March 8 (UPI) — The human body operates on multiple “clocks” that, based on lifestyle and genetic factors, influence the biological age of its organ systems, a study published Tuesday by Cell Reports found.
Using biomarkers — measurable levels of specific cells or proteins in the body that can be used to spot changes — and statistical modeling, an international team of researchers was able to gauge the biological ages of various organ systems, they said.
Based on the findings, there appear to be multiple “clocks” within the body that vary widely based on factors including genetics and lifestyle in each individual, the researchers said.
“There has been a lack of practical applications in a population-based sample for precisely estimating the aging rates of live people’s organs and systems,” study co-author Xiuqing Zhang said in a press release.
“So, we decided to design one,” said Zhang, a researcher with the Beijing Genomics Institute and China National GeneBank in Shenzhen, China.
In previous studies involving mice, researchers have been able to reverse the aging of organs and tissue by removing certain cells called senescent cells.
However, this study suggests that different organ systems within the body can age more slowly or more quickly, depending on their composition, which may be influenced by lifestyle factors — such as health and diet — and inherited characteristics passed down within families, the researchers said.
For the study, the researchers recruited more than 4,000 volunteers ages 20 to 45 living in the Shenzhen region of China and asked them to supply blood and stool samples, as well as facial skin images.
Participants were also required to undergo physical fitness examinations, the researchers said.
With the collected data, the researchers were able to measure 403 features of the body, including physical fitness, digestion/metabolism, immunity, body fat and muscle composition, physical fitness, heart and lung function, skin health and brain function.
The researchers then developed an aging-rate index that could be used to correlate different bodily systems with each other.
Based on their findings, they classified participants either as aging faster or aging slower than their chronological age.
The biological ages of different organs and systems had diverse correlations, and not all were expected, the researchers said.
Although healthy weight and high physical fitness levels were expected to have a positive impact, having a more diverse gut microbiota indicated a younger gut while at the same time having a negative impact on the aging of the kidneys, according to the researchers.
This may be due to the diversity of species causes the kidneys to do more work, they said.
The researchers plan to regularly follow up with the study participants to track the development of aging and confirm their findings.
“Our study used approaches that can help improve our understanding of aging and, more importantly, could be used some day in real healthcare practice,” co-author Xun Xu said in a press release.
“We used biomarkers that could be identified from blood and stool samples plus some measurements from a routine body checkup,” said Xu, who is also a researcher with the Beijing Genomics Institute and China National GeneBank in Shenzhen, China.