https://orcid.org/0000-0002-4905-1939
Abstract
Urban farms are spaces designated for the cultivation of plants for food security, medicinal and curative purposes. Since the turn of the century, they have become more widespread and health benefits have been claimed; however, no consensus exists regarding this information. Hence, this study aims to provide information about the health effects of urban farming.
Protocol register number CRD42023448001. We followed the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Studies addressing urban farming interventions in any population group were included without age limitation of publication from PubMed, DOAJ, CAB Abstracts and NIH. Risk of bias was assessed using the Risk of Bias In Non-randomized Studies - of Interventions tool, and data were narratively synthesized.
The search retrieved 2578 manuscripts, reduced to seven after screening. Urban farming’s impact on health has been reflected in the physical domain by increasing self-reported health levels, physical activity, perceived general health, healthy eating and decreasing drug use. Parasites’ presence has also been reported. In the mental aspect, urban farming is associated with relaxation and stress reduction. From a social perspective, urban farms provide a sense of belonging, personal growth and happiness.
The benefits of urban farming outweigh the disadvantages. Further research should be conducted to clarify the potential benefits of this practice.
Introduction
Urban farming is derived from the concept of urban and peri-urban agriculture proposed by the Food and Agriculture Organization (FAO) of the United Nations, which refers to practices that generate food and other products through agricultural production and related processes. 1 It occurs in a space exclusively designated for plant cultivation for food, medicinal or curative purposes.2–4 According to the American Society of Landscape Architects, the practice of urban farming dates to 3500 BCE, when Mesopotamian farmers began to plant plots in developing cities. Subsequently, expanded to ancient Egypt (2500 BCE); the Aztec civilization in Mexico (1100 BCE); more recently to the United Kingdom, Germany, the United States, Canada and Australia, among others (19th and 20th centuries); and Japan, which is considered to be at the forefront of innovation in urban farming in the 21st century and where it has expanded by 36% in the last 10 years.2,5
According to FAO, an urban farming user can be considered as those people who carry out practices that result in the production of food and related products through land spaces destined for agricultural purposes within cities and surrounding areas.1 Although no concrete data are available regarding the number of urban farming users, statistics reveal that 55% of the world’s population lives in cities, 800 million people worldwide are involved in urban farming, 79% of the world’s food is produced for urban consumption, and 266 million households participate in crop production in developing countries.6–8 Over time, urban farming has diversified to the point that it has become a livelihood for its users, highlighting its potential benefits to the general state of health from producing crops free of pesticides and fertilizers.2,5
The World Health Organization (WHO), states that improvement interventions are those activities performed at any level of the health system to achieve an improvement in the quality of health services.9 In this sense, improvement interventions that encompass urban farming have addressed the results of its practice in a variety of population groups.10–12 Urban farming has also been praised as a measure to mitigate economic expenses, increase environmental sustainability and food and nutritional security, a provision of labour and livelihoods and recently to promote a healthy lifestyle.7,8,13–15 However, thus far, no information has connected the scientific evidence regarding the impact of urban farming on health to provide a straightforward understanding for health professionals in their decision making.13,16
Through scientific evidence demonstrating the impact of urban farming interventions on different health strata, users could make decisions that promote responsible urban farming practice. The purpose of the present study was to perform a systematic review to synthesize the published scientific evidence on the relationship of urban farming and physical, mental and social health outcomes.
Materials and methods
Registration, protocol and statement adherence
Following PRISMA-P guidelines, we registered a previous protocol in PROSPERO (protocol number CRD42023448001) and it can be accessed at https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023448001. Subsequently, we performed a systematic review that adhered to the recommendations of the Cochrane Handbook for Systematic Reviews of Interventions, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and synthesis without meta-analysis (SWiM). Supplementary data can be accessed at https://osf.io/3rj6d/?view_only=2e8b5864486549ceb4bc927959b20a1b.
Focus question
What is the health impact of improvement interventions involving urban farming?
Eligibility criteria and information sources
Eligibility criteria were established according to the PIOS (population, intervention, outcome, study design)17 tool. A control group was not considered because such a group would not have corresponded to the main purpose of the study. No restriction was established regarding the age of the manuscripts included or their language of publication. Detailed information can be found in Table 1 in supplementary data.
From February 2023 to May 2023, authors conducted a literature search in PubMed, DOAJ, NCBI and CAB Abstracts, with snowball search by exploring references to the selected articles.
