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Lifestyle-, environmental-, and additional health factors associated with an increased sperm DNA fragmentation: a systematic review and meta-analysis.
Szabó, A, Váncsa, S, Hegyi, P, Váradi, A, Forintos, A, Filipov, T, Ács, J, Ács, N, Szarvas, T, Nyirády, P, et al
Reproductive biology and endocrinology : RB&E. 2023;21(1):5
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The World Health Organization defines infertility as regular unprotected sexual intercourse without achieving conception within a year. In recent years, there has been a growing demand for functional, objective parameters reflecting fertility status more clearly than classical parameters. Of these, sperm DNA fragmentation (SDF) and the DNA fragmentation index – denoting the percentage of sperm with damaged DNA – seem to be of utmost importance. The aim of this study was to investigate all risk factors that may potentially be increasing SDF. This study is a systematic review and meta-analysis of one hundred and ninety articles. The earliest studies were published in 2003, and the latest in 2021. Results show that several modifiable risk factors negatively affect SDF, namely; a. health conditions: varicocele [when veins become enlarged inside the pouch of skin that holds the testicles] and impaired glucose tolerance, b. infections: Chlamydia, c. malignancies: testicular tumours, and d. lifestyle factors: smoking, alcohol consumption and body mass index. Authors conclude that several lifestyle-, environmental-, and additional health factors are associated with increased SDF.
Abstract
INTRODUCTION Infertility affects one in every six couples in developed countries, and approximately 50% is of male origin. In 2021, sperm DNA fragmentation (SDF) testing became an evidence-based test for fertility evaluations depicting fertility more clearly than standard semen parameters. Therefore, we aimed to summarize the potential prognostic factors of a higher SDF. METHODS We conducted a systematic search in three medical databases and included studies investigating any risk factors for SDF values. We calculated mean differences (MD) in SDF with 95% confidence interval (CI) for exposed and non-exposed individuals. RESULTS We included 190 studies in our analysis. In the group of associated health conditions, varicocele (MD = 13.62%, CI: 9.39-17.84) and impaired glucose tolerance (MD = 13.75%, CI: 6.99-20.51) had the most significant increase in SDF. Among malignancies, testicular tumors had the highest impact, with a maximum of MD = 11.3% (CI: 7.84-14.76). Among infections, the overall effects of both Chlamydia and HPV were negligible. Of lifestyle factors, smoking had the most disruptive effect on SDF - an increase of 9.19% (CI: 4.33-14.06). Different periods of sexual abstinence did not show significant variations in SDF values. Age seemed to have a more drastic effect on SDF from age 50 onwards, with a mean difference of 12.58% (CI: 7.31-17.86). Pollution also had a detrimental effect - 9.68% (CI: 6.85-12.52). CONCLUSION Of the above risk factors, varicocele, impaired glucose tolerance, testicular tumors, smoking, pollution, and paternal age of over 50 were associated with the highest SDF. TRIAL REGISTRATION CRD42021282533.
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The effectiveness of interventions during the first 1,000 days to improve energy balance-related behaviors or prevent overweight/obesity in children from socio-economically disadvantaged families of high-income countries: a systematic review.
Lioret, S, Harrar, F, Boccia, D, Hesketh, KD, Kuswara, K, Van Baaren, C, Maritano, S, Charles, MA, Heude, B, Laws, R
Obesity reviews : an official journal of the International Association for the Study of Obesity. 2023;24(1):e13524
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The first 1,000 days is an opportune time to support parents, as primary caregivers and role model, to promote a healthy lifestyle and prevent obesity for their children. The aim of this study was to update the current evidence on the effectiveness of family-based interventions implemented during pregnancy and up to 2 years of age to improve energy balance-related behaviours and growth, or prevent overweight (OW)/ obesity (OB), in children growing up in families experiencing socio-economic disadvantage. This study is a systematic review of thirty-three studies which corresponded to 24 distinct interventions. Of the 24 interventions, nearly all were (cluster) randomised controlled trials; three had a quasi-experimental design. Results show that there is some effectiveness on behavioural and anthropometric outcomes in young children when programmes target and are tailored to families experiencing socioeconomic disadvantage. Authors conclude that a holistic, multilevel and proportionate interventions are likely to more effective and sustainably address the issue of social inequalities and inequities. Additionally, more thorough process evaluation of such complex interventions using mixed methods is needed to better understand why interventions worked or not, by which mechanisms of action (if any), for whom and in which context.
