New study reveals that your body's cells age rapidly within a day

Researchers recently found that calculating the biological age of our cells and tissue by adding up epigenetic modifications might not be the correct way.

Our cells carry a genetic code that guides the production of proteins vital for survival. Over time and through challenges, small changes are made, acting as 'genetic switches' that influence how cells follow these instructions without altering the code itself.

The biological age of our cells and tissues is frequently ascertained by adding up these changes. However, researchers have recently proven that the changes might fluctuate throughout the day, meaning that tests based on a single tissue sample are less exact than they could be.

Over 72 hours, the researchers examined several blood samples from a 52-year-old man, examining 17 distinct epigenetic clocks inside each specimen's collection of white blood cells.

They noticed a significant variation in 13 out of the 17 epigenetic clocks throughout the day, looking 'younger' in the early morning and 'older' around midday, with relative variations equal to approximately 5.5 years' worth of changes. This implies that a single epigenetic test at a specific time of day may not provide the correct biological age.

"The majority of the aging studies investigating epigenetic clocks use whole blood as the tissue of interest. However, experiments in our lab and from other groups have shown that white blood cell subtype counts and their proportions oscillate with a 24 hour periodicity," statistician Karolis Koncevičius from Vilnius University and colleagues wrote in their published paper.

Relying on a single individual's samples allowed the team to focus on a specific set of changes. However, age changes were also observed by further analysing several blood samples collected from a small group over five hours.

What could be the reason behindvariationsin epigenetic clocks?

Some of these cellular age variations might be attributed to the fact that human blood includes various types of white blood cells at different times of the day. Even with a single kind of white blood cell as the focus, some metrics still showed age variation.

The findings imply that to acquire the most accurate picture of how old your cells are, scientists may need to collect many samples at different times of day in the future. A full estimate of the epigenetic age range may also enable for more accurate projections of the risk of age-related disorders in people.

(With inputs from agencies)