Main characteristics of the included studies
| Authors/year/country | Population (number of participants, sex, age, co-morbidity = CM) | Methodological approach and study design | Intervention description and purpose | Unit of results measurement | Results (intervention group) | Results (control group if exists) | Conclusions | Findings |
|---|---|---|---|---|---|---|---|---|
| Beavers et al., 2022 EE.UU. | 28 gardeners. NO control group reported. Male and female >18 years CM not reported | Qualitative Community-based participatory research | Qualitative interviews to examine the perceived physical and mental health effects of urban farming | The grouping of codes follows broad topics relevant to the main research questions. | Physical Health: Improved dietary habits. It is physically demanding. This practice maintains health during aging. Physical Activity: Participants with disability limitations or pain benefit from physical activity on urban farms. Mental well-being: Stress relief and relaxation. Mood improvement. Contributes to personal growth by helping others. | No control group reported | Prominent physical health impacts attributed to urban farming included providing an enjoyable source of activity, management of chronic diseases, improved physical functioning, improvement of mood, relieved stress, spirituality, personal growth and an opportunity for helping others. | Urban farming may improve physical and mental health among diverse groups |
| Harada et al., 2021 Japón | 1718 participants in allotments and experience farms and 651 in the control group. Male and female >40 years CM not reported | Quantitative Cross-sectional | Surveys were conducted to investigate the differences in mental health and physical activity among urban farmers and non-farmers | Percentage of scores on a 0 to 100 scale in surveys | Physical activity: 54.9% Self-rated health: 82.7% Mental health: 64.1% | Physical activity: 16.6% Self-rated health: 14.6% Mental health: 14.6% | Participants in both types of urban agriculture reported a significant improvement in their health compared to non-participants (self-rated health, mental health, physical activity) | Urban farming promotes longevity and has the potential to be effective, particularly in aging populations |
| Matthys et al., 2007 Ivory Coast | 586 urban garden users and 130 control groups were surveyed. Male and female >1 year CM not reported | Quantitative Cross-sectional | Laboratory analysis of parasite presence in feces among urban garden users and non-users. | % prevalence of infection of parasites | Prevalence of: hookworm infections: 24.7%, lumbricoides in 1.1%, entamoeba coli 53.3% and Blastocystishominis 37.5% was found in participants | Prevalence of hookworm infections: 14.6% Not other infections declared | Schistosomiasis mansoni and Hookworm infection was associated with specific agricultural activities | Health education and active participation of urban farmers are recommended for schistosomiasis and soil-transmitted helminthiasis |
| Safitri et al., 2021 Indonesia | 22 female users Female Age not reported CM not reported | Qualitative Case study | The purpose of the study was to discuss the implementation urban farming as women empowerment | Qualitative descriptive analysis using code clustering | Urban farming management provides training and education Female users view healthy food as a benefit | No control group reported | Women’s motivation to be involved in urban farming is essential | The benefit of urban farming has provided economic benefits, social networks, and knowledge about providing healthy food |
| Sereenonchai & Arunrat, 2022 Tailandia | 325 users Male and female Age not reported CM not reported | Quantitative and qualitative Cross-sectional study Thematic content analysis | Snowball sampling is used to compare the benefits of urban farming between users and non-users | A comparison of the significance values of measured variables regarding beneficiaries, owners and continuers of urban farms | Perceived behavioral control: P > 0.05 Perceived benefits: P > 0.05 Perceived readiness: P > 0.05 Perceived risks: P > 0.05 Perceived obstacles: P > 0.05 | No control group reported | Several key factors are required if the villager intends to continue urban farming | Promotes interaction among community members |
| Shacham et al., 2012 EE.UU. | 11 participants. No control group Male and female >18 years CM: VIH+ | Quantitative and qualitative Prospective single armed intervention trial Thematic content analysis | Mixed methods intervention. Twice a week for eight weeks, participants engaged in urban farming activities to examine how urban farming practices have changed | Quantitative: Depression severity score: Mean of the expressed depressive symptoms from the PHQ-9 survey Anxiety severity: Evaluated using the mean of the expressed Patient Health Questionnaire-9 scores General health assessment. Crack or cocaine use: Number of days of using the drug Qualitative: Coding related to feasibility, benefits and barriers of an intervention | Quantitative: The initial depression severity score was 12.7 (SD = 5.2), while the follow-up score was 11.3 (SD = 6.6). The initial degree of anxiety was 11.2 (SD = 3.2), while the follow-up score was 7.7 (SD = 4.4) Initial use of crack or cocaine was 1.67, while the follow-up score was 1.0. Qualitative: Having a place to go in the morning can be very beneficial for users of urban farms. Participants acquired numerous hands-on skills. Participants were happy to have an opportunity to expand their knowledge of plant life and farming. Intent to give back to their community with newly acquired skills | No control group reported | Participants reported less distress symptoms, improved overall general health and reduced frequency of illicit drug use | Depressed, unemployed individuals with HIV who experience distress symptoms have the potential to re-engage in a community-based activity that is meaningful and social with this activities |
