Chronic illnesses like heart disease, cancer, and stroke are leading killers of older Americans that have strong links to problems with our DNA. People who age well compared to others and remain healthy longer likely have genes that somehow work better — but how? To find out, School of Public Health researchers have received at 4-year grant from the National Heart, Lung, and Blood Institute to compare the patterns of genes that appear to be turned off or on in healthy and sick older adults to see if they are a predictor for who successfully ages.
One mechanism for switching a gene on or off is called “methylation” and it can change how cells in the body function. The study of methylation is a component of an area of health research known as “epigenetics.”
“We know that DNA methylation can be affected by early life exposures and adult behaviors, such as smoking,” said lead investigator Professor James Pankow.
Pankow is studying how methylation appears and changes in people by looking at the DNA samples of middle-aged people taken over a 20-year period. Professor Ellen Demerath is a co-investigator on the project, which uses data and blood samples from the 30-year Atherosclerosis Risk in Communities Study (ARIC). Pankow and Demerath are collaborating on the project with faculty from the University of Texas at Houston.
The DNA changes are being reviewed in two groups of people who all began the ARIC study in the 1980s as healthy and middle-aged adults. One group remained healthy into older adulthood, while the other developed disabilities, cognitive impairments, and major chronic diseases, like cancer and diabetes as they aged.
“Few population studies have investigated DNA methylation in large numbers of people, or looked at changes in methylation patterns over several decades of life,” says Pankow.
DNA samples taken at the start of the study will be compared with samples taken from participants 20 years later. The researchers are looking to see if their methylation patterns have remained the same or changed over time.
“We suspect that DNA methylation patterns measured in healthy middle-age adults will be predictors of who remains healthy as they grow older and who suffers from chronic diseases and disability,” says Pankow.
Pankow hopes that study will reveal a discernable pattern of methylation in healthy people, which could give researchers ideas for where to focus on improving health through the changeable aspects of our DNA.
“Increasing our understanding of the trajectory of successful aging may help with the design of public health interventions focused on modifiable risk factors,” says Pankow. “It could also lead to the development of new therapeutic agents that will make successful aging an attainable goal for more people.”