WEDNESDAY, March 27, 2013 — Scientists are learning more and more about what makes some people age faster than others and the consequences of that accelerated internal aging — such as earlier onset of age-related conditions like heart disease and cancer. A study out today offers further evidence that telomeres, which sit at the end of our chromosomes, play a key role in the process.
Researchers across eight countries, working together as part of the ENGAGE Consortium, measured the lengths of telomeres in more than 48,000 people. They also examined their DNA, identifying seven genetic variants associated with telomere length. Then they tested to see if those variants, as they suspected, increased the likelihood of developing certain health problems.
Indeed, the researchers did find links between the genetic variants and multiple sclerosis, celiac disease, and various types of cancer, including colorectal cancer. But they were most excited by the connection they noticed between the genetic variants and coronary artery disease.
"These are really exciting findings," said study lead author Nilesh Samani, MD, the British Heart Foundation Professor of Cardiology at the University of Leicester, in a press release. "We had previous evidence that shorter telomere lengths are associated with increased risk of coronary artery disease but were not sure whether this association was causal or not. This research strongly suggests that biological aging plays an important role in causing coronary artery disease … This provides a novel way of looking at the disease and at least partly explains why some patients develop it early and others don't develop it at all even if they carry other risk factors."
The researchers hope that their findings, published in the journal Nature Genetics, will lead to additional research on the health benefits of manipulating the length of telomeres. One day in the future, doctors might be able to modify telomeres to slow or reverse changes in the body's organs that happen with age.
Richard Cawthon, MD, PhD, who studies the genetics of human aging at the University of Utah, thinks the study will make people realize how important aging itself is in terms of disease. “Age is the single largest risk factor for every major disease that kills adults,” said Dr. Cawthon, who did not work on the British study. “If you can really focus on the aging process, and trying to slow it down, that should postpone all these diseases. And if you slow it down enough, you might be able to eliminate a lot of these diseases,” he said.
It's not fully known why some people develop heart disease or cancer when others don't, or why some people get sick earlier than others. And while lifestyle factors like smoking, skipping physical activity, and eating poorly undoubtedly play a role, learning more about how genetics might predispose people to these age-related conditions can surely help people age in a healthier way.