| Soga et al, 2017 Japón | 165 Urban Allotment Gardening users y 167 control Male and female 61.9 years mean age CM not reported | Quantitative Cross-sectional | Respondents provided self-reported information on five health outcomes to observe health improvements among urban garden users | Perceived General Health, Subjective Health Complaints, General Mental Health, and Social Cohesion were assessed using a % evaluation on a scale of 0 to 100 in surveys BMI was calculated using self-reported height and weight | Compared with the control group, there was a significant improvement in Perceived General Health, Subjective Health Complaints, General Mental Health and Social Cohesion The BMI of the two groups did not differ significantly | Not declared, only statistical differences between groups | Users had significant positive effects on perceived general health and social cohesion and negative effects on subjective health complaints and general mental health | This study has a major implication for policy, as it suggests that urban allotments have great potential for preventative healthcare |
| Authors/year/country | Population (number of participants, sex, age, co-morbidity = CM) | Methodological approach and study design | Intervention description and purpose | Unit of results measurement | Results (intervention group) | Results (control group if exists) | Conclusions | Findings |
|---|---|---|---|---|---|---|---|---|
| Beavers et al., 2022 EE.UU. | 28 gardeners. NO control group reported. Male and female >18 years CM not reported | Qualitative Community-based participatory research | Qualitative interviews to examine the perceived physical and mental health effects of urban farming | The grouping of codes follows broad topics relevant to the main research questions. | Physical Health: Improved dietary habits. It is physically demanding. This practice maintains health during aging. Physical Activity: Participants with disability limitations or pain benefit from physical activity on urban farms. Mental well-being: Stress relief and relaxation. Mood improvement. Contributes to personal growth by helping others. | No control group reported | Prominent physical health impacts attributed to urban farming included providing an enjoyable source of activity, management of chronic diseases, improved physical functioning, improvement of mood, relieved stress, spirituality, personal growth and an opportunity for helping others. | Urban farming may improve physical and mental health among diverse groups |
| Harada et al., 2021 Japón | 1718 participants in allotments and experience farms and 651 in the control group. Male and female >40 years CM not reported | Quantitative Cross-sectional | Surveys were conducted to investigate the differences in mental health and physical activity among urban farmers and non-farmers | Percentage of scores on a 0 to 100 scale in surveys | Physical activity: 54.9% Self-rated health: 82.7% Mental health: 64.1% | Physical activity: 16.6% Self-rated health: 14.6% Mental health: 14.6% | Participants in both types of urban agriculture reported a significant improvement in their health compared to non-participants (self-rated health, mental health, physical activity) | Urban farming promotes longevity and has the potential to be effective, particularly in aging populations |
| Matthys et al., 2007 Ivory Coast | 586 urban garden users and 130 control groups were surveyed. Male and female >1 year CM not reported | Quantitative Cross-sectional | Laboratory analysis of parasite presence in feces among urban garden users and non-users. | % prevalence of infection of parasites | Prevalence of: hookworm infections: 24.7%, lumbricoides in 1.1%, entamoeba coli 53.3% and Blastocystishominis 37.5% was found in participants | Prevalence of hookworm infections: 14.6% Not other infections declared | Schistosomiasis mansoni and Hookworm infection was associated with specific agricultural activities | Health education and active participation of urban farmers are recommended for schistosomiasis and soil-transmitted helminthiasis |
| Safitri et al., 2021 Indonesia | 22 female users Female Age not reported CM not reported | Qualitative Case study | The purpose of the study was to discuss the implementation urban farming as women empowerment | Qualitative descriptive analysis using code clustering | Urban farming management provides training and education Female users view healthy food as a benefit | No control group reported | Women’s motivation to be involved in urban farming is essential | The benefit of urban farming has provided economic benefits, social networks, and knowledge about providing healthy food |
| Sereenonchai & Arunrat, 2022 Tailandia | 325 users Male and female Age not reported CM not reported | Quantitative and qualitative Cross-sectional study Thematic content analysis | Snowball sampling is used to compare the benefits of urban farming between users and non-users | A comparison of the significance values of measured variables regarding beneficiaries, owners and continuers of urban farms | Perceived behavioral control: P > 0.05 Perceived benefits: P > 0.05 Perceived readiness: P > 0.05 Perceived risks: P > 0.05 Perceived obstacles: P > 0.05 | No control group reported | Several key factors are required if the villager intends to continue urban farming | Promotes interaction among community members |
| Shacham et al., 2012 EE.UU. | 11 participants. No control group Male and female >18 years CM: VIH+ | Quantitative and qualitative Prospective single armed intervention trial Thematic content analysis | Mixed methods intervention. Twice a week for eight weeks, participants engaged in urban farming activities to examine how urban farming practices have changed | Quantitative: Depression severity score: Mean of the expressed depressive symptoms from the PHQ-9 survey Anxiety severity: Evaluated using the mean of the expressed Patient Health Questionnaire-9 scores General health assessment. Crack or cocaine use: Number of days of using the drug Qualitative: Coding related to feasibility, benefits and barriers of an intervention | Quantitative: The initial depression severity score was 12.7 (SD = 5.2), while the follow-up score was 11.3 (SD = 6.6). The initial degree of anxiety was 11.2 (SD = 3.2), while the follow-up score was 7.7 (SD = 4.4) Initial use of crack or cocaine was 1.67, while the follow-up score was 1.0. Qualitative: Having a place to go in the morning can be very beneficial for users of urban farms. Participants acquired numerous hands-on skills. Participants were happy to have an opportunity to expand their knowledge of plant life and farming. Intent to give back to their community with newly acquired skills | No control group reported | Participants reported less distress symptoms, improved overall general health and reduced frequency of illicit drug use | Depressed, unemployed individuals with HIV who experience distress symptoms have the potential to re-engage in a community-based activity that is meaningful and social with this activities |
