April 25, 2023 – Measuring biological aging has turn out to be so precise with DNA-based technology that researchers have shown that trauma or stressful life events can rapidly speed up the aging process. But additionally they found that recovering from these experiences can return the aging process to its baseline.
This is considered one of the primary studies to point out that aging doesn't necessarily go in a single direction. It could also be too early to tear up your AARP membership card, however the leads to mice and humans look promising.
“People just assumed that biological age increases with age. And that's true, but there are variations,” said Dr. James Patrick White, co-author of the study and assistant professor of medication at Duke University in Durham, North Carolina.
Although all of us experience stressful events, their impact on the aging process can change quickly.
“Maybe you’re stressed, maybe you’ve had trauma, maybe you have a stressor that’s accelerating this. [your aging]” said White, who is also a senior fellow at the Center for the Study of Aging at Duke.
“The question was always: Are you stuck there? And we show that's not the case. You can go back a little bit if the stressor is removed,” he said.
The study was published online in the journal on April 21 Cell metabolism.
Turn back the time
White, co-senior author Vadim N. Gladyshev, PhD, and their colleagues found that pregnancy, hip fracture, and severe COVID illness were traumatic or stressful enough to accelerate aging. In contrast, planned surgery did not accelerate aging in the short term.
The idea that aging is a two-way street comes in part from experiments with mice. Putting two mice together – one young and one old – so they share the same bloodstream is a technique called parabiosis. This technique has been around for decades. But now “the novel thing is that we're showing epigenetic acceleration. The young mouse is getting older, the old mouse is getting younger. And the cool thing is that when we then separate the mice and remove the old blood, the young mouse will return this accelerated aging to its chronological age,” White said.
The research was possible because of advances in measuring DNA methylation. Researchers can now look at individual sites on DNA where predictable methylation occurs over time. The sensitivity of these second-generation “DNA methylation clocks” has increased to the point where they can measure changes in biological aging within days or weeks.
White and his colleagues used blood samples from elderly patients before emergency hip surgery, the morning after, and after four to seven days of recovery. They found a significant increase in biological age markers. “Notably, this increase occurred in less than 24 hours, and biological age returned to baseline four to seven days after surgery,” the researchers noted.
They found that other patients did not experience significant changes in biological age markers associated with elective colorectal surgery.
Stress is not the same as stress
In general, the aging process in humans returns to its normal baseline after a stressor is removed. However, there may be differences between people: some fully return to their previous chronological age, some only partially, and others not at all.
“That begs the question, 'Why?'” White said.
For example, when they compared people who had recovered from severe COVID, they showed that women tended to age more than men. The reason for this is unknown and could be investigated in future studies.
Resilience also counts.
“I would imagine that if you can't cope with something and the stress continues, you're likely to accelerate biological aging and expose yourself to age-related problems more than someone who can recover,” White said.
It is also unknown whether psychological and physical stress contribute equally to this accelerated aging.
Aging is not a “continuous decline”
“I consider this a breakthrough,” said Dr. Florence Comite, a Yale-trained precision medicine physician and founder of the Comite Center for Precision Medicine & Health in New York City, when asked for comment.
“I actually have all the time believed that aging will not be a gradual decline,” she said. There are many things going on beneath the surface, she continued, including changes in muscles, hormones, metabolism and the way the body stores visceral fat in various organ systems. Family history and genetics can also influence aging.
Comite views aging as “a kind of start-stop process… rather than a steady, uninterrupted decline.”
“I feel this offers us the chance to dig deeper,” she said. “It's just the start of opening up the sector.”
Comite is co-author of a Study 2022 that checked out DNA methylation and COVID. The results showed that folks over 50 with COVID usually tend to experience faster biological aging than younger people.
Overall, the finding that folks can reverse the negative effects of stress or trauma is positive.
“We have much more reserves than we think or believe,” White said.
Interventions to show off the accelerated aging related to stress or trauma could be almost definitely to work for individuals with chronic diseases, chronic disease sequelae, severe infections like COVID and even cancer, Comite said. But they probably wouldn't help people battling the final stress of on a regular basis life, she said.
In the longer term, the technology may be used to check the effectiveness of anti-aging drugs.