April 25, 2023 – Measuring biological aging has become so precise with DNA-based technology that researchers have shown that trauma or stressful life events can rapidly accelerate the rate of aging. But they also found that recovery after the experience could return aging to its original level.
This is one of the first studies to show that aging doesn’t have to happen in one direction. It may be too early to shred your AARP membership card, but the evidence from mice and humans looks promising.
“People just assumed that when you get older, your biological age goes with it. And that’s true, but there are variations,” said James Patrick White, PhD, co-senior author of the study and assistant professor of medicine at Durham University in the US.
Although we all go through stressful events, its effects on aging can change rapidly.
“You may be stressed, you may have some trauma, you may have whatever your stressor is that is accelerating. [your aging]said White, who is also a senior fellow at Duke’s Center for the Study of Aging.
“The question has always been. Well, you’re stuck there. And we show that this is not the case. You can bounce back a little bit once that stressor is removed,” he said.
It study Published online April 21 in the journal Cellular metabolism.
Turning back the clock
White, co-senior author, Ph.D. Vadim N. Gladyshev and colleagues found that pregnancy, breaking a hip, and having severe COVID are traumatic or stressful enough to accelerate aging. In contrast, elective surgery did not accelerate aging in the short term.
The idea that aging is not a one-way street comes in part from experiments in mice. Pairing two mice, one young and one old, together so that they have the same blood circulation is a technique called parabiosis. The technique has been around for decades. But now “what’s new here is that we’re showing epigenetic acceleration. A young mouse grows old, an old mouse grows young. And the most interesting thing is that when we then separate the mice and take the old blood, the young mouse reverses it. accelerated aging toward his chronological age,” White said.
The research was made possible by advances in the measurement of DNA methylation. Investigators can now look at individual DNA sites where methylation occurs predictably over time. The sensitivity of these second-generation “DNA methylation clocks” has increased to the point that they can show biological aging changes measured in days or weeks.
White and colleagues used blood samples from elderly patients before emergency hip surgery, the morning after, and 4 to 7 days after recovery. They found a significant increase in biological age markers. “Remarkably, this increase occurred within 24 hours, and biological age returned to baseline 4-7 days after surgery,” the researchers noted.
They found that there were no significant changes in biological age markers associated with elective colorectal surgery in other patients.
Not all stress is the same
In general, the aging process in humans returns to its normal baseline after the stressor is removed. But there can be differences between people, with some fully returning to their previous chronological age, some only partially, and others not at all.
“That opens up the question of ‘Why?'” White said.
As an example, when they compared people who had recovered from severe COVID, aging tended to recover more among women than among men. The cause is unknown and will be investigated in future studies.
Flexibility is also important.
“I would imagine that if you can’t deal with something and the stress continues, you’re going to accelerate biological aging and open yourself up to age-related problems, probably sooner than anyone who can recover,” White said.
Another unknown is whether psychological and physical stress contribute equally to this acceleration of aging.
Aging is not a ‘relentless decline’
“I see it as progress,” said Florence Committee, MD, a Yale-trained precision medicine physician and founder of the Committee Center for Precision Medicine and Health in New York, when asked for comment.
“I myself have always believed that aging does not occur in a steady state of decline,” he said. There are many issues that occur beneath the surface, he continued, including changes in muscle, hormones, metabolism and how the body internalizes fat in various organ systems. Family history and genetics can also alter aging.
The committee thinks of aging “more as a stop/start … rather than a steady, unrelenting decline.”
“I think this will give us an opportunity to dig deeper,” he said. “It’s just going to be the beginning of opening up the field.”
Co-author of the committee A 2022 study that looked at DNA methylation and COVID. The results showed that people over the age of 50 were more likely to experience faster biological aging with COVID than younger people.
Overall, the conclusion that people can reverse the negative effects of stress or trauma is positive.
“We have a lot more reserve than we think we have or think we deserve,” White said.
Interventions to turn off accelerated aging related to stress or trauma are likely to work for people with chronic disease, chronic disease sequelae, serious infections like COVID, or even cancer. But they are unlikely to help people dealing with the general stress of everyday life, he said.
In the future, the technology could also be used to see how well anti-aging drugs work.