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The Cochrane Database of Systematic... Dec 2018Vitamins and minerals play multiple functions within the central nervous system which may help to maintain brain health and optimal cognitive functioning.... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Vitamins and minerals play multiple functions within the central nervous system which may help to maintain brain health and optimal cognitive functioning. Supplementation of the diet with various vitamins and minerals has been suggested as a means of maintaining cognitive function, or even of preventing dementia, in later life.
OBJECTIVES
To evaluate the effects of vitamin and mineral supplementation on cognitive function in cognitively healthy people aged 40 years or more.
SEARCH METHODS
We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group's (CDCIG) specialised register, as well as MEDLINE, Embase, PsycINFO, CINAHL, ClinicalTrials.gov and the WHO Portal/ICTRP from inception to 26th January 2018.
SELECTION CRITERIA
We included randomised controlled trials that evaluated the cognitive effects on people aged 40 years or more of any vitamin or mineral supplements taken by mouth for at least three months.
DATA COLLECTION AND ANALYSIS
Study selection, data extraction, and quality assessments were done in duplicate. Vitamins were considered broadly in the categories of B vitamins, antioxidant vitamins, and combinations of both. Minerals were considered separately, where possible. If interventions and outcomes were considered sufficiently similar, then data were pooled. In order to separate short-term cognitive effects from possible longer-term effects on the trajectory of cognitive decline, data were pooled for various treatment durations from 3 months to 12 months and up to 10 years or more.
MAIN RESULTS
In total, we included 28 studies with more than 83,000 participants. There were some general limitations of the evidence. Most participants were enrolled in studies which were not designed primarily to assess cognition. These studies often had no baseline cognitive assessment and used only brief cognitive assessments at follow-up. Very few studies assessed the incidence of dementia. Most study reports did not mention adverse events or made only very general statements about them. Only 10 studies had a mean follow-up > 5 years. Only two studies had participants whose mean age was < 60 years at baseline. The risk of bias in the included studies was generally low, other than a risk of attrition bias for longer-term outcomes. We considered the certainty of the evidence behind almost all results to be moderate or low.We included 14 studies with 27,882 participants which compared folic acid, vitamin B12, vitamin B6, or a combination of these to placebo. The majority of participants were aged over 60 years and had a history of cardio- or cerebrovascular disease. We found that giving B vitamin supplements to cognitively healthy adults, mainly in their 60s and 70s, probably has little or no effect on global cognitive function at any time point up to 5 years (SMD values from -0.03 to 0.06) and may also have no effect at 5-10 years (SMD -0.01). There were very sparse data on adverse effects or on incidence of cognitive impairment or dementia.We included 8 studies with 47,840 participants in which the active intervention was one or more of the antioxidant vitamins: ß-carotene, vitamin C or vitamin E. Results were mixed. For overall cognitive function, there was low-certainty evidence of benefit associated with ß-carotene after a mean of 18 years of treatment (MD 0.18 TICS points, 95% CI 0.01 to 0.35) and of vitamin C after 5 years to 10 years (MD 0.46 TICS points, 95% CI 0.14 to 0.78), but not at earlier time points. From two studies which reported on dementia incidence, there was low-certainty evidence of no effect of an antioxidant vitamin combination or of vitamin E, either alone or combined with selenium. One of the included studies had been designed to look for effects on the incidence of prostate cancer; it found a statistically significant increase in prostate cancer diagnoses among men taking vitamin E.One trial with 4143 participants compared vitamin D3 (400 IU/day) and calcium supplements to placebo. We found low- to moderate-certainty evidence of no effect of vitamin D3 and calcium supplements at any time-point up to 10 years on overall cognitive function (MD after a mean of 7.8 years -0.1 MMSE points, 95% CI -0.81 to 0.61) or the incidence of dementia (HR 0.94, 95% CI 0.72 to 1.24). A pilot study with 60 participants used a higher dose of vitamin D3 (4000 IU on alternate days) and found preliminary evidence that this dose probably has no effect on cognitive function over six months.We included data from one trial of zinc and copper supplementation with 1072 participants. There was moderate-certainty evidence of little or no effect on overall cognitive function (MD 0.6 MMSE points, 95% CI -0.19 to 1.39) or on the incidence of cognitive impairment after 5 years to 10 years. A second smaller trial provided no usable data, but reported no cognitive effects of six months of supplementation with zinc gluconate.From one study with 3711 participants, there was low-certainty evidence of no effect of approximately five years of selenium supplementation on the incidence of dementia (HR 0.83, 95% CI 0.61 to 1.13).Finally, we included three trials of complex supplements (combinations of B vitamins, antioxidant vitamins, and minerals) with 6306 participants. From the one trial which assessed overall cognitive function, there was low-certainty evidence of little or no effect on the TICS (MD after a mean of 8.5 years 0.12, 95% CI -0.14 to 0.38).
