Aging can feel like a gradual journey, but research indicates that it’s actually more complex than that.
If you’ve ever woken up and looked in the mirror, wondering if aging has sped up, you’re not alone in those thoughts.
A 2024 study on the molecular aspects of aging reveals that humans undergo two significant shifts, typically around the ages of 44 and 60.
According to geneticist Michael Snyder from Stanford University, who shared insights when the findings were published, “We don’t just change over time; some changes are quite dramatic.”
He elaborated, stating that the mid-40s and early 60s are pivotal periods, regardless of the molecular class being examined.
For a quick overview of the study’s results, you might want to check out the video below:
Aging is not just a matter of time; it’s also tied to a higher risk of various diseases.
In their research, Snyder and his team explored the biology behind aging to understand these transformations better, which could help manage and treat related diseases.
The team monitored 108 adults who provided biological samples over several years.
They observed that the risk for some conditions, like Alzheimer’s and cardiovascular disease, tends to spike sharply at certain ages rather than increase gradually.
This prompted them to further investigate the biomarkers related to aging for identifiable changes.
By utilizing the participant samples, the researchers assessed various biomolecules, including RNA, proteins, lipids, and microbiota from numerous areas of the body, creating a dataset of 135,239 biological features.
On average, each participant provided 47 samples over a period of 626 days, with the longest one contributing 367 samples. This resulted in over 246 billion data points, which the research team analyzed for patterns.
Prior studies also observed non-linear trends in molecular compositions linked with aging in both rats and humans.
Research on other species like fruit flies, mice, and zebrafish also suggests a stepwise aging mechanism.
Snyder and his collaborators found that around 81% of the molecules they analyzed exhibited changes at these two key stages. The transformations tend to peak in the mid-40s and again in the early 60s, albeit with different profiles.
The mid-40s peak revealed changes in molecular processes related to lipid metabolism, caffeine, and alcohol, along with issues pertaining to cardiovascular health and skin and muscle function.
In contrast, the early 60s peak was linked to changes in carbohydrate and caffeine metabolism, cardiovascular conditions, skin and muscle, immune function, and kidney health.
During the mid-40s, women generally experience menopause or perimenopause, but the researchers ruled this out as a primary cause of these changes, noting that men also showed significant molecular alterations at this stage.
This finding suggests that while menopause might play a role in women’s changes, there are likely other influential factors affecting both genders, as explained by Xiaotao Shen, a metabolomicist previously at Stanford, now at Nanyang Technological University in Singapore.
She added, “Determining and examining these elements should be a focus for future studies.”
The researchers acknowledge that their sample size is relatively small and that they only included biological samples from individuals aged 25 to 70.
Future investigations could further explore this phenomenon, taking a more detailed look across a broader demographic to understand how human bodies evolve over time.
The results were published in Nature Aging.
A prior version of this article appeared in August 2024.