| Soga et al, 2017 Japón | 165 Urban Allotment Gardening users y 167 control Male and female 61.9 years mean age CM not reported | Quantitative Cross-sectional | Respondents provided self-reported information on five health outcomes to observe health improvements among urban garden users | Perceived General Health, Subjective Health Complaints, General Mental Health, and Social Cohesion were assessed using a % evaluation on a scale of 0 to 100 in surveys BMI was calculated using self-reported height and weight | Compared with the control group, there was a significant improvement in Perceived General Health, Subjective Health Complaints, General Mental Health and Social Cohesion The BMI of the two groups did not differ significantly | Not declared, only statistical differences between groups | Users had significant positive effects on perceived general health and social cohesion and negative effects on subjective health complaints and general mental health | This study has a major implication for policy, as it suggests that urban allotments have great potential for preventative healthcare |
Main characteristics of the included studies
| Authors/year/country | Population (number of participants, sex, age, co-morbidity = CM) | Methodological approach and study design | Intervention description and purpose | Unit of results measurement | Results (intervention group) | Results (control group if exists) | Conclusions | Findings |
|---|---|---|---|---|---|---|---|---|
| Beavers et al., 2022 EE.UU. | 28 gardeners. NO control group reported. Male and female >18 years CM not reported | Qualitative Community-based participatory research | Qualitative interviews to examine the perceived physical and mental health effects of urban farming | The grouping of codes follows broad topics relevant to the main research questions. | Physical Health: Improved dietary habits. It is physically demanding. This practice maintains health during aging. Physical Activity: Participants with disability limitations or pain benefit from physical activity on urban farms. Mental well-being: Stress relief and relaxation. Mood improvement. Contributes to personal growth by helping others. | No control group reported | Prominent physical health impacts attributed to urban farming included providing an enjoyable source of activity, management of chronic diseases, improved physical functioning, improvement of mood, relieved stress, spirituality, personal growth and an opportunity for helping others. | Urban farming may improve physical and mental health among diverse groups |
| Harada et al., 2021 Japón | 1718 participants in allotments and experience farms and 651 in the control group. Male and female >40 years CM not reported | Quantitative Cross-sectional | Surveys were conducted to investigate the differences in mental health and physical activity among urban farmers and non-farmers | Percentage of scores on a 0 to 100 scale in surveys | Physical activity: 54.9% Self-rated health: 82.7% Mental health: 64.1% | Physical activity: 16.6% Self-rated health: 14.6% Mental health: 14.6% | Participants in both types of urban agriculture reported a significant improvement in their health compared to non-participants (self-rated health, mental health, physical activity) | Urban farming promotes longevity and has the potential to be effective, particularly in aging populations |
| Matthys et al., 2007 Ivory Coast | 586 urban garden users and 130 control groups were surveyed. Male and female >1 year CM not reported | Quantitative Cross-sectional | Laboratory analysis of parasite presence in feces among urban garden users and non-users. | % prevalence of infection of parasites | Prevalence of: hookworm infections: 24.7%, lumbricoides in 1.1%, entamoeba coli 53.3% and Blastocystishominis 37.5% was found in participants | Prevalence of hookworm infections: 14.6% Not other infections declared | Schistosomiasis mansoni and Hookworm infection was associated with specific agricultural activities | Health education and active participation of urban farmers are recommended for schistosomiasis and soil-transmitted helminthiasis |
| Safitri et al., 2021 Indonesia | 22 female users Female Age not reported CM not reported | Qualitative Case study | The purpose of the study was to discuss the implementation urban farming as women empowerment | Qualitative descriptive analysis using code clustering | Urban farming management provides training and education Female users view healthy food as a benefit | No control group reported | Women’s motivation to be involved in urban farming is essential | The benefit of urban farming has provided economic benefits, social networks, and knowledge about providing healthy food |
| Sereenonchai & Arunrat, 2022 Tailandia | 325 users Male and female Age not reported CM not reported | Quantitative and qualitative Cross-sectional study Thematic content analysis | Snowball sampling is used to compare the benefits of urban farming between users and non-users | A comparison of the significance values of measured variables regarding beneficiaries, owners and continuers of urban farms | Perceived behavioral control: P > 0.05 Perceived benefits: P > 0.05 Perceived readiness: P > 0.05 Perceived risks: P > 0.05 Perceived obstacles: P > 0.05 | No control group reported | Several key factors are required if the villager intends to continue urban farming | Promotes interaction among community members |
