
The studies were selected in the electronic databases PubMed, Science Direct, Scopus and Web of Science.
RESULTS
A total of 22 articles were selected, which nine manuscripts we perform the meta-analysis. The summary effect estimate did not indicate any significant association between consumption versus non-consumption of total vitamin E and breast cancer risk. After assessing the effects of vitamin E supplementation on breast cancer risk, only two had data for comparison and vitamin E supplementation presented no impact on breast cancer risk. However, the summary effect estimate from the included studies indicated that vitamin E consumption was inversely associated with breast cancer recurrence in the control group. There are no significant results regarding dietary or supplemental vitamin E intake and BC risk reduction.
CONCLUSION
Finally, regarding recurrence, survival, and mortality, the results indicated that vitamin E consumption was inversely associated with breast cancer recurrence, although no association was found for breast cancer mortality.
Topics: Humans; Female; Vitamin E; Breast Neoplasms; Neoplasm Recurrence, Local; Diet; Dietary Supplements
PubMed: 36963866
DOI: 10.1016/j.clnesp.2023.01.032 -
Frontiers in Nutrition 2022Brain 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...
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, = 54.7%, = 0.007), β-carotene (RR = 0.78, 95%CI:0.66-0.93, = 0, = 0.460), and folate (RR = 0.66, 95%CI:0.55-0.80, = 0, = 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, = 0, = 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% ( = 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.
PubMed: 35967781
DOI: 10.3389/fnut.2022.935706 -
Nutrition and Cancer 2022The term vitamin E describes tocopherols and tocotrienols, whose chemical variations result in different biological activities including antioxidants. Neuroprotective...
The term vitamin E describes tocopherols and tocotrienols, whose chemical variations result in different biological activities including antioxidants. Neuroprotective effects of alpha-tocopherol against different toxins are assumed, therefore, it is discussed as a possible protective factor for adverse effects in cancer treatment. In July 2020, a systematic search was conducted searching five databases (Embase, Cochrane, PsychInfo, Cinahl, Medline) to find studies concerning the impact of α-tocopherol application and its potential harm on cancer patients. From 7546 search results, 22 publications referring to 20 studies with 1941 patients were included. Included patients were diagnosed with various cancer types and stages. Outcome variables were overall survival of cancer, symptom management of mucositis and chemotherapy-induced peripheral neuropathy (CIPN). The studies had different methodological qualities (mainly acceptable) and reported heterogeneous results: some reported significant improvement of mucositis and CIPN while others did not find changes concerning these endpoints. Due to heterogeneous results and methodical limitations of the included studies, a clear statement regarding the effectiveness of α-tocopherol as complementary treatment for cancer patients is not possible. Despite findings regarding reduction of oral side effects, usage of α-tocopherol during therapy must be discouraged because of potential negative influence on survival rates.
Topics: Antioxidants; Humans; Mucositis; Neoplasms; Protein Isoforms; Tocotrienols; Vitamin E; alpha-Tocopherol
PubMed: 34918607
DOI: 10.1080/01635581.2021.2014905 -
Hepatology (Baltimore, Md.) Mar 2024The association between fiber or whole grain intakes and the risk of liver cancer remains unclear. We assessed the associations between fiber or whole grain intakes and...
BACKGROUND AND AIMS
The association between fiber or whole grain intakes and the risk of liver cancer remains unclear. We assessed the associations between fiber or whole grain intakes and liver cancer risk among 2 prospective studies, and systematically reviewed and meta-analyzed these results with published prospective studies.
APPROACH AND RESULTS
A total of 111,396 participants from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) and 26,085 men from the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study were included. Intakes of total fiber and whole grains were estimated from validated food frequency questionnaires. Study-specific HRs and 95% CI with liver cancer risk were estimated using multivariable-adjusted Cox regression. We systematically reviewed existing literature, and studies were combined in a dose-response meta-analysis. A total of 277 (median follow-up = 15.6 y) and 165 (median follow-up = 16.0 y) cases of liver cancer were observed in Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial and Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, respectively. Dietary fiber was inversely associated with liver cancer risk in Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (HR 10g/day : 0.69; 95% CI: 0.55-0.86). No significant associations were observed between whole grain intakes and liver cancer risk in either study. Our meta-analysis included 2383 incident liver cancer cases (7 prospective cohorts) for fiber intake and 1523 cases (5 prospective cohorts) for whole grain intake; combined HRs for liver cancer risk were 0.83 (0.76-0.91) per 10 g/day of fiber and 0.92 (0.85-0.99) per 16 g/day (1 serving) of whole grains.
CONCLUSIONS
Dietary fiber and whole grains were inversely associated with liver cancer risk. Further research exploring potential mechanisms and different fiber types is needed.