Abstract
This narrative systematic review examined effectiveness of interventions during pregnancy and up to 2 years of age in improving energy balance-related behaviors or prevent overweight/obesity in children from families experiencing socio-economic disadvantage. We identified 24 interventions, from 33 articles, since 1990. Overall, despite their heterogeneity and variability in internal and external validity, there was some evidence of beneficial impact of interventions on obesity risk (4/15), and associated behaviors, e.g.: breastfeeding (9/18), responsive feeding (11/16), diet (7/8), sedentary (1/3) and movement (4/7) behaviors, and sleep (1/2). The most effective interventions aimed at promoting breastfeeding commenced antenatally; this was similar for the prevention of obesity, provided the intervention continued for at least 2 years postnatally and was multi-behavioral. Effective interventions were more likely to target first-time mothers and involve professional delivery agents, multidisciplinary teams and peer groups. Among ethnic/racial minorities, interventions delivered by lay agents had some impact on dietary behavior but not weight outcomes. Co-creation with stakeholders, including parents, and adherence to theoretical frameworks were additional ingredients for more pragmatic, inclusive, non-judgmental, and effective programs. The growing body of evidence on obesity prevention interventions targeting families experiencing socio-economic disadvantage is promising for reducing early inequalities in obesity risk.
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Effectiveness of Therapeutic Patient Education Interventions in Obesity and Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
Correia, JC, Waqas, A, Huat, TS, Gariani, K, Jornayvaz, FR, Golay, A, Pataky, Z
Nutrients. 2022;14(18)
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Obesity and diabetes mellitus (DM) account for the highest burden of non-communicable diseases. Obesity is also highly comorbid with type 2 DM with a prevalence of 8.5% among adults around the globe. The aims of this study were to present (a) a critical synthesis of the theoretical basis and development of therapeutic patient education (TPE) interventions for obesity and diabetes, and (b) quantitative evidence for the efficacy of these interventions across a range of biomedical, psychosocial and psychological outcomes. This study is a systematic review and meta-analysis of fifty-four randomised controlled trials. Results show that: - TPE interventions bring about significant improvements in biomedical outcomes among patients with DM and obesity. - there weren’t significant differences in the quality of life of participants undergoing TPE interventions (inconclusive as only data from two studies were considered). - interventions delivered through different media and delivery formats may be equally effective. Authors conclude that the use of electronic media such as short messaging services, website-based educational programs and animation media can be used to deliver TPE effectively.
Abstract
Diabetes mellitus (DM) and obesity account for the highest burden of non-communicable diseases. There is increasing evidence showing therapeutic patient education (TPE) as a clinically and cost-effective solution to improve biomedical and psychosocial outcomes among people with DM and obesity. The present systematic review and meta-analysis present a critical synthesis of the development of TPE interventions for DM and obesity and the efficacy of these interventions across a range of biomedical, psychosocial and psychological outcomes. A total of 54 of these RCTs were identified among patients with obesity and diabetes and were thus qualitatively synthesized. Out of these, 47 were included in the quantitative synthesis. There was substantial heterogeneity in the reporting of these outcomes (I2 = 88.35%, Q = 317.64), with a significant improvement noted in serum HbA1c levels (standardized mean difference (SMD) = 0.272, 95% CI: 0.118 to 0.525, n = 7360) and body weight (SMD = 0.526, 95% CI: 0.205 to 0.846, n = 1082) in the intervention group. The effect sizes were comparable across interventions delivered by different modes and delivery agents. These interventions can be delivered by allied health staff, doctors or electronically as self-help programs, with similar effectiveness (p < 0.001). These interventions should be implemented in healthcare and community settings to improve the health outcomes in patients suffering from obesity and DM.
