Part Two. The urgent need for action
Chapter One. Chronic diseases: causes and health impact
The underlying determinants of chronic diseases – the “causes of the causes” – are a reflection of the major forces driving social, economic and cultural change – globalization, urbanization, population ageing, and the general policy environment. The role of poverty is described in the next chapter. Globalization refers to the increasing interconnectedness of countries and the openness of borders to ideas, people, commerce and financial capital. Globalization drives chronic disease population risks in complex ways, both directly and indirectly. The health-related advantages of globalization include the introduction of modern technologies, such as information and communication technologies for health-care systems.
The negative health-related effects of globalization include the trend known as the “nutrition transition”: populations in low and middle income countries are now consuming diets high in total energy, fats, salt and sugar. The increased consumption of these foods in these countries is driven partly by shifts in demand-side factors, such as increased income and reduced time to prepare food. Supply-side determinants include increased production, promotion and marketing of processed foods and those high in fat, salt and sugar, as well as tobacco and other products with adverse effects on population health status. A significant proportion of global marketing is now targeted at children and underlies unhealthy behaviour. The widespread belief that chronic diseases are only “diseases of affluence” is incorrect. Chronic disease risks become widespread much earlier in a country’s economic development than is usually realized. For example, population levels of body mass index and total cholesterol increase rapidly as poor countries become richer and national income rises. They remain steady once a certain level of national income is reached, before eventually declining (see next chapter) (4).
In the second half of the 20th century, the proportion of people in Africa, Asia and Latin America living in urban areas rose from 16% to 50%. Urbanization creates conditions in which people are exposed to new products, technologies, and marketing of unhealthy goods, and in which they adopt less physically active types of employment. Unplanned urban sprawl can further reduce physical activity levels by discouraging walking or bicycling. As well as globalization and urbanization, rapid population ageing is occurring worldwide. The total number of people aged 70 years or more worldwide is expected to increase from 269 million in 2000 to 1 billion in 2050. High income countries will see their elderly population (defined as people 70 years of age and older) increase from 93 million to 217 million over this period, while in low and middle income countries the increase will be 174 million to 813 million – more than 466%.
The general policy environment is another crucial determinant of population health. Policies by central and local government on food, agriculture, trade, media advertising, transport, urban design and the built environment shape opportunities for people to make healthy choices. In an unsupportive policy environment it is difficult for people, especially those in deprived populations, to benefit from existing knowledge on the causes and prevention of the main chronic diseases.