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Journal of Affective Disorders Apr 2023Depression is a common mental illness that afflicts over 300 million individuals worldwide. Despite a variety of therapeutic options available, a significant number of... (Review)
Review
BACKGROUND & RATIONALE
Depression is a common mental illness that afflicts over 300 million individuals worldwide. Despite a variety of therapeutic options available, a significant number of depressed patients fail to respond to treatment. Current guidelines for treating depression suggest that supplementation of essential nutrients may be an appropriate adjunctive to treatment, but research investigating full dietary interventions for depressed patients is scarce.
STUDY OBJECTIVE
The primary aim of this study was to systematically review published scientific literature investigating full dietary interventions as treatment for individuals with a diagnosis of depression. In doing so, we assessed existing evidence for recommendation of a dietary intervention and reviewed theory of how diet may be important in this context.
METHODS
A systematic search was conducted using OVID to search Medline, PsychINFO, and EMBASE, and PubMed for relevant publications. Only studies including full dietary interventions for patients with Major Depressive Episode, Major Depressive Disorder, Persistent Depressive Disorder, Seasonal Affective Disorder, or Dysthymia, as diagnosed using criteria defined in the chapter of "Depressive Disorders" in the DSM, were included.
RESULTS
Only five studies met the inclusion criteria for this review. All five studies included in this review reported improvements in mood following dietary intervention as compared to the comparison group. However, heterogeneity in both the dietary intervention and the outcome(s) measured made it difficult to compare these studies against each other and to generalize them to larger populations.
CONCLUSION
The findings of this review provide preliminary evidence for the positive impact of dietary interventions in the treatment of depressed patients. However, the mechanism by which particular diets induce positive changes in mood, be it through anti-inflammatory mechanisms or via weight loss in overweight patients, is unclear. Future research investigating the impact of dietary interventions on a large-scale is warranted and needed.
Topics: Humans; Depression; Depressive Disorder, Major; Diet; Overweight; Seasonal Affective Disorder
PubMed: 36738997
DOI: 10.1016/j.jad.2023.01.094 -
Inflammopharmacology Oct 2023Melatonin is a neurohormone secreted predominantly by the pineal gland that is demonstrated to be associated with the pathogenesis of multiple sclerosis (MS). This... (Review)
Review
BACKGROUND
Melatonin is a neurohormone secreted predominantly by the pineal gland that is demonstrated to be associated with the pathogenesis of multiple sclerosis (MS). This research desires to evaluate the tolerability and beneficial effects of exogenous melatonin supplementations in patients with MS.
METHODS
This study was executed following the PRISMA 2020 statement. Both observational and interventional studies which reported the clinical effectiveness and/or safety of melatonin supplementation in patients with MS were included in this systematic review. Ovid, PubMed, Scopus, Embase, and Web of Science databases were searched and the risk of bias in included studies was assessed using the Joanna Briggs Institute (JBI) critical appraisal tools based on study design.
RESULTS
Out of 1304 results of database searches, finally, 14 articles, including 7 randomized controlled trials (RCTs), 6 case-control studies, and one quasi-experimental study, were included based on the full-text review. Included phenotypes of MS were mostly relapsing-remitting MS (RRMS) (in 11 studies); it was secondary progressive MS (SPMS) in only one study, and two other studies had a mixture of the different phenotypes. The course of treatment with melatonin supplementation was between 2 weeks and 12 months. There were no substantial safety issues. Although melatonin was associated with enhanced oxidative stress and inflammation status, concerning the clinical benefits, limited studies suggested improvements in sleep conditions, cognitive outcomes, and fatigue in MS.
DISCUSSION
There are insufficient data to support the regular melatonin prescription in MS. Limitations such as the small number of included studies, the diversity of the dosage, route, and duration of melatonin administration, and the diversity of assessment tests lead to unconvincing findings in this study. There is a need for future studies to achieve a comprehensive judgment on this subject.
Topics: Humans; Melatonin; Multiple Sclerosis; Multiple Sclerosis, Relapsing-Remitting; Treatment Outcome; Dietary Supplements
PubMed: 37429996
DOI: 10.1007/s10787-023-01271-4 -
Nutrition (Burbank, Los Angeles County,... 2021According to in vivo and in vitro studies, melatonin appears to be a potential supplement for obesity reduction. The aim of this study was to review the literature on... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
According to in vivo and in vitro studies, melatonin appears to be a potential supplement for obesity reduction. The aim of this study was to review the literature on randomized clinical trials that evaluated the effects of melatonin supplementation on anthropometric indicators of obesity in humans.
