If someone says "There is no evidence that..." be suspicious. Usually, they want you to think that the thing there is "no evidence for" is therefore not true. In fact, it could mean that they don't know of the evidence that does exist, or that there is no proof, or that not enough research has been done, or that the "pro" lobby has presented partial evidence only. And in the case of the pharmaceutical industry for example, it could mean that evidence has been deliberately suppressed. I mean, there's no evidence that the far side of Saturn isn't peopled by little green men either.   And I don't have to hang my wooden-bodied harmonicas out in a net bag on the washing line any more to get rid of the disgusting smell. Grow up, smokers.