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The Cochrane Database of Systematic... Jan 2023Osteoporosis is a condition where bones become fragile due to low bone density and impaired bone quality. This results in fractures that lead to higher morbidity and... (Review)
Review
BACKGROUND
Osteoporosis is a condition where bones become fragile due to low bone density and impaired bone quality. This results in fractures that lead to higher morbidity and reduced quality of life. Osteoporosis is considered a major public health concern worldwide. For this reason, preventive measurements need to be addressed throughout the life course. Exercise and a healthy diet are among the lifestyle factors that can help prevent the disease, the latter including intake of key micronutrients for bone, such as calcium and vitamin D. The evidence on whether supplementation with calcium and vitamin D improves bone mineral density (BMD) in premenopausal women is still inconclusive. In this age group, bone accrual is considered to be the goal of supplementation, so BMD is relevant for the future stages of life.
OBJECTIVES
To evaluate the benefits and harms of calcium and vitamin D supplementation, alone or in combination, to increase the BMD, reduce fractures, and report the potential adverse events in healthy premenopausal women compared to placebo.
SEARCH METHODS
We used standard, extensive Cochrane search methods. The latest search was 12 April 2022.
SELECTION CRITERIA
We included randomised controlled trials in healthy premenopausal women (with or without calcium or vitamin D deficiency) comparing supplementation of calcium or vitamin D (or both) at any dose and by any route of administration versus placebo for at least three months. Vitamin D could have been administered as cholecalciferol (vitamin D) or ergocalciferol (vitamin D).
DATA COLLECTION AND ANALYSIS
We used standard Cochrane methods. Outcomes included total hip bone mineral density (BMD), lumbar spine BMD, quality of life, new symptomatic vertebral fractures, new symptomatic non-vertebral fractures, withdrawals due to adverse events, serious adverse events, all reported adverse events and additional withdrawals for any reason.
MAIN RESULTS
We included seven RCTs with 941 participants, of whom 138 were randomised to calcium supplementation, 110 to vitamin D supplementation, 271 to vitamin D plus calcium supplementation, and 422 to placebo. Mean age ranged from 18.1 to 42.1 years. Studies reported results for total hip or lumbar spine BMD (or both) and withdrawals for various reasons, but none reported fractures or withdrawals for adverse events or serious adverse events. Results for the reported outcomes are presented for the three comparisons: calcium versus placebo, vitamin D versus placebo, and calcium plus vitamin D versus placebo. In all comparisons, there was no clinical difference in outcomes, and the certainty of the evidence was moderate to low. Most studies were at risk of selection, performance, detection, and reporting biases. Calcium versus placebo Four studies compared calcium versus placebo (138 participants in the calcium group and 123 in the placebo group) with mean ages from 18.0 to 47.3 years. Calcium supplementation may have little to no effect on total hip or lumbar spine BMD after 12 months in three studies and after six months in one study (total hip BMD: mean difference (MD) -0.04 g/cm, 95% confidence interval (CI) -0.11 to 0.03; I = 71%; 3 studies, 174 participants; low-certainty evidence; lumbar spine BMD: MD 0 g/cm, 95% CI -0.06 to 0.06; I = 71%; 4 studies, 202 participants; low-certainty evidence). Calcium alone supplementation does not reduce or increase the withdrawals in the trials (risk ratio (RR) 0.78, 95% CI 0.52 to 1.16; I = 0%; 4 studies, 261 participants: moderate-certainty evidence). Vitamin D versus placebo Two studies compared vitamin D versus placebo (110 participants in the vitamin D group and 79 in the placebo group), with mean ages from 18.0 to 32.7 years. These studies reported lumbar spine BMD as a mixture of MDs and percent of change and we were unable to pool the results. In the original studies, there were no differences in lumbar BMD between groups. Vitamin D alone supplementation does not reduce or increase withdrawals for any reason between groups (RR 0.74, 95% CI 0.46 to 1.19; moderate-certainty evidence). Calcium plus vitamin D versus placebo Two studies compared calcium plus vitamin D versus placebo (271 participants in the calcium plus vitamin D group and 270 in the placebo group; 220 participants from Woo 2007 and 50 participants from Islam 2010). The mean age range was 18.0 to 36 years. These studies measured different anatomic areas, one study reported total hip BMD and the other study reported lumbar spine BMD; therefore, data were not pooled for this outcome. The individual studies found no difference between groups in percent of change on total hip BMD (-0.03, 95% CI -0.06 to 0; moderate-certainty evidence), and lumbar spine BMD (MD 0.01, 95% CI -0.01 to 0.03; moderate-certainty evidence). Calcium plus vitamin D supplementation may not reduce or increase withdrawals for any reason (RR 0.82, 95% CI 0.29 to 2.35; I = 72%; 2 studies, 541 participants; low-certainty evidence).