| Shacham et al., 2012 EE.UU. | 11 participants. No control group Male and female >18 years CM: VIH+ | Quantitative and qualitative Prospective single armed intervention trial Thematic content analysis | Mixed methods intervention. Twice a week for eight weeks, participants engaged in urban farming activities to examine how urban farming practices have changed | Quantitative: Depression severity score: Mean of the expressed depressive symptoms from the PHQ-9 survey Anxiety severity: Evaluated using the mean of the expressed Patient Health Questionnaire-9 scores General health assessment. Crack or cocaine use: Number of days of using the drug Qualitative: Coding related to feasibility, benefits and barriers of an intervention | Quantitative: The initial depression severity score was 12.7 (SD = 5.2), while the follow-up score was 11.3 (SD = 6.6). The initial degree of anxiety was 11.2 (SD = 3.2), while the follow-up score was 7.7 (SD = 4.4) Initial use of crack or cocaine was 1.67, while the follow-up score was 1.0. Qualitative: Having a place to go in the morning can be very beneficial for users of urban farms. Participants acquired numerous hands-on skills. Participants were happy to have an opportunity to expand their knowledge of plant life and farming. Intent to give back to their community with newly acquired skills | No control group reported | Participants reported less distress symptoms, improved overall general health and reduced frequency of illicit drug use | Depressed, unemployed individuals with HIV who experience distress symptoms have the potential to re-engage in a community-based activity that is meaningful and social with this activities |
| Soga et al, 2017 Japón | 165 Urban Allotment Gardening users y 167 control Male and female 61.9 years mean age CM not reported | Quantitative Cross-sectional | Respondents provided self-reported information on five health outcomes to observe health improvements among urban garden users | Perceived General Health, Subjective Health Complaints, General Mental Health, and Social Cohesion were assessed using a % evaluation on a scale of 0 to 100 in surveys BMI was calculated using self-reported height and weight | Compared with the control group, there was a significant improvement in Perceived General Health, Subjective Health Complaints, General Mental Health and Social Cohesion The BMI of the two groups did not differ significantly | Not declared, only statistical differences between groups | Users had significant positive effects on perceived general health and social cohesion and negative effects on subjective health complaints and general mental health | This study has a major implication for policy, as it suggests that urban allotments have great potential for preventative healthcare |
| Authors/year/country | Population (number of participants, sex, age, co-morbidity = CM) | Methodological approach and study design | Intervention description and purpose | Unit of results measurement | Results (intervention group) | Results (control group if exists) | Conclusions | Findings |
|---|---|---|---|---|---|---|---|---|
| Beavers et al., 2022 EE.UU. | 28 gardeners. NO control group reported. Male and female >18 years CM not reported | Qualitative Community-based participatory research | Qualitative interviews to examine the perceived physical and mental health effects of urban farming | The grouping of codes follows broad topics relevant to the main research questions. | Physical Health: Improved dietary habits. It is physically demanding. This practice maintains health during aging. Physical Activity: Participants with disability limitations or pain benefit from physical activity on urban farms. Mental well-being: Stress relief and relaxation. Mood improvement. Contributes to personal growth by helping others. | No control group reported | Prominent physical health impacts attributed to urban farming included providing an enjoyable source of activity, management of chronic diseases, improved physical functioning, improvement of mood, relieved stress, spirituality, personal growth and an opportunity for helping others. | Urban farming may improve physical and mental health among diverse groups |
| Harada et al., 2021 Japón | 1718 participants in allotments and experience farms and 651 in the control group. Male and female >40 years CM not reported | Quantitative Cross-sectional | Surveys were conducted to investigate the differences in mental health and physical activity among urban farmers and non-farmers | Percentage of scores on a 0 to 100 scale in surveys | Physical activity: 54.9% Self-rated health: 82.7% Mental health: 64.1% | Physical activity: 16.6% Self-rated health: 14.6% Mental health: 14.6% | Participants in both types of urban agriculture reported a significant improvement in their health compared to non-participants (self-rated health, mental health, physical activity) | Urban farming promotes longevity and has the potential to be effective, particularly in aging populations |
| Matthys et al., 2007 Ivory Coast | 586 urban garden users and 130 control groups were surveyed. Male and female >1 year CM not reported | Quantitative Cross-sectional | Laboratory analysis of parasite presence in feces among urban garden users and non-users. | % prevalence of infection of parasites | Prevalence of: hookworm infections: 24.7%, lumbricoides in 1.1%, entamoeba coli 53.3% and Blastocystishominis 37.5% was found in participants | Prevalence of hookworm infections: 14.6% Not other infections declared | Schistosomiasis mansoni and Hookworm infection was associated with specific agricultural activities | Health education and active participation of urban farmers are recommended for schistosomiasis and soil-transmitted helminthiasis |
| Safitri et al., 2021 Indonesia | 22 female users Female Age not reported CM not reported | Qualitative Case study | The purpose of the study was to discuss the implementation urban farming as women empowerment | Qualitative descriptive analysis using code clustering | Urban farming management provides training and education Female users view healthy food as a benefit | No control group reported | Women’s motivation to be involved in urban farming is essential | The benefit of urban farming has provided economic benefits, social networks, and knowledge about providing healthy food |
| Sereenonchai & Arunrat, 2022 Tailandia | 325 users Male and female Age not reported CM not reported | Quantitative and qualitative Cross-sectional study Thematic content analysis | Snowball sampling is used to compare the benefits of urban farming between users and non-users | A comparison of the significance values of measured variables regarding beneficiaries, owners and continuers of urban farms | Perceived behavioral control: P > 0.05 Perceived benefits: P > 0.05 Perceived readiness: P > 0.05 Perceived risks: P > 0.05 Perceived obstacles: P > 0.05 | No control group reported | Several key factors are required if the villager intends to continue urban farming | Promotes interaction among community members |