AUTHORS' CONCLUSIONS
We did not find evidence that any vitamin or mineral supplementation strategy for cognitively healthy adults in mid or late life has a meaningful effect on cognitive decline or dementia, although the evidence does not permit definitive conclusions. There were very few data on supplementation starting in midlife (< 60 years); studies designed to assess cognitive outcomes tended to be too short to assess maintenance of cognitive function; longer studies often had other primary outcomes and used cognitive measures which may have lacked sensitivity. The only positive signals of effect came from studies of long-term supplementation with antioxidant vitamins. These may be the most promising for further research.
Topics: Adult; Aged; Antioxidants; Ascorbic Acid; Calcium; Cholecalciferol; Cognition; Cognitive Dysfunction; Copper; Dementia; Dietary Supplements; Folic Acid; Humans; Middle Aged; Minerals; Randomized Controlled Trials as Topic; Selenium; Vitamin A; Vitamin B 12; Vitamin B 6; Vitamin E; Vitamins; Zinc; beta Carotene
PubMed: 30556597
DOI: 10.1002/14651858.CD011906.pub2 -
European Journal of Nutrition Oct 2022The associations between blood retinol, retinol-binding protein (RBP) concentrations and diabetes mellitus were inconsistent in literature. The objective is to... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
The associations between blood retinol, retinol-binding protein (RBP) concentrations and diabetes mellitus were inconsistent in literature. The objective is to investigate these associations by a systematic review and meta-analysis and provide basis for clinical intervention.
METHODS
PubMed, Web of science, and Cochrane databases were searched from the beginning to July 1, 2021. A total of 13 studies on retinol and 31 studies on RBP are included in the current meta-analysis.
RESULTS
The blood retinol concentration was significantly lower in the type I diabetes mellitus (T1DM) [standardized mean difference (SMD) (95% CI): - 0.59 (- 0.81, - 0.37), P < 0.01] and gestational diabetes mellitus (GDM) patients [SMD (95% CI): - 0.54 (- 0.87, - 0.20), P < 0.01] than in the controls. However, the difference was not significant between the type II diabetes mellitus (T2DM) patients and the controls. The RBP concentration was significantly higher in the diabetic patients than in the controls [SMD (95% CI): 0.24 (0.12, 0.35), P < 0.01]. Particularly, the RBP concentration was significantly higher in the T2DM and GDM patients.
CONCLUSION
The blood retinol concentration was negatively associated with T1DM and GDM, while the blood RBP concentration was positively associated with T2DM and GDM. Future work should use a more sensitive retinol measurement method like retinol isotope dilution method to confirm whether blood retinol concentration differs between the diabetes patients and the controls.
Topics: Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetes, Gestational; Female; Humans; Observational Studies as Topic; Pregnancy; Retinol-Binding Proteins; Vitamin A
PubMed: 35318493
DOI: 10.1007/s00394-022-02859-2 -
Antioxidants (Basel, Switzerland) Aug 2023β-Carotene, which is a prominent carotenoid with notable antioxidant properties, may play a role in countering the oxidative stresses induced by malaria. The... (Review)
Review
BACKGROUND
β-Carotene, which is a prominent carotenoid with notable antioxidant properties, may play a role in countering the oxidative stresses induced by malaria. The association between β-carotene levels and malaria is not yet fully understood, prompting this systematic review and meta-analysis.
