In terms of biological aging, the body seems to change gears three times in our lifetime, research in 2019 suggests – 34 years, 60 years and 78 years being the key thresholds.
In other words, there is evidence that aging is not a long and continuous process that moves at the same rate throughout our lives.
The findings could help us understand more about how our bodies begin to break down with age and how age-specific diseases – including Alzheimer’s or cardiovascular disease – could be better addressed.
The same study also proposed a new way to reliably predict people’s ages using the levels of protein (proteome) in their blood.
“Through the profound exploitation of the aging plasma proteome, we have identified undulating changes during human life,” the researchers wrote in their paper, published in December 2019.
These changes were the result of groups of proteins moving in distinct patterns, culminating in the appearance of three waves of aging.
The team analyzed data from the blood plasma of 4,263 people between the ages of 18 and 95, analyzing the levels of about 3,000 different proteins that move through these biological systems and act as a snapshot of what is happening in the body. : of these, 1,379 were found to vary with age.
While these protein levels often remain relatively constant, the researchers found that there were large changes in the readings of several proteins around young adulthood (age 34), middle late age (age 34). 60 years) and advanced age (age 78).
Why and how this happens is not yet clear; but if the proteins can be traced back to their sources, they could allow a doctor, for example, to warn you that your liver is aging faster than an ordinary person’s.
It also emphasizes the link between aging and blood, which has been observed in previous studies.
“We’ve known for a long time that measuring certain proteins in your blood can give you information about a person’s health – lipoproteins for cardiovascular health, for example,” said neurologist Tony Wyss-Coray of Stanford Alzheimer’s Disease Research. Center (ADRC) at that time.
But it has not been estimated that so many different levels of protein – about a third of all that we have analyzed – change significantly with age.
The researchers were able to create a system by which the mixture of 373 selected proteins in the blood could be used to accurately predict one’s age in about three years or so.
Interestingly, when the system failed to predict too young an age, the subject was usually very healthy for their age.
Another finding from the study provides more evidence of something long suspected: men and women age differently. Of the 1,379 proteins that were shown to change with age, 895 (almost two-thirds) were significantly more predictive for one sex compared to the other.
These are still early findings – researchers say any clinical applications could still be five to 10 years free – and much more work will be needed to find out how all of these proteins are markers for aging and whether they whether or not it actually contributes to it.
However, it increases the possibility that one day you will have a blood test that could 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. This could inform everything from knowing what to drink and eat to potentially add to a few years of life, to identifying treatments to prevent some of the worst age-related conditions.
“Ideally, you want to know how virtually anything you’ve taken or done affects your physiological age,” Wyss-Coray said.
The research was published in Nature medicine.
A version of this article was first published in December 2019.