Most of us know that quitting smoking, achieving a healthy weight, and limiting alcohol intake can increase the length and quality of our lives. It’s widely known that lifestyle choices have an enormous impact on health. Accordingly, the healthcare industry—from physicians to dietary supplement suppliers—is shifting its focus from disease treatment to health promotion and disease prevention.

But do we Americans take this healthy living rhetoric seriously enough? A new study in the March 10, 2004 issue of the Journal of the American Medical Association found that about half of all deaths in the United States in 2000 could be attributed to a limited number of preventable factors, many of which relate to health behaviors: smoking, poor diet and physical inactivity, alcohol consumption, preventable infectious and parasitic disease (i.e., pneumonia , influenza ), environmental toxins, motor vehicle crashes, firearms, sexual behaviors, and illicit drug use.

About the Study

Researchers performed a literature search of studies published between 1980 and 2002 that described links between risk behaviors and mortality. In addition, they used data from the Centers for Disease Control and Prevention to identify causes and numbers of deaths in 2000. Combining these data, the researchers estimated the number of deaths that were attributable to each major cause.

They compared these estimates with data from a Journal of the American Medical Association study published in 1993, which described the major causes of death in the United States in 1990.

The Findings

In 2000, approximately 2.4 million people died in the United States. The table below describes how each major risk factor contributed to these deaths:

CauseNumber of deaths in 2000Change since 1990
Smoking435,000Increase of 35,000 deaths
Poor diet and physical inactivity400,000Increase of 100,000 deaths
Alcohol consumption85,000Reduction of 15,000 deaths
Infectious and parasitic disease (excluding HIV ) 75,000Reduction of 15,000 deaths
Toxic agents (excluding secondhand smoke)55,000Not reported
Motor vehicle crashes43,000Reduction of 4,000 deaths
Firearms29,000Reduction of 7,000 deaths
Sexual behavior (including HIV)20,000Reduction of 10,000 deaths
Illicit drug use17,000Reduction of 3,000 deaths

*Note – These numbers are estimates, not exact numbers

Although the rate of smoking slightly declined during the 1990s, the deaths attributed to smoking appear to have increased. This is presumably due to the fact that smokers die of their habit only after many years (so we may see a decline later on) and in the 2000, the researchers included infant deaths due to maternal smoking and deaths due to secondhand smoking, neither of which were included in the 1990 analysis.

The researchers noted the decline in deaths related to infectious and parasitic disease was most likely due to an increase in vaccinations in older adults, and the declines in deaths due to sexual behavior and illicit drug use were most likely due to improved medical treatments for the diseases associated with these behaviors.

While these results are certainly intriguing, they have limitations. First, the study did not measure the impact of these factors on quality of life, such as disability and lost productivity. Also, the estimations of deaths attributable to these risk factors are imprecise at best, and should only be used to demonstrate a trend.

How Does This Affect You?

The 1993 study revealed that smoking was far and away the leading cause of death in 1990. These results indicate that while smoking was still the leading cause of death in 2000, poor diet and physical inactivity will likely overtake smoking as the leading cause of death unless Americans dramatically change these behaviors.

US rates of obesity tend to reflect our eating and exercise habits. The prevalence of obesity significantly increased during the 1990s. Obesity raises your risk of many diseases, including type 2 diabetes , heart disease , high blood pressure , and stroke . While there is no magic cure for obesity, a weight-loss program that includes a combination of diet, exercise, and behavior modification can significantly improve your health.

This is clearly an uphill battle. When we live in a society awash with inexpensive, high calorie food, and a culture that values driving cars, watching television, and surfing the Internet, it is no wonder we have an obesity epidemic on our hands. Under these circumstances, keeping fit in America takes a great deal of effort. But the stakes are high, so hopefully you’re up to the challenge.