You can study the way the human body reacts to different foods and substances and determine whether something is healthy or not. Over time there has been plenty of studies made on all food groups, and you can look at these studies to know what substances are beneficial. Though you still have to be wary of sponsored studies, like the ones paid for by the american egg board which claim that the egg is the healthiest food in the world, the answer to life, the universe and everything. Or the ones by the milk and dairy association, who would like you to believe that it is necessary to drink over 9000 liters of milk a day.
Okay. Those are some pretty bold claims. Now I will say that countries with the most vaccines have the worst infant death rates, and that the health of unvaccinated children and adolescents does not seem to differ from those who have been vaccinated (click the links).
And I don't want to get into conspiracy stuff here, but FYI big pharma makes bazillions a year by selling vaccines, and it is in their best interest to promote vaccination by creating leaflets like the one you just linked.