Spain just surpassed Italy to become the world's healthiest country. That's according to the 2019 edition of the Bloomberg Healthiest Country Index, which ranks 169 economies according to factors that contribute to overall health. Spain placed sixth in the previous gauge, published in 2017. Four additional European nations were among the top 10 in 2019: Iceland (third place), Switzerland (fifth), Sweden (sixth) and Norway (ninth). Japan was the healthiest Asian nation, jumping three places from the 2017 survey into fourth and replacing Singapore, which dropped to eighth. Australia and Israel rounded out the top 10 at seventh and 10th place. The index grades nations based on variables including life expectancy while imposing penalties on risks such as tobacco use and obesity. It also takes into consideration environmental factors including access to clean water and sanitation. Researchers say eating habits may provide clues to health levels enjoyed by Spain and Italy [#2 on the list], as a "Mediterranean diet, supplemented with extra-virgin olive oil or nuts, had a lower rate of major cardiovascular events than those assigned to a reduced-fat diet," according to a study led by the University of Navarra Medical School. Meanwhile in North America, Canada's 16th-place ranking far surpassed the U.S. and Mexico, both of which dropped slightly to 35th and 53rd. Life expectancy in the U.S. has been trending lower due to deaths from drug overdoses and suicides.