evidence-based blog of Filippo Dibari

Posts Tagged ‘systematic review’

Diet and physical activity for the prevention of noncommunicable diseases in low- and middle-income countries: a systematic policy review

In Over-nutrition on June 2, 2014 at 1:09 pm

by Lachat C, Otchere S, Roberfroid D, Abdulai A, Seret FM, Milesevic J, Xuereb G, Candeias V, Kolsteren P

PLoS Med. 2013;10(6):e1001465

(download the paper here)

 

Abstract

 

BACKGROUND:

Diet-related noncommunicable diseases (NCDs) are increasing rapidly in low- and middle-income countries (LMICs) and constitute a leading cause of mortality.

Although a call for global action has been resonating for years, the progress in national policy development in LMICs has not been assessed. This review of strategies to prevent NCDs in LMICs provides a benchmark against which policy response can be tracked over time.

METHODS AND FINDINGS:

We reviewed how government policies in LMICs outline actions that address salt consumption, fat consumption, fruit and vegetable intake, or physical activity. A structured content analysis of national nutrition, NCDs, and health policies published between 1 January 2004 and 1 January 2013 by 140 LMIC members of the World Health Organization (WHO) was carried out.

We assessed availability of policies in 83% (116/140) of the countries. NCD strategies were found in 47% (54/116) of LMICs reviewed, but only a minority proposed actions to promote healthier diets and physical activity.
The coverage of policies that specifically targeted at least one of the risk factors reviewed was lower in Africa, Europe, the Americas, and the Eastern Mediterranean compared to the other two World Health Organization regions, South-East Asia and Western Pacific. Of the countries reviewed, only 12% (14/116) proposed a policy that addressed all four risk factors, and 25% (29/116) addressed only one of the risk factors reviewed. Strategies targeting the private sector were less frequently encountered than strategies targeting the general public or policy makers.

CONCLUSIONS:

This review indicates the disconnection between the burden of NCDs and national policy responses in LMICs. Policy makers urgently need to develop comprehensive and multi-stakeholder policies to improve dietary quality and physical activity.

Interventions to improve water quality and supply, sanitat ion and hygiene practices, and their effects on the nutritional status of children (Review)

In Under-nutrition on October 5, 2013 at 1:07 pm

by Dangour AD, Watson L, Cumming O, Boisson S, Che Y, Velleman Y, Cavill S, Allen E, Uauy R

Editorial group: Cochrane Public Health Group. Issue 8, 2013.

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(download here)

Plain Language Summary

The effect of interventions to improve water quality and supply, provide sanitation and promote handwashing with soap on physical growth in children
In low-income countries an estimated 165 million children under the age of five years suffer from chronic undernutrition causing them to be short in height and 52 million children suffer from acute undernutrition causing them to be very thin. Poor growth in early life increases the risks of illness and death in childhood. The two immediate causes of childhood undernutrition are inadequate dietary intake and infectious diseases such as diarrhoea. Water, sanitation and hygiene (WASH) interventions are frequently imp
lemented to reduce infectious diseases; this review evaluates the effect that WASH interventions may have on nutrition outcomes in children. The review includes evidence from randomised and non-randomised interventions designed to (i) improve the microbiological quality of drinking water or protect the microbiological quality of water prior to consumption; (ii) introduce new or improved water supply or improve distribution; (iii) introduce or expand the coverage and use of facilities designed to improve sanitation; or (iv) promote handwashing with soap after defecation and disposal of child faeces, and prior to preparing and handling food, or a combination of these interventions, in children aged under 18 years.
We identified 14 studies of such interventions involving 22,241 children at baseline and nutrition outcome data for 9,469 children. Meta-analyses of the evidence from the cluster-randomised trials suggests that WASH interventions confer a small benefit on growth in children under five years of age. While potentially important, this conclusion is based on relatively short-term studies, none of which is of high methodological quality, and should therefore be treated with caution. There are several large, robust studies underway in low-income country settings that should provide evidence to inform these findings.
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Home fortification of foods with multiple micronutrient powders for health and nutrition in children under two years of age (Review)

In Under-nutrition on June 2, 2013 at 1:12 pm

by De-Regil LM, Suchdev PS, Vist GE, Walleser S, Peña-Rosas JP

Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.

(download)

Summary

Use of a powder mix of vitamins and minerals to fortify complementary foods immediately before consumption and improve health and nutrition in children under two years of age.

