Prioritizing Preventable Causes of US Deaths

Modifiable risk factors responsible for many premature or preventable deaths fall into three main categories: Lifestyle factors such as smoking and physical inactivity; Dietary risk factors such as a high salt intake and a low intake of fruits and vegetables; And "metabolic" risk factors, such as obesity and hypertension, which shorten life expectancy by increasing the odds of developing CVD and diabetes.

With health care costs skyrocketing, it's important to know how many deaths are caused by each risk factor before developing policies and programs to improve the nation's health. Although previous studies have provided some information, they have not used consistent and comparable methods to estimate the number of deaths attributable to different risk factors. In addition, previous studies have rarely considered dietary and metabolic risk factors.

In a new study, jointly funded by the CDC and the Association of Schools of Public Health, Harvard researchers estimated the number of deaths due to 12 different modifiable risk factors.

Study Methods and Findings

The researchers used a method called "comparative risk assessment." They retrieved data on exposures to the 12 selected risk factors from US national health surveys, and obtained information on deaths from different diseases from the US National Health Center for Health Statistics. They also used previously published studies to estimate how much each risk factor increased the risk from a disease, and applied a mathematical model to estimate the number of deaths related to each factor.

Smoking and high blood pressure, which both have effective interventions, are responsible for the largest number of preventable deaths, followed by obesity, physical inactivity and high salt intake. Notably, 84,000 deaths were attributable to insufficient omega-3 intake, slightly higher than high trans fatty acid intake (82,000).

Comment

Though the study focused upon the most common causes of death such as cancer, heart disease and respiratory diseases, the findings that inadequate consumption of omega-3, and fruits and vegetables are important risk factors may be notable for visual health as well. EPA and DHA (from fish), as well as lutein and zeaxanthin (from produce), have been strongly linked to the risk of AMD and, possibly, other ocular conditions. The typical intake of EPA and DHA for example is 100-200 mg daily, while the AREDS-2 trial is testing 1,000 mg. In addition, 10 mg of lutein and 2 mg of zeaxanthin are being employed in AREDS-2, while the average daily consumption of these carotenoids is 2 mg.

Reference

Danaei G, et al. The Preventable Causes of Death in the United States: Comparative Risk Assessment of Dietary, Lifestyle, and Metabolic Risk Factors. PLoS Med 6(4): e1000058.