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Digital technology to support lifestyle and health behaviour changes in surgical patients: systematic review.
Robinson, A, Husband, AK, Slight, RD, Slight, SP
BJS open. 2021;5(2)
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Digital technologies are becoming an integral part of modern-day life. In a surgical context, recent evidence has linked better patient physical preparedness before surgery with improved outcomes and benefits after surgery. The aim of this study was to determine whether digital technologies are effective at supporting patients undergoing elective surgery to change their health behaviours, focusing on physical activity, weight, and dietary intake. This study is a systematic review of 17 studies, of which 10 where randomised controlled trials. Results demonstrate that: - in patients undergoing elective surgery, digital technology can support behaviour change successfully, physical activity, dietary intake and weight loss. - digital technology effectiveness in the elective surgical population may be linked to three factors: delivery of an intervention, timing of the intervention and behavioural change theories underpinning the intervention design. - high overall retention rates across studies indicate the acceptability of modern technologies in surgical care. Authors conclude that digital technologies may effectively support behavioural change in patients undergoing elective surgery.
Abstract
BACKGROUND Digital technologies (such as smartphone applications, activity trackers, and e-learning platforms) have supported patients with long-term conditions to change their lifestyle health behaviours. The aim of this study was to examine the effectiveness of digital technologies in supporting patients undergoing elective surgery to change their health behaviours. METHODS A systematic review was conducted of articles reporting a digital intervention supporting behaviour change in adult patients who underwent elective bariatric, oncological or orthopaedic surgery. MEDLINE, Embase, CINAHL, PsycINFO, Web of Science, and Scopus were searched from inception to March 2019 for quantitative intervention studies with a specific focus on physical activity, dietary intake, and weight loss in patients before and after surgery (PROSPERO CRD42019127972). The Joanna Briggs Institute critical appraisal checklist was used to assess study quality. RESULTS Of 3021 citations screened, 17 studies were included comprising 4923 surgical patients; these included experimental (pre-post design, feasibility studies, and RCTs) and observational studies. Three factors were identified as effective for supporting health behaviour change in elective surgical populations: digital technology delivery, implementation, and theoretical underpinning. Six of eight studies that referred to behaviour change theories observed significant improvements in health behaviour relating to reduced weight regain, and improved lifestyle choices for physical activity and diet. Meta-analysis was not possible because of heterogeneous outcome measures. CONCLUSION Digital technologies may effectively support behavioural change in patients undergoing elective surgery.
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Laboratory features of severe vs. non-severe COVID-19 patients in Asian populations: a systematic review and meta-analysis.
Ghahramani, S, Tabrizi, R, Lankarani, KB, Kashani, SMA, Rezaei, S, Zeidi, N, Akbari, M, Heydari, ST, Akbari, H, Nowrouzi-Sohrabi, P, et al
European journal of medical research. 2020;25(1):30
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The coronavirus disease 2019 (COVID-19) outbreak started in December 2019 in China has spread sharply all over the world. Apart from the clinical symptoms and pulmonary computed tomography findings, a large number of COVID-19 confirmed patients showed laboratory fluctuations. The aim of this study was to quantify the results of previously published studies, comparing the laboratory fluctuations, and some new combined inflammatory laboratory tests in severe/critical versus non-severe confirmed infected cases of COVID-19. This study is a systemic review and meta-analysis which included 22 studies with a total of 3396 patients who were classed into two groups: 720 in severe and 2676 in non-severe groups. Results showed that the results of complete blood count test, liver and kidney function tests, inflammatory/infection markers, serum electrolytes and glucose were significantly different between severe and non-severe cases of COVID-19. In fact, there was significant decreased levels of certain types of white blood cells (lymphocyte, monocyte, eosinophil), haemoglobin, and platelet, whereas elevated neutrophil [white blood cell] counts among the complete blood count indices in severe vs. non-severe patients. Authors conclude that further well-methodologically designed studies from other populations are strongly recommended.
