Often, the Nobel Prize in Physiology or Medicine is given for work done years ago. So it went with this year’s award, to three American scientists who were just curious about how cells protect themselves when they divide. None of these scientists dreamed that their findings would have dramatic implications for the study of aging or cancer. They simply wanted to understand a basic phenomenon.

While all three are attached to U.S. research facilities, only one, Carol W. Greider, of Johns Hopkins University School of Medicine, is U.S.-born. Elizabeth H. Blackburn, of the University of California, San Francisco, came from Australia. Jack W. Szostak, at Massachusetts General Hospital, was born in London.

About 20 years ago, all three were experimenting with chromosomes. Chromosomes have protective structures at their ends, often likened to the tips of shoelaces, that get shorter each time a cell divides, until eventually the cell dies. The three researchers discovered an enzyme, telomerase, that thwarts the shortening process. Generally, it is active only at the outset of life, but it seems to be present when cancer cells proliferate. Telomerase’s discovery solved a basic biological puzzle, and changed the research template for a host of diseases as well as for many questions on aging.

Americans are used to dominating the Nobel in medicine. Yet U.S. students’ proficiency in math and science has been eroding, and fewer Americans are entering scientific fields. The cutting-edge research institutions here still attract top talent, but much of it is foreign-born. And the supply has slowed. Visa restrictions imposed after the 9/11 attacks have blocked many scientists from working here. Asia and Europe are proving more welcoming. Whether Americans will still lead in medical research 20 years from now is a real question.

If the federal government invests generously in basic research, the answer could be positive. It is also vital for the U.S. to boost math and science education, and to promote scientific careers.

It is encouraging that two women were among this year’s winners of the prize. (Only eight women had won it previously, and never two at once.) Their success signals some progress for women in science, and could well inspire more girls to enter scientific fields.

As the health-care debate continues, Americans are mindful of U.S. medicine’s great advances. But the system for delivering on those achievements falls woefully short. Many other nations can report better overall health outcomes. We look forward to the day when Americans can be as proud of their health-care system as of their researchers.