SEATTLE -- How weight changes as individuals get older might be a clue to how long they'll live, according to new research that suggests that weight trajectories could serve as informative biomarkers of aging and longevity.
The study was presented on November 14 at the Gerontological Society of America (GSA) 2024 Annual Scientific Meeting.
Researchers at Duke University, Durham, North Carolina, analyzed weight trajectories of Framingham Heart Study participants over a 50-year period and compared those who lived beyond 95 (longevity group) with those who died before age 85 (conventional lifespan group). They also examined survival trajectories after age 80 on the basis of different maximum weight and weight decline slopes.
Individuals who lived past age 95 reached their highest weight around age 75, approximately 15 years later than those with conventional lifespans, the study found. Those who didn't live as long hit their peak weight around age 60. The long-lived group also lost weight more slowly after reaching their peak.
The findings suggest that weight patterns might show how well a body is aging, according to Svetlana V. Ukraintseva, PhD, professor in the Social Science Research Institute at Duke University, and the study's author.
"Body weight doesn't matter; what matters is when you reach the maximum peak, which becomes a marker of frailty and resilience," said Ukraintseva.
Maintaining weight or losing it slowly in the later years could be a sign that the body is holding up well against aging, said Ukraintseva.
"We see the same aging shift in human populations after World War II, which may indicate that we are aging a little bit slower than people in the past."
Both a later maximum weight and a flatter slope of weight decline significantly predicted better survival after age 80 and increased chances of extreme longevity, according to the study.
Previous studies involving mice have found a similar pattern, which prompted Ukraintseva and her team to study weight as a marker of biologic resilience. While more research is needed in humans, these findings could help clinicians assess another indication of who might live longer than a conventional lifespan and potentially develop ways to promote healthy aging.
"The optimal weight for survival may be different than in healthcare," said Ukraintseva. "If you look at cross-sectional data, you can't say what body weight is good or bad."
"We should look at trajectories and not just one snapshot of body weight," she said.
The findings also suggest that clinicians should reconsider biologic norms of what is considered a healthy weight for older adults.
Clinicians should counsel and help older adults before age 80 manage weight to protect against high-risk diseases for a conventional lifespan, according to Ukraintseva.
"But after age 80, specific diseases like cancer and cardiovascular disease risk declines and is less of a contributor to all-cause mortality," she said.
This doesn't mean individuals should try to gain weight as they get older. Instead, the research suggests that how a body naturally changes with age might give clues about overall health and potential lifespan.
"The same risk factors for diseases before age 80 can be a protective factor after age 85," she said. "After age 80, we should only consider interventions that keep them more biologically resilient."
The researchers had no financial conflicts to disclose.