Abstract
BACKGROUND More severe cases of COVID- 19 are more likely to be hospitalized and around one-fifth, needing ICU admission. Understanding the common laboratory features of COVID-19 in more severe cases versus non-severe patients could be quite useful for clinicians and might help to predict the model of disease progression. This systematic review and meta-analysis aimed to compare the laboratory test findings in severe vs. non-severe confirmed infected cases of COVID-19. METHODS Electronic databases were systematically searched in PubMed, EMBASE, Scopus, Web of Science, and Google Scholar from the beginning of 2019 to 3rd of March 2020. Heterogeneity across included studies was determined using Cochrane's Q test and the I2 statistic. We used the fixed or random-effect models to pool the weighted mean differences (WMDs) or standardized mean differences and 95% confidence intervals (CIs). FINDINGS Out of a total of 3009 citations, 17 articles (22 studies, 21 from China and one study from Singapore) with 3396 ranging from 12 to1099 patients were included. Our meta-analyses showed a significant decrease in lymphocyte, monocyte, and eosinophil, hemoglobin, platelet, albumin, serum sodium, lymphocyte to C-reactive protein ratio (LCR), leukocyte to C-reactive protein ratio (LeCR), leukocyte to IL-6 ratio (LeIR), and an increase in the neutrophil, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, blood urea nitrogen (BUN), creatinine (Cr), erythrocyte Sedimentation Rate (ESR), C-reactive protein (CRP), Procalcitonin (PCT), lactate dehydrogenase (LDH), fibrinogen, prothrombin time (PT), D-dimer, glucose level, and neutrophil to lymphocyte ratio (NLR) in the severe group compared with the non-severe group. No significant changes in white blood cells (WBC), Creatine Kinase (CK), troponin I, myoglobin, IL-6 and K between the two groups were observed. INTERPRETATION This meta-analysis provides evidence for the differentiation of severe cases of COVID-19 based on laboratory test results at the time of ICU admission. Future well-methodologically designed studies from other populations are strongly recommended.
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Prevalence, Severity and Mortality associated with COPD and Smoking in patients with COVID-19: A Rapid Systematic Review and Meta-Analysis.
Alqahtani, JS, Oyelade, T, Aldhahir, AM, Alghamdi, SM, Almehmadi, M, Alqahtani, AS, Quaderi, S, Mandal, S, Hurst, JR
PloS one. 2020;15(5):e0233147
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This meta-analysis reviewed 15 studies covering a total of 2473 confirmed COVID-19 patients to summarise the potential risk factors for smokers and patients with chronic obstructive pulmonary disease (COPD), a dysfunction of the lung associated with limitation in airflow. They found that neither COPD or smoking increased the initial risk of contracting COVID-19 with only 2% and 9% respectively of the cases falling into these categories. However, both groups had increased risk of developing more servere forms of COVID-19 requiring hospitalisation, admission to Intensive Care Units (ICU), mechanical ventilation, and ultimately death, with a much higher mortality rate of 60% versus other patients. Current smokers were also shown to have double the risk of complications versus ex-smokers. The most severe cases were generally in the older age brackets, with coexisting comorbidities and a hypothesized greater amount of lung damage. Both groups showed signs of acute inflammation and had a much slower recovery compared to non-smokers and patients without COPD. Despite the low prevalence of these groups contracting COVID-19, these people should be considered vulnerable because of the severity of symptoms and greater burden on healthcare.