METHODS
A rigorous search of databases, including Nursing and Allied Health Premium, EMBASE, MEDLINE, Ovid, PubMed, Scopus, and Google Scholar, was undertaken to collate studies that focused on β-carotene levels in malaria patients. The selected studies underwent critical appraisal, followed by data extraction for a meta-analysis.
RESULTS
Of the 2498 records initially identified, 10 were deemed suitable for synthesis. A considerable number of these studies indicated a pronounced reduction in β-carotene levels among malaria patients in contrast with uninfected individuals. The meta-analysis, encompassing 421 malaria patients and 240 uninfected controls, revealed a significant correlation between reduced β-carotene levels and malaria ( < 0.01, Hedges's g: -1.26, 95% CI: -2.00-(-0.53), I: 93.86%, seven studies).
CONCLUSIONS
The conducted systematic review and meta-analysis corroborated the correlation between lower β-carotene levels and malaria. The intricate relationship between malaria and β-carotene merits deeper exploration. A comprehensive understanding of this association might pave the way for innovative therapeutic approaches leveraging the antioxidant attributes of β-carotene to combat malaria-induced oxidative stress.
PubMed: 37759990
DOI: 10.3390/antiox12091687 -
Brain, Behavior, and Immunity Oct 2023Major depression (MDD) and bipolar disorder (BD) are linked to immune activation, increased oxidative stress, and lower antioxidant defenses. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Major depression (MDD) and bipolar disorder (BD) are linked to immune activation, increased oxidative stress, and lower antioxidant defenses.
OBJECTIVES
To systematically review and meta-analyze all data concerning biomarkers of reverse cholesterol transport (RCT), lipid-associated antioxidants, lipid peroxidation products, and autoimmune responses to oxidatively modified lipid epitopes in MDD and BD.
METHODS
Databases including PubMed, Google scholar and SciFinder were searched to identify eligible studies from inception to January 10th, 2023. Guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed.
RESULTS
The current meta-analysis included 176 studies (60 BD and 116 MDD) and examined 34,051 participants, namely 17,094 with affective disorders and 16,957 healthy controls. Patients with MDD and BD showed a) significantly decreased RCT (mainly lowered high-density lipoprotein cholesterol and paraoxonase 1); b) lowered lipid soluble vitamins (including vitamin A, D, and coenzyme Q10); c) increased lipid peroxidation and aldehyde formation, mainly increased malondialdehyde (MDA), 4-hydroxynonenal, peroxides, and 8-isoprostanes; and d) Immunoglobulin (Ig)G responses to oxidized low-density lipoprotein and IgM responses to MDA. The ratio of all lipid peroxidation biomarkers/all lipid-associated antioxidant defenses was significantly increased in MDD (standardized mean difference or SMD = 0.433; 95% confidence intervals (CI): 0.312; 0.554) and BD (SMD = 0.653; CI: 0.501-0.806). This ratio was significantly greater in BD than MDD (p = 0.027).
CONCLUSION
In MDD/BD, lowered RCT, a key antioxidant and anti-inflammatory pathway, may drive increased lipid peroxidation, aldehyde formation, and autoimmune responses to oxidative specific epitopes, which all together cause increased immune-inflammatory responses and neuro-affective toxicity.