METHODS
We conducted a systematic review with meta-analysis in the following databases: Pubmed, LILACS, Scielo, Scopus, Web of Science, Cochrane, and Embase. We included studies that evaluated melatonin supplementation's effects, compared with placebo, on anthropometric measures, including body weight, body mass index (BMI), and waist circumference, in people ≥18 y of age. This systematic review and meta-analysis were registered on PROSPERO: CRD42021241079.
RESULTS
Of the 23 studies included, 11 showed significant results from melatonin supplementation on weight loss, BMI, or waist circumference, compared with placebo. In the meta-analysis, melatonin supplementation significantly reduced body weight (standardized mean difference, -0.48; 95% confidence interval, -0.94 to -0.02; P = <0.01; I = 92%). Results for BMI and waist circumference were null. The I tests were significant for the analyses with significant results.
CONCLUSION
The results demonstrated that melatonin supplementation was responsible for significantly reducing body weight. More studies are needed before melatonin can be recommended for weight loss.
Topics: Body Mass Index; Body Weight; Dietary Supplements; Humans; Melatonin; Obesity; Randomized Controlled Trials as Topic; Waist Circumference
PubMed: 34626955
DOI: 10.1016/j.nut.2021.111399 -
Critical Reviews in Food Science and... 2023Folic acid, a water-soluble vitamin B nutrient, plays an important role not only in maintaining a healthy pregnancy but also in offspring brain development and function,... (Meta-Analysis)
Meta-Analysis
Folic acid, a water-soluble vitamin B nutrient, plays an important role not only in maintaining a healthy pregnancy but also in offspring brain development and function, however, it remains unclear whether maternal folic acid (FA) supplementation associated with the risk of different postnatal neurodevelopmental outcomes. Here, we performed a systematic review and meta-analysis on the impact of maternal FA supplementation on a wide range of postnatal neurodevelopmental outcomes which include intellectual development, risk of autistic traits, ADHD, behavior, language, and psychomotor problems, using studies extracted from the following databases, including MEDLINE, Web of Science, Cochrane Library, Scopus, EMBASE, and PsychInfo. Thirty-two cohort studies and seven case-control studies were included in this meta-analysis. In the present study, we found that prenatal FA supplementation had a positive impact on offspring's neurodevelopmental outcomes, including improved intellectual development and reduced risk of autism traits, ADHD, behavioral, and language problems. We also found that FA over-supplementation was not associated with an improvement in offspring's brain development, and may have a negative impact on offspring's neurodevelopmental outcomes. This study proved the first panoramic review on the relationship of FA supplementation with offspring's neurodevelopment. Further studies focusing on different dosages and periods of FA supplementation are needed.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2021.1993781 .
Topics: Pregnancy; Female; Humans; Dietary Supplements; Folic Acid; Brain; Child Development; Cognition; Vitamins
PubMed: 34672229
DOI: 10.1080/10408398.2021.1993781 -
The Cochrane Database of Systematic... Jun 2015Gestational weight gain is positively associated with fetal growth, and observational studies of food supplementation in pregnancy have reported increases in gestational... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Gestational weight gain is positively associated with fetal growth, and observational studies of food supplementation in pregnancy have reported increases in gestational weight gain and fetal growth.
OBJECTIVES
To assess the effects of education during pregnancy to increase energy and protein intake, or of actual energy and protein supplementation, on energy and protein intake, and the effect on maternal and infant health outcomes.
SEARCH METHODS
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 January 2015), reference lists of retrieved studies and contacted researchers in the field.
SELECTION CRITERIA
Randomised controlled trials of dietary education to increase energy and protein intake, or of actual energy and protein supplementation, during pregnancy.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed trials for inclusion and assessed risk of bias. Two review authors independently extracted data and checked for accuracy. Extracted data were supplemented by additional information from the trialists we contacted.
