A recent study in PLoS Medicine, an open-access medical journal published by the Public Library of Science, found that four preventable risk factors for chronic diseases can cut life expectancy for men by 4.9 years, and 4.1 years for women.

Of the four risk factors – smoking, adiposity, and high blood pressure and glucose – reducing smoking had the greatest affect on life expectancy, especially among men. According to the study, by smoking less, men could add 2.5 years to their lives, while women could add 1.8 years. Losing weight added 1.3 years for both men and women.

According to the CDC, 45 percent of adults have hypertension, hypercholesterolemia, or diabetes; 13 percent have two of these conditions, and 3 percent have all three. Furthermore, an estimated 15 percent have one or more of these conditions, but haven’t been diagnosed.

The study analyzed data from the National Health and Nutrition Examination Survey and the Behavioral Risk Factor Surveillance System. Full results are available at www.plosmedicine.org.