People staying up late are likely to die younger, a study found.
Straits Times: Night owls risk dying younger, should sleep in: Study
This study was performed in the UK as a large prospective cohort. The participants were categorized into lark or owl according to their identity. As a result, there is ten percent higher risk of fatality in six years. Waking late at night group were also suffering from psychological problems.
Same as other non-interventional studies, there is a possibility of confounder between the exposure and outcome. People who stay at night might have insomnia, depression, or other psychiatric diseases. Then, going bed early would not prolong their health.
The researchers hypothesize that there are genetic factors to determine your circadian rhythm. Therefore, waking up in the early morning for owl people is no longer beneficial. Instead, avoiding jobs which need early wakeup will be preferable. This concept is rather unique.
I saw another survey that a considerable amount of teenagers are owl styled. If true, the time high school begins should be delayed.