Sometimes all that is required is just to outperform1 those who try to derail the students' careers.
If your students excel in what they do and in their careers, treating them in a biased way would hold significantly less ground. There may well be 2-3 people who mistreat them, but their supervisors won't care about their background simply because they have seen that they get the job done.
If your students are prepared to make an effort to outperform the people who mistreatprove that their gender\age\race or anything bias being thrown at them is completely irrelevant. By doing so, not only will they better themselves, they completely invalidate bias arguments thrown at them. Even if at first their supervisors are the biased ones, sticking to their goal and excelling at their careers would either get them higher than the supervisor (perhaps by switching work places to a better position somewhere) or the supervisor would change their minds.
The core of my suggestions is to explain how being dedicated and motivated often solves the bias people in the industry, and as an added bonus, they gain from it regardless of the bias people.
1That shouldn't be described as a goal. It's largely a way to relate excelling at their careers to Teaching the mistreatment they might encountervalue of hard work should do the trick. And it's important that they remain modestFor a highly dedicated person, and not retaliatevery high performance requirements (such as ones that dispute any relevance of one's age\gender\race or anything bias being thrown at those who mistreat them) are more a motivator than a discouraging factor.