AUTHORS' CONCLUSIONS
Our results do not support the isolated or combined use of calcium and vitamin D supplementation in healthy premenopausal women as a public health intervention to improve BMD in the total hip or lumbar spine, and therefore it is unlikely to have a benefit for the prevention of fractures (vertebral and non-vertebral). The evidence found suggests that there is no need for future studies in the general population of premenopausal women; however, studies focused on populations with a predisposition to diseases related to bone metabolism, or with low bone mass or osteoporosis diagnosed BMD would be useful.
Topics: Humans; Female; Adolescent; Young Adult; Adult; Middle Aged; Vitamin D; Calcium; Bone Density; Quality of Life; Vitamins; Calcium, Dietary; Osteoporosis; Fractures, Bone; Cholecalciferol; Randomized Controlled Trials as Topic
PubMed: 36705288
DOI: 10.1002/14651858.CD012664.pub2 -
Advances in Nutrition (Bethesda, Md.) May 2017Nutrition is considered to be a possible factor in the pathogenesis of the neurological disease multiple sclerosis (MS). Nutrition intervention studies suggest that diet... (Review)
Review
Nutrition is considered to be a possible factor in the pathogenesis of the neurological disease multiple sclerosis (MS). Nutrition intervention studies suggest that diet may be considered as a complementary treatment to control the progression of the disease; a systematic review of the literature on the influence of diet on MS was therefore conducted. The literature search was conducted by using Medlars Online International Literature (MEDLINE) via PubMed and Scopus. Forty-seven articles met the inclusion criteria. The reviewed articles assessed the relations between macro- and micronutrient intakes and MS incidence. The patients involved used alternative therapies (homeopathy), protocolized diets that included particular foods (herbal products such as grape seed extract, ginseng, blueberries, green tea, etc.), or dietary supplements such as vitamin D, carnitine, melatonin, or coenzyme Q10. Current studies suggest that high serum concentrations of vitamin D, a potent immunomodulator, may decrease the risk of MS and the risk of relapse and new lesions, while improving brain lesions and timed tandem walking. Experimental evidence suggests that serum vitamin D concentration is lower during MS relapses than in remission and is associated with a greater degree of disability [Expanded Disability Status Scale (EDSS) score >3]. The findings suggest that circulating vitamin D concentrations can be considered a biomarker of MS and supplemental vitamin D can be used therapeutically. Other studies point to a negative correlation between serum vitamin B-12 concentrations and EDSS score. Vitamin B-12 has fundamental roles in central nervous system function, especially in the methionine synthase-mediated conversion of homocysteine to methionine, which is essential for DNA and RNA synthesis. Therefore, vitamin B-12 deficiency may lead to an increase in the concentration of homocysteine. Further research is clearly necessary to determine whether treatment with vitamin B-12 supplements delays MS progression.
Topics: Diet; Dietary Supplements; Disease Progression; Humans; Multiple Sclerosis; Nutritional Status; Vitamin B 12; Vitamin B 12 Deficiency; Vitamin D; Vitamin D Deficiency; Vitamins
PubMed: 28507011
DOI: 10.3945/an.116.014191 -
The Cochrane Database of Systematic... Mar 2019Multiple-micronutrient (MMN) deficiencies often coexist among women of reproductive age in low- and middle-income countries. They are exacerbated in pregnancy due to the... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Multiple-micronutrient (MMN) deficiencies often coexist among women of reproductive age in low- and middle-income countries. They are exacerbated in pregnancy due to the increased demands of the developing fetus, leading to potentially adverse effects on the mother and baby. A consensus is yet to be reached regarding the replacement of iron and folic acid supplementation with MMNs. Since the last update of this Cochrane Review in 2017, evidence from several trials has become available. The findings of this review will be critical to inform policy on micronutrient supplementation in pregnancy.
OBJECTIVES
To evaluate the benefits of oral multiple-micronutrient supplementation during pregnancy on maternal, fetal and infant health outcomes.
