People age quickly in two bursts during middle and later life, according to new research that highlights the "nonlinear" timeline of ageing.
ADVERTISEMENTOur biological and chronological clocks may not be quite in sync, according to a new study from Stanford University that found that people age rapidly in at least two spurts: once at age 44, and again at age 60.
The study, which was published in the journal Nature Aging, tracked the pace of molecular change for 108 people aged 25 to 75 over a median of 1.7 years.
While it’s a small sample, the findings have serious health implications, given the risk of cardiovascular disease, dementia, Parkinson’s, and other problems increases with age.
"We’re not just changing gradually over time; there are some really dramatic changes," Michael Snyder, director of the Center for Genomics and Personalized Medicine at Stanford University and the study’s senior author, said in a statement.
"It turns out the mid-40s is a time of dramatic change, as is the early 60s".
Those two periods weren’t exactly alike. For example, around the participants’ mid-40s, there were changes in molecules related to cardiovascular disease and lipid and alcohol metabolism, suggesting people’s bodies break down alcohol and fats less efficiently once they reach this age.
Meanwhile, in their early 60s, there was a "rapid decline" in immune regulation, which could help explain why older individuals are more vulnerable to illness.
The researchers also found people aged 60 and up were more prone to kidney problems, type 2 diabetes, and cardiovascular disease.
Ageing shifts in both men and women
The findings could help "clarify changes that we see in everyday life in the clinic," Mirko Petrovic, chair of the department of internal medicine and paediatrics at Ghent University and president of the European Geriatric Medicine Society, told Euronews Health. He was not involved with the study.
Researchers first thought that the drastic changes in the mid-40s could be related to menopause or perimenopause, but when they broke out the data, they found that these shifts occurred for both women and men.
Notably, the study said that lifestyle factors – such as alcohol and caffeine intake and exercise levels – could be driving the changes, rather than ageing-related biological shifts alone.
"Healthy lifestyle is very important for ageing in general [and] certain lifestyle interventions work better at certain ages," Joris Deelen, research group leader at the Max Planck Institute for Biology of Ageing in Germany, told Euronews Health.
Yet it’s also not clear how inevitable these shifts are, or whether they happen at the same pace for people with different levels of health, according to Deelen, who was not involved with the study.
"We don't know how it would look, for example, for very healthy or very unhealthy people, or how different it would be," Deelen said.
The new findings are in line with previous research on the pathways of biological ageing, including a 2019 study that identified another spike around 80 years old.
ADVERTISEMENT"There is a huge level of interpersonal variability at old age," Petrovic said.
A deeper understanding of how people age at the molecular level could help clinicians "to predict what is going to happen, to make an early diagnosis, and also based on that, to organise or to prepare prevention strategies".