Abstract
BACKGROUND Coronavirus disease 2019 (COVID-19) is an evolving infectious disease that dramatically spread all over the world in the early part of 2020. No studies have yet summarized the potential severity and mortality risks caused by COVID-19 in patients with chronic obstructive pulmonary disease (COPD), and we update information in smokers. METHODS We systematically searched electronic databases from inception to March 24, 2020. Data were extracted by two independent authors in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Study quality was assessed using a modified version of the Newcastle-Ottawa Scale. We synthesized a narrative from eligible studies and conducted a meta-analysis using a random-effects model to calculate pooled prevalence rates and 95% confidence intervals (95%CI). RESULTS In total, 123 abstracts were screened and 61 full-text manuscripts were reviewed. A total of 15 studies met the inclusion criteria, which included a total of 2473 confirmed COVID-19 patients. All studies were included in the meta-analysis. The crude case fatality rate of COVID-19 was 7.4%. The pooled prevalence rates of COPD patients and smokers in COVID-19 cases were 2% (95% CI, 1%-3%) and 9% (95% CI, 4%-14%) respectively. COPD patients were at a higher risk of more severe disease (risk of severity = 63%, (22/35) compared to patients without COPD 33.4% (409/1224) [calculated RR, 1.88 (95% CI, 1.4-2.4)]. This was associated with higher mortality (60%). Our results showed that 22% (31/139) of current smokers and 46% (13/28) of ex-smokers had severe complications. The calculated RR showed that current smokers were 1.45 times more likely [95% CI: 1.03-2.04] to have severe complications compared to former and never smokers. Current smokers also had a higher mortality rate of 38.5%. CONCLUSION Although COPD prevalence in COVID-19 cases was low in current reports, COVID-19 infection was associated with substantial severity and mortality rates in COPD. Compared to former and never smokers, current smokers were at greater risk of severe complications and higher mortality rate. Effective preventive measures are required to reduce COVID-19 risk in COPD patients and current smokers.
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Internet-Delivered Acceptance and Commitment Therapy for Anxiety Treatment: Systematic Review.
Kelson, J, Rollin, A, Ridout, B, Campbell, A
Journal of medical Internet research. 2019;21(1):e12530
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Anxiety and its related conditions are highly prevalent on a global scale. A potential solution for people with anxiety is Acceptance and Commitment Therapy (ACT)—a psychological treatment that teaches mindfulness skills to help people accept their anxiety and commit to living in accordance with personal values. The aim of this study was to provide a comprehensive and up-to-date account on the empirical status of internet-delivered ACT for anxiety. This study is a systemic review of 20 studies. More than half of the studies were randomised control trials. Findings indicate small-to-large anxiety reductions among participants (suffering from generalized anxiety disorder, social anxiety disorder and illness anxiety disorder) after internet-derived ACT on standardized measures (studies n=18), thus indicating the beneficial impact of internet-derived ACT on anxiety. Authors conclude that their current findings indicate that internet-derived ACT can be an effective and acceptable treatment for some anxiety conditions among young to middle aged adults in Western societies.
Abstract
BACKGROUND Anxiety conditions are debilitating and prevalent throughout the world. Acceptance and Commitment Therapy (ACT) is an effective, acceptance-based behavioral therapy for anxiety. However, there are treatment barriers (eg, financial, geographical, and attitudinal), which prevent people from accessing it. To overcome these barriers, internet-delivered ACT (iACT) interventions have been developed in recent years. These interventions use websites to deliver ACT information and skill training exercises on the Web, either as pure self-help or with therapist guidance. OBJECTIVE This systematic review aimed to examine the therapeutic impact of iACT on all anxiety conditions. METHODS The EMBASE, MEDLINE, ProQuest Central, PsycINFO, Scopus, and Web of Science databases were searched up to September 2018. The titles and abstracts of remaining records after deduplication were screened by 2 authors with a total of 36 full-text articles being retained for closer inspection next to eligibility criteria. Empirical studies of all designs, population types, and comparator groups were included if they appraised the impact of iACT treatment on any standardized measure of anxiety. Included studies were appraised on methodological quality and had their data extracted into a standardized coding sheet. Findings were then tabulated, and a narrative synthesis was performed because of the heterogeneity found between studies. RESULTS A total of 20 studies met inclusion criteria. There were 11 randomized controlled trials (RCTs) and 9 uncontrolled pilot studies. Participants across all studies were adults. The anxiety conditions treated were as follows: generalized anxiety disorder (GAD), social anxiety disorder (SAD), illness anxiety disorder (IAD), and general anxiety symptoms, with or without comorbid physical and mental health problems. A total of 18 studies reported significant anxiety reduction after iACT treatment. This was observed in studies that delivered iACT with (n=13) or without (n=5) therapist guidance. The average attrition rate across all included studies during the active iACT treatment phase was 19.19%. In the 13 studies that assessed treatment satisfaction, participants on average rated their iACT experience with above average to high treatment satisfaction. CONCLUSIONS These findings indicate that iACT can be an efficacious and acceptable treatment for adults with GAD and general anxiety symptoms. More RCT studies are needed to corroborate these early iACT findings using empirical treatments in active control groups (eg, internet-delivered cognitive behavioral therapy). This would potentially validate the promising results found for SAD and IAD as well as address the full spectrum of anxiety disorders.