| Shacham et al., 2012 EE.UU. | 11 participants. No control group Male and female >18 years CM: VIH+ | Quantitative and qualitative Prospective single armed intervention trial Thematic content analysis | Mixed methods intervention. Twice a week for eight weeks, participants engaged in urban farming activities to examine how urban farming practices have changed | Quantitative: Depression severity score: Mean of the expressed depressive symptoms from the PHQ-9 survey Anxiety severity: Evaluated using the mean of the expressed Patient Health Questionnaire-9 scores General health assessment. Crack or cocaine use: Number of days of using the drug Qualitative: Coding related to feasibility, benefits and barriers of an intervention | Quantitative: The initial depression severity score was 12.7 (SD = 5.2), while the follow-up score was 11.3 (SD = 6.6). The initial degree of anxiety was 11.2 (SD = 3.2), while the follow-up score was 7.7 (SD = 4.4) Initial use of crack or cocaine was 1.67, while the follow-up score was 1.0. Qualitative: Having a place to go in the morning can be very beneficial for users of urban farms. Participants acquired numerous hands-on skills. Participants were happy to have an opportunity to expand their knowledge of plant life and farming. Intent to give back to their community with newly acquired skills | No control group reported | Participants reported less distress symptoms, improved overall general health and reduced frequency of illicit drug use | Depressed, unemployed individuals with HIV who experience distress symptoms have the potential to re-engage in a community-based activity that is meaningful and social with this activities |
| Soga et al, 2017 Japón | 165 Urban Allotment Gardening users y 167 control Male and female 61.9 years mean age CM not reported | Quantitative Cross-sectional | Respondents provided self-reported information on five health outcomes to observe health improvements among urban garden users | Perceived General Health, Subjective Health Complaints, General Mental Health, and Social Cohesion were assessed using a % evaluation on a scale of 0 to 100 in surveys BMI was calculated using self-reported height and weight | Compared with the control group, there was a significant improvement in Perceived General Health, Subjective Health Complaints, General Mental Health and Social Cohesion The BMI of the two groups did not differ significantly | Not declared, only statistical differences between groups | Users had significant positive effects on perceived general health and social cohesion and negative effects on subjective health complaints and general mental health | This study has a major implication for policy, as it suggests that urban allotments have great potential for preventative healthcare |
Search strategy, selection and collection process
Each database was searched using a different Boolean operator and MeSH term. Detailed information can be found in Table 2 in supplementary data. The articles were selected as follows: G.C.V. and B.D.F.G. searched PubMed, G.M.N.R. and M.N.A.O. DOAJ and G.C.V. and G.M.N.R. examined CAB Abstracts. Article relevance was verified through its title, abstract and finally full text. At each stage, a consensus was established; an agreement was reached in any case of discrepancy regarding the eligibility of the articles, and M.A.A.N.C. acted as an impartial moderator.
In the data extraction process, G.C.V. and B.D.F.G. served as data collectors, and G.M.N.R. and M.A.A.N.C. participated as reviewers of the retrieved information. In the case of disagreements, M.N.A.O. support was requested. Data collection was carried out using Microsoft Excel tables and arranged according to the variable of interest and inclusion criteria in each column. A summary of the assumptions considered by the authors is presented in Table 3 in supplementary data.
Assessment of risk of bias in the study and heterogeneity in reported effects
G.C.V. and M.N.A.O. participated in the assessment of the risk of bias using the ‘Risk of Bias In Non-randomized Studies - of Interventions’ (ROBINS-I) tool and the Excel template proposed by McGuinness and Higgins.18 Before data analysis, B.D.F.G. and M.A.A.N.C. verified the information and added a general risk column. Subsequently, the templates were uploaded to the Robvis website (https://mcguinlu.shinyapps.io/robvis/). Detailed information of the domains included is represented in Table 4 in supplementary data.
Methodological heterogeneity was analyzed concerning differences in methodological approach, study design and risk of bias and clinical heterogeneity in terms of differences in participants (age and co morbidities), interventions type and development, or data outcomes (physical, mental or social health impact stated) when entered and compared visually in Excel.
Synthesis methods
The SWiM guideline19 was used to synthesize the results. We grouped the interventions according to the concept of health proposed by the WHO20; impact on physical, mental and social health in order to elucidate possible differences in all health fields. If no concrete evidence could be found to justify the above, the results could be grouped according to the targeted population group after the protocol had been registered.
Health impact percentages and statistical significance data (in the case of a quantitative study) and the codes emerging from interviews (in the case of a qualitative study) were used. A narrative analysis of quantitative and qualitative data was chosen, as a meta-analysis did not fit the research question.
Certainty of evidence
We used the ‘Grading of Recommendations Assessment, Development and Evaluation’ (GRADE) approach21 for each included manuscript; subsequently, an overall judgment was made using the GRADE pro guideline development tool (GDT) to create summary-of-findings tables. B.D.F.G and M.A.A.N.C. performed the process independently, disagreements were resolved by consensus. Supplementary data contains detailed information.
