People who die prematurely — that is, before the age of 70 — can usually chalk up their mortality to one of five leading causes of death: heart diseases, cancer, injuries, strokes, and chronic lower respiratory diseases, according to the Centers for Disease Control and Prevention (CDC). These ailments and accidents are usually more drastic in third world countries, where health care systems aren’t fully developed yet.

But according to a new study published in The Lancet, researchers have found that premature mortality is dropping. In the study, 16 researchers from different countries examined mortality trends between 2000 and 2010, and found promising results: “We actually found that mortality is falling very rapidly,” lead researcher Ole Norheim, professor of global public health at the University of Bergen, Norway, said. Mortality was decreasing by one-third for children and one-sixth for adults under the age of 70 around the world. And in developing countries, where the risk of mortality is much higher due to lower standards of public health and sanitation, deaths declined by about 24 percent over the last ten years.

Researchers feel this is an encouraging trend: “I don’t think people realize how positive these trends are and how important this would be for health worldwide,” Norheim told TIME. “People’s probability of surviving up to the age of 70 is actually much, much better now, compared to 1970.” A number of improvements in public health care around the globe contributed to this decline, such as better maternal and infant care, improved preventive and combative measures against infectious diseases, and cleaner sanitation and water.

According to the CDC, up to 900,000 Americans die prematurely from the five leading causes of death, as shown below. The CDC also states, however, that up to 20-40 percent of these deaths could be prevented.

If this decreasing trend continues, Norheim and his research team claim, we might see a 40% decline in premature mortality over the next 20 years. In addition to improving things like poor sanitation and lack of healthcare for mothers and children in developing countries, targeting the obesity epidemic in the U.S. and “obese” countries could have a drastic impact on premature deaths caused by diabetes and heart disease. But Norheim believes that one particular thing could make the biggest difference: and that’s to curb the number of smokers out there. “If prices [of cigarettes] were doubled, that would reduce smoking by 1/3,” Norheim told TIME. “That would mean millions of lives saved.”