SEARCH METHODS
For this 2018 update, on 23 February 2018 we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP), and reference lists of retrieved studies. We also contacted experts in the field for additional and ongoing trials.
SELECTION CRITERIA
All prospective randomised controlled trials evaluating MMN supplementation with iron and folic acid during pregnancy and its effects on pregnancy outcomes were eligible, irrespective of language or the publication status of the trials. We included cluster-randomised trials, but excluded quasi-randomised trials. Trial reports that were published as abstracts were eligible.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We assessed the quality of the evidence using the GRADE approach.
MAIN RESULTS
We identified 21 trials (involving 142,496 women) as eligible for inclusion in this review, but only 20 trials (involving 141,849 women) contributed data. Of these 20 trials, 19 were conducted in low- and middle-income countries and compared MMN supplements with iron and folic acid to iron, with or without folic acid. One trial conducted in the UK compared MMN supplementation with placebo. In total, eight trials were cluster-randomised.MMN with iron and folic acid versus iron, with or without folic acid (19 trials)MMN supplementation probably led to a slight reduction in preterm births (average risk ratio (RR) 0.95, 95% confidence interval (CI) 0.90 to 1.01; 18 trials, 91,425 participants; moderate-quality evidence), and babies considered small-for-gestational age (SGA) (average RR 0.92, 95% CI 0.88 to 0.97; 17 trials; 57,348 participants; moderate-quality evidence), though the CI for the pooled effect for preterm births just crossed the line of no effect. MMN reduced the number of newborn infants identified as low birthweight (LBW) (average RR 0.88, 95% CI 0.85 to 0.91; 18 trials, 68,801 participants; high-quality evidence). We did not observe any differences between groups for perinatal mortality (average RR 1.00, 95% CI 0.90 to 1.11; 15 trials, 63,922 participants; high-quality evidence). MMN supplementation led to slightly fewer stillbirths (average RR 0.95, 95% CI 0.86 to 1.04; 17 trials, 97,927 participants; high-quality evidence) but, again, the CI for the pooled effect just crossed the line of no effect. MMN supplementation did not have an important effect on neonatal mortality (average RR 1.00, 95% CI 0.89 to 1.12; 14 trials, 80,964 participants; high-quality evidence). We observed little or no difference between groups for the other maternal and pregnancy outcomes: maternal anaemia in the third trimester (average RR 1.04, 95% CI 0.94 to 1.15; 9 trials, 5912 participants), maternal mortality (average RR 1.06, 95% CI 0.72 to 1.54; 6 trials, 106,275 participants), miscarriage (average RR 0.99, 95% CI 0.94 to 1.04; 12 trials, 100,565 participants), delivery via a caesarean section (average RR 1.13, 95% CI 0.99 to 1.29; 5 trials, 12,836 participants), and congenital anomalies (average RR 1.34, 95% CI 0.25 to 7.12; 2 trials, 1958 participants). However, MMN supplementation probably led to a reduction in very preterm births (average RR 0.81, 95% CI 0.71 to 0.93; 4 trials, 37,701 participants). We were unable to assess a number of prespecified, clinically important outcomes due to insufficient or non-available data.When we assessed primary outcomes according to GRADE criteria, the quality of evidence for the review overall was moderate to high. We graded the following outcomes as high quality: LBW, perinatal mortality, stillbirth, and neonatal mortality. The outcomes of preterm birth and SGA we graded as moderate quality; both were downgraded for funnel plot asymmetry, indicating possible publication bias.We carried out sensitivity analyses excluding trials with high levels of sample attrition (> 20%). We found that results were consistent with the main analyses for all outcomes. We explored heterogeneity through subgroup analyses by maternal height, maternal body mass index (BMI), timing of supplementation, dose of iron, and MMN supplement formulation (UNIMMAP versus non-UNIMMAP). There was a greater reduction in preterm births for women with low BMI and among those who took non-UNIMMAP supplements. We also observed subgroup differences for maternal BMI and maternal height for SGA, indicating greater impact among women with greater BMI and height. Though we found that MMN supplementation made little or no difference to perinatal mortality, the analysis demonstrated substantial statistical heterogeneity. We explored this heterogeneity using subgroup analysis and found differences for timing of supplementation, whereby higher impact was observed with later initiation of supplementation. For all other subgroup analyses, the findings were inconclusive.MMN versus placebo (1 trial)A single trial in the UK found little or no important effect of MMN supplementation on preterm births, SGA, or LBW but did find a reduction in maternal anaemia in the third trimester (RR 0.66, 95% CI 0.51 to 0.85), when compared to placebo. This trial did not measure our other outcomes.
