Is cardiovascular stem cell science 'homeopathy'?

There have been dozens of stem cell trials focused on strengthening the heart. They have largely failed; any purported successes have been dubious at best. And a new Nature study — in mice — suggests why.

Turns out that injecting dead cells, or even a chemical, into the heart can trigger the body’s wound-healing mechanisms — an inflammatory response. That could help explain why some stem cell studies for broken hearts lead to modest improvement. The science behind injecting stem cells to rebuild diseased heart tissue has been tested in hundreds of critically ill patients — and seems less likely than ever to help.

“It’s sort of an ‘Aha!’ feeling,” one developmental biologist told the Washington Post. “My personal view is that we’ve done so many of these studies, particularly for the heart, I think it would be a waste of time starting up any new ones. Whether or not the old ones should be continued — I call it expensive homeopathy.”