Here is another reason to keep smiling; new research has shown that anxiety can shorten your life.

Researchers found that women who suffered from a common type of anxiety called "phobic anxiety" had shorter telomeres. Telomeres are the protective caps at the ends of chromosomes that protect genetic information on the chromosomes. The length of telomere can give an idea about cell aging.

Shortened telomeres are linked to health risks like cancers, heart diseases, dementia and even death, a news release says.

In the present study, the researchers analyzed blood samples of more than 5,200 women between the ages of 40 and 69. These women were a part of the Nurses' Health Study. All the participants were also given a questionnaire to measure their anxiety levels.

Researchers found a positive relation between anxiety and telomere length. Women with high phobic anxiety levels had short telomeres.

Phobic anxiety could be any situation, event, or object which causes fear or stress. This could be fear of heights, flying, enclosed spaces or crowds.

The study doesn't show a cause and effect relation, the researchers say,

"Many people wonder about whether—and how—stress can make us age faster. So, this study is notable for showing a connection between a common form of psychological stress—phobic anxiety—and a plausible mechanism for premature aging. However, this type of study design cannot prove cause-and-effect or which problem came first—the anxiety or shorter telomeres," said Olivia Okereke, Department of Psychiatry and an author of the present study.

Previous research has shown that depression can accelerate aging. Premature aging signs can begin during childhood itself as studies have shown that childhood adversity can shorten telomere length predisposing children who've faced adversity at an early age to many diseases. Researchers say that telomere shortening doesn't occur before depression but rather the telomere shortens as depression progresses.

Certain techniques like, mediation may help in slowing the rate of cellular aging by keeping the mind away from negative thoughts. Researchers say that meditation reduces stress, builds positive mood and causes hormonal changes that help in maintaining telomere length.

The study was published in PLoS ONE