"It all depends on the quality of information that the celebrity is purveying," Linden said. "If it's good information, it can inform. If it's bad information, it can promote a lot of harm."
He added that there's no question that when former basketball star Magic Johnson told the world he had AIDS, it was a "turning point" for AIDS awareness.
But just as a celebrity can promote a questionable treatment, he or she can also shower an organization with attention even though another that might be more deserving, Linden and Schwitzer said of Paltrow's support for Stand Up to Cancer, which gets nonprofit status under its parent organization, Entertainment Industry Foundation.
Although it raises awareness and research dollars and has a host of celebrity supporters, Schwitzer asked why Paltrow didn't choose to speak for the American Cancer Society or promote federally funded research through the National Cancer Institute.
"It's a trade-off here of, yes, it can be easy to see that there might be a public good from a broad statement of support for research, but why for that organization and why not for others?" he said. "We should look beyond face value and realize that there are things behind testimonies in health care. There's always another side. There's always another angle. There's always another issue to be thinking about."