More and more people are living past age 100 and it’s all about healthy living— and genetics.

The Boston University School of Medicine New England Centenarian Study (NECS) has the largest collection of data on centenarians in the world. Since 1995, when the study started, the number of centenarians has gone from 1 per 10,000 people to 1 per 5,000 in the U.S. NECS has 130 subjects who are 110 years of age or older— a group known as supercentenarians.

“At any one time in the U.S., there are about 70 supercentenarians alive,” Dr. Thomas Perls, professor of medicine at Boston Medical Center and director of NECS, told FoxNews.com

So what makes these long-living adults special? While researchers found that people who reach 100 years of age do get age-related diseases, including heart disease, stroke, diabetes, cancer, hypertension and Alzheimer’s, they tend to manage these diseases much better than others. In other words, they find a way to live with these illnesses, rather than die from them.

“[Centenarians] compress their disability toward the end of their lives because they handle those diseases a lot better than other people who’ve died from them,” Perls said.

Supercentenarians  seem to spend, on average, only the last five years of life with any age-related disease.

Perls estimates that 70 percent  of the aging process can be attributed to health-related behaviors, while 30 percent is genetic.

“Most of us should be able to get to 90,” he said. “It’s a matter of us helping our genes, not fighting time. [We] shouldn’t smoke, drink, [we] should exercise regularly, avoid red meat, maybe be vegetarian, manage stress well.”

While healthy people may be able to live to 90, protective genes that slow down aging may be responsible for the extra-long lifespan of supercentenarians. Perls estimates that, for those over age 110, aging becomes 70 percent genetic and 30 percent environmental, in terms of protective factors.

Perls and his team have found that, while the majority of the population ages differently from one another, those who live very, very long lives are clinically alike and likely also genetically similar— and “incredibly rare.”

The group’s past research found that 130 genes seem to play a role in slowing aging. Understanding the biochemical pathways these genes affect may someday help scientists develop drugs that combat age-related diseases.

“Each gene by itself has a tiny effect, but as a group [they] can have a very big effect; it isn’t just one magical gene,” Perls said.

There are more female centenarians (85 percent) than male (15 percent), a difference Perls calls a double-edged sword. While more women live longer, they’re also more likely to have to live with age-related diseases and their disabilities. Men who live to extreme ages are less likely to be affected by disease, and therefore are typically more independent than women, he said.

As the baby boomer generation ages, the number of centenarians in the U.S. will continue to rise. Currently there are between 50,000 to 60,000 centenarians living in the U.S. – and that number is projected to grow to anywhere between 800,000 to 4 million for the year 2060.  Because supercentenarians are so rare, Perls estimates their population could double today’s, to about 120-140 in the year 2060.

“I think if we have a lot [of centenarians], it’s a marker of a relatively more healthy society, because people are aging and getting there primarily because of better health habits, better access to medical care, [and] better socioeconomic conditions that allow people to at least get through to their 80s,” Perls said. “And maybe, [with healthy lifestyle habits], some [of those people can] go on to 100 that otherwise wouldn’t have had the chance.”