AUTHORS' CONCLUSIONS
Our findings suggest a positive impact of MMN supplementation with iron and folic acid on several birth outcomes. MMN supplementation in pregnancy led to a reduction in babies considered LBW, and probably led to a reduction in babies considered SGA. In addition, MMN probably reduced preterm births. No important benefits or harms of MMN supplementation were found for mortality outcomes (stillbirths, perinatal and neonatal mortality). These findings may provide some basis to guide the replacement of iron and folic acid supplements with MMN supplements for pregnant women residing in low- and middle-income countries.
Topics: Dietary Supplements; Drug Interactions; Female; Folic Acid; Humans; Infant, Newborn; Infant, Small for Gestational Age; Iron, Dietary; Micronutrients; Perinatal Mortality; Pregnancy; Pregnancy Complications; Pregnancy Outcome; Premature Birth; Randomized Controlled Trials as Topic
PubMed: 30873598
DOI: 10.1002/14651858.CD004905.pub6 -
The Cochrane Database of Systematic... May 2020Multiple sclerosis (MS) is a common demyelinating disease of the central nervous system. Although the exact pathogenesis remains unknown, the leading theory is that it... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Multiple sclerosis (MS) is a common demyelinating disease of the central nervous system. Although the exact pathogenesis remains unknown, the leading theory is that it results from immune system dysregulation. Approved disease-modifying therapy appears to modulate the immune system to improve MS-related outcomes. There is substantial interest in the ability of dietary interventions to influence MS-related outcomes. This is an update of the Cochrane Review 'Dietary interventions for multiple sclerosis' (Farinotti 2003; Farinotti 2007; Farinotti 2012).
OBJECTIVES
To assess the effects of dietary interventions (including dietary plans with recommendations for specific whole foods, macronutrients, and natural health products) compared to placebo or another intervention on health outcomes (including MS-related outcomes and serious adverse events) in people with MS.
SEARCH METHODS
On 30 May 2019, we searched CENTRAL, MEDLINE, Embase, and Web of Science. We also searched ClinicalTrials.gov, World Health Organization International Clinical Trials Registry Platform (ICTRP), and Networked Digital Library of Theses and Dissertations (NDLTD). We checked reference lists in identified trials and requested information from trial authors to identify any additional published or unpublished data.
SELECTION CRITERIA
We included any randomized controlled trial (RCT) or controlled clinical trial (CCT) examining the effect of a dietary intervention versus placebo or another intervention among participants with MS on MS-related outcomes, including relapses, disability progression, and magnetic resonance imaging (MRI) measures.
DATA COLLECTION AND ANALYSIS
We used standard methodological procedures expected by Cochrane. Planned primary outcomes were number of participants experiencing relapse and change in disability progression, according to a validated disability scale at the last reported follow-up. Secondary outcomes included MRI activity, safety, and patient-reported outcomes. We entered and analysed data in Review Manager 5.
MAIN RESULTS
We found 41 full-text articles examining 30 trials following full-text review. Participants were adults with MS, defined by established criteria, presenting to MS clinics in Europe, North America, and the Middle East. Study design varied considerably, although all trials had at least one methodological issue leading to unknown or high risk of bias. Trials examined: supplementation to increase polyunsaturated fatty acids (PUFAs) (11 trials); a variety of antioxidant supplements (10 trials); dietary programmes (3 trials); and other dietary supplements (e.g. acetyl L-carnitine, biotin, creatine, palmitoylethanolamide, probiotic, riboflavin) (6 trials). In three trials comparing PUFAs with monounsaturated fatty acids (MUFAs), the evidence was very uncertain concerning difference in relapses (risk ratio (RR) 1.02, 95% confidence interval (CI) 0.88 to 1.20; 3 studies, 217 participants; 75% in the PUFA group versus 74% in the MUFA group; very low-certainty evidence). Among four trials comparing