"Future researchers should focus on the age discrepancy for its potential to show a big picture snapshot of human health and disease at a molecular level"
Dr Yinan Zheng, Feinberg School of Medicine, Northwestern
“This could become a new early warning sign of cancer,” said senior author Dr Lifang Hou, chief of cancer epidemiology, who led the study.
“The discrepancy between the two ages appears to be a promising tool that could be used to develop an early detection blood test for cancer.
“People who are healthy have a very small difference between their epigenetic/biological age and chronological age.
“People who develop cancer have a large difference and people who die from cancer have a difference even larger than that. Our evidence showed a clear trend.”
Genes change how they function depending on external lifestyle factors which can be measured.
If someone was living a perfect lifestyle, withouth any toxins, biological age would keep track with actual age, as measured by birthdays. But environmental factors can speed up the process, which is why people who smoke and drink often look years older than they actually are.
Scientists at Northestern devised a blood test which measures 71 blood DNA markers which are impacted by a person's environment and lifestyle.
They then collected blood samples from 442 people between 1999 and 2013, all who were cancer free at the beginning of the study. Those who will develop cancer were found to have a biological age of around six months older than their chronological age while those who went to die of cancer were about 2.2 years older, the study found.
It is the first study to link the discrepancy between biological age and chronological age with both cancer development and cancer death.
“Our results suggest future researchers should focus on the age discrepancy for its potential to show a big picture snapshot of human health and disease at a molecular level,” said first author Yinan Zheng, a predoctoral fellow at Feinberg School of Medicine, Northwestern.
Northwestern scientists now are studying whether individuals can lower their bioligcal age through lifestyle improvements such as increasing exercise and having a healthier diet.
The research was published in the online journal EBioMedicine.