Want to know how well you are aging? You might not even need a blood test; researchers have developed a simple cheek swab test that could predict mortality risk.

An individual's biological age is typically estimated using epigenetic clocks that measure DNA methylation changes in blood and other tissues. However, earlier this year, researchers from Tally Health developed a next-generation clock called CheekAge, which utilizes methylation data from cheek cells, making sample collection easier.

In the latest study published in Frontiers in Aging, the research team tested how well CheekAge predicted mortality from any cause in a cohort of 1,513 women and men born between 1921 and 1936.

Every three years, the participants had their DNA methylation measured at about 450,000 sites in their blood cells. The most recent methylation data, along with their mortality status, was used to calculate CheekAge and its link to mortality risk. Mortality data was obtained from the Scottish National Health Service Central Register.

"[Our results show that] CheekAge is significantly associated with mortality in a longitudinal dataset and outcompetes first-generation clocks trained in datasets containing blood data," the researchers wrote in a news release.

The study also revealed that for every one standard deviation increase in CheekAge, the risk of all-cause mortality surged by 21%, showing its strong link to mortality risk in older adults.

CheekAge was developed by correlating the methylation levels at around 200,000 sites with an overall health and lifestyle score, linked to changes in physiological aging. The results of the study revealed that CheekAge can accurately predict mortality risk, even when using epigenetic data from a different tissue as input.

"The fact that our epigenetic clock trained on cheek cells predicts mortality when measuring the methylome in blood cells suggests there are common mortality signals across tissues. This implies that a simple, non-invasive cheek swab can be a valuable alternative for studying and tracking the biology of aging," the researchers said.

The researchers examined specific DNA methylation sites linked to mortality, meaning genes near these sites may influence lifespan and age-related diseases. For example, they identified the PDZRN4 gene, which may prevent tumors, and ALPK2, associated with cancer and heart health in animals. Other important genes have been linked to cancer, osteoporosis, inflammation, and metabolic syndrome.

"We also demonstrate that specific methylation sites are especially important for this correlation, revealing potential links between specific genes and processes and human mortality captured by our clock," said Dr. Maxim Shokhirev, the study's first author.

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