PUFAs with MUFAs, there may be little to no difference in global impression of deterioration (RR 0.85, 95% CI 0.71 to 1.03; 4 studies, 542 participants; 40% in the PUFA group versus 47% in the MUFA group; low-certainty evidence). In two trials comparing PUFAs with MUFAs (102 participants), there was very low-certainty evidence for change in disability progression. None of the PUFA versus MUFA trials examined MRI outcomes. In one trial comparing PUFAs with MUFAs (40 participants), there were no serious adverse events; based on low-certainty evidence. In two trials comparing different PUFAs (omega-3 versus omega-6), there may be little to no difference in relapses (RR 1.02, 95% CI 0.62 to 1.66; 2 studies, 129 participants; 30% in the omega-3 versus 29% in the omega-6 group; low-certainty evidence). Among three trials comparing omega-3 with omega-6, there may be little to no difference in change in disability progression, measured as mean change in Expanded Disability Status Scale (EDSS) (mean difference (MD) 0.00, 95% CI -0.30 to 0.30; 3 studies, 166 participants; low-certainty evidence). In one trial comparing omega-3 with omega-6, there was likely no difference in global impression of deterioration (RR 0.99, 95% CI 0.51 to 1.91; 1 study, 86 participants; 29% in omega-3 versus 29% in omega-6 group; moderate-certainty evidence). In one trial comparing omega-3 with omega-6 (86 participants), there was likely no difference in number of new T1- weighted gadolinium-enhancing lesions, based on moderate-certainty evidence. In four trials comparing omega-3 with omega-6, there may be little to no difference in serious adverse events (RR 1.12, 95% CI 0.38 to 3.31; 4 studies, 230 participants; 6% in omega-3 versus 5% in omega-6 group; low-certainty evidence). In four trials examining antioxidant supplementation with placebo, there may be little to no difference in relapses (RR 0.98, 95% CI 0.59 to 1.64; 4 studies, 345 participants; 17% in the antioxidant group versus 17% in the placebo group; low-certainty evidence). In six trials examining antioxidant supplementation with placebo, the evidence was very uncertain concerning change in disability progression, measured as mean change of EDSS (MD -0.19, 95% CI -0.49 to 0.11; 6 studies, 490 participants; very low-certainty evidence). In two trials examining antioxidant supplementation with placebo, there may be little to no difference in global impression of deterioration (RR 0.99, 95% 0.50 to 1.93; 2 studies, 190 participants; 15% in the antioxidant group versus 15% in the placebo group; low-certainty evidence). In two trials examining antioxidant supplementation with placebo, the evidence was very uncertain concerning difference in gadolinium-enhancing lesions (RR 0.67, 95% CI 0.09 to 4.88; 2 studies, 131 participants; 11% in the antioxidant group versus 16% in the placebo group; very low-certainty evidence). In three trials examining antioxidant supplementation versus placebo, there may be little to no difference in serious adverse events (RR. 0.72, 95% CI 0.17 to 3.08; 3 studies, 222 participants; 3% in the antioxidant group versus 4% in the placebo group; low-certainty evidence).
AUTHORS' CONCLUSIONS
There are a variety of controlled trials addressing the effects of dietary interventions for MS with substantial variation in active treatment, comparator, and outcomes of interest. PUFA administration may not differ when compared to alternatives with regards to relapse rate, disability worsening, or overall clinical status in people with MS, but evidence is uncertain. Similarly, at present, there is insufficient evidence to determine whether supplementation with antioxidants or other dietary interventions have any impact on MS-related outcomes.
Topics: Adult; Antioxidants; Diet, Fat-Restricted; Diet, Paleolithic; Diet, Vegetarian; Dietary Supplements; Disease Progression; Fatty Acids, Monounsaturated; Fatty Acids, Omega-3; Fatty Acids, Omega-6; Fatty Acids, Unsaturated; Humans; Multiple Sclerosis; Randomized Controlled Trials as Topic; Recurrence
PubMed: 32428983
DOI: 10.1002/14651858.CD004192.pub4 -
Advances in Nutrition (Bethesda, Md.) Nov 2018Infertility, which affects ∼15% of the world's population, is a global public health issue recognized by the WHO. Therefore, it is of major clinical and public health... (Meta-Analysis)
