A new study by researchers at the Yale School of Public Health found that nearly half of adult Americans aged 65 and older were able to improve their cognitive and physical health over time.

The research revealed that the improvements were not limited to a select group of individuals but were, instead, rather common.

“Many people equate aging with an inevitable and continuous loss of physical and cognitive abilities,” said lead author Becca Levy, an international expert on psychosocial determinants of aging health. “What we found is that improvement in later life is not rare, it’s common, and it should be included in our understanding of the aging process.”

According to a news release from the Yale School of Public Health, the researchers followed more than 11,000 participants in the Health and Retirement Study, a federally supported longitudinal survey of older Americans. The team tracked changes in cognition using a global performance assessment and physical function using walking speed, a measure often described by geriatricians as a “vital sign” because of its strong links to disability, hospitalization, and mortality.

Over a follow-up period of up to 12 years, 45% of participants improved in at least one of the two domains. About 32% improved cognitively, while 28% improved physically, and many of those gains exceeded thresholds considered clinically meaningful.

The authors also found that participants who held more positive beliefs about aging at the start of the study were significantly more likely to show improvement, even after accounting for factors such as age, sex, education, depression, chronic disease burden, and length of follow-up.

Levy said the findings can be missed when researchers focus only on averages. While averages may show decline across a population, individual trajectories reveal that a meaningful share of older adults improve over time.

The findings are published in the journal Geriatrics.

“Our findings suggest there is often a reserve capacity for improvement in later life,” she said. “And because age beliefs are modifiable, this opens the door to interventions at both the individual and societal level.”

Previous research conducted by Levy at Yale found that adopting positive beliefs about getting older can extend your life expectancy by up to 7.5 years. This is a greater survival advantage than maintaining low blood pressure or avoiding smoking.