The aging process isn’t a steady decline, but rather appears to occur in two distinct phases marked by rapid change, according to a recent study published in Nature Aging. Understanding these shifts could lead to more targeted strategies for preventing age-related illnesses.
Researchers at Stanford University followed 108 adults over several years, collecting regular biological samples to track changes at a molecular level. The study, which analyzed over 246 billion data points across 135,239 biological characteristics – including RNA, proteins, lipids, and gut/skin/oral/nasal microbiome types – revealed that significant transformations occur around the mid-40s and early 60s.
“We don’t just gradually change,” said geneticist Michael Snyder of Stanford University. “Notice really dramatic shifts at specific stages of life.”
Approximately 81% of the molecules studied showed noticeable changes during one or both of these periods. In the mid-40s, researchers observed alterations in the metabolism of fats, caffeine, and alcohol, as well as changes related to cardiovascular health, skin, and muscle function. The early 60s brought shifts linked to carbohydrate metabolism, immune function, kidney function, and again, skin and muscle health, and cardiovascular disease.
The changes observed around age 44 partially coincide with the pre-menopausal stage in women, but the study found these shifts also occur in men, suggesting broader underlying factors are at play. These findings suggest that the molecular changes driving aging are not solely tied to hormonal shifts.
Researchers acknowledge that the sample size is relatively minor and emphasize the need for larger, more comprehensive studies to fully understand how the human body changes throughout life and to pinpoint the key drivers of these sudden aging shifts. The study’s findings could pave the way for more personalized approaches to healthcare and preventative medicine, allowing for interventions tailored to specific stages of life.