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Key Risk Factors Affecting Farmers' Mental Health: A Systematic Review.
Daghagh Yazd, S, Wheeler, SA, Zuo, A
International journal of environmental research and public health. 2019;16(23)
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The prevalence of psychological stress among farmers and farm workers is greater than that of non-farmers. The mental health of farmers can be affected by several factors, including pesticide exposure, financial problems, climate issues, and poor physical health. A total of 167 studies are included in this systematic review incorporating data from the studies conducted in 34 countries, including the United Kingdom, the United States and Australia. There is a need for risk assessment that influences farmers' mental health, according to this systematic review. There is a need for more robust studies to evaluate the impact of climate change and pesticide exposure on farmers' mental health and to determine which strategies can be used to help them find therapies. Using the results of this systematic review, healthcare professionals can raise awareness about mental health issues and assist farmers in identifying the symptoms, allowing them to seek help.
Abstract
Recently, concern has increased globally over farmers' mental health issues. We present a systematic review of the outcomes, locations, study designs, and methods of current studies on farmers' mental health. In particular, this review aims to fill an important gap in understanding of the potential key risk factors affecting farmers' mental health around the world. 167 articles on farmer mental health were included in a final systematic review using a standardized electronic literature search strategy and PRISMA guidelines. The four most-cited influences on farmers' mental health in the reviewed literature respectively were pesticide exposure, financial difficulties, climate variabilities/drought, and poor physical health/past injuries. The majority of studies were from developed countries, most specifically from the United States, Australia, and the United Kingdom. Comparative studies on the mental health of farmers and other occupational workers showed mixed results, with a larger portion identifying that psychological health disturbances were more common in farmers and farm-workers. Knowledge of farmer psychological disorder risk factors and its impacts are essential for reducing the burden of mental illness. Further research will be required on climate change impacts, developing country farmers' mental health, and information on how to reduce help-seeking barriers amongst farmers.
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Environmental Factors and the Risk of Brain Tumours in Young People: A Systematic Review.
Zumel-Marne, A, Castano-Vinyals, G, Kundi, M, Alguacil, J, Cardis, E
Neuroepidemiology. 2019;53(3-4):121-141
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Brain tumours (BT) are the second most common cancer type in children and young adults. The aim of this study was to review and summarize the scientific literature about exposure to environmental factors and BT risk. This study is a systematic review of 70 articles of which 69% (n = 49) had >200 cases recruited. Results indicate a possible association between exposure to heavy metals, passive smoking, water and air pollutants, use of pesticides and living on a farm with farm animals, meat consumption during preconception, pregnancy or early infancy and an increased risk of BT in children and young adults. Authors conclude that larger scale studies with better exposure assessment are needed to evaluate possible associations between environmental risk factors and BT in young people.
