There is ample evidence to support the notion that while economic development is generally positively associated with human health [8
], this is not always the case, either over the short-term, in relation to booms and recessions [18
], or over the long-term [21
]. It should be obvious, for example, that as the measure of economic growth, that is GDP, is determined by throughput, irrespective of outcome, it is possible that contributors to GDP could be health negative, or “illth” creating.(The term “illth” was first coined by the 19th Century English novelist John Ruskin (1857) who recognised that in the economic discussions of value of the time, no account had been taken of production of objects that cause harm or are socially undesirable. Ruskin referred to the outcome of those objects that are harmful or socially undesirable but still have value in exchange as “illth”.) Around 10% of GDP in developed countries, for example, is made up of revenue from tobacco, alcohol, and drug sales, many of which can have an adverse effect on human health (it is ironic that some cigarette manufacturers also manufacture surgical equipment, thus catering for both ends of the spectrum, making and doubling the benefit for GDP from smoking).
Of course, this has not always been the case, and hence to be comprehensive, any proposition of a link between economic growth and health needs to be dynamic. Growth has unarguably been positively related to human longevity and health overall, as witnessed by the big improvements in longevity in developed countries since the industrial revolution [8
]. In developing economies however there is an “epidemiological transition” [23
], where a switch occurs from a high prevalence of infectious disease to a growing prevalence of chronic diseases, after which mortality rates continue to decrease (although at a decreasing rate), but there is a growing increase in morbidity as reflected in the measure of years of life spent with a disability (YLD) component of disability adjusted life years (DALYs). The point leading up to this has euphemistically been referred to as a “sweet spot” in human development, where this reflects a point of optimal returns [7
]. In economic terms this reflects the start of a point of diminishing marginal rates of return from continued investment in the growth paradigm.
The recent work by Tapia Granados and others [22
] has begun to objectify the point at which this might have already occurred in relation to some aspects of human health. In analysing Swedish mortality and economic data from 1800 to 2000, Tapia Granados and Ionides [24
] have shown the beginnings of a diminishing rate of returns on the growth model in relation to mortality rates in the last half of the 20th Century. This coincides, not unexpectedly, with the levelling of improvements in health made from the decrease in infectious diseases associated with development, and the consequent increase in chronic diseases associated with modern lifestyles, driven as they are by the modern environment. It is this switch, from predominantly microbe-related infectious disease, to lifestyle-related chronic disease, and the consequent shift in the human immune reaction from an acute response to an invading organism, to a chronic reaction to nonmicrobial, lifestyle-related “inducers” [25
] that differentiates the early from late stages of economic development. This has been shown in several developing societies and is currently being witnessed in China and India in accelerated form.
Other support for the developing adverse effects of development, beyond a point, is gained from studying the situation in reverse. Cuba, for example, was forced into economic decline after Russia's withdrawal in 1989 resulting in a 1000
kcal/day average decrease in food intake. The following decade was characterised by an improvement in many aspects of chronic disease; overall mortality decreased by 20%, obesity was halved, and deaths from heart disease reduced by 35% and stroke by 18% [26
]. Only cancers, which could be expected to have a longer lag-time in relation to causality, had not, at the time of study been affected. Nauru, a tiny island in the South Pacific, whose economy was based on superphosphate exported for fertilising the farm-lands of Australia and New Zealand, is another example. After exhaustion of its superphosphate supplies and consequent economic slump in the 1990s, Nauruans have decreased their obesity and diabetes levels dramatically from amongst the highest rates in the world [27
]. Similarly, Hodge et al. [28
] have shown the effects of development on obesity in villages in Papua-New Guinea. In quantifying measures of “modernity” such as cars, TV, microwaves, etc., Hodge et al. report a linear association between villages scoring high on modernity and high on measures of obesity, which is at least a marker, if not a determinant of chronic disease. In a closer examination of causality of such changes, researchers have found a link between lifestyles and disease. Using postwar Japan as an example, Tapia-Granados and colleagues found that times of economic prosperity correspond to increased consumption of tobacco, alcohol, and saturated fat; inactivity, work pressures, inadequate sleep, social isolation, traffic injuries, and social isolation [29
], all of which have links with metaflammation and chronic disease [4
From a different perspective, negative developments in environmental degradation, such as manifest in climate change, also point to diminishing returns from unlimited growth. Studies on carbon and other greenhouse gas emissions, for example, show a highly positive association between atmospheric concentration of these and economic fluctuations [30
], as might be expected. In a comparative analysis proposed recently [31
], a converging causal hierarchy has been proposed between biological and ecological disruptions, which synthesises these effects and metaphorically ties them to “inflammation” (meta—versus ecoflammation), as shown in .
Relational epidemiology between chronic disease and climate change.
An awareness of the convergence of health, climate, and macroeconomics gives rise to a need for consideration of all three phenomena.