Turns out that one isn’t just the loneliest number, it’s the number that makes us old, fast. Researchers at Cornell University have found that the social pain of loneliness produces changes in the body that mimic the aging process and increase the risk of heart disease. A Cornell news release reports that the researchers, who measured cardiovascular reactivity and recovery in 91 young adults (18-30 years old) and 91 older adults (65-80 years old), found that the cardiovascular response of the lonely young adults to the social stressor task looked more like that of the nonlonely older adults. They also found that loneliness increased resting blood pressure, cardiovascular stress reactivity and cardiovascular recovery times in the older people. In fact, the recovery time of the lonely older adults was so delayed they didn’t return to baseline levels during the two-hour-long follow-up period. Read more from Cornell.