Topics: Humans; Bipolar Disorder; Lipid Peroxidation; Depression; Antioxidants; Depressive Disorder, Major; Aldehydes; Biomarkers; Cholesterol; Lipids
PubMed: 37557967
DOI: 10.1016/j.bbi.2023.08.007 -
Annals of Hematology Jul 2023All-trans retinoic acid (ATRA) application is a novel treatment approach for primary immune thrombocytopenia (ITP). This study aimed to evaluate the efficacy and safety... (Meta-Analysis)
Meta-Analysis
All-trans retinoic acid (ATRA) application is a novel treatment approach for primary immune thrombocytopenia (ITP). This study aimed to evaluate the efficacy and safety of ATRA in the treatment of ITP. The databases of PubMed (MEDLINE), EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and China National Knowledge Internet were searched on August 5, 2022, to find randomized controlled trials (RCTs) and observational studies. Five observational studies and four RCTs from China were included, and 760 Chinese patients were analyzed. In the five observational studies, the pooled overall response rate (ORR) and complete response rate (CRR) were 59.5% (95% confidence interval [CI], 52.4-66.4%) and 20.6% (95% CI, 14.3-27.6%), respectively. In the selected four RCTs, the pooled odds ratios for sustained response rate, ORR, and CRR were 3.00 (95% CI, 1.97-4.57; P < 0.01), 3.21 (95% CI, 2.15-4.78; P < 0.01), and 2.12 (95% CI, 1.17-3.86; P = 0.01), respectively. ATRA was associated with a reduction in relapse rate and salvage treatment rate (odds ratio, 0.30; 95% CI, 0.18-0.50; P < 0.01; 0.36; 95% CI, 0.23-0.56; P < 0.01, respectively). The pooled odds ratios for grade 1-2 dry skin, headache (or dizziness), and rash acneiform were 49.99 (95% CI, 16.05-155.67; P < 0.01), 1.75 (95% CI, 0.98-3.12; P = 0.06), and 0.37 (95% CI, 0.10-1.34; P = 0.13), respectively. This study suggests that ATRA may significantly improve the initial and long-term response of patients with ITP.
Topics: Humans; Purpura, Thrombocytopenic, Idiopathic; Tretinoin; Chronic Disease; Remission Induction; China
PubMed: 37166528
DOI: 10.1007/s00277-023-05263-w -
Journal of Special Operations Medicine... 2021Vitamin A is a generic term for compounds that have biological activity similar to that of retinol and includes carotenoids like β-carotene and α-carotene. Some... (Meta-Analysis)
Meta-Analysis
Vitamin A is a generic term for compounds that have biological activity similar to that of retinol and includes carotenoids like β-carotene and α-carotene. Some studies suggest high dietary intake of vitamin A can increase bone fracture risk. This investigation involved a systematic review and meta-analysis examining the association between vitamin A and fracture risk. Published literature was searched to find studies that (1) involved human participants, (2) had prospective cohort or case-control study designs, (3) contained original quantitative data on associations between dietary intake of vitamin A and fractures, and (4) provided either risk ratios (RRs), odds ratios (ORs), or hazard ratios (HRs) with 95% confidence intervals (95% CIs) comparing various levels of vitamin A consumption to fracture risk. Thirteen studies met the review criteria. Meta-analyses indicated that risk of hip fracture was increased by high dietary intake of total vitamin A (RR = 1.29; 95% CI = 1.07-1.57) or retinol (RR = 1.23; 95% CI = 1.02-1.48). Hip fracture risk was reduced by high dietary intake of total carotene (RR = 0.62; 95% CI = 0.42-0.93), β-carotene (RR = 0.72; 95% CI = 0.58-0.89), or α-carotene (RR = 0.81; 95% CI = 0.67-0.97). Total fracture risk was not associated with any vitamin A compound. High intake of total vitamin A or retinol increased hip fracture risk, while high intake of some carotenoids reduced hip fracture risk.
Topics: Case-Control Studies; Fractures, Bone; Hip Fractures; Humans; Prospective Studies; Risk Factors; Vitamin A; beta Carotene
PubMed: 34105132
DOI: 10.55460/OGLF-K9ZU -
Epilepsy & Behavior : E&B Mar 2023In people with epilepsy achieving optimal dietary intake may be hampered by psychological and physical comorbidities associated with seizures, medication use,... (Review)
Review
PURPOSE
In people with epilepsy achieving optimal dietary intake may be hampered by psychological and physical comorbidities associated with seizures, medication use, socioeconomic disadvantage and the use of therapeutic diets. This systematic review aimed to evaluate the reported dietary intake and nutritional status of children and adults with epilepsy.