Deficiencies of vitamins and minerals, particularly of iron, vitamin A and zinc, affect approximately half of the infants and young children under two years of age worldwide. Exclusive breastfeeding until six months of age and continued breastfeeding for at least two years are recommended to maintain children’s adequate health and nutrition. After six months of age, infants start receiving semi-solid foods but the amount of vitamins and minerals can be insufficient to fulfil all the requirements of the growing baby.

Micronutrient powders (MNP) are single-dose packets of powder containing iron, vitamin A, zinc and other vitamins and minerals that can be sprinkled onto any semi-solid food at home or at any other point of use to increase the content of essential nutrients in the infant’s diet during this period. This is done without changing the usual baby diet.

This review includes eight good quality trials that involved 3748 infants and young children from low income countries in Asia, Africa and the Caribbean. We found that a variety of MNP formulations containing between five and 15 vitamins and minerals have been given for between two and 12 months to infants and young children aged six to 23 months of age.

The use of MNP containing at least iron, zinc and vitamin A for home fortification of foods was associated with a reduced risk of anaemia and iron deficiency in children under two. The studies did not find any effects on growth. Although the acceptability of this innovative intervention was high, there is no additional benefit to usually recommended iron drops or syrups, however few studies compared these different interventions. No deaths were reported in the trials and information on side effects and morbidity, including malaria, was scarce.

The use of MNP was beneficial for male and female infants and young children six to 23 months of age, independent of whether they lived in settings with different anaemia and malaria backgrounds or whether the intervention was provided for two, six or 12 months. The most appropriate arrangements for use (daily or intermittently), the appropriate vitamin and mineral composition of the mix of powders and the way to deliver this intervention effectively in public health programmes to address multiple micronutrient deficiencies remain unclear.

 

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Efficacy and Safety of Therapeutic Nutrition Products for Home Based Therapeutic Nutrition for Severe Acute Malnutrition: A Systematic Review

In Under-nutrition on May 20, 2012 at 9:41 am

by Tarun Gera

Indian Pediatrics (2010); vol. 47. Pages: 709-718.

(Free text available)

Abstract

Context: Severe acute malnutrition (SAM) in children is a significant public health problem in India with associated increased morbidity and mortality. The current WHO recommendations on management of SAM are based on facility based treatment. Given the large number of children with SAM in India and the involved costs to the care-provider as well as the care-seeker, incorporation of alternative strategies like home based management of uncomplicated SAM is important. The present review assesses (a) the efficacy and safety of home based management of SAM using ‘therapeutic nutrition products’ or ready to use therapeutic foods (RUTF); and (b) efficacy of these products in comparison with F-100 and home-based diet.

Evidence Acquisition: Electronic database (Pubmed and Cochrane Controlled Trials Register) were scanned using keywords ‘severe malnutrition’, ‘therapy’, ‘diet’, ‘ready to use foods’ and ‘RUTF’. Bibliographics of identified articles, reviews and books were scanned. The information was extracted from the identified papers and graded according to the CEBM guidelines.

Results: Eighteen published papers (2 systematic reviews, 7 controlled trials, 7 observational trials and 2 consensus statements) were identified. Systematic reviews and RCTs showed RUTF to be at least as efficacious as F-100 in increasing weight (WMD=3.0 g/kg/day; 95% CI -1.70, 7.70) and more effective in comparison to home based dietary therapies. Locally made RUTFs were as effective as imported RUTFs (WMD=0.07 g/kg/d; 95% CI=-0.15, 0.29). Data from observational studies showed the energy intake with RUTF to be comparable to F-100. The pooled recovery rate, mortality and default in treatment with RUTF was 88.3%, 0.7% and 3.6%, respectively with a mean weight gain of 3.2 g/kg/day. The two consensus statements supported the use of RUTF for home based management of uncomplicated SAM.

Conclusions: The use of therapeutic nutrition products like RUTF for home based management of uncomplicated SAM appears to be safe and efficacious. However, most of the evidence on this promising strategy has emerged from observational studies conducted in emergency settings in Africa. There is need to generate more robust evidence, design similar products locally and establish their efficacy and cost-effectiveness in a ‘non-emergency’ setting, particularly in the Indian context.

