A study in Diabetes Care finds invisible bits of fruit on your hands can mess up your finger prick blood tests, making blood sugar levels look higher than they really are.
Researchers say that's because sugars from fruit will stay on your fingers until you wash them with tap water.
Even alcohol swabs don't solve the problem.
The message, authors say, is to wash your hands before using a blood sugar meter, and do not rely on alcohol swabs, especially if you've been handling any fruit.