PubMed: 38441973
DOI: 10.1097/HEP.0000000000000819 -
Surgery For Obesity and Related... Apr 2021Vitamin E, a fat-soluble vitamin with antioxidant properties, is thought to modulate enzymes involved in signal transduction, affect gene expression, and have... (Review)
Review
Vitamin E, a fat-soluble vitamin with antioxidant properties, is thought to modulate enzymes involved in signal transduction, affect gene expression, and have immunomodulatory capabilities. Severe vitamin E deficiency is associated with neuronal disorders, impaired immune response, hemolytic anemia, and oxidative-based disorders. Patients who undergo bariatric surgery (BS), especially malabsorptive procedures, are at greater risk of developing fat-soluble vitamin deficiencies. Current data on vitamin E statuses among BS patients are limited. Therefore, this systematic review has summarized the scientific literature on vitamin E and examined its status among patients following different types of BS. Searches of the MEDLINE and Embase databases were performed, followed by hand-searching of reference lists from all relevant papers. Of the 671 initially identified articles, 24 met the inclusion criteria: 1 study on adjustable gastric banding patients (n = 21), 4 studies on sleeve gastrectomy patients (n = 173), 12 studies on Roux-en-Y gastric bypass patients (n = 689) and 12 studies on biliopancreatic diversion with or without duodenal switch (n = 799) or single anastomosis duodeno-ileal bypass with sleeve gastrectomy patients (n = 163). Results suggest that patients who undergo malabsorptive procedures are at higher risk of developing vitamin E deficiency, although clinical manifestations of vitamin E deficits following BS are rarely documented. The optimal dose of vitamin E supplementation required for prevention of deficiency or for treatment following BS has yet to be established. Future observational and intervention studies are needed to bridge the gaps in existing knowledge.
Topics: Bariatric Surgery; Biliopancreatic Diversion; Gastrectomy; Gastric Bypass; Humans; Obesity, Morbid; Vitamin E
PubMed: 33323330
DOI: 10.1016/j.soard.2020.10.029 -
Nutrients Feb 2023The increasing burden of nonalcoholic fatty liver disease (NAFLD) requires innovative management strategies, but an effective pharmacological agent has yet to be found.... (Review)
Review
The increasing burden of nonalcoholic fatty liver disease (NAFLD) requires innovative management strategies, but an effective pharmacological agent has yet to be found. Apart from weight loss and lifestyle adjustments, one isomer of the vitamin E family-alpha-tocopherol-is currently recommended for nondiabetic steatohepatitis patients. Another member of the vitamin E family, tocotrienol (T3), has anti-inflammatory and antioxidant properties that reach beyond those of alpha-tocopherol, making it a potential agent for use in NAFLD management. This systematic review aimed to provide an overview of the effects of T3 supplementation on NAFLD from both clinical and preclinical perspectives. A literature search was performed in October 2022 using PubMed, Scopus and Web of Science. Original research articles reporting NAFLD outcomes were included in this review. The search located 12 articles (8 animal studies and 4 human studies). The literature reports state that T3 isomers or natural mixtures (derived from palm or annatto) improved NAFLD outcomes (liver histology, ultrasound or liver profile). However, the improvement depended on the severity of NAFLD, study period and type of intervention (isomers/mixture of different compositions). Mechanistically, T3 improved lipid metabolism and prevented liver steatosis, and reduced mitochondrial and endoplasmic reticulum stress, inflammation and ultimately liver fibrosis. In summary, T3 could be a potential agent for use in managing NAFLD, pending more comprehensive preclinical and human studies.
Topics: Animals; Humans; Non-alcoholic Fatty Liver Disease; Tocotrienols; alpha-Tocopherol; Liver; Vitamin E
PubMed: 36839192
DOI: 10.3390/nu15040834 -
Clinical Nutrition ESPEN Dec 2021Cardiovascular diseases (CVDs) are the number one cause of mortality worldwide. Apolipoprotein B (ApoB), apolipoprotein A1 (ApoA1), and ApoB/ApoA1 ratio are considered... (Meta-Analysis)
Meta-Analysis
BACKGROUND AND AIM
Cardiovascular diseases (CVDs) are the number one cause of mortality worldwide. Apolipoprotein B (ApoB), apolipoprotein A1 (ApoA1), and ApoB/ApoA1 ratio are considered as predictors of CVD alongside with lipid profile. Evidence suggest that nutrients with antioxidant properties, especially vitamin E, are essential for a healthy cardiovascular system. The aim of present meta-analysis was to determine the effect alpha-tocopherol on ApoA1 and ApoB levels.
METHODS
PubMed-Medline and SCOPUS databases and Google Scholar were searched up to July 2021. Random-effects model was employed to perform meta-analysis. In order to find heterogeneity sources, subgroup analysis was performed. Trim and fill analysis was performed in case of presence of publication bias. Quality assessment was performed using Cochrane Collaboration's tool.
