Fight Aging!

Physiological and other forms of stress are known to affect the immune system. Epigenetic age measured from a blood sample is an assessment of immune cells, not the organism as a whole. One might expect any sort of stress put on the immune system to alter measures of epigenetic age conducted on blood samples, but quite different results might emerge from an assessment of epigenetic age conducted on tissue biopsies.

This study used DNA methylation (DNAm)-based aging clocks to measure changes in biological age in response to diverse forms of stress. The researchers began with a laboratory experiment known to produce aged physiology in young mice or restore youthful physiology to old mice by surgically joining young, 3-month-old mice with older, 20-month-old mice, which allowed them to share their blood. At the molecular level, they found that the biological age of the young mice increased when measured with most aging clocks. Once the young mice were separated from the old mice and therefore were no longer experiencing the older mouse physiology, their biological age returned to youthful levels. This finding suggested that biological age is malleable and potentially reversible, and these changes are reported by DNAm aging clocks.

Next, the researchers examined blood samples from people who had recently experienced stressful situations, including surgery (emergency versus elective), pregnancy, or severe COVID-19. Analysis of blood samples from patients who underwent emergency surgery showed their biological age increased the morning after surgery and returned to pre-surgery levels four to seven days later. Elective surgeries, on the other hand, had less impact on biological age, which the authors attribute to pre-operative regimens known to aide recovery. Pregnancy in both mice and humans led to increased biological age at delivery, which reverted to lower biological age following delivery and recovery.

Link: https://www.nia.nih.gov/news/stress-induced-increases-biological-age-are-reversible