Abstract
BACKGROUND Brain tumours (BT) are one of the most frequent tumour types in young people, although little is known about their risk factors. OBJECTIVE The objective of the current work was to review and summarize the scientific literature concerning exposure to environmental factors and BT risk in young people (<25 years old). METHODS PUBMED, Embase, Cochrane Library, Scopus, IME-Biomedina (bibliographic database of Consejo Superior de Investigaciones Científicas) and Web of science databases were searched. A score to assess the quality of the methodological information was created. RESULTS Some possible associations between BT risk in young people were reported for cadmium, consumption of well water, presence of nitrate or nitrate-nitrogen in tap water, mother's passive smoking, air pollution, parental handling of pesticides at home and/or professional pesticide treatment within houses, living on a farm and/or with farm animals, some parental occupations and high amount of meat consumption. CONCLUSIONS Although many of the studies reviewed suggest associations between the environmental exposures and BT in children and young adults, at present no reliable conclusion can be drawn as most results are based on small number of cases and exposure assessment is limited. Large-scale studies with better exposure assessment are needed to shed light on these possible associations, especially on exposure to heavy metals, tab water consumption, pesticides and parental smoking.
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Nutritional labelling for healthier food or non-alcoholic drink purchasing and consumption.
Crockett, RA, King, SE, Marteau, TM, Prevost, AT, Bignardi, G, Roberts, NW, Stubbs, B, Hollands, GJ, Jebb, SA
The Cochrane database of systematic reviews. 2018;2:CD009315
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Poor quality diets are a threat to health internationally and a challenge to health services. Implementing methods to change people's choices is difficult; even those who start making healthier choices often find it hard to maintain long-term. There is recognition that our environment has a powerful influence over our food choices and altering this may stimulate behavioural change. Nutritional labels provide information about the nutritional content of a food or drink. The type of information provided varies e.g. what nutrients they describe (e.g. macronutrients like fat or energy content) and the form also varies e.g. as a single number, as a proportion of a guideline for daily consumption, or with colours indicative of relative healthiness. Nutritional labelling has been rolled-out in many forms, across many countries but there is currently no consensus as to the best way of applying this information to products to stimulate healthier food choices. This review explored whether nutritional labels persuade consumers to buy alternative types of food and included 28 articles. Findings from these 28 articles suggest that nutritional labelling specially indicating energy content may cause people to opt to buy foods with a lower energy content in restaurants. This result (only based on 3 studies) suggests that nutritional labelling could be rolled-out on menus in restaurants, but high-quality research is required. Higher-quality research is also needed to explore the impact of nutritional labelling in shops and vending machines.
Abstract
BACKGROUND Nutritional labelling is advocated as a means to promote healthier food purchasing and consumption, including lower energy intake. Internationally, many different nutritional labelling schemes have been introduced. There is no consensus on whether such labelling is effective in promoting healthier behaviour. OBJECTIVES To assess the impact of nutritional labelling for food and non-alcoholic drinks on purchasing and consumption of healthier items. Our secondary objective was to explore possible effect moderators of nutritional labelling on purchasing and consumption. SEARCH METHODS We searched 13 electronic databases including CENTRAL, MEDLINE and Embase to 26 April 2017. We also handsearched references and citations and sought unpublished studies through websites and trials registries. SELECTION CRITERIA Eligible studies: were randomised or quasi-randomised controlled trials (RCTs/Q-RCTs), controlled before-and-after studies, or interrupted time series (ITS) studies; compared a labelled product (with information on nutrients or energy) with the same product without a nutritional label; assessed objectively measured purchasing or consumption of foods or non-alcoholic drinks in real-world or laboratory settings. DATA COLLECTION AND ANALYSIS Two authors independently selected studies for inclusion and extracted study data. We applied the Cochrane 'Risk of bias' tool and GRADE to assess the quality of evidence. We pooled studies that evaluated similar interventions and outcomes