A New Spin on Malthus?

An article in The New York Times succinctly summarized the World Health Organization's (WHO) recent report on the leading causes of death in the world: “As the world's population ages, gets richer, smokes more, eats more, and drives more, noncommunicable diseases will become bigger killers than infectious ones over the next 20 years.”¹ The WHO report is comprehensive in scope; it looks at 70 key health indicators in 193 member states.² Although it speaks to larger global trends, the report also has an important message for Americans. After curing or effectively treating some of the major killers in history, we run the risk of succumbing to our own success and affluence.

DECREASING BURDENOF INFECTIOUS DISEASE

Infectious diseases, still a burden for the developing world, are being treated more effectively even in the poorest of nations. The number of persons living with HIV infection is on the rise but at a lower rate than previously predicted. In fact, annual AIDS mortality will account for 1.8% of deaths in 2030 compared with 3% at present. Countries plagued by malaria are dramatically increasing their use of insecticide-treated nets. As AIDS, malaria, and tuberculosis become less prominent causes of death, other disease processes unfortunately will offset the gains made by control of infectious diseases.¹

RISING TIDE OF LIFESTYLE-RELATED ILLNESSES

In the future, 6 to 8 of the leading causes of death will be related to tobacco. The United States made the list of the top 10 countries where two-thirds of the world's smokers reside.

The other lifestyle-related risk factor that is making an increasingly greater contribution to mortality is obesity and its sequelae. For example, diabetes mellitus already accounts for 1.9% of mortality worldwide and the percentage will jump to 3.3% in the future. Since type 2 diabetes mellitus is related to excess weight, and the prevalence of obesity is increasing, this is not at all surprising. Vascular diseases and hypertension as causes of stroke are already responsible for 9.7% of worldwide mortality; this percentage will climb to 12.1% of deaths. Hypertensive heart disease is predicted to move up from 14th place as a cause of mortality to 8th place.

Noncommunicable diseases associated with an affluent lifestyle, especially the epidemics of obesity and smoking, are spreading beyond the United States and other wealthy nations. Tobacco companies are focusing their marketing on young people in poorer countries. Surveys of adolescents by the WHO have shown that 20% of them have clothes that display cigarette advertising logos.^1,2 Tobacco companies also are targeting women, especially in societies that previously discouraged their smoking. US-based fast food franchises have grown worldwide and are now one of our leading exporters of salt, fat, and calories.

Malthus proposed that population growth and competition for food sources would limit population size through a Darwinian competition for life-sustaining resources. Instead, it seems that affluence has increased our food supply (much of it unhealthy) and our access to relatively inexpensive tobacco products so that population growth will be regulated in a disturbing but still preventable manner.

References:

REFERENCES:

1. McNeil DG Jr. Noninfectious illnesses are expected to become top killers within 20 years. New York Times. June 3, 2008. www.nytimes.com/2008/06/03. Accessed June 10, 2008.

2. World Health Organization. World Health Statistics 2008. www.who.int/whosis/whostat/2008/en/index.html. Accessed June 10, 2008.