The British Lung Foundation (BLF) has today published ‘The impact of cannabis on your lungs’, a report which claims to be “the most comprehensive review of research data yet compiled on the subject”.
In fact, although the report references a great deal of scientific research, the way it presents its conclusions is a dangerously irresponsible mix of conjecture, extremist opinion and scaremongering. In particular, the claim by Dame Helena Shovelton, Chief Executive of the BLF, that cannabis cigarettes are 20 times more dangerous than tobacco cigarettes is cherry picked sensationalism. It comes from a study in 2008 from New Zealand that looked at fewer than 80 lung cancer patients. This preposterous claim was calculated by “logistic regression”.
One of the largest case controlled studies of cannabis smokers ever undertaken was by Dr Donald Tashkin of UCLA in 2006. It looked at more than 2000 subjects. Extraordinarily, although the BLF report references a great deal of Dr Tashkin’s work, this, the most significant study of all, is not mentioned.