METHODS
A systematic literature search was completed across Ovid MEDLINE, EMBASE and CINAHL (all from inception to 4 November 2021). We included studies that reported dietary intake in adults and children diagnosed with epilepsy compared with local reference ranges, control groups or general populations. Studies using interventions and therapeutic diets were excluded. Risk of bias was assessed using the Study Quality Assessment Tools by the National Heart, Lung and Blood Institute. A descriptive analysis was performed due to the heterogenous nature of the data.
RESULTS
The initial search returned 1214 articles. Full-text screening was completed for 98 studies and 19 studies met eligibility criteria and were included for extraction. These comprised of seven paediatric studies, eight adult studies and four studies that included both adult and paediatric cohorts. Sample size of cases in each study ranged from 17 to 3,220. Vitamin A, C, D and folate were the most frequently reported vitamins. Calcium, iron and zinc were the most commonly reported minerals. Most studies showed that people with epilepsy had poorer dietary intake and nutritional status compared with control groups or reference standards.
CONCLUSION
There were limited studies on dietary intake and nutritional status in people with epilepsy. Most available studies suggested poorer status compared to non-epilepsy controls. The development of a validated dietary assessment tool specifically for epilepsy cohorts would enable comparison of findings across studies, and aid with appropriately tailoring nutrition advice to individuals with epilepsy.
Topics: Adult; Child; Humans; Nutritional Status; Vitamins; Epilepsy; Calcium, Dietary; Eating
PubMed: 36702056
DOI: 10.1016/j.yebeh.2023.109090 -
Nutrients Feb 2023Food insecurity is a public health problem as it affects a wide array of individuals in the population. It can be characterized by food deprivation, lack of essential... (Meta-Analysis)
Meta-Analysis Review
Food insecurity is a public health problem as it affects a wide array of individuals in the population. It can be characterized by food deprivation, lack of essential nutrition, lack of dietary education, lack of adequate storage conditions, poor absorption, and poor overall nutrition. The relationship between food insecurity and micronutrient deficiency requires more effort to deepen and discuss the relationship. This systematic review aimed to evaluate the association between food insecurity and micronutrient deficiency in adults. The research was conducted according to PRISMA using the Medline/Pubmed, Lilacs/BVS, Embase, Web of Science, and Cinahl databases. Studies carried out with male and female adults were included, which investigated the correlation or association between food insecurity and the nutritional status of micronutrients. There were no publication year, country, or language restrictions. A total of 1148 articles were found, and 18 of these were included, carried out mainly on the American continent and with women. The most evaluated micronutrients were iron and vitamin A. Food insecurity was associated with nutrient deficiency in 89% ( = 16) of the studies. As a result of the meta-analysis, it was observed that there is a greater chance of anemia and low levels of ferritin among food insecure individuals. It is concluded that food insecurity is associated with micronutrient deficiency. Understanding these problems allows the creation of public policies capable of contributing to changes. Protocol registration: This review was registered on the PROSPERO-International Prospective Register of Systematic Reviews database-CRD42021257443.
Topics: Humans; Adult; Male; Female; Micronutrients; Iron; Diet; Nutritional Status; Food Insecurity; Food Supply
PubMed: 36904074
DOI: 10.3390/nu15051074 -
Annals of the New York Academy of... Apr 2017Adolescence is a critical stage in the life cycle, and adequate nutrition is necessary for the proper growth and development of individuals and their offspring. Here, we... (Meta-Analysis)
Meta-Analysis Review
Adolescence is a critical stage in the life cycle, and adequate nutrition is necessary for the proper growth and development of individuals and their offspring. Here, we comprehensively review all published systematic reviews (through October 2016) on adolescents (10-19 years) and women of reproductive age, including pregnant women, which targeted interventions related to nutrition. For interventions where there was no existing systematic review on adolescents, we reviewed primary studies/trials. We included interventions on micronutrient supplementation (iron, folic acid, iron-folic acid (IFA), calcium, vitamin D, vitamin A, zinc, iodine, and multiple micronutrients), food/protein energy supplementation, nutrition education for pregnant adolescents, obesity prevention and management, and management of gestational diabetes. We identified a total of 35 systematic reviews, of which only five were conducted on adolescents, and 107 primary studies on adolescents. Our review suggests that iron alone, IFA, zinc, and multiple micronutrient supplementation in adolescents can significantly improve serum hemoglobin concentration. While zinc supplementation in pregnant adolescents showed improvements in preterm birth and low birth weight, we found a paucity of trials on calcium, vitamin D, vitamin A, and iodine supplementation. We found limited evidence on food/protein energy supplementation in adolescents. Interventions to prevent and manage obesity showed a nonsignificant impact on reducing body mass index. This review underscores the importance of adolescent nutrition interventions. It is imperative that countries design nutritional interventions, particularly for adolescents.
