Stress can cause physical impacts to the body, such as increased heart rate and blood pressure, the release of adrenaline and cortisol (肾上腺素和皮质醇). If adrenaline and cortisol levels are increased for an extended period of time, that can damage DNA and cells.
In a new paper, published in April in the journal Cell Metabolism, researchers described how they measured biological age by looking for changes in DNA’s structure connected to aging.
In the first stage of the research, the researchers surgically attached three-month-old mice to twenty-month-old mice so that blood could flow between them. Over three months, the biological age of the younger mice increased while they shared blood with the older mice. But after the younger mice were separated and allowed to recover for two months, their biological age fell once again.
Then, the researchers looked at human DNA from blood samples gathered in previous studies to measure how human bodies react to stress.
In one stage, the researchers examined blood samples from elderly patients. Patients who had received emergency surgery for a fractured hip (髋部骨折) had an increased biological age the morning after the procedure, but it returned to pre-surgery levels four to seven days later. However, the researchers did not find the same effect in patients who had undergone elective hip surgery or colorectal (结肠直肠的) surgery.
The team also looked at patients who had been hospitalized with Covid-19, but these results varied by sex. While the biological age of female patients dropped within two weeks of recovery, that of men did not.
“The study looked at biological age both before and after stressful events. There are just very, very few studies that have looked at these clocks before and after some kind of intervention (干预),” Daniel Belsky, a medical scientist at Columbia University who did not participate in the study, tells The Scientist.
The study shows that biological age is “much more dynamic than people previously thought,” Jesse Poganik, a co-author of the study, tells Live Science. “You can have these very severe stress events, which increase biological age, but it can be short-lived, if the stress is short-lived, then the age can be restored.”
【小题1】What did the researchers find about the biological age of the younger mice?| A．It increased during blood sharing. |
| B．It could be restored by blood sharing. |
| C．It dropped when they were attached to the older mice. |
| D．It returned to pre-sharing levels as soon as they were separated. |
| A．Those who had had fractured hip surgery. |
| B．Those who had received colorectal surgery. |
| C．Those who had undergone elective hip surgery. |
| D．Those women who had been hospitalized with Covid-19. |
| A．It stands out in similar studies. | B．It is truly remarkable. |
| C．It has some limitations. | D．It is influential. |
| A．Biological age can be measured easily |
| B．Recovering from stress is a long process |
| C．Stress ages you with not permanent effect |
| D．Stress’ harming human bodies means protecting them well |