Results
Study selection
The literature search yielded a total of 2578 original manuscripts, of which 12 were manually eliminated because they had been duplicated. When the information was screened, 1875 manuscripts were eliminated when analyzed by title and abstract, and 589 were eliminated when analyzed in full text because they did not present a topic in accordance with the purpose of the present systematic review. Afterward, 95 articles were excluded after eligibility assessment with reasons. In the end, seven original articles were included in the data analysis. The excluded articles, as well as the reasons for their exclusion, can be found in the supplementary material. The detailed information according to each step is shown in Fig. 1.
PRISMA study selection flowchart.
Study characteristics
Among the studies, two used qualitative methods,22,23 two mixed method,11,16 and three were quantitative10,12,24; two were conducted in the United States,11,23 two in Japan,10,24 one in Thailand,16 one in Ivory Coast12 and one in Indonesia.22 Regarding control groups, two studies involved a comparison group,10,12 and all involved men and women, except Safitri et al.17 PubMed database produced the highest number of manuscripts included in this review with six research papers,10–12,16,22,23 followed by DOAJ with one.24 Detailed information is presented in Table 1.
Risk of bias in studies
Two articles presented low risk (28.57%),10,23 and five were classified as moderate risk (71.43%).11,12,16,22,24 Detailed information can be found Fig. 1 in supplementary data. The analysis results of bias risk, both by domain and overall, are displayed in Fig. 2.
Risk of bias by domain and overall employing ROBINS tool.
Results regarding individual studies
Impact on physical health
Six manuscripts address the impact of interventions involving urban farming on physical health.10–12,22–24 Four of them mention a significantly positive impact on users of urban farming compared to users who had not.10–12,24 Changes in self-reported health were reported in 82.7% and 14.6% of users and non-users, respectively (P < 0.0001), and changes in physical activity were reported in 54.9% and 16.6% of users and non-users, respectively (P < 0.0001) among older adults.10 Drastic changes with positive effects on perceived general health and negative effects on subjective health complaints, as well as statistically significant increases in physical activity and improved diet from increased vegetable intake have also been reported. Habits such as smoking tobacco and drinking alcohol did not show significant changes24; however, the days of use of heroin, crack, or opioids increased, specifically in the HIV+ population group.11
On the other hand, a report by Beavers et al.23 describes the practice of urban farming as physically demanding, categorizing it as strenuous and tiring and representing the only source of physical activity for these users; however, urban farming supports the intake of fruits and vegetables, weight loss, joint movement and general improvement in systemically compromised users by keeping them active, exposing them to the sun in a measured way to generate vitamin D and improve sleep. It has also been reported that urban farming empowers women with training and education, which reflects healthy food intake.22
In contrast, risks of urban farming have also been exposed, including the presence of parasites such as Schistosoma mansoni, which has been reported in 50.1% and 22.9% of users and non-users, respectively; hookworm in 24.7% and 14.6% of users and non-users, respectively; and others such as Entamoeba coli, lumbricoides, Trichuris trichiura and Blastocystis hominis. The presence of parasites has been attributed to direct contact with soil by urban farming users, mainly infants.12
Impact on mental health
Five manuscripts address the impact on urban farming users’ mental health,10,11,16,23,24 highlighting an improvement of 64.1% and 14.6% of users and non-users, respectively (P < 0.0001).10 Overall mental health also exhibited a significant difference between users and non-users (P < 0.0001), mainly attributed to considering urban farming to be a source of mental relaxation, social interaction and connection to nature.24
Consistent with the above observations, urban farming has been associated with terms such as ‘peace,’ ‘calm’, ‘grounded’ and ‘refreshed’ in users and is considered a practice that promotes stress relief and relaxation. It has also been associated with the reduction of negative emotions, improved mood and feelings of general improvement.23
Sereenonchai and Arunrat16 employed psychological theories to assess the impact of urban farming on its users and argue that attitude, awareness of benefits and perceived disposition are positively related to urban farming. Contrary, perceived risks and obstacles were not stated. Specifically in the HIV+ population, urban farming has been considered a positive practice, suggesting improvement in depression, severe anxiety (significance data not stated), mood, promotion of manual skills acquisition and mindfulness.11
Impact on social health
Four articles examine urban farming’s impact on social health.11,16,23,24 Urban farming has been linked to societal cohesion, but no statistically significant difference was found between users and non-users.24 Regarding the findings mentioned previously, benefits are produced from the enjoyment of social interaction, the desire for more social interaction,16 and the opportunity for coexistence, promoting a sense of community.24 In addition, it has been found that urban farming contributes to personal growth through social support, expressing feelings and happiness from supporting peers and bonding in a spiritual community by connecting to a spiritual idea.23
For people living with HIV, a feeling of social contribution by intending to give back to their community with their newly acquired skills, teaching others, becoming leaders, practicing volunteerism and having intention to create more socially meaningful projects has been reported.11
Heterogeneity assessment
The manuscripts included in the synthesis of results presented substantial methodological and clinical heterogeneity. Regarding the analysis of methodological heterogeneity, three manuscripts presented quantitative methodological approach,10,11,24 two mixed methods11,16 and two qualitative.22,23 Concerning study design, quantitative studies were cross-sectional10,12,16,24 and prospective,11 and those with a qualitative approach had a case study,22 community-based participatory research23 and thematic content analysis11,16 as study design. The risk of bias was moderate in five of the included publications,11,12,16,22,24 while two were classified as low risk.10,23
