I don't have a direct link to poor health - but sleep performs many functions we are just starting to understand, and feeling tired is usually an indicator that you need sleep.
Replacing that with a buzz from an insecticide - and that is the purpose for which plants produce caffeine - on a regular basis doesn't feel like a great idea.
If you have a specific link between the 'insecticide' and poor health let's hear it - otherwise it's just a ridiculous statement.