The principles we espouse on Science-Based Medicine are vitally important, but some of the subjects we address are not so important in the big scheme of things. Homeopathy and electrodermal diagnostic devices don’t actually harm very many people. For today’s post, I’m going to follow the Willie Sutton rule and go where the money is, so to speak.
Smoking is the leading preventable cause of death. No prospective double blind randomized controlled studies have been done, or ever could be done; but a mountain of evidence converging from many avenues has established the health dangers of smoking beyond any doubt. Hill’s criteria of causation have been amply fulfilled. Smoking causes 90% of all deaths from lung cancer and chronic obstructive pulmonary disease (COPD). It increases the risk of coronary heart disease, stroke, several types of cancer, infertility, stillbirth, sudden infant death syndrome (SIDS), osteoporosis, and premature skin aging (wrinkles). The dangers of second-hand smoke have been amply documented, and where smoke-free laws have been passed there has been a drop in the incidence of heart attacks and of emergency room visits for children with asthma.
Two new studies published in The New England Journal of Medicine reinforce what we already knew and offer both good news and bad news. (more…)