MAIN RESULTS
We examined 149 reports corresponding to 65 trials. Of these trials, 17 were included, 46 were excluded, and two are ongoing. Overall, 17 trials involving 9030 women were included. For this update, we assessed methodological quality of the included trials using the standard Cochrane criteria (risk of bias) and the GRADE approach. The overall risk of bias was unclear. Nutritional education (five trials, 1090 women) Women given nutritional education had a lower relative risk of having a preterm birth (two trials, 449 women) (risk ratio (RR) 0.46, 95% CI 0.21 to 0.98, low-quality evidence), and low birthweight (one trial, 300 women) (RR 0.04, 95% CI 0.01 to 0.14). Head circumference at birth was increased in one trial (389 women) (mean difference (MD) 0.99 cm, 95% CI 0.43 to 1.55), while birthweight was significantly increased among undernourished women in two trials (320 women) (MD 489.76 g, 95% CI 427.93 to 551.59, low-quality evidence), but did not significantly increase for adequately nourished women (MD 15.00, 95% CI -76.30 to 106.30, one trial, 406 women). Protein intake increased significantly (three trials, 632 women) (protein intake: MD +6.99 g/day, 95% CI 3.02 to 10.97). No significant differences were observed on any other outcomes such as neonatal death (RR 1.28, 95% CI 0.35 to 4.72, one trial, 448 women, low-quality evidence), stillbirth (RR 0.37, 95% CI 0.07 to 1.90, one trial, 431 women, low-quality evidence), small-for-gestational age (RR 0.97, 95% CI 0.45 to 2.11, one trial, 404 women, low-quality evidence) and total gestational weight gain (MD -0.41, 95% CI -4.41 to 3.59, two trials, 233 women). There were no data on perinatal death. Balanced energy and protein supplementation (12 trials, 6705 women)Risk of stillbirth was significantly reduced for women given balanced energy and protein supplementation (RR 0.60, 95% CI 0.39 to 0.94, five trials, 3408 women, moderate-quality evidence), and the mean birthweight was significantly increased (random-effects MD +40.96 g, 95% CI 4.66 to 77.26, Tau² = 1744, I² = 44%, 11 trials, 5385 women, moderate-quality evidence). There was also a significant reduction in the risk of small-for-gestational age (RR 0.79, 95% CI 0.69 to 0.90, I² = 16%, seven trials, 4408 women, moderate-quality evidence). No significant effect was detected for preterm birth (RR 0.96, 95% CI 0.80 to 1.16, five trials, 3384 women, moderate-quality evidence) or neonatal death (RR 0.68, 95% CI 0.43 to 1.07, five trials, 3381 women, low-quality evidence). Weekly gestational weight gain was not significantly increased (MD 18.63, 95% CI -1.81 to 39.07, nine trials, 2391 women, very low quality evidence). There were no data reported on perinatal death and low birthweight. High-protein supplementation (one trial, 1051 women)High-protein supplementation (one trial, 505 women), was associated with a significantly increased risk of small-for-gestational age babies (RR 1.58, 95% CI 1.03 to 2.41, moderate-quality evidence). There was no significant effect for stillbirth (RR 0.81, 95% CI 0.31 to 2.15, one trial, 529 women), neonatal death (RR 2.78, 95% CI 0.75 to 10.36, one trial, 529 women), preterm birth (RR 1.14, 95% CI 0.83 to 1.56, one trial, 505 women), birthweight (MD -73.00, 95% CI -171.26 to 25.26, one trial, 504 women) and weekly gestational weight gain (MD 4.50, 95% CI -33.55 to 42.55, one trial, 486 women, low-quality evidence). No data were reported on perinatal death. Isocaloric protein supplementation (two trials, 184 women)Isocaloric protein supplementation (two trials, 184 women) had no significant effect on birthweight (MD 108.25, 95% CI -220.89 to 437.40) and weekly gestational weight gain (MD 110.45, 95% CI -82.87 to 303.76, very low-quality evidence). No data reported on perinatal mortality, stillbirth, neonatal death, small-for-gestational age, and preterm birth.
AUTHORS' CONCLUSIONS
This review provides encouraging evidence that antenatal nutritional education with the aim of increasing energy and protein intake in the general obstetric population appears to be effective in reducing the risk of preterm birth, low birthweight, increasing head circumference at birth, increasing birthweight among undernourished women, and increasing protein intake. There was no evidence of benefit or adverse effect for any other outcome reported.Balanced energy and protein supplementation seems to improve fetal growth, and may reduce the risk of stillbirth and infants born small-for-gestational age. High-protein supplementation does not seem to be beneficial and may be harmful to the fetus. Balanced-protein supplementation alone had no significant effects on perinatal outcomes.The results of this review should be interpreted with caution. The risk of bias was either unclear or high for at least one category examined in several of the included trials, and the quality of the evidence was low for several important outcomes. Also, as the anthropometric characteristics of the general obstetric population is changing, those developing interventions aimed at altering energy and protein intake should ensure that only those women likely to benefit are included. Large, well-designed randomised trials are needed to assess the effects of increasing energy and protein intake during pregnancy in women whose intake is below recommended levels.
