Life Expectancy in the U.S. Lower Than Europe?

So  I was just reading an article on CNN, and there was one that I thought you guys might find interesting. Studies have shown, based off of 2012 world average life expectancies, that the average life expectancy is about 2 years less than Europe and other developed countries. Why is that? According to Andrew Fenelon, senior author of this study, most of the gap exists in middle-age persons from age 25-65. However, Fenelon claims that another major cause of this is a significant rise in infant death in the U.S. as well. To further discover what is "killing" Americans, Fenelon looked into injuries, which are "the leading cause of death for Americans between 1 and 44 years of age." The three things most responsible for injury deaths were drug poisonings, gun violence, and car accidents. Most of these injury deaths were seemingly either accidents or suicides. Because of the abuses of drugs and alcohol and the significant rise in suicides in the United States since 1999, death rates have been on the rise since. However, if you take a look at life expectancy statistics from the 1980's, the United States outweighed most other countries. So what's changed? What has Europe done(or the U.S not done) to raise their life expectancy? And how will we, as Americans, take steps to change this? You do want a long, happy life don't you?