An American team of scientists at the Northwestern University released a study in the PNAS journal that presented a simple blood test called “TimeSignature” that determines the biological clock of every individual. However, some members of the scientific community disagree with the concept.
There are already many indicators of the human body’s biological clock, such as melatonin at night or cortisol peak in the morning. However, until now, the time a person’s body thinks it is couldn’t be determined precisely.
The biological clock is a multi-oscillating system, with a central clock that orchestrates the timing of peripheral clocks. The Chicago researchers used mononuclear cells called PBMC (peripheral blood mononuclear cells). These cells have the characteristic of having a peripheral clock in phase with the main clock. Rosemary Braun’s team has successfully developed an algorithm to determine an individual’s internal time from the expression level of messenger RNA in these PBMC cells.
“TimeSignature” blood test to determine the biological clock has only been tested on healthy individuals
The “TimeSignature” blood test that allegedly determine the biological clock of every individual is not yet proven entirely as the method was only developed and used on healthy subjects, some experts said.
Accordingly, the study conducted by the scientists at the Northwestern University doesn’t take interpatient variability, especially in subjects suffering from various diseases. Also, the model doesn’t take into account individuals who have a profound disruption at the circadian rhythm level.
According to some experts, the study carried out by the Northwestern University assumed that the internal clock, that biological clock, works in the same manner for every person. However, this is not true, and this new data must be corroborated with medical expertise, and these tests must be conducted on more subjects, even on persons suffering from various diseases or circadian rhythm disturbances.