Topics: Diet; Dietary Proteins; Dietary Supplements; Energy Intake; Female; Fetal Development; Humans; Pregnancy; Pregnancy Outcome; Premature Birth; Prenatal Care; Prenatal Education; Randomized Controlled Trials as Topic; Stillbirth; Weight Gain
PubMed: 26031211
DOI: 10.1002/14651858.CD000032.pub3 -
Nutrition Research (New York, N.Y.) Mar 2015Appearance-based interventions have had some success in reducing smoking and sun exposure. Appearance may also motivate dietary behavior change if it was established... (Review)
Review
Appearance-based interventions have had some success in reducing smoking and sun exposure. Appearance may also motivate dietary behavior change if it was established that dietary improvement had a positive impact on appearance. The aims of this review are to evaluate the current evidence examining the relationship between dietary intake and appearance and to determine the effectiveness of dietary interventions on perceived or actual appearance. An electronic search of English-language studies up to August 2012 was conducted using Cochrane, MEDLINE, Embase, CINAHL, Web of Science, SCOPUS, and PsycINFO databases. Studies that included participants aged at least 18 years, that observed or altered dietary intake from actual food or dietary supplement use, and assessed appearance-related outcomes were considered eligible. Data from 27 studies were extracted and assessed for quality using standardized tools. Nineteen studies were assessed as being of "positive" and 4 of "neutral" quality. All observational studies (n = 4741 participants) indicated that there was a significant association between various aspects of dietary intake and skin coloration and skin aging. The majority (16 studies, 769 participants) evaluated the effect of dietary supplements on skin appearance among women. Only 1 study examined the effect of actual food intake on appearance. Significant improvements in at least 1 actual or perceived appearance-related outcome (facial wrinkling, skin elasticity, roughness, and skin color) following dietary intervention were shown as a result of supplementation. Further studies are needed in representative populations that examine actual food intake on appearance, using validated tools in well-designed high-quality randomized control trials.
Topics: Aging; Diet; Feeding Behavior; Humans; Motivation; Perception; Physical Appearance, Body; Skin; Skin Pigmentation
PubMed: 25600848
DOI: 10.1016/j.nutres.2014.12.002 -
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 -
The Cochrane Database of Systematic... Jun 2019Nutritional interventions to prevent stunting of infants and young children are most often applied in rural areas in low- and middle-income countries (LMIC). Few... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Nutritional interventions to prevent stunting of infants and young children are most often applied in rural areas in low- and middle-income countries (LMIC). Few interventions are focused on urban slums. The literature needs a systematic assessment, as infants and children living in slums are at high risk of stunting. Urban slums are complex environments in terms of biological, social, and political variables and the outcomes of nutritional interventions need to be assessed in relation to these variables. For the purposes of this review, we followed the UN-Habitat 2004 definitions for low-income informal settlements or slums as lacking one or more indicators of basic services or infrastructure.
OBJECTIVES
To assess the impact of nutritional interventions to reduce stunting in infants and children under five years old in urban slums from LMIC and the effect of nutritional interventions on other nutritional (wasting and underweight) and non-nutritional outcomes (socioeconomic, health and developmental) in addition to stunting.
SEARCH METHODS
The review used a sensitive search strategy of electronic databases, bibliographies of articles, conference proceedings, websites, grey literature, and contact with experts and authors published from 1990. We searched 32 databases, in English and non-English languages (MEDLINE, CENTRAL, Web of Science, Ovid MEDLINE, etc). We performed the initial literature search from November 2015 to January 2016, and conducted top up searches in March 2017 and in August 2018.
SELECTION CRITERIA
Research designs included randomised (including cluster-randomised) trials, quasi-randomised trials, non-randomised controlled trials, controlled before-and-after studies, pre- and postintervention, interrupted time series (ITS), and historically controlled studies among infants and children from LMIC, from birth to 59 months, living in urban slums. The interventions included were nutrition-specific or maternal education. The primary outcomes were length or height expressed in cm or length-for-age (LFA)/height-for-age (HFA) z-scores, and birth weight in grams or presence/absence of low birth weight (LBW).