Organic foods. Good for your health? We do not know, today. Maybe tomorrow…

In Under-nutrition on May 18, 2012 at 11:58 am

This morning, a friend of mine has solicited some insight about the relation between organic food and public health nutrition impact. I looked into the available systematic reviews from peer-reviewed journals. These are the results from the found studies – I could not find much more out there.

There are at least two ways to interpret these controversial papers* written by researchers from the London School of Hygiene and Tropical Medicine and other institutions, and whose abstracts are reported beneath.

  • The first interpretation is that “there is not sufficient evidence that eating organic may have a positive impact on human health“. Painful as it is, that is a matter of fact. However, there is more that can be learnt.
  • The second interpretation is that “the state of the art of the quality of research in the field of organic food and nutrition is (very?) poor“. Therefore, there is need not only for more research, but also with much higher quality standards.

Is there a third perspective about this topic? Other papers available?

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* The papers retrieved are:

Nutrition-related health effects of organic foods: a systematic review

Alan D DangourKaren LockArabella HayterAndrea Aikenhead,Elizabeth Allen, and Ricardo Uauy

Am J Clin Nutr July 2010vol. 92 no. 1 203-210

Abstract

Background: There is uncertainty over the nutrition-related benefits to health of consuming organic foods.

Objective: We sought to assess the strength of evidence that nutrition-related health benefits could be attributed to the consumption of foods produced under organic farming methods.

Design: We systematically searched PubMed, ISI Web of Science, CAB Abstracts, and Embase between 1 January 1958 and 15 September 2008 (and updated until 10 March 2010); contacted subject experts; and hand-searched bibliographies. We included peer-reviewed articles with English abstracts if they reported a comparison of health outcomes that resulted from consumption of or exposure to organic compared with conventionally produced foodstuffs.

Results: From a total of 98,727 articles, we identified 12 relevant studies. A variety of different study designs were used; there were 8 reports (67%) of human studies, including 6 clinical trials, 1 cohort study, and 1 cross-sectional study, and 4 reports (33%) of studies in animals or human cell lines or serum. The results of the largest study suggested an association of reported consumption of strictly organic dairy products with a reduced risk of eczema in infants, but the majority of the remaining studies showed no evidence of differences in nutrition-related health outcomes that result from exposure to organic or conventionally produced foodstuffs. Given the paucity of available data, the heterogeneity of study designs used, exposures tested, and health outcomes investigated, no quantitative meta-analysis was justified.

Conclusion: From a systematic review of the currently available published literature, evidence is lacking for nutrition-related health effects that result from the consumption of organically produced foodstuffs.

Nutritional quality of organic foods: a systematic review

Alan D Dangour,  Sakhi K Dodhia,  Arabella Hayter,  Elizabeth AllenKaren Lock, and Ricardo Uauy

Am J Clin Nutr September 2009 vol. 90 no. 3 680-685

Abstract

Background: Despite growing consumer demand for organically produced foods, information based on a systematic review of their nutritional quality is lacking.

Objective: We sought to quantitatively assess the differences in reported nutrient content between organically and conventionally produced foodstuffs.

Design: We systematically searched PubMed, Web of Science, and CAB Abstracts for a period of 50 y from 1 January 1958 to 29 February 2008, contacted subject experts, and hand-searched bibliographies. We included peer-reviewed articles with English abstracts in the analysis if they reported nutrient content comparisons between organic and conventional foodstuffs. Two reviewers extracted study characteristics, quality, and data. The analyses were restricted to the most commonly reported nutrients.

Results: From a total of 52,471 articles, we identified 162 studies (137 crops and 25 livestock products); 55 were of satisfactory quality. In an analysis that included only satisfactory-quality studies, conventionally produced crops had a significantly higher content of nitrogen, and organically produced crops had a significantly higher content of phosphorus and higher titratable acidity. No evidence of a difference was detected for the remaining 8 of 11 crop nutrient categories analyzed. Analysis of the more limited database on livestock products found no evidence of a difference in nutrient content between organically and conventionally produced livestock products.

Conclusions: On the basis of a systematic review of studies of satisfactory quality, there is no evidence of a difference in nutrient quality between organically and conventionally produced foodstuffs. The small differences in nutrient content detected are biologically plausible and mostly relate to differences in production methods.

A third paper tackles the topic more indirectly, but does not add much to the reported impact on the public health nutrition issue.

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