Meta-Analysis
Infertility, which affects ∼15% of the world's population, is a global public health issue recognized by the WHO. Therefore, it is of major clinical and public health importance to investigate whether modifiable lifestyle factors-such as stress, drug use, smoking, alcohol intake, and diet-may influence human fertility. A systematic review and meta-analysis of randomized clinical trials (RCTs) from the MEDLINE-PubMed database was conducted to assess the effect of nutrients, dietary supplements, or food on sperm quality parameters. In total, 28 articles were included for qualitative analysis and 15 for quantitative meta-analysis. Total sperm concentrations [expressed as mean differences (MDs); 95% CIs, in spermatozoa (spz)/mL] were increased by selenium (3.91 × 106 spz/mL; 3.08, 4.73 spz/mL), zinc (1.48 × 106 spz/mL; 0.69, 2.27 spz/mL), omega-3 (n-3) fatty acids (10.98 × 106 spz/mL; 10.25, 11.72 spz/mL), and coenzyme Q10 (CoQ10) (5.93 × 106 spz/mL; 5.36, 6.51 spz/mL). Sperm counts were increased by ω-3 fatty acids (18.70 × 106 spz/mL; 16.89, 20.51 spz/mL) and CoQ10 supplementation (10.15 × 106 spz/mL; 8.34, 11.97 spz/mL). Sperm total motility was increased by selenium (3.30%; 2.95%, 3.65%), zinc (7.03%; 6.03%, 8.03%), ω-3 fatty acids (7.55%; 7.09%, 8.01%), CoQ10 (5.30%; 4.98%, 5.62%), and carnitines (7.84%; 6.54%, 9.13%), whereas sperm progressive motility was increased only after supplementation with carnitines (7.45%; 6.24%, 8.67%). Finally, sperm morphology was enhanced by selenium (1.87%; 1.50%, 2.24%), ω-3 fatty acid (0.91%; 0.69%, 1.13%), CoQ10 (1.06%; 0.72%, 1.41%), and carnitine (4.91%; 3.68%, 6.15%) supplementation. This meta-analysis of RCTs suggests that some dietary supplements could beneficially modulate sperm quality parameters and affect male fertility. However, results must be cautiously interpreted due to the limited sample size of the meta-analyzed studies and the considerable observed interstudy heterogeneity.The present study and the corresponding search protocol were registered at the PROSPERO registry at http://www.crd.york.ac.uk/PROSPERO as CRD42017058380.
Topics: Adult; Dietary Supplements; Humans; Infertility, Male; Male; Nutrients; Randomized Controlled Trials as Topic; Sperm Count; Sperm Motility; Spermatozoa
PubMed: 30462179
DOI: 10.1093/advances/nmy057 -
Nutrients Mar 2022Lung cancer is one of the most common neoplasms globally, with about 2.2 million new cases and 1.8 million deaths annually. Although the most important factor in... (Meta-Analysis)
Meta-Analysis Review
Lung cancer is one of the most common neoplasms globally, with about 2.2 million new cases and 1.8 million deaths annually. Although the most important factor in reducing lung cancer risk is lifestyle change, most patients favour the use of supplements, for example, rather than quitting smoking or following a healthy diet. To better understand the efficacy of such interventions, a systematic review was performed of data from randomized controlled trials concerning the influence of beta-carotene supplementation on lung cancer risk in subjects with no lung cancer before the intervention. The search corpus comprised a number of databases and eight studies involving 167,141 participants, published by November 2021. The findings indicate that beta-carotene supplementation was associated with an increased risk of lung cancer (RR = 1.16, 95% CI = 1.06-1.26). This effect was even more noticeable among smokers and asbestos workers (RR = 1.21, 95% CI = 1.08-1.35) and non-medics (RR = 1.18, 95% CI = 1.07-1.29). A meta-regression found no relationship between the beta-carotene supplementation dose and the size of the negative effect associated with lung cancer risk. Our findings indicate that beta-carotene supplementation has no effect on lung cancer risk. Moreover, when used as the primary chemoprevention, beta-carotene may, in fact, increase the risk of lung cancer.
Topics: Antioxidants; Dietary Supplements; Humans; Lung Neoplasms; Smoking; beta Carotene
PubMed: 35405977
DOI: 10.3390/nu14071361 -
Advances in Nutrition (Bethesda, Md.) Dec 2021Although levodopa remains the most effective drug for symptomatic management of Parkinson's Disease (PD), treatment during advanced disease stages may raise...
