by Rebecca Nesbit
Many people in the west eat meat every day, and possibly dairy products most meals. Traditionally, diets elsewhere had lower levels of protein, and it’s common for people have lost the enzyme, lactase, needed to digest dairy products.
But rapid economic and income growth, urbanisation, globalisation, and marketing by food companies are leading to a dramatic shift of Asian diets away from staples and towards livestock and dairy products, vegetables and fruit, and fats and oils.
In a recent paper ‘Horizon scan of global conservation issues for 2011’ William Sutherland from Cambridge University, along with scientists from 3 continents, chose the environmental consequences of increased milk consumption in Asia as a major cause of concern for biodiversity conservation.
When we’re born we are able to digest dairy products, but this changes when we are weaned. However, people can develop tolerance to milk proteins by drinking milk and consuming dairy products as children. If access to dairy products means this becomes normal in China, milk consumption may rise dramatically.
It’s not just the consumption of dairy products that will have an impact on farming and biodiversity. Across Asia, per capita meat consumption increased from 11 to 26 kg per year between 1980 and 2000.
It takes more water and more land to raise cattle than it does to grow crops, so changes in land use to accommodate more dairy cattle will have wide reaching effects. For a start, farming cattle leads to greater emissions of the greenhouse gases methane and nitrous oxide. The land needed to grow food for cattle will result in the clearance of forests, leading to a reduction in biodiversity and a loss of the services that these forests provided, such as water purification.
The link between diets and the local availability of resources is being severed. It is this globalisation that allows the dietary changes we are seeing, but also shows how far the social and environmental implications stretch. Infrastructure changes are needed for food to be transported, sometimes across continents, which can destroy habitats and increase carbon emissions. Societies will change as subsistence farmers become employees of large corporations.
Sutherland WJ et al. (2011) Horizon scan of global conservation issues for 2011. Trends in Ecology and Evolution 26, 10-6
Changing Asian Diets:
Pingali P (2007) Westernization of Asian diets and the transformation of food systems: implications for research and policy. Food Policy 3, 281–298