I don't think there will ever be enough evidence as long as consumers are willing to be spoon fed whatever the pharmaceutical industry will create, at least until they've bought up all the supplement companies and then it will be okay.
For most people, health is a past time, a hobby. As time passes by, so does their health. Very few people make it their business to take care of their health, their body. They wait until their health is spent and then try to reclaim what they watched slip away. If they're lucky enough to get it back, they usually repeat the behaviors that lost it in the first place. Make your health, your business. Honor the gift of life!