Although levodopa remains the most effective drug for symptomatic management of Parkinson's Disease (PD), treatment during advanced disease stages may raise unpredictable motor fluctuations and other complications. Counteracting these complications with other pharmacological therapies may prompt a vicious circle of side effects, and here, nutritional therapy may have great potential. Knowledge about the role of diet in PD is emerging and multiple studies have investigated nutritional support specifically with respect to levodopa therapy. With this systematic review, we aim to give a comprehensive overview of dietary approaches to optimize levodopa treatment in PD. A systematic search was performed using the databases of PubMed and Scopus between January 1985 and September 2020. Nutritional interventions with the rationale to optimize levodopa therapy in human PD patients were eligible for this study and their quality was assessed with the Cochrane risk-of-bias tool. In total, we included 22 papers that addressed the effects of dietary proteins (n = 10), vitamins (n = 7), fiber (n = 2), soybeans (n = 1), caffeine (n = 1), and ketogenic diets (n = 1) on levodopa therapy. Interventions with protein redistribution diets (PRDs), dietary fiber, vitamin C, and caffeine improved levodopa absorption, thereby enhancing clinical response and reducing motor fluctuations. Furthermore, supplementation of vitamin B-12, vitamin B-6, and folic acid successfully reduced high homocysteine concentrations that emerged from levodopa metabolism and promoted many metabolic and clinical complications, such as neuropathology and osteoporosis. In conclusion, dietary interventions have the potential to optimize levodopa efficacy and control side effects. Nutrition that improves levodopa absorption, including PRDs, fiber, vitamin C, and caffeine, is specifically recommended when fluctuating clinical responses appear. Supplements of vitamin B-12, vitamin B-6, and folic acid are advised along with levodopa initiation to attenuate hyperhomocysteinemia, and importantly, their potential to treat consequent metabolic and clinical complications warrants future research.
Topics: Antiparkinson Agents; Diet; Humans; Levodopa; Parkinson Disease; Vitamin B 12
PubMed: 34113965
DOI: 10.1093/advances/nmab060 -
Nutrients Jun 2020The foundations of neurodevelopment across an individual's lifespan are established in the first 1000 days of life (2 years). During this period an adequate supply of...
The foundations of neurodevelopment across an individual's lifespan are established in the first 1000 days of life (2 years). During this period an adequate supply of nutrients are essential for proper neurodevelopment and lifelong brain function. Of these, evidence for choline has been building but has not been widely collated using systematic approaches. Therefore, a systematic review was performed to identify the animal and human studies looking at inter-relationships between choline, neurological development, and brain function during the first 1000 days of life. The database PubMed was used, and reference lists were searched. In total, 813 publications were subject to the title/abstract review, and 38 animal and 16 human studies were included after evaluation. Findings suggest that supplementing the maternal or child's diet with choline over the first 1000 days of life could subsequently: (1) support normal brain development (animal and human evidence), (2) protect against neural and metabolic insults, particularly when the fetus is exposed to alcohol (animal and human evidence), and (3) improve neural and cognitive functioning (animal evidence). Overall, most offspring would benefit from increased choline supply during the first 1000 days of life, particularly in relation to helping facilitate normal brain development. Health policies and guidelines should consider re-evaluation to help communicate and impart potential choline benefits through diet and/or supplementation approaches across this critical life stage.
Topics: Age Factors; Animals; Brain; Choline; Cognition; Dietary Supplements; Female; Humans; Infant; Infant Nutritional Physiological Phenomena; Infant, Newborn; Male; Maternal Nutritional Physiological Phenomena; Maternal-Fetal Exchange; Pregnancy
PubMed: 32531929
DOI: 10.3390/nu12061731 -
BMJ (Clinical Research Ed.) Aug 2019To assess effects of increasing omega-3, omega-6, and total polyunsaturated fatty acids (PUFA) on diabetes diagnosis and glucose metabolism. (Meta-Analysis)
Meta-Analysis
Omega-3, omega-6, and total dietary polyunsaturated fat for prevention and treatment of type 2 diabetes mellitus: systematic review and meta-analysis of randomised controlled trials.
OBJECTIVE
To assess effects of increasing omega-3, omega-6, and total polyunsaturated fatty acids (PUFA) on diabetes diagnosis and glucose metabolism.
DESIGN
Systematic review and meta-analyses.
DATA SOURCES
Medline, Embase, Cochrane CENTRAL, WHO International Clinical Trials Registry Platform, Clinicaltrials.gov, and trials in relevant systematic reviews.
ELIGIBILITY CRITERIA
Randomised controlled trials of at least 24 weeks' duration assessing effects of increasing α-linolenic acid, long chain omega-3, omega-6, or total PUFA, which collected data on diabetes diagnoses, fasting glucose or insulin, glycated haemoglobin (HbA), and/or homoeostatic model assessment for insulin resistance (HOMA-IR).
