As human longevity increases, so does scrutiny of why some of us enjoy longer, healthier lives.
The New England Centenarian Study (NECS), begun in 1995 at Harvard University and based at Boston University since 2002, studies centenarians and their family members for answers to longevity, but with a different slant.
“We are not studying disease, we are studying the absence of disease,’’ says Stacy Andersen, PhD who, with Tom Perls, MD, is co-director of the NECS.
Among its most recent findings, the NECS has found that exceptional longevity runs strongly in families.
“Your chances of living to 100 increases by eight to 17 times if you have a sibling who reached 100,’’ says Andersen, an assistant professor of medicine at Boston University. The NECS is based at Boston University’s Chobanian and Avedisian School of Medicine.
According to the CDC, as of 2022, the average lifespan was 80.2 for American women and 74.8 for American men.
NECS studies answer the old nurture versus nature argument; but as time passes, the argument takes a surprising turn. Healthy living accounts for about 70% of longevity until one’s 90s.
“The average longevity (living to one’s 90s) is mostly attributed to favorable health habits, behaviors, and environment and only about 30% is due to favorable genetics,” Andersen says. “However, living to the most extreme ages (age 105+ years) appears to be due to the reverse; about 70% good genetics and 30% good health habits and environment.’’
The Female Advantage
It helps if you are female, up to a point. Eighty-five percent of centenarians are women (15% are men). Women account for 90% of supercentenarians, those who live to 110+. A separate study of supercentenarians is part of the NECS.
Andersen says that although women are better at handling age-related diseases than men —men are at higher risk to die from these diseases — males who survive to very old age (100+) are in better health than women.
For why the genders age differently, NECS researchers are looking at a phenomenon known as antagonistic pleiotropy, in which what was good for young humans (testosterone, fertility) can cause illness in the aged.
She says a study of Seventh-day Adventist church members at Loma Linda University is a good example of nurture over nature: The group’s average age expectancy is 86 for men and 89 for women, eight to 10 years longer than the rest of the population. Adventists tend to be vegetarian, don’t smoke, regularly exercise, and spend a lot of time with their families and with their religion.
Psychological Factors
And then there is the ephemeral. Andersen says that among the centenarians enrolled in the NECS, longevity also springs from the psychological benefit of having purpose, goals, kinship with friends and family, and challenges to the brain. The NECS-enrolled centenarians tend to be extroverts, outgoing and positive, she said.
“Looking at the psychological profile of our centenarians, we found that although they lived through a lot of difficult times — like the Great Depression — and lost family members, they are able to efficiently deal with these situations, process them and move forward. They appreciate every day,’’ Andersen says.
Moreover, offspring of centenarians rated higher than the general population about having purpose in life, feeling they have goals and knowing what they want to accomplish, the NECS found.
Centenarians Have Less Money
For some more information, Anderson suggested that we look at the most recent U.S. Census Bureau report on centenarians, released in 2014. It compared the characteristics of the nation’s 55,000 centenarians those of the 40 million people ages 65 years and older. According to the report, 17% of centenarians lived below the poverty line, versus 9% of the 65-and-older population.
It’s likely that many centenarians have simply outlived their money over the years. But some other findings revealed in the report may also contribute to this poverty-line gap. For example, centenarians were less likely to receive Social Security income (83%) than the 65-and-older group (88%). Centenarians were also less likely to receive retirement income (24%) than the 65-and-older population (38%).
The report also found centenarians were less likely to have at least a high school diploma (57%, vs. 77% for the 65-and-up crowd) and less likely to be married. Just 3% of women centenarians were married, compared with 41% of women 65 and older. Among men, 23% of centenarians were married, versus 71% of men 65 and older.
Race and Housing Stats May Surprise
Longevity also is reported based on race and ethnicity. According to CDC period table statistics from 2018, 2.5% of White girls and 0.9% of White boys at birth will live to 100 in the United States. But although Blacks Americans have a shorter life expectancy, 3.2% of Black girls and 1.1% of Black boys will live to 100. For Hispanics, 5.6% of girls and 2.2% of boys will live to 100, the CDC reports. The NECS references these statistics on its website.
Andersen said that of the NECS participants, 60% live alone, 28% with a child or other family member, and 6%, each, with either a spouse or a hired caregiver. Fifty-percent of these centenarians live in their own home/townhome, 30% in an apartment, 14% in assisted living, and 3% in a nursing home.
“However, this is not representative of centenarians in the general population because those who volunteer for studies tend to be healthier on average,’’ Andersen says.
Foods and Genes
NECS findings say that centenarian participants tend to eat the same diet as the general population, leading Andersen and her colleagues to consider this:
“It’s not only what you eat, but also how your body processes what you eat,’’ she says.
NECS has begun more intensive research into the diets of participating centenarians, looking at how often they eat each food group weekly, and studying stool samples and scans and tissue studies of brain matter from deceased members of the study.
Andersen says she and her colleagues have been surprised at and grateful for the number of participants and family members willing, at death, to donate their brains.
The recent findings also indicate that centenarians have as many disease-related genetic variants as the average population, but they have genetic advantages likely due to variants that slow aging and decrease the risk for aging-related diseases. This includes heart disease, stroke, cancer, diabetes and Alzheimer’s disease.
Cognitive Impairment: a 50/50 Chance
The latest centenarian mortality report from the CDC, taken in 2014 and updated in 2016, said the top five causes of death among those 100 and older are heart disease, Alzheimer’s disease, stroke, cancer and influenza and pneumonia.
Andersen says the NECS has found that half of participating centenarians have cognitive impairment but deal with it, and the other half never have cognitive impairment. She says that advanced age is the number one risk factor for developing Alzheimer’s disease.
“NECS aims to flip most studies done on the elderly; we’re studying how to completely avoid having to deal with Alzheimer’s,’’ she says.
To advance knowledge of attaining healthy old age, NECS disseminates its findings in medical and science journals, and by giving talks to physicians, researchers and community groups.
Cognitive testing of centenarian participants is done at NECS imaging/MRI centers in Boston, Atlanta, New York and Los Angeles, or by Zoom, Andersen says.
The Big Picture
The New England Centenarian Study includes four studies of exceptional longevity that are funded by the National Institute on Aging (NIA), an institute of the National Institutes of Health (NIH). Andersen and Perls lead the Resilience/Resistance Against Alzheimer’s Disease in Centenarians and Offspring project. That study’s goal is to define resistance and resilience to cognitive decline and Alzheimer’s, in order to discover the biology that enables centenarians to maintain cognitive function similar to those 30 years younger. From that data the aim is to devise preventive strategies and medications.
Andersen, 45, began her work with the NECS as a college intern 25 years ago.
“The work has really changed my view of aging, which I see as a really great opportunity to reflect upon what you have been through, and to still be engaged in life, completely.’’
Eleanor O’Sullivan is a writer for Rethinking65. In a four-decade career in journalism, she has reviewed many books on best practices for financial advisors.