A growing body of research suggests that chronic illness is not an inevitable consequence of aging, but more often the result of lifestyle choices. "People used to say, ’who would want to be 100" says Dr. Thomas Perls, an instructor at Harvard Medical School and director of the New England Centenarian Study. "Now they’re realizing it’s an opportunity." High-tech medicine isn’t likely to change the outlook dramatically; drugs and surgery can do only so much to sustain a body once it starts to fail. But there is no question we can lengthen our lives while shortening our deaths. The tools already exist, and they’re within virtually everyone’s reach. Life expectancy in the United States has nearly doubled since a century ago—from 47 years to 76 years. And though centenarians are still rare, they now constitute the fastest growing segment of the U.S. population. Their ranks have increased 16-fold over the past six decades from 3,700 in 1940 to roughly 61,000 today. The Census Bureau projects that 1 in 9 baby boomers (9 million of the 80 million people born between 1946 and 1964) will survive into their late 90s, and that 1 in 26 (or 3 million) will reach 100. "A century ago, the odds of living that long were about one in 500," says Lynn Adler, founder of the National Centenarian Awareness Project and the author of "Centenarians: The Bonus Years." "That’s how, far we’ve come." If decrepitude were an inevitable part of aging, these burgeoning numbers would spell trouble. But the evidence suggests that Americans are living better, as well as longer. The disability rate among people older than 65 has fallen steadily since the early 1980s, according to Duke University demographer Kenneth Manton, and a shrinking percentage of seniors are plagued by hypertension, arteriosclerosis and dementia. Moreover, researchers have found that the oldest of the old often enjoy better health than people in their 70s. The 79 centenarians in Perls’s New England study have all lived independently through their early 90s, taking an average of just one medication. And when the time comes for these hearty souls to die, they don’t linger. In a 1995 study, James Lubitz of the Health Care Financing Administration calculated that medical expenditures for the last two years of life— statistically the most expensive—average ＄ 22,600 for people who die at 70, but just $ 8,300 for those who make it past 100. These insights have spawned a revolution in the science of aging. "Until recently, there was so much preoccupation with diseases that little work was done on the characteristics that permit people to do well," says Dr. John Rowe, the New York geriatrician who heads the MacArthur Foundation’s Research Network on Successful Aging. Research confirms the old saying that it pays to choose your parents well. But the way we age depends less on who we are than on how we live what we eat, how much we exercise and how we employ our minds. People past 100 can be described as all of the following EXCEPT that ______.