(Michelle Starr’s post from the SCIENCE ALERT on 28 July 2025.)
Study Reveals Turning Point
When Your Body's Aging Accelerates: The passage of time may be linear, but
the course of human aging is not. Rather than a gradual transition, your life
staggers and lurches through the rapid growth of childhood, the plateau of
early adulthood, to an acceleration in aging as the decades progress.
Now, a new study has identified a turning point at
which that acceleration typically takes place: at around age 50. After this
time, the trajectory at which your tissues and organs age is steeper than the
decades preceding, according to a study of proteins in human bodies across a
wide range of adult ages – and your veins are among the fastest to decline.
"Based on aging-associated protein changes, we developed tissue-specific proteomic age clocks and characterized organ-level aging trajectories. Temporal analysis revealed an aging inflection around age 50, with blood vessels being a tissue that ages early and is markedly susceptible to aging," writes a team led by scientists from the Chinese Academy of Sciences. "Together, our findings lay the groundwork for a systems-level understanding of human aging through the lens of proteins."
Humans have a remarkably long lifespan compared to
most other mammals, but it comes at some costs. One is a decline in organ
function, leading to a rise in risk of chronic disease as the years mount up.
We don't have a very good understanding of the
patterns of aging in individual organs, so the researchers investigated how
proteins in different tissues change over time. They collected tissue samples
from a total of 76 organ donors between the ages of 14 and 68 who had died of
accidental traumatic brain injury.
These samples covered seven of the body's systems:
cardiovascular (heart and aorta), digestive (liver, pancreas, and intestine),
immune (spleen and lymph node), endocrine (adrenal gland and white adipose),
respiratory (lung), integumentary (skin), and musculoskeletal (muscle). They
also took blood samples.
The team constructed a catalogue of the proteins found in these systems, taking careful note of how their levels changed as the ages of the donors increased. The researchers compared their findings to a database of diseases and their associated genes, and found that expressions of 48 disease-related proteins increased with age. These included cardiovascular conditions, tissue fibrosis, fatty liver disease, and liver-related tumors.
The most stark changes occurred between the ages of
45 and 55, the researchers found. It's at this point that many tissues undergo
substantial proteomic remodeling, with the most marked changes occurring in the
aorta – demonstrating a strong susceptibility to aging. The pancreas and spleen
also showed sustained change.
Study Reveals Turning Point When Your Body's Aging
Suddenly Accelerates: To test their findings, the researchers isolated a
protein associated with aging in the aortas of mice, and injected it into young
mice to observe the results. Test animals treated with the protein had reduced
physical performance, decreased grip strength, lower endurance, and lower
balance and coordination compared to non-treated mice. They also had prominent
markers of vascular aging.
Previous work by other researchers showed another two peaks in aging, at around 44, and again at around 60. The new result suggests that human aging is a complicated, step-wise process involving different systems. Working out how aging is going to affect specific parts of the body at specific times could help develop medical interventions to make the process easier.
"Our study is poised to construct a
comprehensive multi-tissue proteomic atlas spanning 50 years of the entire
human aging process, elucidating the mechanisms behind proteostasis imbalance
in aged organs and revealing both universal and tissue-specific aging
patterns," the researchers write. "These insights may facilitate the
development of targeted interventions for aging and age-related diseases,
paving the way to improve the health of older adults."
