No, remember Newton's joke that he thought he had had lunch once when he saw his friend eating the leftover chicken bones? It is said that Newton did not eat meat in his later years, but he did not eat meat in broth because the doctor told him that gout could not eat meat. Einstein only said some good things about vegetarianism in some letters, but he actually ate meat. In fact, just giving some examples of celebrity vegetarianism does not help to show that vegetarianism is more beneficial.