Health, "illth," and economic growth: medicine, environment, and economics at the crossroads.

Economic growth has been the single biggest contributor to population health since the Industrial Revolution. The growth paradigm, by definition, is dynamic, implying similar diminishing returns on investment at both the macro- and the micro-economic levels. Changes in patterns of health in developing countries, from predominantly microbial-related infectious diseases to lifestyle-related chronic diseases (e.g., obesity, type 2 diabetes) beyond a point of economic growth described as the epidemiologic transition, suggest the start of certain declining benefits from further investment in the growth model. These changes are reflected in slowing improvements in some health indices (e.g., mortality, infant mortality) and deterioration in others (e.g., disability-associated life years, obesity, chronic diseases). Adverse environmental consequences, such as climate change from economic development, are also related to disease outcomes through the development of inflammatory processes due to an immune reaction to new environmental and lifestyle-related inducers. Both increases in chronic disease and climate change can be seen as growth problems with a similar economic cause and potential economic and public health-rather than personal health-solutions. Some common approaches for dealing with both are discussed, with a plea for greater involvement by health scientists in the economic and environmental debates in order to deal effectively with issues like obesity and chronic disease.