If you look in the mirror and see Amalgams on the occlusal (biting) surface of the tooth every time you chew or grind your teeth at night you are releasing mercury in vapor form and storing it somewhere in your body. You are still young and likely don't notice much now. Mercury toxicity is cumulative over time. If you decide to have them removed there is no need in finding a 'natural' dentist. Just make sure your dentist uses a rubber dam to isolate the tooth as he removes the Amalgam with his high speed drill. Composite fillings also look better as they are the same color as your teeth.
This is much simpler on one surface fillings, multi-surface huge fillings are not as easily done with the composite and are not as durable as the Amalgams possibly requiring an expensive crown as the solution.