Next time you see a celebrity giving advice about medical treatments or backing scientific research and campaigns, think twice before following his or her advice.
Little scientific awareness on the part of many stars and their quite often nonsense scientific claims has led the educational charity “Sense About Science” to launch a campaign urging celebrities - or their agents - to contact them before making public any statements that may contribute to scientific misinformation.
The charity has recently published a leaflet, “Science for Celebrities“, with examples of misleading claims by various celebrities followed by corrections from experts. The document will be distributed to VIP restaurants, clubs and management agencies across the UK.
Because stars are in the public eye, their opinions shape and have an impact on how people view certain issues. Is it therefore a matter of public interest that celebrities assume their responsibility of being properly informed before joining particular campaigns and endorsing products that are presented as being scientifically grounded when in fact they are not.
So if you are a celebrity about to make a statement on a science-related issue, you now have the chance to check your facts before making them public. The initiative is backed by over a thousand scientists from many disciplines, who are just a phone call away and committed to promoting accurate information on health, lifestyle issues and science in general.
Original Source (s):

I believe the celebrities who speak publicly about scientific issues are trying to do something good. But their occasional misstatements may not be helping the cause of science. At the same time, celebrity misstatements are just a symptom of a much larger problem - that the public generally doesn’t understand about what science is, and what it does.
I hope many celebrities read this leaflet! But I also hope they don’t come under too much criticism for not getting it right the first time. It’s not their fault that our educational system in American is leading people into scientific ignorance.
Deborah
I always question what a celebrety says about a scientific question. After all their knowledge is “alleged” just like most politicians. The unfortunate thing is that some people view their words as “the truth”. My whole view of this thing can be summed up by by a TV comercial. This actor is giving medical advice and he says that he plays a doctor on TV.