DATA COLLECTION AND ANALYSIS
We screened and then retrieved titles and abstracts as full text if potentially eligible for inclusion. Working independently, one review author screened all titles and abstracts and extracted data on the selected population, intervention, comparison, and outcome parameters and two other authors assessed half each. We calculated mean selection difference (MD) and 95% confidence intervals (CI). We performed intervention-level meta-analyses to estimate pooled measures of effect, or narrative synthesis when meta-analyses were not possible. We used P less than 0.05 to assess statistical significance and intervention outcomes were also considered for their biological/health importance. Where effect sizes were small and statistically insignificant, we concluded there was 'unclear effect'.
MAIN RESULTS
The systematic review included 15 studies, of which 14 were randomised controlled trials (RCTs). The interventions took place in recognised slums or poor urban or periurban areas. The study locations were mainly Bangladesh, India, and Peru. The participants included 9261 infants and children and 3664 pregnant women. There were no dietary intervention studies. All the studies identified were nutrient supplementation and educational interventions. The interventions included zinc supplementation in pregnant women (three studies), micronutrient or macronutrient supplementation in children (eight studies), nutrition education for pregnant women (two studies), and nutrition systems strengthening targeting children (two studies) intervention. Six interventions were adapted to the urban context and seven targeted household, community, or 'service delivery' via systems strengthening. The primary review outcomes were available from seven studies for LFA/HFA, four for LBW, and nine for length.The studies had overall high risk of bias for 11 studies and only four RCTs had moderate risk of bias. Overall, the evidence was complex to report, with a wide range of outcome measures reported. Consequently, only eight study findings were reported in meta-analyses and seven in a narrative form. The certainty of evidence was very low to moderate overall. None of the studies reported differential impacts of interventions relevant to equity issues.Zinc supplementation of pregnant women on LBW or length (versus supplementation without zinc or placebo) (three RCTs)There was no evidence of an effect on LBW (MD -36.13 g, 95% CI -83.61 to 11.35), with moderate-certainty evidence, or no evidence of an effect or unclear effect on length with low- to moderate-certainty evidence.Micronutrient or macronutrient supplementation in children (versus no intervention or placebo) (eight RCTs)There was no evidence of an effect or unclear effect of nutrient supplementation of children on HFA for studies in the meta-analysis with low-certainty evidence (MD -0.02, 95% CI -0.06 to 0.02), and inconclusive effect on length for studies reported in a narrative form with very low- to moderate-certainty evidence.Nutrition education for pregnant women (versus standard care or no intervention) (two RCTs)There was a positive impact on LBW of education interventions in pregnant women, with low-certainty evidence (MD 478.44g, 95% CI 423.55 to 533.32).Nutrition systems strengthening interventions targeting children (compared with no intervention, standard care) (one RCT and one controlled before-and-after study)There were inconclusive results on HFA, with very low- to low-certainty evidence, and a positive influence on length at 18 months, with low-certainty evidence.
AUTHORS' CONCLUSIONS
All the nutritional interventions reviewed had the potential to decrease stunting, based on evidence from outside of slum contexts; however, there was no evidence of an effect of the interventions included in this review (very low- to moderate-certainty evidence). Challenges linked to urban slum programming (high mobility, lack of social services, and high loss of follow-up) should be taken into account when nutrition-specific interventions are proposed to address LBW and stunting in such environments. More evidence is needed of the effects of multi-sectorial interventions, combining nutrition-specific and sensitive methods and programmes, as well as the effects of 'up-stream' practices and policies of governmental, non-governmental organisations, and the business sector on nutrition-related outcomes such as stunting.