using a random-effects meta-analysis, and we synthesised data from other studies in a narrative summary. MAIN RESULTS We included 28 studies, comprising 17 RCTs, 5 Q-RCTs and 6 ITS studies. Most (21/28) took place in the USA, and 19 took place in university settings, 14 of which mainly involved university students or staff. Most (20/28) studies assessed the impact of labelling on menus or menu boards, or nutritional labelling placed on, or adjacent to, a range of foods or drinks from which participants could choose. Eight studies provided participants with only one labelled food or drink option (in which labelling was present on a container or packaging, adjacent to the food or on a display board) and measured the amount consumed. The most frequently assessed labelling type was energy (i.e. calorie) information (12/28).Eleven studies assessed the impact of nutritional labelling on purchasing food or drink options in real-world settings, including purchases from vending machines (one cluster-RCT), grocery stores (one ITS), or restaurants, cafeterias or coffee shops (three RCTs, one Q-RCT and five ITS). Findings on vending machines and grocery stores were not interpretable, and were rated as very low quality. A meta-analysis of the three RCTs, all of which assessed energy labelling on menus in restaurants, demonstrated a statistically significant reduction of 47 kcal in energy purchased (MD -46.72 kcal, 95% CI -78.35, -15.10, N = 1877). Assuming an average meal of 600 kcal, energy labelling on menus would reduce energy purchased per meal by 7.8% (95% CI 2.5% to 13.1%). The quality of the evidence for these three studies was rated as low, so our confidence in the effect estimate is limited and may change with further studies. Of the remaining six studies, only two (both ITS studies involving energy labels on menus or menus boards in a coffee shop or cafeteria) were at low risk of bias, and their results support the meta-analysis. The results of the other four studies which were conducted in a restaurant, cafeterias (2 studies) or a coffee shop, were not clearly reported and were at high risk of bias.Seventeen studies assessed the impact of nutritional labels on consumption in artificial settings or scenarios (henceforth referred to as laboratory studies or settings). Of these, eight (all RCTs) assessed the effect of labels on menus or placed on a range of food options. A meta-analysis of these studies did not conclusively demonstrate a reduction in energy consumed during a meal (MD -50 kcal, 95% CI -104.41, 3.88, N = 1705). We rated the quality of the evidence as low, so our confidence in the effect estimate is limited and may change with further studies.Six laboratory studies (four RCTs and two Q-RCTs) assessed the impact of labelling a single food or drink option (such as chocolate, pasta or soft drinks) on energy consumed during a snack or meal. A meta-analysis of these studies did not demonstrate a statistically significant difference in energy (kcal) consumed (SMD 0.05, 95% CI -0.17 to 0.27, N = 732). However, the confidence intervals were wide, suggesting uncertainty in the true effect size. We rated the quality of the evidence as low, so our confidence in the effect estimate is limited and may change with further studies.There was no evidence that nutritional labelling had the unintended harm of increasing energy purchased or consumed. Indirect evidence came from five laboratory studies that involved mislabelling single nutrient content (i.e. placing low energy or low fat labels on high-energy foods) during a snack or meal. A meta-analysis of these studies did not demonstrate a statistically significant increase in energy (kcal) consumed (SMD 0.19, 95% CI -0.14to 0.51, N = 718). The effect was small and the confidence intervals wide, suggesting uncertainty in the true effect size. We rated the quality of the evidence from these studies as very low, providing very little confidence in the effect estimate. AUTHORS' CONCLUSIONS Findings from a small body of low-quality evidence suggest that nutritional labelling comprising energy information on menus may reduce energy purchased in restaurants. The evidence assessing the impact on consumption of energy information on menus or on a range of food options in laboratory settings suggests a similar effect to that observed for purchasing, although the evidence is less definite and also of low quality.Accordingly, and in the absence of observed harms, we tentatively suggest that nutritional labelling on menus in restaurants could be used as part of a wider set of measures to tackle obesity. Additional high-quality research in real-world settings is needed to enable more certain conclusions.Further high-quality research is also needed to address the dearth of evidence from grocery stores and vending machines and to assess potential moderators of the intervention effect, including socioeconomic status.