Nearly two-thirds of deaths in the world are caused by non-communicable diseases such as cancer, diabetes and heart and lung disease, which are rapidly increasing at a cost to the global economy of trillions of dollars, according to UN estimates and preliminary results of a new study.

UN Secretary-General Ban Ki-moon said in a report circulated yesterday that while the international community had focused on communicable diseases such as HIV/AIDS, malaria and tuberculosis, the four main non-communicable diseases "have emerged relatively unnoticed in the developing world and are now becoming a global epidemic".

The report says 36 million people died from non-communicable diseases in 2008, representing 63 per cent of the 57 million global deaths that year.

Nearly 80 per cent of deaths from these diseases were in the developing world, and nine million deaths were of people under the age of 60, it said.

In 2030, the report said, these diseases were projected to claim the lives of 52 million people.

Mr Ban said the rapidly increasing magnitude of non-communicable diseases was fuelled by rising risk factors including tobacco use, unhealthy diet, lack of physical activity, obesity and harmful alcohol use.