Growing Global Appetite for Meat, Milk Presents Health Risks

Boosting production also ups danger of human and animal diseases

February 15, 2011

A Chinese vendor sells slaughtered chickens at an open air market in Shandong province on Feb. 9, 2010.

As the human population has grown and become wealthier, the demand for high-quality animal protein has skyrocketed.

For example, from 1990 to 2005, Asia alone added roughly one billion humans, but 10 billion chickens, according to UN figures.

Farmers are raising more animals in smaller spaces than in the past and in places that have not been used this way before, like in virgin forests or near-dense urban environments. And this intensification is often taking place in poor conditions and with few regulations, according to animal disease expert Delia Grace from the International Livestock Research Institute.

"You can get conditions which actually have never been experienced during the time of animal intensification in the West, or anywhere else in the world," says Grace. "And these kinds of completely novel conditions are giving rise to novel diseases."

According to Grace, most of those novel diseases do not cause a great deal of harm. But some do. A recent example is the H5N1 avian influenza, also known as bird flu. More than 300 people have died from it to date, and the virus continues to circulate, killing one person in Cambodia this year. However, one good thing has come out of the experience.