Speaking more than one language could be connected to slower aging, according to a new study. An international team of researchers looked at data from more than 86,000 adults from 27 European countries. They were all aged between 51 and 90. The researchers used this data to create models of people's "biological age" based on things like their physical and mental health, and compared it to the number of years they had actually lived. They found that people from countries where people mostly speak only one language were about twice as likely to have a biological age that was older than their real age. And people from countries where people usually speak more than one language were 2.17 times less likely to be aging faster than their real age. In fact, the more languages people usually spoke, the less likely they were to age faster. Experts have said that at least half of the world's population speaks more than one language. However, up to 75% of people who speak English as a first language only speak English. The benefits of learning a second language are clear, according to the study. The researchers said people should be encouraged to keep their brains active by learning and using more languages. This is something that governments could think about as a way to help protect people's health, they added. They described language learning as a low-cost way to improve our health as we get older. But experts say learning or speaking more languages isn't the only way to slow our aging. According to the American Heart Association, there are eight key things you can do to slow your body's aging: eat better, sleep well, stay active, don't smoke, and manage your weight, blood sugar, blood pressure and cholesterol.