NEW YORK, Aug 26: People experience rapid aging during two distinct periods in middle and later life, according to new research that underscores the "nonlinear" progression of aging.

A study from Stanford University has revealed that individuals age quickly during two specific phases: around age 44 and again at age 60. The study, published in Nature Aging, monitored the pace of molecular changes in 108 participants aged 25 to 75 over an average of 1.7 years.

While the study’s sample size is small, the findings have significant health implications, particularly as the risk of conditions such as cardiovascular disease, dementia, and Parkinson’s disease increases with age.

"We’re not just changing gradually over time; there are some really dramatic changes," stated Michael Snyder, director of the Center for Genomics and Personalized Medicine at Stanford University and the study’s senior author. "It turns out the mid-40s is a time of dramatic change, as is the early 60s."

The two periods of rapid aging were not identical. In the mid-40s, changes were observed in molecules related to cardiovascular disease, as well as lipid and alcohol metabolism, suggesting that the body's ability to process alcohol and fats declines after this age. In the early 60s, there was a "rapid decline" in immune regulation, potentially explaining why older individuals are more susceptible to illness.

Additionally, the study found that those aged 60 and older were more likely to develop kidney problems, type 2 diabetes, and cardiovascular disease.

These findings could help explain changes commonly seen in clinical practice, according to Mirko Petrovic, chair of the Department of Internal Medicine and Pediatrics at Ghent University and president of the European Geriatric Medicine Society, who was not involved in the study.

Initially, researchers suspected that the significant changes observed in the mid-40s might be linked to menopause or perimenopause. However, further analysis showed that these shifts occurred in both women and men.

The study also highlighted the role of lifestyle factors, such as alcohol and caffeine consumption and exercise, in driving these changes, rather than biological aging alone.

"A healthy lifestyle is very important for aging in general, and certain lifestyle interventions work better at certain ages," said Joris Deelen, research group leader at the Max Planck Institute for Biology of Aging in Germany, who was not involved in the study.

However, Deelen cautioned that it is unclear whether these shifts are inevitable or if they occur at the same rate in individuals with varying health levels. "We don't know how it would look, for example, for very healthy or very unhealthy people, or how different it would be," he added.

The findings align with previous research on the pathways of biological aging, including a 2019 study that identified another spike in aging around 80 years old.

"There is a huge level of interpersonal variability in old age," said Petrovic.

Understanding aging at the molecular level could enable clinicians to predict future health outcomes, make early diagnoses, and develop targeted prevention strategies.