Concerning the analysis of clinical heterogeneity, only one article mentioned having a population with some morbidity.11 Regarding age, this was variable since two manuscripts did not state the age of participants,16,22 one of them mentioned subjects from one to over 40 years old,12 and four had included adults over 18 years old without specifying age range.10,11,23,24 In relation to the type of intervention, six manuscripts employed an intervention of the education and behavior change type,10,11,16,22–24 and only one of environmental alterations.12 In data outcomes, two articles reported only the impact of urban farming on one aspect of health,12,22 two on two aspects10,16 and three on all aspects.11,23,24
Certainty of evidence
Certainty of evidence analyzed by domain presented the following results: risk of bias: not serious; inconsistency: not serious; indirectness: not serious; imprecision: serious (with reasons); total of events: 7; importance: critical (with reasons). No disagreements arose in establishing the certainty of the evidence. We state that there is ‘moderate’ evidence that the practice of urban farming can be associated with positive effects on physical, mental and social health, because most of the interventions are focused on education and behavior change, there are no data from longitudinal studies and there were no statistically significant differences in some of the included studies. A prognostic table generated by the GRADE pro GDT tool can be found in the supplementary data.
Discussion
Main findings of this study
Through this systematic review was shown that urban farming’s health impacts have been reflected in the three states of health proposed by WHO, namely physical, mental and social. While there has been a positive impact on the above three areas, there have also been negative impacts on physical health.
What is already known on this topic
The literature states that urban farming practice improves social capital, food security,7,8 wellbeing, physical activity and promotion and support of healthy eating patterns, even in densely populated cities.4,13,15,25 It also highlights that urban farming can be viewed as a supply chain that provides food to the population,14 and could improve dietary intake.7,8,10,11,16,23,24
What this study adds
Our study suggests that urban farming improvement interventions can have a positive impact on all three spheres of the WHO concept of health. Moreover, these benefits are detailed in different population groups, which could serve as a basis for the subsequent implementation of public health strategies. The integration of a holistic perspective that transcends the mere evaluation of biomedical indicators is highlighted, exploring the psychosocial dimension, featuring how participation in urban farming impact mental and social health. This approach complements the WHO conceptualization of health by recognizing the intrinsic interconnectedness between the physical, mental and social dimensions of well-being. It is also emphasized the importance of community interactions and social cohesion in health.
This study offers directions for future research in the area, taking into account the gaps in knowledge, advantages and disadvantages of the methods used in urban garden interventions to enrich their implementation and positive impact on health.
Limitations of this study
The limitations of this study were mainly related to the scarce literature and the fact that some studies had no control group to compare. On the other hand, having included only original articles may be considered a limitation as there are manuscripts in gray literature. Another limitation lies in the study design of the included studies, which prevents us from establishing definitive causal relationships and there is the possibility of uncontrolled variables and underlying confounding factors that may affect causal inference. However, this broader perspective introduces the complexity of measuring and quantifying social phenomena, which could affect the objectivity of the measurements. The inclusion of qualitative methods, although enriching, also introduces a subjective component that could influence the interpretation of the results.
In addition, there are data that were found in the previous literature search and that were not found in this review, such as stress factor in users for maintaining their lands,25 the high level of lead and other chemicals in the soil of urban areas,26,27 political barriers that could affect the implementation of urban farming,28 results in more population groups such as pregnant women,29 and the conflicts generated due to differences in cultivation methods,30 for this reason it is suggested that the results obtained be generalized with caution.
Conclusion
Physical and mental health showed significant differences when contrasting the results between users and non-users of urban farming; however, health in the social stratum was not. Older adult population group showed significant improvements in the physical domain. The positive repercussions related to the physical, mental and social health of urban farming users in different population groups outweigh its negative effects.
Further research should be conducted to clarify the potential benefits of urban farming in communities in which there is a high prevalence of co-morbidities, a need to increase social cohesion and a need to foster improved mental health. Society and government should be involved in improving the health of the entire population. Researchers are encouraged to share their protocols for developing interventions based on theoretical foundations to generate evidence-based results. It is possible to use the results of this study to inform future public health policy implementation to benefit vulnerable communities.
Acknowledgments
The authors would like to thank Dr. Irma Eugenia García-López from the Universidad Autónoma del Estado de México for her support on this research.
Competing interests
The authors declare no conflicts of interest.
Fundings
The authors did not receive any funding for this research.
Guillermo Cano-Verdugo, PhD
Brianda Daniela Flores-García, PhD
Georgina Mayela Núñez-Rocha, PhD
María Natividad Ávila-Ortíz, PhD
María Argelia Akemi Nakagoshi-Cepeda, PhD
