WASHINGTON — It’s starting to get crowded in the 100-year-olds’ club.
Once virtually nonexistent, the world’s population of centenarians is projected to reach nearly 6 million by midcentury.
That’s pushing the median age toward 50 in many developed nations and challenging views of what it means to be old and middle-aged.
The number of centenarians already has jumped from an estimated few thousand in 1950 to more than 340,000 worldwide today, with the highest concentrations in the U.S. and Japan, according to the latest Census Bureau figures and a report being released today by the National Institute on Aging.
Their numbers are projected to grow at more than 20 times the rates of the total population by 2050, making them the fastest growing age segment. Demographers attribute booming long-livers to decades of medical advances and improved diets. Genetics and lifestyle also play a factor. So, too, do doctors who are more willing to aggressively treat the health problems of people once considered too old for such care.