RESULTS
Seven eligible studies, involving 1284 individuals were included. Mean age of participants ranged between 25.4 and 59 years. There was no significant effect of vitamin E supplementation on Apo A1 (SMD = 0.22 IU/d; 95% CI: -0.38, 0.28; P = 0.481) and Apo B levels (SMD = -0.62 IU/d; 95% CI: -1.94, 0.70; P = 0.360).
CONCLUSION
No remarkable effect of vitamin E supplementation was observed on ApoA1 and ApoB levels in adults. Additional studies investigating the influence of vitamin E on apolipoproteins as primary outcome with larger sample size are suggested.
Topics: Adult; Antioxidants; Apolipoprotein A-I; Apolipoproteins; Dietary Supplements; Humans; Middle Aged; Vitamin E
PubMed: 34857183
DOI: 10.1016/j.clnesp.2021.09.013 -
Sao Paulo Medical Journal = Revista... 2021Despite the several options available for supplements containing vitamins C and E, evidence regarding the prevalence of deficiency or insufficiency of these vitamins is... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Despite the several options available for supplements containing vitamins C and E, evidence regarding the prevalence of deficiency or insufficiency of these vitamins is weak.
OBJECTIVES
To estimate the prevalence of deficiency or insufficiency of vitamins C and E and associated factors among women of childbearing age, in Brazil.
DESIGN AND SETTING
Systematic review and meta-analysis conducted at a Brazilian public university.
METHODS
A search from index inception until May 2020 was conducted. Meta-analyses were performed using inverse variance for fixed models, with summary proportions calculation using Freeman-Tukey double arcsine (base case). Reporting and methodological quality were assessed using the Joanna Briggs Institute tool for prevalence studies.
RESULTS
Our review identified 12 studies, comprising 1,316 participants, especially breastfeeding women. There was at least one quality weakness in all studies, mainly regarding sampling method (i.e. convenience sampling) and small sample size. The prevalence of vitamin C deficiency ranged from 0% to 40%. Only vitamin E deficiency was synthetized in meta-analyses, with mean prevalences of 6% regardless of the alpha-tocopherol cutoff in plasma, and 5% and 16% for cutoffs of < 1.6-12.0 mmol/l and < 16.2 mmol/l, respectively. The cumulative meta-analysis suggested that a trend to lower prevalence of vitamin E deficiency occurred in recent studies.
CONCLUSIONS
Although the studies identified in this systematic review had poor methodological and reporting quality, mild-moderate vitamin C and E deficiencies were identified, especially in breastfeeding women. Thus, designing and implementing policies does not seem to be a priority, because the need has not been properly dimensioned among women of childbearing age in Brazil.
REGISTRATION NUMBER IN PROSPERO
CRD42020221605.
Topics: Ascorbic Acid; Brazil; Dietary Supplements; Female; Humans; Prevalence; Vitamins
PubMed: 34586287
DOI: 10.1590/1516-3180.2020.0799.R1.0904221 -
Frontiers in Nutrition 2022This study systematized information about vitamin E concentration in healthy breast milk during different stages of lactation in order to support the strategies of...
OBJECTIVE
This study systematized information about vitamin E concentration in healthy breast milk during different stages of lactation in order to support the strategies of protecting postpartum women and infants.
METHODS
Studies published before April 30th, 2021, which detected vitamin E concentration in breast milk of healthy women by High Performance Liquid Chromatography (HPLC) or Ultra High Performance Liquid Chromatographic (UHPLC), were evaluated. The databases of CNKI (Chinese), WanFang Data (Chinese), VIP (Chinese), PubMed, Cochrane Library, Web of Science and Embase were searched. The random effect models were used to conduct meta-analysis by the statistical software package Stata 14.0.
RESULTS
In all 4,791 searched publications, 53 with full text were selected, which included 46 descriptive studies, 1 case-control study, 1 non-randomized controlled trial, and 5 randomized controlled trials. The pooled mean of vitamin E concentration was 10.57 mg α-TE/L (95%CI 8.94-12.20) in colostrum, 4.03 mg α-TE/L (95%CI 3.29-4.77) in transitional milk and 3.29 mg α-TE/L (95%CI 2.95-3.64) in mature milk. Subgroup analysis showed that vitamin E concentration of colostrum in Asian countries was lower than that in Western countries in colostrum and transitional milk.
CONCLUSIONS
Vitamin E concentration in breast milk decreased during lactation until the mature milk was produced. The vitamin E concentration of colostrum in Asian countries was evidently lower than that in Western countries. The vitamin E concentration in mature milk is similar in different regions. The concentration of vitamin E in breast milk started to be stable from about 2 to 3 weeks postpartum until 4 or 6 months postpartum, but it needs additional evidence to support.
PubMed: 36438759
DOI: 10.3389/fnut.2022.1050011