In terms of biological aging, the body seems to shift gears three times during our lifetime, research indicates from 2019 – with 34 years, 60 years and 78 years being the most important thresholds.
In other words, there is evidence that aging is not one long, continuous process that moves the same lifestyle.
The findings could help us understand more about how our bodies begin to break down as we age, and how specific age-related diseases – including Alzheimer’s or cardiovascular disease – can be better addressed.
The same study also presented a new way to reliably predict people’s ages using the protein levels (the proteome) in their blood.
“By deeply exploiting the aging of the plasma proteome, we have identified undulating changes during human life,” the researchers wrote in their paper, published in December 2019.
“These changes were due to clusters of proteins moving in different patterns, resulting in the emergence of three waves of aging.”
The team analyzed data from the blood plasma of 4,263 people aged 18 to 95, looked at the levels of about 3000 different proteins that move through these biological systems and as a screenshot of what is going on in the body: 1,379 of them were found to to vary with age.
Although these protein levels often remain relatively constant, the researchers found that large shifts occurred in the readings of multiple proteins around young adulthood (age 34), late middle age (60 years), and age (78 years).
Why and how this happens is not yet clear; but if the proteins can be traced back to their origin, it may enable a doctor to warn you, for example, that your liver is aging faster than the average person.
It also highlights the link between aging and the blood, something that has been noticed in previous studies.
“We have known for a long time that measuring certain proteins in the blood can give you information about a person’s health – lipoproteins for cardiovascular health, for example,” says neurologist Tony Wyss-Coray, of the Stanford Alzheimer’s Disease Research Center ( ADRC) at the time.
“But it’s not appreciated that so many different protein levels – about a third of all the amounts we looked at – change significantly with increasing age.”
The researchers were able to set up a system to use the mixture of 373 selected proteins in the blood to accurately predict someone’s age within about three years.
Interestingly, the topic was usually very healthy for the age as the system failed by predicting an age.
Another finding from the study provides more evidence for something that has long been suspected: men and women age differently. Of the 1,379 proteins found to change with age, 895 (nearly two-thirds) were significantly more predictable for one sex compared to the other.
These are still early findings – according to the researchers, clinical applications could still be five to ten years off – and it’s going to take a lot more work to figure out how all of these proteins are a sign of aging, and whether they actually contribute. to it.
Nevertheless, it increases the possibility that one day you may have a blood test that can measure how well you are aging, at least at the cellular level.
And the more we know about aging, the more we can do to counteract it. It can inform everything, from knowing what to drink and eat to a few years of life, to identifying treatments to prevent some of the worst age-related ones.
“Ideally, you want to know how virtually anything you have taken or done affects your physiological age,” Wyss-Coray said.
The research was published in Physical Medicine.
A version of this article was first published in December 2019.