Topics: Adolescent; Adolescent Nutritional Physiological Phenomena; Diabetes, Gestational; Dietary Supplements; Early Intervention, Educational; Early Medical Intervention; Evidence-Based Medicine; Female; Humans; Micronutrients; Nutritional Requirements; Obesity; Pregnancy
PubMed: 28436101
DOI: 10.1111/nyas.13335 -
Advances in Nutrition (Bethesda, Md.) Nov 2023Accumulation of deoxyribonucleic acid (DNA) damage diminishes cellular health, increases risk of developmental and degenerative diseases, and accelerates aging.... (Review)
Review
Protective Effects of Micronutrient Supplements, Phytochemicals and Phytochemical-Rich Beverages and Foods Against DNA Damage in Humans: A Systematic Review of Randomized Controlled Trials and Prospective Studies.
Accumulation of deoxyribonucleic acid (DNA) damage diminishes cellular health, increases risk of developmental and degenerative diseases, and accelerates aging. Optimizing nutrient intake can minimize accrual of DNA damage. The objectives of this review are to: 1) assemble and systematically analyze high-level evidence for the effect of supplementation with micronutrients and phytochemicals on baseline levels of DNA damage in humans, and 2) use this knowledge to identify which of these essential micronutrients or nonessential phytochemicals promote DNA integrity in vivo in humans. We conducted systematic literature searches of the PubMed database to identify interventional, prospective, cross-sectional, or in vitro studies that explored the association between nutrients and established biomarkers of DNA damage associated with developmental and degenerative disease risk. Biomarkers included lymphocyte chromosome aberrations, lymphocyte and buccal cell micronuclei, DNA methylation, lymphocyte/leukocyte DNA strand breaks, DNA oxidation, telomere length, telomerase activity, and mitochondrial DNA mutations. Only randomized, controlled interventions and uncontrolled longitudinal intervention studies conducted in humans were selected for evaluation and data extraction. These studies were ranked for the quality of their study design. In all, 96 of the 124 articles identified reported studies that achieved a quality assessment score ≥ 5 (from a maximum score of 7) and were included in the final review. Based on these studies, nutrients associated with protective effects included vitamin A and its precursor β-carotene, vitamins C, E, B1, B12, folate, minerals selenium and zinc, and phytochemicals such as curcumin (with piperine), lycopene, and proanthocyanidins. These findings highlight the importance of nutrients involved in (i) DNA metabolism and repair (folate, vitamin B, and zinc) and (ii) prevention of oxidative stress and inflammation (vitamins A, C, E, lycopene, curcumin, proanthocyanidins, selenium, and zinc). Supplementation with certain micronutrients and their combinations may reduce DNA damage and promote cellular health by improving the maintenance of genome integrity.
Topics: Humans; Prospective Studies; Selenium; Lycopene; Cross-Sectional Studies; Curcumin; Proanthocyanidins; Randomized Controlled Trials as Topic; Vitamins; Vitamin A; Micronutrients; Folic Acid; Zinc; Beverages; Phytochemicals; DNA; DNA Damage; Biomarkers; Dietary Supplements
PubMed: 37573943
DOI: 10.1016/j.advnut.2023.08.004