People who work nights don’t seem to have worse health markers like weight, blood pressure, or blood sugar compared to similar people who only work days—so night shifts probably don’t mess up your metabolism, heart, or immune system in this group of Germans.

Working nights might affect your health differently depending on things like your gender, when you naturally feel awake or sleepy, or how much money you make — but this study didn’t check any of those things, so we can’t fully explain why other studies have found different results.

People who used to work nights don’t seem to have more health problems like diabetes or heart disease risks later on than people who never worked nights—even when you account for their age and medicines they take.

Korean women in their 40s who work nights or irregular shifts are almost twice as likely to have high insulin resistance — a sign their body isn’t using sugar properly — compared to those who work regular daytime hours.