More than three billion people currently live in urban areas and this figure is projected to soar to six billion (approximately 70% of the world’s population) within 30 years [1
]. This increased trend towards urbanisation has profound implications for human health, with urban lifestyles being associated with a number of adverse health outcomes, such as decreased levels of physical activity [2
], increased consumption of high-energy foods [3
] and social and psychological stress [4
]. Indeed, chronic and non-communicable diseases (e.g., depression, anxiety, high blood pressure, diabetes) are becoming increasingly common in urban areas [6
]. In consequence, promoting healthy lifestyles, which is regarded as a key part of the preventative health care approach [9
], in towns and cities is a major challenge in the 21st century [10
Nature in cities has great potential to provide an inexpensive intervention to assist in addressing many of these issues [11
]. It is widely recognised that regular contact with nature is related to a range of favourable health outcomes, such as increased psychological well-being [13
], general health [15
] and social cohesion [16
]. Indeed, epidemiological studies show that the quantity of neighbourhood greenspace is significantly related to the incidence of various chronic and non-communicable diseases, including depression and anxiety symptoms [17
], diabetes and obesity [18
], and circulatory and heart disease [19
]. It is therefore increasingly accepted that regular doses of nature are an essential part of maintaining a healthy lifestyle [11
] and, in some instances, can be used as a preventative measure [14
Allotment gardening provides city dwellers with opportunities to experience nature in their daily life. Research has shown that allotment gardens, and other types of community gardens, deliver various health benefits to people, including recovery from stress and fatigue [21
], increased self-esteem [24
], improved life satisfaction [25
] and better social networks [26
]. Recent studies also showed that engagement with allotment gardening is related to improved physical health [24
]. Nevertheless, the majority of evidence of these beneficial effects has, to date, been based on qualitative and descriptive approaches [21
], and empirical evidence from quantitative analysis is still scarce [24
]. Moreover, as most of the existing published research has been performed in Western societies (Europe and North America), it is unclear whether and to what extent the findings can be generalised more widely [20
Given this wide variety of associated health benefits, it is perhaps unsurprising that allotment gardening is today a popular pastime in many countries [28
]. There are numerous allotments in Europe; in the U.K. alone, for example, there are estimated to be c
. 330,000 allotment plots across the country [30
]. In Asia, where urban design and culture is very different, allotment gardening appears to be similarly popular; indeed in Japan, there are currently estimated to be c
. 190,000 allotment plots (note that more than 80% of this figure comes from urban areas), with both their number and total size increasing annually [31
]. Given the scale of, and the rising interest towards, allotment gardening, there is great potential for its use to promote healthy lifestyles for urban communities.
As the world’s largest mega-city, Tokyo, Japan, provides an interesting opportunity to examine the health benefits of allotment gardening. It has an extremely high population density (>6000 people per km2
]), with more than 80% of people living in apartments with no access to private gardens [33
]. This is coupled with very low per capita public green space (3 m2
]), resulting in people’s daily experiences of nature being extremely limited. Thus, publicly-owned allotments are likely to play a key role in allowing residents to actively engage with nature and, thus attain health benefits there from. Here, using the Tokyo population, we quantify the effects of allotment gardening on physical, psychological and social health. We surveyed 332 people to first test whether residents who used allotments (hereinafter “gardeners”) reported better health across five health outcomes, compared to those who did not (hereinafter “non-gardeners”). We then examined possible relationships between the frequency and duration of allotment gardening and health outcomes.
In the present study, we have shown that allotment gardeners, compared to non-gardeners, reported significantly better perceived general health, mental health and social cohesion, and these findings hold even after controlling for the socio-demographic and lifestyle variables. Our study provides support for the notion that participating in allotment gardening is associated with improved health [20
]. Below we discuss several, not mutually exclusive, potential mechanistic pathways through which allotment gardening could improve respondents’ health.
