If the school reunion was not proof enough, scientists have confirmed that people grow old at radically different rates, with some aging much faster than their fresh-faced former classmates.

A study of nearly one thousand 38-year-olds found that while most had biological ages close to the number of birthdays they had notched up, others were far younger or older.

Researchers used 18 physiological markers, including blood pressure, organ function, and metabolism, to assess the biological age of each of the participants. For some, the past dozen years had taken no obvious toll on their body’s biology.

Read the article “Old Before Your Time? People Age at Wildly Different Rates, Study Confirms” on theguardian.com.