Study: Your body’s cells age rapidly in just a day

Researchers have recently questioned the accuracy of determining the biological age of cells by measuring epigenetic modifications. Traditionally, the biological age has been estimated by tallying these changes, which act like “genetic switches” affecting protein production based on the genetic code without altering the code itself. However, new findings suggest that these modifications can vary significantly throughout the day, casting doubt on the reliability of single-sample tests.

In a study observing multiple blood samples from a 52-year-old man over a 72-hour period, scientists analyzed 17 different epigenetic clocks within the white blood cells of each sample. They discovered substantial fluctuations in 13 of the clocks, with cells appearing “younger” in the early morning and “older” around midday, showing changes akin to about 5.5 years. This indicates that the timing of sample collection can dramatically impact the perceived biological age.

The research, led by statistician Karolis Koncevičius and colleagues at Vilnius University, highlights that most aging studies using epigenetic clocks have relied on whole blood samples. They noted that the composition of white blood cells changes cyclically over a 24-hour period, which might explain the variations observed in cellular age.

Further investigation involving multiple blood samples from a small group over five hours showed similar age variations, reinforcing the hypothesis that different types of white blood cells present at various times influence these results.

The study suggests that for a more accurate assessment of cellular age and associated risks of age-related diseases, it may be necessary to collect multiple samples at different times of the day. This approach would provide a broader understanding of an individual’s epigenetic age range and potentially lead to more precise health prognostics.