First, allotments, along with other types of urban greenspace, provide people with an opportunity to interact directly with nature. Indeed, exposure to nature benefits psychological health through mechanistic pathways that are now well established, namely attention restoration theory [47
] and stress reduction theory [48
]. Notably, in the present study, approximately half of gardeners identified having contact with nature as a motivation for allotment gardening. This result indicates that, even in a highly urbanised area like Tokyo, where natural environments and features have largely been lost, people still seek meaningful regular contact with nature and actually recognise, and appreciate, some of the beneficial effects from nature experiences [49
]. Given this, urban allotments have the potential to play an important role in not only helping people to maintain their psychological health, but also countering the ongoing loss of human–nature interactions—the “extinction of experience” [49
Second, allotment gardening involves a moderate intensity of physical activity, which promotes people’s physical fitness and health, as well as delivering additional psychological health benefits. We observed that gardeners spent more than 20 h per month, on average, engaging with gardening activities. Since regular physical exercise promotes general health conditions and reduces the risk of a range of chronic diseases [51
], this result has a significant implication for public health. Indeed, gardeners reported a significantly lower number of health complaints compared to non-gardeners. However, we did not find clear differences in BMI, a reliable indicator of overweight or obesity, between gardeners and non-gardeners, which is not congruent with the findings of recent studies performed in Europe [24
]. One possible reason for this is that being overweight or obese is not a severe health problem in our study region: Japan has one of the lowest rates of obesity across the world [52
]. The extent of health benefits people obtain from allotment gardening is likely to depend on the social and cultural contexts of the society.
Third, allotment gardening provides people with opportunities to interact with others in a social setting (e.g., transmitting knowledge of vegetable cultivation and bartering vegetables), thus promoting a sense of community and social ties. Indeed, we observed significantly higher levels of social cohesion in gardeners compared to non-gardeners. This result strengthens the notion that allotment and community gardens within urban areas generate social capital through the development of a cohesive social network [27
]. Increased social cohesion offers important implications for public health, as it is known to be a key determinant of psychological health [53
Lastly, participating in allotment gardening is likely to increase people’s vegetable consumption. We observed that gardeners reported significantly higher frequency of vegetable intake (Table 1
), which would undoubtedly be due to increased opportunities to consume vegetables grown in their own allotment plots. Indeed, in our study, growing vegetables to eat was the second-most important motivation for gardening. More importantly, participating in allotment gardening is also likely to improve people’s knowledge of nutrition and vegetable preferences, which may, in turn, increase their vegetable consumption [54
]. Because greater vegetable intake is associated with lower risk of major chronic diseases [55
], such a behavioural change can, from a long-term perspective, have a huge impact on public health outcomes.
This study used a cross-sectional design, which inevitably has both advantages and limitations. The main advantage is that it allows comparison of the effects of many different variables (risk factors) simultaneously. Indeed, using regression analysis and model averaging approaches, we showed that participating in allotment gardening had a significant impact on respondents’ health as well as other socio-demographic and lifestyle variables. The limitation, on the other hand, is that this study design cannot definitively establish cause–effect relationships. Other studies have, however, provided such support (see [20
]). Van den Berg and Custer [56
], for example, investigated people’s psychological health before and after 30 min of outdoor gardening and found a significant reduction in stress levels after the treatment. More importantly, their study suggested that neuroendocrine processes mediate the relationship between gardening and improved psychological health. Clinical studies employing horticultural therapy have also observed that gardening activities ameliorate the severity of depression and anxiety symptoms in patients with psychological disorders and its effect persists over a few months (e.g., [57
]). Further studies tracking people’s health over time would provide valuable information for understanding the long-term effects of allotment gardening.
Neither frequency nor duration of gardening significantly affected respondents’ health (Figure S1
). In other words, gardeners who used an allotment at a low frequency, and for a short duration, reported similar levels of health compared to those who did so regularly and for longer. This is a critically important finding because it indicates that even a low frequency, and short duration, of gardening is associated with improved health outcomes. Indeed, a recent UK study suggested that a single session of 30 min of allotment gardening produces a significant psychological health benefit to people [24
]. Although more evidence is necessary, our study implies that allotment gardening is an effective health promotion tool, which can be easily fitted into urban lifestyles.
We found no difference in Nature Relatedness scores (an indicator of an individual’s emotional bonds with nature) between gardeners and non-gardeners. This result is notable because it suggests that the health benefits of allotment gardening are not limited to specific groups of people (i.e., those who feel strong affinities to nature), rather they are applicable to the wider population. Also, there was no difference in socioeconomic (household income) levels between gardeners and non-gardeners. Furthermore, a large proportion of the gardener sample was comprised of older people—those who may be more likely to be physically inactive and socially isolated. These findings highlight that urban allotments can contribute to reducing health inequality within populations through the provision of equal opportunities to interact with nature [58
We acknowledge that there are some limitations to our study. First, as this study employed a non-randomised setting in the study design, one must be careful with drawing definite conclusions. Second, although we considered various socio-demographic and lifestyle variables in the analysis, there may be other factors affecting people’s health outcomes. Third, we used a self-reported questionnaire to determine the relationship between participating in allotment gardening and health. A strength of self-reported health questionnaires is the ability to reach respondents who might not be willing to participant in the more comprehensive health study; however, there is some limitation in that self-reported health responses do not always accurately reflect actual nature exposure or health.