DATA SYNTHESIS
Statistical analysis included random effects meta-analyses using relative risk and mean difference, and sensitivity analyses. Funnel plots were examined and subgrouping assessed effects of intervention type, replacement, baseline risk of diabetes and use of antidiabetes drugs, trial duration, and dose. Risk of bias was assessed with the Cochrane tool and quality of evidence with GRADE.
RESULTS
83 randomised controlled trials (mainly assessing effects of supplementary long chain omega-3) were included; 10 were at low summary risk of bias. Long chain omega-3 had little or no effect on likelihood of diagnosis of diabetes (relative risk 1.00, 95% confidence interval 0.85 to 1.17; 58 643 participants, 3.7% developed diabetes) or measures of glucose metabolism (HbA mean difference -0.02%, 95% confidence interval -0.07% to 0.04%; plasma glucose 0.04, 0.02 to 0.07, mmol/L; fasting insulin 1.02, -4.34 to 6.37, pmol/L; HOMA-IR 0.06, -0.21 to 0.33). A suggestion of negative outcomes was observed when dose of supplemental long chain omega-3 was above 4.4 g/d. Effects of α-linolenic acid, omega-6, and total PUFA on diagnosis of diabetes were unclear (as the evidence was of very low quality), but little or no effect on measures of glucose metabolism was seen, except that increasing α-linolenic acid may increase fasting insulin (by about 7%). No evidence was found that the omega-3/omega-6 ratio is important for diabetes or glucose metabolism.
CONCLUSIONS
This is the most extensive systematic review of trials to date to assess effects of polyunsaturated fats on newly diagnosed diabetes and glucose metabolism, including previously unpublished data following contact with authors. Evidence suggests that increasing omega-3, omega-6, or total PUFA has little or no effect on prevention and treatment of type 2 diabetes mellitus.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO CRD42017064110.
Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Dietary Fats, Unsaturated; Dietary Supplements; Fasting; Fatty Acids, Omega-3; Fatty Acids, Omega-6; Fatty Acids, Unsaturated; Female; Glycated Hemoglobin; Humans; Insulin; Insulin Resistance; Male; Primary Prevention; Randomized Controlled Trials as Topic; Secondary Prevention
PubMed: 31434641
DOI: 10.1136/bmj.l4697 -
Nutrients Nov 2021Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder common from childhood to adulthood, affecting 5% to 12% among the general population in...
UNLABELLED
Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder common from childhood to adulthood, affecting 5% to 12% among the general population in developed countries. Potential etiological factors have been identified, including genetic causes, environmental elements and epigenetic components. Nutrition is currently considered an influencing factor, and several studies have explored the contribution of restriction and dietary supplements in ADHD treatments. Iron is an essential cofactor required for a number of functions, such as transport of oxygen, immune function, cellular respiration, neurotransmitter metabolism (dopamine production), and DNA synthesis. Zinc is also an essential trace element, required for cellular functions related to the metabolism of neurotransmitters, melatonin, and prostaglandins. Epidemiological studies have found that iron and zinc deficiencies are common nutritional deficits worldwide, with important roles on neurologic functions (poor memory, inattentiveness, and impulsiveness), finicky appetite, and mood changes (sadness and irritability). Altered levels of iron and zinc have been related with the aggravation and progression of ADHD.
OBJECTIVE
This is a systematic review focused on the contribution of iron and zinc in the progression of ADHD among children and adolescents, and how therapies including these elements are tolerated along with its effectiveness (according to PRISMA guidelines).
METHOD
The scientific literature was screened for randomized controlled trials published between January 2000 to July 2021. The databases consulted were Medline, PsycINFO, Web of Science, and Google Scholar. Two independent reviewers screened studies, extracted data, and assessed quality and risk of bias (CONSORT, NICE, and Cochrane checklists used).
CONCLUSION
Nine studies met the eligibility criteria and were selected. Evidence was obtained regarding the contribution of iron-zinc supplementation in the treatment of ADHD among young individuals. The discussion was focused on how the deficits of these elements contribute to affectation on multiple ADHD correlates, and potential mechanisms explaining the mediational pathways. Evidence also suggested that treating ADHD with diet interventions might be particularly useful for specific subgroups of children and adolescents, but further investigations of the effects of these diet interventions are needed.
Topics: Adolescent; Attention Deficit Disorder with Hyperactivity; Child; Dietary Supplements; Ferrous Compounds; Humans; Randomized Controlled Trials as Topic; Zinc
PubMed: 34836314
DOI: 10.3390/nu13114059