Researchers studied DNA samples of more than 5,600 people born in 1966. Thirty-one years later, they found that those who’d been unemployed for at least two years were more than twice as likely to have short telomeres. What does that have to do with aging? A lot: telomeres are protective caps located at the ends of chromosomes and shorten throughout your lifetime. As they shrink, they’re linked to a greater risk of age-related illnesses including type 2 diabetes and heart disease.  Blame stress. Unemployment is stressful and increased levels of the stress hormone cortisol may snip telomeres and shorten your lifespan, says study author Leena Ala-Mursula, MD. Previous research has found that too much work can be just as harmful to your DNA as too little, so whether you’re chained to your desk or tweaking your résumé, the advice is the same: Avoid cigarettes, maintain a healthy BMI, and get plenty of physical activity—all of these behaviors are associated with normal telomere length and also fend off disease as you age, Dr. Ala-Mursula says. (No time to exercise at the office? Check out these 7 ways to get fit at work.)   More from Prevention: 2-Minute Stress Solutions