What are the impacts of urban agriculture programs on food security in low and middle-income countries? (systematic review)

Background

Urban Agriculture is considered to contribute to improved food security among the income poor in urban contexts across developing countries. Much literature exists on the topic assuming a positive relationship. The aim of this review was to collect and analyse available evidence on the impact of urban agriculture in low and middle-income countries.

Methods

We employed systematic review methods to identify all relevant and reliable research on UA’s impact on food security and nutrition. Only impact evaluations that set out to measure the effectiveness of UA interventions on food security, as compared to the effects of not engaging in UA, qualified for inclusion. Studies had to have a comparison group and at least two data points.

Results

Systematic searches resulted in 8142 hits, and screening of abstracts resulted in 198 full texts identified. No studies met the review’s inclusion criteria. Therefore, the review found no available evidence that supports or refutes the suggestion that urban agriculture positively impacts on individual or household food security in low and middle-income countries. The largest proportion of studies at full text stage was excluded based on study design, as they were not impact evaluations, i.e. they did not have a comparison group and at least data points. Two observations were made: Firstly, searches yielded a range of studies that consider associations between UA and certain aspects of food security. Secondly, there is a large pool of cross-sectional studies on UA’s potential to contribute to increased food security, particularly from west and east Africa.

Conclusions

The research currently available does not allow for any conclusions to be made on whether or not urban agriculture initiatives contribute to food security. The fact that impact evaluations are absent from the current evidence-base calls for increased efforts to measure the impact of urban agriculture on food security in low and middle-income countries through rigorous impact evaluations. With regard to systematic review methodology, this review alludes to the value of compiling a systematic map prior to engaging in a full systematic review.

Keywords

Urban agriculture, Food security, Nutrition, Impact, Systematic review, Urbanisation

Background

Issues of food security and nutrition have wide reaching implications for people and their environments, particularly in low and middle-income countries. One proposed solution is urban agriculture, which has been widely upheld as a solution to the food-crisis facing increasingly metropolitan populations. It is believed to provide the urban poor with food and a source of potential income, whilst improving the urban environment and reducing pressure on finite farmland. Although it faded from many development agendas in the 1990’s, urban agriculture has seen a resurgence since a peak in global food prices in the late 2000’s. There are, however, potential disadvantages to this increasing drive for urban agriculture including associated urban health risks and implications for the environment. The usage of waste-water, for example, may contaminate produced food and intensive irrigation might lead to the spread of malaria and water borne diseases, as well as threatening already limited water supplies. Soil erosion and the intensive use of fertilizers and pesticides might also present health risks to urban populations and damage the environment. Despite the potential benefits and harms of urban agriculture, the evidence-base is not well understood. Given the current policy drive to promote urban agriculture, there is an urgent need to understand its effects on urban populations and their environments.

Methods/design

This review will seek out, select, appraise and synthesise evidence on the impacts of urban agriculture on food security and nutrition. We will employ systematic review methodology to ensure that our review of the evidence is comprehensive, transparent and replicable. In addition to searching electronic databases, we will examine websites and contact academics, practitioners and policy-makers for relevant research. All potentially relevant literature will be screened against pre-specified criteria and assessed for risk of bias using established critical appraisal tools. This is to ensure that we only include the evidence in which we have confidence. Depending on the nature of the available data, we will then synthesise the available evidence using statistical meta-analysis and/or narrative synthesis. Our findings will be disseminated in a variety of ways to ensure that the evidence is available for policy-makers and practitioners.