Topics: Bangladesh; Case-Control Studies; Child, Preschool; Controlled Before-After Studies; Developing Countries; Diet, Healthy; Dietary Supplements; Growth Disorders; Humans; India; Infant; Micronutrients; Mothers; Nutrients; Nutrition Therapy; Peru; Poverty Areas; Pregnant Women; Randomized Controlled Trials as Topic; Thinness; Urban Population; Wasting Syndrome; Zinc
PubMed: 31204795
DOI: 10.1002/14651858.CD011695.pub2 -
The Cochrane Database of Systematic... Jan 2021Phenylketonuria is an inherited disease for which the main treatment is the dietary restriction of the amino acid phenylalanine. The diet has to be initiated in the... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Phenylketonuria is an inherited disease for which the main treatment is the dietary restriction of the amino acid phenylalanine. The diet has to be initiated in the neonatal period to prevent or reduce mental handicap. However, the diet is very restrictive and unpalatable and can be difficult to follow. A deficiency of the amino acid tyrosine has been suggested as a cause of some of the neuropsychological problems exhibited in phenylketonuria. Therefore, this review aims to assess the efficacy of tyrosine supplementation for phenylketonuria. This is an update of previously published versions of this review.
OBJECTIVES
To assess the effects of tyrosine supplementation alongside or instead of a phenylalanine-restricted diet for people with phenylketonuria, who commenced on diet at diagnosis and either continued on the diet or relaxed the diet later in life. To assess the evidence that tyrosine supplementation alongside, or instead of a phenylalanine-restricted diet improves intelligence, neuropsychological performance, growth and nutritional status, mortality rate and quality of life.
SEARCH METHODS
We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Trials Register which is comprised of references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings. Additional studies were identified from handsearches of the Journal of Inherited Metabolic Disease (from inception in 1978 to 1998). The manufacturers of prescribable dietary products used in the treatment of phenylketonuria were also contacted for further references. Date of the most recent search of the Group's Inborn Errors of Metabolism Trials Register: 07 December 2020.
SELECTION CRITERIA
All randomised or quasi-randomised trials investigating the use of tyrosine supplementation versus placebo in people with phenylketonuria in addition to, or instead of, a phenylalanine-restricted diet. People treated for maternal phenylketonuria were excluded.
DATA COLLECTION AND ANALYSIS
Two authors independently assessed the trial eligibility, methodological quality and extracted the data.
MAIN RESULTS
Six trials were found, of which three trials reporting the results of a total of 56 participants, were suitable for inclusion in the review. The blood tyrosine concentrations were significantly higher in the participants receiving tyrosine supplements than those in the placebo group, mean difference 23.46 (95% confidence interval 12.87 to 34.05). No significant differences were found between any of the other outcomes measured. The trials were assessed as having a low to moderate risk of bias across several domains.
AUTHORS' CONCLUSIONS
From the available evidence no recommendations can be made about whether tyrosine supplementation should be introduced into routine clinical practice. Further randomised controlled studies are required to provide more evidence. However, given this is not an active area of research, we have no plans to update this review in the future.
Topics: Dietary Supplements; Humans; Intelligence; Neuropsychological Tests; Phenylalanine; Phenylketonurias; Placebos; Randomized Controlled Trials as Topic; Tyrosine
PubMed: 33427303
DOI: 10.1002/14651858.CD001507.pub4 -
Nutrition & Metabolism 2018The aim of this systematic review was to assess the effect of fructo-oligosaccharide supplementation on glucose homeostasis. The search process was based on the... (Review)
Review
The aim of this systematic review was to assess the effect of fructo-oligosaccharide supplementation on glucose homeostasis. The search process was based on the selection of publications listed in the Pubmed-Medline database until April 2016 to identify studies evaluating the impact of short-chain fructo-oligosaccharides or oligofructose on glucose homeostasis. Twenty-nine trials were included in the systematic review and the meta-analysis was performed on twelve of these papers according to the inclusion criteria. Fasting blood concentrations of glucose and insulin were selected as pertinent criteria of glucose homeostasis for the meta-analysis. The consumption of fructo-oligosaccharides decreased fasting blood glycaemia levels, whatever the metabolic status (healthy, obese or diabetic) and diet (low-fat or high-fat) throughout the experiment. This reduction was linear with prebiotic dose (from 0 to 13% of the feed). Fasting insulinaemia also decreased linearly with fructo-oligosaccharide supplementation but the reduction was only significant in rodents fed a low-fat diet. Potential underlying mechanisms include gut bacterial fermentation of fructo-oligosaccharides to short-chain fatty acids (SCFA) and bacterial modulation of bile acids, both interacting with host metabolism. This systemic review, followed by the meta-analysis, provides evidence that fructo-oligosaccharide supplementation has a significant effect on glucose homeostasis whatever the health status and diet consumed by animals.
PubMed: 29416552
DOI: 10.1186/s12986-018-0245-3