Is medication the best answer for my son who has mild ADD -diet changes and supplements not working? He is 10.

I always suspected my son had some aspect of ADD/ADHD - After much frustration with the schools/teachers, he was diagnosed with mild ADD - Attentive Feature. Teachers and schools have done nothing to address the problem and have subtly pushed for medication. I have tried dietary changes - no sugar, no preservatives or food additives, as well as giving supplements and while his attention and ability to concentrate/ focus may have improved minimally, he continues to struggle at school. He is too smart to qualify for help - he scores within the average range on his tests, and yet can't function within the clroom. His teachers don't help only telling me what he can't do. I have conferenced with them on strategies to help him overcome his weaknesses and capitalizing on his strengths, but nothing is working. I am not the kind of parent who doles out medications freely, but I'm at a loss as to what to do. My naturopath would be flabergasted that I'm even considering meds.